Oil Pressure questions + HV pumps, pump drive and collar [Archive]

Paul Wright

23rd-September-2004, 12:03 PM

Here's pictures of the broken plastic collar in my 1/4 million mile '78 Caprice tow wagon:
Broken HV Pump photo's (http://pg.photos.yahoo.com/ph/pcwright77/detail?.dir=48b9&.dnm=c056.jpg)

The OEM plastic collars normally last 100,000 miles or more with a stock pump. This one lasted about 65,000 miles. Melling specifically says in their instructions not to use it with the M55HV pump or the warranty is void. As you can see from the pictures, the strain of high volume and / or high pressure can fatigue and fail the pump input shaft.

Steel collared shafts for rear sump pumps can be had for less than $20. I am getting closer to production on one for the short ChevyII front sump pump.

BTW, I replaced the broken high volume pump (what a dumb mistake) with a std volume pump, but with a ZZ4 spring. I then installed a Canton billet "no bypass" oil filter mount, plus I also installed an ARP shaft so this NEVER happens again.

Even though it ran for several minutes with ZERO oil pressure, the crank was not scored and I only needed to replace the rod bearings.

Not an easy job with the engine still in the car but start to finish it only took a weekend. I just wish I also replaced the rear crank main seal while I had the pan off!

66IISS

24th-May-2005, 09:13 PM

Hey everyone

We're still workin on assembling the 406, and we're just about ready to put on the oil pan. Well, when i went to put on the oil pump, ran into a little snag. The stock rod uses a plastic sleeve at the spot where the oil pump shaft meets the rod that connects it to the distributer, whereas the arp version uses a metal sleeve. the plastic sleeve has a groove on it that holds onto the oil pump shaft. The arp version doesn't have this, so when i go to put the oil pump in the shaft just falls off. Is there any logical way i can get the shaft to stay on the oil pump while i assemble it? The shaft and the pump are both brand new

Thanks

chevyllx2

24th-May-2005, 10:47 PM

You can use the plastic sleeve form the old one, we did it on ours and it is still working great. Just don't break it when you take it off. We also tried the arp unit and ran into the same problem, there must be a better fix for it rather than re-using the old sleeve.

Ryan

NovatoriusRex

25th-May-2005, 12:21 AM

I put a big blob of assembly lube on the end of the oil pump shaft when I installed mine. That held it long enough for me to get the pump installed and the motor flipped back over.

Paul Wright

25th-May-2005, 10:17 AM

What pump, shaft and pan combo are you using? The front sump shaft is unique and there is no HD version except for the one I designed.
HD Front sump parts poll (http://stevesnovasite.com/forums/showthread.php?t=3896)
If you have a rear sump pan and pump use the rear sump shaft.
The metal collar should have a roll pin to secure it.
The ARP collar is roll formed in place and should not fall off.

patman

25th-May-2005, 10:56 AM

Dumb question here...

Paul, I know you've had plans on the drawing board to do some HD front-sump pump drive shafts, and you have said it is doable, but not really cost-effective. Instead of having the whole shaft assembly machined from scratch, would it be any easier/cheaper to start with a HD rear sump shaft and re-machine that to make it shorter? I'm not sure of the metallurgy involved, so that may not be feasible,but...thought I'd ask.

Paul Wright

25th-May-2005, 11:52 AM

I have thought about that. The original Durango Deuce shaft was simply a modified stock shaft. It's more than just drilling for a metal collar because of the shorter pump. In the picture below you can see the standard metal collar dimension doesn't give enough clearance at the cap. Drilling the pin hole higher would weaken the mild steel shaft so it's not as simple as you might think, but it's not outrageously difficult either.

The new design has a number of improvements that aren't necessary for every application but I wanted to only make ONE part number.
Cutting down an ARP shaft difficult because the material is too tough.
ARP's material is proprietary so I can't buy it to make my own and they won't make a limited run from my blueprint for cheap. I already have an equivalent material spec'ed that eliminates post heat treating and is still machinable. I'm looking at getting a CNC kit for my lathe. If that pans out I can make the new style shafts at home. I'm also playing around with a new, more compact gerotor oil pump design that eliminates the need for expensive ChevyII pan cores and wimpy ChevyII pumps.

66IISS

25th-May-2005, 05:29 PM

We're using a Canton Racing rear sump pan, with a Canton rear pickup and a melling std. volume oil pump. the problem isn't with the collar falling off the arp shaft, but rather the oil pump shaft, the collar fits loosly on the oil pump and falls off any time it's flipped upside down, which makes installing the oil pan and windage tray a bit of a challenge....

I was thinking maybe a dab or RTV?

We do have the right arp shaft, it's for the rear sump.

65 Post

25th-May-2005, 09:41 PM

With the engine upside down on the engine stand, drop the shaft into the pump shaft hole. Align the slot in the tang and bolt the pump on and torque it down. The shaft won't fall out and will drop onto the pump shaft when you flip the engine over. If you want to test it, when you flip it over, turn the shaft with a long screwdriver from the top. It won't be as tight as with the plastic sleeve, but it is better. Trust me. It floats. And don't, I repeat, don't put any RTV on it. It'll just end up in the oil pan. Dave

66IISS

26th-May-2005, 04:30 PM

NovatoriusRex

26th-May-2005, 04:48 PM

yea, i figured the rtv was probably a really bad idea, i was also wondering about some good thick axle grease? the thing is, we're no where near done with our engine and i don't want to get everything else assembled just to have the oil pump shaft fall out at a later date

If your distributor isn't installed, then you can insure the pump shaft gets reseated properly after the motor is flipped upright, but before installing the distributor, by taking 65 Post's suggestion to use a long screwdriver to turn the shaft to get it re-engaged properly.

The collar is going to keep the shaft from going anyplace it shouldn't, even if it does slip off of the pump input a bit. There's really no place for it to go. There isn't enough clearance between the pump and the cap for it to go anywhere it shouldn't.

It's nice to see it seated while it's upside down, but there's really nothing to worry about if it slips a bit.

LIL NOVE

2nd-August-2005, 06:29 PM

@ a constant 3k rpm, oil pressure is @ 62-65 psi. and @ 4k prm constant, oil pressure drops to 40 psi. i've already checked oil level, and even put about 1/2 qt extra in,and pick-up has enough space from the oil pan. i have a SOLID ROLLER CAM, who says OIL RESTRICTORS??????? i figure the oil isnt getting to the bottow fast enough. anyone please.......

JOHN

JBimmolate

2nd-August-2005, 06:31 PM

What weight oil are you running?

Miles :D

LIL NOVE

2nd-August-2005, 06:42 PM

im using 20-50 pennzoil, i was thinkin about running 10-40. but im also thinking, 20-50 turns into water once its hot. also i wanna run KENDALL when i go to the track, i heard that **** is like honey. i never noticed if the pressure was different when i was runnin 10-40, but than again its only recently that i've been running the car @ a constant 4K........

JOHN

hey miles, u work @ a diff shop????? where in NORCAL????

72GreenRally

2nd-August-2005, 06:57 PM

20-50 is actually thicker than 10-40. The numbers refer to the number of seconds it takes a measured amount of fluid to pass through an orifice. So, 10-40 takes 10 seconds hot, and 40 seconds cold for the same amount of oil to pass throught the same size orifice.

Randy

NOGO

2nd-August-2005, 07:51 PM

I have the same problem with my 383. I tried draining 1 quart and the oil pressure got better, but still would drop down. If you have the same results, it is most likely excessive windage. I just purchased a windage tray kit from Milodon and will install it this week. Ill let you know if it fixes it. I have already had the pan off to check the pump and pickup, changed oil weights and even tried a synthetic with no change.

LIL NOVE

3rd-August-2005, 03:59 PM

i feel ur pain. let me know about the windage tray. i'll check out ur results before i do the oil restrictors. thanks

JOHN

Rice Killer

20th-August-2005, 06:08 PM

when my motor is warmed up my oil pressure reads just a hair over 0 at idle but at 2500 rpm (for instance) it reads over 50psi.

Is it ok to run like this?

Jeffblk72

20th-August-2005, 06:31 PM

I believe the correct pressure is supposed to be around 40 psig. You may have a bubble in your line or a bad guage or even a pickup blockage or level problem. I would not run like that. If your pressure is to low to register at idle, and there's nothing wrong with the guage or line, that can't be doing your bearings and valvetrain any good. Valve noise is a good indicator of low oil pressure or level.

Rice Killer

20th-August-2005, 07:31 PM

My oil pressure line is clear and I can see the line is not completely filled with oil. (Checked when running)

mychevyii20

20th-August-2005, 07:38 PM

Engine new, old, miles? 0 is not good. If an old engine, what viscosity oil?

I had an Aerostar and after 90K I had to run 20-50. The oil pump had worn some.

Viscosity helps some, but probably not enough if at 0.

On the stock SBC 20 at idle was common.

batman09

20th-August-2005, 08:16 PM

My oil pressure at idle is 25psi.Something is wrong :confused: Keep troubleshooting....don't blow up your motor :eek: bm

69NovaSS

20th-August-2005, 08:56 PM

when my motor is warmed up my oil pressure reads just a hair over 0 at idle but at 2500 rpm (for instance) it reads over 50psi.

Is it ok to run like this?

I have heard that even as low as 7psi at idle is plenty...I however would be very concerned about mine if I only had 7psi at idle...all I can say is "Houston we have a problem". Is this a fresh motor? What weight of oil are you running? are you sure the guage is accurate? :)

Jeffblk72

21st-August-2005, 10:16 AM

What make and model OP guage do you have? It sounds like you have the plastic capillary. Those are on the economy guages but you can buy the kit from autometer. Our Pontiac had that type of line on autogage brand guage but we redid the dash and switched to the model one step below liquid filled which has steel braid. Anyway the movement on the pressure gauge is called a D'arsenval. Made of brass, it looks like a coiled tube. As pressure increases, the coil unwinds moving the indcator needle. Air is far more compressible than oil. Bubbles will throw it off. Burp the line and see if it helps. Also don't neglect the other replies. All of them bring great things to consider. By the way, how is hok paint to work with? Your car reminds me of the old silver mint that mine was.

wskaiser

21st-August-2005, 11:37 AM

. Air is far more compressible than oil. Bubbles will throw it off. Burp the line and see if it helps.
.

Air is more compressable than oil is correct but once the pressure stabilizes it will read correctly even with air in the line. It will be slower to reach
pressure and will show pressure longer when the engine is shut off until the air pressure bleeds off but the end result is the gauge will read correctly under operating conditions even with air in the lines.

Paul Wright

21st-August-2005, 12:59 PM

You've probably overcrimped the little brass ferrule under the tube nut.

You'll need to get a new one from Home depot and try again

novaboy009

21st-August-2005, 07:21 PM

I had to switch over my mega-mile, beat to death, almost impossible to kill 307 to 50W20. It read 0 psi at idle after getting off the highway or driving at a constant rpm for awhile. With the thick oil I have about 15-20 psi at idle. All better:).

Kev

keithsixty3

21st-August-2005, 08:26 PM

Air is more compressable than oil is correct but once the pressure stabilizes it will read correctly even with air in the line. It will be slower to reach
pressure and will show pressure longer when the engine is shut off until the air pressure bleeds off but the end result is the gauge will read correctly under operating conditions even with air in the lines.
Pressure is pressure in a dial guage.You are not compressing the oil nor the air,(compressing liquid would be an ugly situation,if possible at all).

wskaiser

21st-August-2005, 09:48 PM

Pressure is pressure in a dial guage.You are not compressing the oil nor the air,(compressing liquid would be an ugly situation,if possible at all).

You have described in better words what I was trying to say but I still say the air in the line is compressed equal to the oil pressure in the line. That is why the gauge response is delayed if there are air bubbles. It takes a while to compress the air on startup and a while for the pressure to bleed off at shutdown, short as it may be.

Jeffblk72

22nd-August-2005, 06:14 AM

Paul Wright

22nd-August-2005, 09:10 AM

Before you make any major changes like 50 weight oil, you might just want to remove the plastic line from the gauge and see if it is open. I'll bet it's crimped nearly closed. This is very common with plastic and copper 1/8 lines.
Check the easy things first.

Rice Killer

22nd-August-2005, 10:27 PM

Checked the plastic tube and its fine. Where do you guys think I'm losing the pressure from?

Paul Wright

22nd-August-2005, 10:33 PM

If you are sure the gauge and line are fine then your bearings are probably worn out.

Old School

22nd-August-2005, 11:27 PM

[QUOTE=novaboy009]I had to switch over my mega-mile, beat to death, almost impossible to kill 307 to 50W20. It read 0 psi at idle after getting off the highway or driving at a constant rpm for awhile. With the thick oil I have about 15-20 psi at idle. All better:).

I have had a similar experience. I built a mild bracket engine with very loose bearing clearances (.0035 rods and .004 mains). I was making use of some parts that were worn and since I was building it for myself I knew there would be no panic or complaints. It was fine on the dragstrip since the engine was started cool and then cooled off after ever run. I eventually put the engine in a street car and had 5 psi oil pressure at idle and 30 psi at 2500 rpm when the car had warmed up to 180 degrees. This was with 10-40 oil. The engine also had a standard oil pump and did not have a high pressure spring. I changed the oil to 4 quarts 20-50 and one quart Lucas. The idle oil pressure went to 22 lbs and the driving speed pressure was 45-50 at 2500-2800. I knew nothing was wrong with the engine except being to loose in the bearing clearances. I put almost 5000 trouble free miles on it before I changed it out to another engine. If you have cut your filter apart and did not find metal particles and residue the oil change is the cheapest and simpliest way to increase pressure. I DO NOT WANT TO TELL YOU TO DO THIS AND THEN SOMETHING BREAKS AND BLOWS UP BECAUSE OF MECHANICAL PROBLEMS. DO THIS ONLY IF YOU THINK THERE IS NO MECHANICAL DAMAGE IN YOUR ENGINE.

keithsixty3

23rd-August-2005, 12:25 AM

In the low pressure world of cars, I'll give you the guage pressure is just that, but air will tend to take up fluctuations (needle twitch). In the area of thermodynamics, I wouldn't stick my neck out and make a statement like that. Sorry, my b.s. in mechanical engineering and FAA mechanic license are showing. As far as fluids go, I wouldn't test that pressure is pressure regardless of medium idea with brake fluid. You'd be suprised how hydraulic fluid boils in a mini cup car or aircraft hydraulic system with just one little biddy bubble.
Pressure is pressure period.Your statement about compressing oil and air was inaccurate.Even in hydraulics arent you pumping the fluid to increase the pressure.Liquid+compression,nasty.I know all about needle fluctuation,I work with it every day.Speaking of hydraulics,we have recently switched over to a synthetic oil that resists those evil temptations of boiling.It also has an increased run life,probably costs triple the amount of the organic based oils.

Rice Killer

23rd-August-2005, 11:09 AM

If you are sure the gauge and line are fine then your bearings are probably worn out.

Both ends of the line are fine. I dont know if the gauge is fine, "its auto gauge".

Old School:

What lucas oil product did you use?

I'll cut my filter after work today and tell you what I see.

Jeffblk72

23rd-August-2005, 11:45 AM

Rice Killer,
The bearings seem to be it. You may want to go with autometer. If the oil gets too hot (need oil temp guage to know for sure), you may want to consider a cooler. Your machine shop may have used their judgment in place of yours if you specified a set of tolerances when they bored, sold you bearings, ect.

For the rest of you
I am not going to argue. By the same token, I was looking at the accuracy in the guage, not its precision, and I don't ever come out and say "you're wrong" without checking what exactly a reference point is. Ten pounds by a certain guage is ten pounds, however is it ten pounds by standard? He could have five at idle and fifty-five at 2500. I can mash on a brake pedal with the same force, exerting the same pressure and have good brakes or little, depending on if there is air in the system and other little things like cylinder sizes and displacements. Isn't it great that auto manufacturers and some aftermarket vendors and machine shops, do things for us and sell us parts designed for their purpose, doing all of the brain work for us so that we don't have to?

Rice Killer

24th-August-2005, 07:41 PM

So do you guys think that if I put new rod bearings and main bearings in, my pressure should be good?

72Orange

24th-August-2005, 08:48 PM

So do you guys think that if I put new rod bearings and main bearings in, my pressure should be good?Have you tried a different gauge? You realy need to hook up a manual gauge to rule out your gauge or the sending unit as the culprits.

MrNorm66

24th-August-2005, 08:49 PM

Why can"t we just up the pressure ?

Norm

batman09

24th-August-2005, 08:54 PM

Why can"t we just up the pressure ?
What does this mean exactly?Please explain. bm

MrNorm66

24th-August-2005, 09:04 PM

Okay, put in a stiffer spring in the oil pump to increase the oil pressure to offset the bigger bearing clearances for now.

Norm

Jeffblk72

24th-August-2005, 09:49 PM

Rice Killer,
You could cool the oil, put in a high pressure pump, use different viscocity oil, a different base oil, change the relief spring as Mr Norm said, or use an external pump and dry sump like a race car (completely off the deep end). All of the suggestions I have seen here in this thread are good and the list here is what I can come up with off the top of my head. If the rods and mains just have too much clearance, it just ain't gonna come up but so far. The rods, and mains are both as you know, pressure fed. The close tolerances between the surfaces restrict the oil flow like your thumb in a water hose. I thought about the gauge because (1) its easy to get to, (2) they aren't perfect and do wear out. In my poorer uneducated days before dilligence and watching the odometer prevailed, I could tell by a very slight lifter tick, that I needed to check oil level or change it at first convenience due to thinnig and lowered pressure by way of bad valve guide seals or just not enough oil to pump up the lifters. If your car had no oil pressure at idle, your engine would let you know in a VERY big and unreversable way. It's just undectectable to the gauge If you raise your pressure through viscocity or other means without verifying the guage, you may blow out the front and rear seals as I did with a wore out escort and 10W40. I would find out, as close as I could, what pressure I did have initally with no changes. I, as others, hope that it is the guage or something easily cured and that you haven't made work for yourself.
Truthfully, the Pontiac we have idles around 60 psig and drives 75 to 80...even hot, and it scared the H--- out of me for a year. I didn't think it would take it. I am sorry to be so longwinded. I've tried to help answer more questions on this site than I have asked and to be as much help as I can be.

72Orange

24th-August-2005, 10:00 PM

Also, if you have oil leaking around your sending unit it may only show up as low PSI when the oil is hot and thin enough to leak through. This can make it appear like it has low oil pressure.

Don't you guys think it would be prudent to verify the oil pressure before you start tearing into the motor?

Rice Killer

24th-August-2005, 11:20 PM

I just found an extra oil pressure gauge laying around that was on the car when I first bought it. Its super cheap so i dont know how accurate this one is.

I hooked it up and drove around for a little bit to warm up the motor. It read the same as my other gauge.

0 psi @ 700 rpm (idle in drive)
25 psi @ 1,500 rpm
50 psi @ 2,500 rpm

Jeffblk72

25th-August-2005, 08:41 AM

Bearings or pump can do this.
If you do the pump, chances are, you put it on the stand. Go ahead and do all your bearings as part of a refresh if you can afford it. If it's a high mileage motor or one that's been worked to death, you may avoid future problems with a refresh.

63SLEEPER

13th-September-2005, 10:30 PM

I switched to a rear sump pan / pump / pickup in my 63. I believe the pump i used was the melling high volume type. My pressure at idle went from 25 to 63 psi. at around 3000 rpm the pressure goes off the gauge at 100psi. I have always used 20/50 weight with this engine, but now i assume that's too much. how much pressure is too much? I think i can replace a spring to lower the pressure, but i would hate to pull the pan again. Any advice?

thanks in advance

-Christian

DriveWFO

13th-September-2005, 10:40 PM

You could try 10W-30 or a synthetic oil.

NOGO

13th-September-2005, 11:10 PM

I used the lighter spring that came with the pump. I have about 20psi at idle and 60 psi max.

Bucksatan

14th-September-2005, 01:03 AM

Thats funny, I switched to a rear pan and gained about 25 psi over the stock chevy II pump. Must be the spring since stock for stock, gear sizes looked identical.

69NovaSS

14th-September-2005, 06:15 AM

You could try 10W-30 or a synthetic oil.

Try the 10w30 weight oil first. that will drop your oil pressure down from the 20 weight oil you are now running. If it is still too high after that you could even switch to 5 weight oil. Just some thoughts. :)

63SLEEPER

14th-September-2005, 09:24 AM

Ok, I'll try a 10w and see if that makes a difference before i change the spring. Is the current oil pressure dangerous? How much is too much?

Thanks,

-Christian

69NovaSS

14th-September-2005, 09:36 AM

Ok, I'll try a 10w and see if that makes a difference before i change the spring. Is the current oil pressure dangerous? How much is too much?

Thanks,

-Christian

I am pretty sure most people would say 100+psi is likely too much. :eek: It takes more HP to drive the same pump at 100psi then it does to drive it at 60psi. So you are losing HP just driving the pump at this psi. How much? I have no idea.

Could it cause leaks, oil pump drive shaft failures, cause the oil filter bypass to open prematurely so that your oil is nolonger being filtered, the higher than normal drag on the distibutor might cause distributor malfuntions, distributor gear premature wear? :confused: Possibly. I dunno.

Personally I would change out the oil ASAP to correct this before I find out the ramifications of 100+psi oil pressure. :)

Paul Wright

14th-September-2005, 10:18 AM

Too much oil pressure and why do you need oil is a thick as mud.
Go to Best of Tech and read up on previous oil pressure questions and posts.

63SLEEPER

14th-September-2005, 12:52 PM

Ok, I'm going to try 10w 30 oil. Will that lower it significantly? The 20w 50 in the pan has no miles. I'd hate fill with 10w 30 and still need to drop the pan to change the spring. Disposing of all of the oil is a pain where i live, plus i don't want to waste any more money.

undercvrSS

14th-September-2005, 12:56 PM

I know from experience too much oli pressure will blow an oil filter apart.

Wally

16th-September-2005, 11:02 PM

New motown block, all bearing clearances were normal mains 0.002-24,new rods 0.018-20, crank, pistons, HR cam and lifters, new 55 melling pump (standard) and right pickup for the Milodon low profile stroker pan with 0.6 pickup to pan clearance. Pressure at idle is 15-20 warm and 50-55 at cruising. If I rev motor to +4k presssure drops to 15-20. All oil galley plugs were sealed on install and I have two different guages, one mechanical and one electric. Anyone have a similar problem? Any help would be appreciated as I had same problem with 400 I just took out. Dont want to trash new engine.
Wally

chuckha62

16th-September-2005, 11:41 PM

Just a guess...If this is a high volume pump, what are the chances the pump is evacuating the pan? Maybe all your oil is not returning fast enough to keep up with that pump moving that much oil.

My $.02 worth...

Chuck

Bucksatan

17th-September-2005, 04:53 AM

Wally

17th-September-2005, 09:59 AM

I think I can rule out the guage as I have replaced the original mechanical with a new one as well as an electric one as a backup test. As stated I have a 7 quart Milodon pan and standard volume Melling pump. Would a standard pump evacuate the pan in literally seconds? On the 400 I had in I had a stock pan and pick up with a HV pump with the same problems I have described so I pulled the motor as I was going to refurbish it and check the bearings etc. Everthing was fine but wondered if a HV pump was emptying the pan which was the reason for the 7 quart pan and stock volume pump on this new motor. puzzled. Why only after 4 k and if i had tight bearing clearances would this not show up across the rev range?
Wally

69NovaSS

17th-September-2005, 10:30 AM

Why only after 4 k and if i had tight bearing clearances would this not show up across the rev range?
Wally

Bearing clearances IMO in the middle or lower end of the tolerance range will normally help your oil pressure not hurt it. Clearances at the loose end of the tolerance range will normally cause your oil pressure to be low at idle but pick up as the rpm increases. At least that is my experence :)

speedster

17th-September-2005, 10:36 AM

where are you getting your oil pressure from? are you using the plastic line or a good braided line? did you say you blocked the oil return passages? do you have screens at the ends of the blocks? if it's not a oil line proublem to the gauge i would have to say you have a serious proublem! :( have you tryed using a differant brand oil oil and weight like a kendall 20w50? i have heard of some syntetics doing wierd stuff with the pressure gauges???

Paul Wright

17th-September-2005, 10:36 AM

You have the all the symptoms of windage and aeration. The long stroke and short pan put the oil level close to the crank. This whips the oil into a froth and because it's saturated with compressable air the oil pressure goes down.
Try running less oil level as a test.

novamike

17th-September-2005, 11:21 AM

I think Paul is right,I bet you had the same pan on both engines!
Mike

Ron Slabaugh

17th-September-2005, 03:31 PM

I also agree with Paul. My 383 did the same thing with a poorly engineered pan/windage tray combo. I bought a really slick louvered tray and pickup screen from Canton Racing Products used together with a home-build rear sump pan. The system holds five quarts (including filter) with the static oil level about 1-inch below the rotating assembly.

My M55 Melling with the ZZ3 spring pulls 60 psi hot to 6,000 rpm with no signs whatsoever of aeration.

Try running five quarts instead of seven and see if things improve.

Wally

17th-September-2005, 05:54 PM

Thanks for the info, I shall reduce the oil level and let you know the results.
Wally

the FLYER

17th-September-2005, 06:31 PM

i used a homemade plate that fit under the oil pump to solve the oil climbing the back of the pan before... i guess it worked, cause it solved my problem on hard acceleration... i think Moroso makes the same plate. the other advice is more thourough though. :) :) :)

John :)

Wally

17th-September-2005, 09:01 PM

Paul Wright take a bow! I drained the oil and filter and replaced it with 4 quarts plus a full filter. Problem has been resolved. Many thanks to those who answer questions on this forum as it is invaluable to folks like me who live in remote areas and dont have access to facilities in larger centers. I often log on here and find the answers or those willing to help. Kudos to the moderators!
Wally

LIL NOVE

19th-September-2005, 03:59 PM

what kind of filter are u running, cause @ 85-100 PSI i was blowing the rubber ring for the filter. thats a strong ***** filter.........

Nova_Guy

19th-September-2005, 04:50 PM

I'd check that guage out first before I swapped anything else.

Fast Eddie

19th-September-2005, 10:16 PM

If it doesn't blow the filter off now, wait until the first cold snap in PA and I am certain it will for sure. Change the pump or the spring ;)

novamike

20th-September-2005, 11:02 AM

Paul Wright

29th-September-2005, 04:53 PM

I think someone should potograph the two pumps and shafts side-by-side so that you can see the differance.My computor skills aren't so good or I would do it!
Yes, this is one of the oddities of "only" on Chevy II's. The front sump system
oil system is one of them.

I've already done that. I merged the thread with the pix of the two shafts into this one. Look back in this thread.

The GM PN for the OEM plastic collar is 3764554.

Installation Tip: Soak this in boiling water to expand it before snapping it on to the stock oil pump and drive shaft.

The part number for the steel collar at NAPA is 6011515 and it costs about $3.

usmcmec

25th-October-2005, 11:14 PM

hey all
i put a new motor in my nova a while back and havin some problems the guy that built is being diffacult (realy long story) anyway at start up oil press is at about 50 to 60 psi no prob there then after it warms up a bit oil press drops down to 15-22 and just stays there no varaince in rps or anything give or take 2 psi or so ive tried a new gauge and lines for the gauge didnt help i also just pulled it thinkin maybe it was the pump no dice there put a bran new high volume oil pump in it didnt help im out of ideas ive herd possibly some plugs in the block it self not sure about that one this thing is giving me fits any help or ideas would be greatly apperciated
thank you all very much
josh
ps its a 350 vortec heads bout 9.5-1 compression alum intake demon carb headers and 3 in flows besides the oil press problem runs ok
thanks

speedster

25th-October-2005, 11:28 PM

not positive but i had a proublem like that and was using a orange filter that rhymes with "ram" !!!! i switched over to a better filter and guess what ????
proublem solved. i used a napa gold filter! a engine builder told me to switch filter brands and was right on the money??? it's cheap and worth a try!

73Novacaine

25th-October-2005, 11:29 PM

What oil weight are you running ? How long has this been going on or is this something new ? How big is the pan your running ?

usmcmec

26th-October-2005, 02:09 AM

stock 5 qt pan has been doin this since i put it in bout 500 miles havent been runnin it over 3,000 for this reason i tried running 20-50 weight and it maybe bumped it up 2 psi ie from 20 to 22 sitin usualy run strait 30 weight could the filter adapter have anything to do to it if it were bypassed pressure would be higher correct? that was the only used part on this eng that i can think of in that system. thankx for the quick words yall
josh

Nova67ss

26th-October-2005, 07:39 AM

Hm I was thinkin, is the oilpickup tube welded to the pump?

If so is it welded with the plunge and spring fore pressure relife out of the pump??

If not the spring could have lost its tension and let pressure "Go" in about 20 psi...

Or it might bee a plugg in the pump thats been faling out?

Just try to give some other angle on this...

Have a racer (not a friend anya more), his car have good oilpressure and when he reach 3000 rpm BOOM the pressure dropps instant to about 30-35 psi... and when the rpm dropps below its up to 50-60 psi again???

he have by himself made some "trix" to the pump and even chimmed the spring with 3!!! washers... and the plunge did stick to pumpbody when he tested it before put it in the engine?!!!

now he chase the problems as a crac in block or the oilpump bottom is loosing its form and leak when engine revs past 3K rpm.. then goes to normal when under 3K rpm..

73Novacaine

26th-October-2005, 02:58 PM

I would do what speedster advised first try a different oil filter if that doesnt solve the problem. Then its either something wrong with the pickup tube or something hung or cloaged in the filter adapter. Where are you gauging it from? Should gauge it from the front for a accurate reading. If its not one of the above problems then Nova67ss might be right a crack in the block somewhere. :awkward:

Paul Wright

26th-October-2005, 03:34 PM

"Rebuilt" doesn't mean it was done correctly. Oil pressure builds when the volume of oil going into the engine galley is greater than the oil volume exiting.
If the oil exiting the system is too great then pressure won't build.
Since you have a high volume pump and it can't maintain pressure then you must have an internal leak. Since it has pressure when cold but but not when hot, that indicates a leak that's aggravated by thermal expansion. I would guess a crack in a galley, but it also could just be bearing clearances are too great.

I don't think it's a missing galley plug or mis installed cam bearing because that would have low pressure when cold or hot.

More oil pressure tips (http://stevesnovasite.com/forums/showthread.php?t=17486) in Best of tech

joey d

26th-October-2005, 07:32 PM

usmcmec

27th-October-2005, 12:20 AM

hey all well the pump is bran new i put a new one from summit racing that has the pickup welded on from the factory
like i said i have tried strait 30 weight oil and 20 -50 weight running 30 weight right now because there is no differance in how it works id be able to tell if the gally was cracked by taking the intake off correct or could it be small enough that you coundt tell
if it were something like that woundt i notice water in the oil or vice versa maybe im way off guess ill try and hunt it down dont think its the filter either cause ive ran a from on break in and then a ac delco the first oil change and then back to a fram didnt make any differance and if the oil filter adapter was blocked off the pressure would be higher correct i dono im at a loss
thanks a lot for the input you all ill try a few mentioned things see if i caint fidgure it out
josh

DriveWFO

27th-October-2005, 08:05 AM

hey all well the pump is bran new i put a new one from summit racing that has the pickup welded on from the factory

How did you set the pickup to pan clearance if it the pickup was welded on at the factory?

69NovaSS

27th-October-2005, 08:36 AM

How did you set the pickup to pan clearance if it the pickup was welded on at the factory?

With a hammer...lol...if the clearance is too much you hit the pan on the outside to "close" the clearance..and it is is too tight you hit the pan on the inside to open it up some...see very simple....that is a perfect example of K.I.S.S. :D

BTW this is just a joke....dont hit your oil pan with a hammer :rolleyes:

Paul Wright

27th-October-2005, 10:21 AM

The problem might be the oil itself. Look at the post, "60 psi until it warms up". I have the exact same problem, and I think it started when I changed to synthetic oil. I idle at 45psi, and after about a half hour it barley idles at 10psi, although if I hit the gas it will go back up to 30 or 40psi. I'm thinking it might be something with the switch from 10 to 30(10w30), soon as that oil heats up it gets thicker and can't move as fast. Maybee try a strait 20 weight.

Joey, Oil gets thinner when it gets hot. Your pressure problem is from loose bearing clearances.

usmec:

A crack in an oil galley doen't mean you also have crack in the cooling jacket.
You won't see a crack that opens when hot unless you magnaflux the block.

73Novacaine

27th-October-2005, 11:48 AM

I think Paul is on the money here. But IMO I wouldnt consider 15psi an extreme, now it if was 6psi then I would tear it down completely. Chance's are there is a spun bearing or bearings. I dont know what else we are missing here that we havent already mentioned. :o

Necro

27th-October-2005, 01:01 PM

Maxturbo

27th-October-2005, 03:32 PM

The more that I ponder the already excellent advice given thus far, the more I think that the propblem is in the oil pump pressure relief / regulating function. I believe that the valve disk (or piston) is stuck / hung in a partially open position, is defective in size, or has an incorrect spring employed.

IF the engine's bearing clearances were excessive, then you would have low idle oil pressure, and when raising the pump / engine speed you would see a rise in oil pressure (and not be maintaining the same pressure as you are in other words).

NE1 else feel similarly?

Paul Wright

27th-October-2005, 04:36 PM

I don't think you are correct for two reasons.
1. The pump is new and unlikely to have a problem unless the spring was damaged by welding the pickup tube on. It's supposed to be removed so it doesn't aneal. If the spring lost it's "spring" then the pressure would be lower at all times.
2. The other guy (Joey D) clearly has excessive clearances as it's independant of temp. usmec's problem exacerbates only when hot so it's probably a crack which was my first choice.
Clearances can also open up when hot so that's still a possibility.

These kind of problems can be very difficult to trace while in the vehicle.
I learned a long time ago to hot test an engine on a run-in stand. It saves tons of aggravation later.

lz07rp

27th-October-2005, 06:04 PM

My .02 worth I lost a motor myself due to a welded on pick up tube. My oil pres. did what you described as a couple of people said the valve was the problem. Or did you try a different gauge? At this point everyone is guessing but all the guesses could be right they all make oil pres. go crazy. Drop your pan pull a cap I would do #1 main its the easist and will show you bearing damage (farthest from the pump). If its brassy then you know what to do from there. When its out and apart like Paul said get it checked for cracks. If it has been that low and ran awhile it probably needs bearings don't forget the cams. Well good luck with it.

Maxturbo

27th-October-2005, 06:28 PM

2. The other guy (Joey D) clearly has excessive clearances as it's independant of temp. usmec's problem exacerbates only when hot so it's probably a crack which was my first choice. I concur with you Paul on Joey D's problem. I am speaking only to usmcmec initial question / concern.

The satisfactory pressure at idle but NOT increasing with RPM build up has me thinking as stated. Excessive clearances would manifest themselves as a prob at idle RPM pressure but oil pressure would still increase as RPM / oil volume increases.

It's in the pump / relief valve IMO. As far as his using a "new" pump...we've all "been there and done that" w/respect to getting faulty components, QA issues, assembly errors and wrong parts received. :(

speedster

27th-October-2005, 07:05 PM

if you do pull the pan again it would'nt hurt to pull the mains and rod caps and use some plasti gage and see how much clearance ya have! then theres no dought if you have a clearance proublem!
the only reason i said filter is because it happened to be and i changed to a napa gold and proublem was solved! for less then $5.00 :D ask your machinist if the mag'd the block to make sure it wasnt cracked??? i would'nt think a guy would build a motor with out doing that but?????? :o

usmcmec

27th-October-2005, 08:22 PM

the pump that is on it right now is bran new i took the one the guy had on there after the rebuild off thinking that was the problem and it didnt change at all same problem tahnk you all so much for all the help i will try and fidgure it out soon and let you all know how it goes
thanks again
joshua

novaguy73

27th-October-2005, 09:02 PM

hey there. Sorry to hear about your oil pressure woes. First i must ask, are you running any kind of lifter with laser cut holes in the bottom? "Direct Lube" some are called. I had the exact same problem and it was because of those damned things. I also went in circles with my oil system to finally go back to a traditional Solid lifter and a Mellings M55-A "Z-28" pump. High volume pumps are not necessary. After researching this a bit I think they have no place in a small block chevy especially a street car with a 5 qt pan. First they cause distributer gear wear. Mine did nothing but cause too much pressure at idle and not enough after 4,000 RPM due to what was probably a cavitation, and it did not respond to RPM. My first move would be to go with an M55-A pump. I would run that pump in anything. Now I idle at 20-25 lbs hot,the pressure climbs with RPM, and its responsive. Also did you have your block magnafluxed before it was built? Have you had any over heating issues with it?

Maxturbo

27th-October-2005, 09:03 PM

the pump that is on it right now is bran new i took the one the guy had on there after the rebuild off thinking that was the problem and it didnt change at all same problem I understand.

I wish that the "fix" was an easy one to determine and correct. Lots of good ideas discussed though.

65 Post

28th-October-2005, 05:41 AM

You're not by any chance running main studs are you? I had an engine that I ran studs on that after it warmed up the Oil pressure dropped from 75 to 20lbs. Pulled my hair out for two days. Changed filter, oil, finally pulled engine. Put it in stand and pulled timing cover looking for missing plug. Nothing. Pulled pan, pickup was on, no blockage, mains looked good. Lo and behold what is this? The oil pump was sitting on the rear main stud. Left a angled gap of about .060-.080. Pulled pump, ground clearance, put all back together, and what do you know. 75lbs oil pressure cold, 70 hot. Now I learned that I have more checking to do with main studs. My .02. Dave

Maxturbo

28th-October-2005, 07:30 AM

Interesting take "Post"! ;) That could support the prob of oil pressure bleeding off some where as the RPM's climb. ;)

On this whole oiling system discussion...now my thoughts have roamed over to the different oil FILTER manufactures and how dif filters provide increased oil pressure. Having heard that discussed, to me (in a full flow oil filter arrangement) are we not learning that some filters are more restrictive, thus creating a reduced down stream reading of oil pressure?

Now, is a more restrictive (higher micron rated) oil filter a better trap for contaminants even though they provide an increased pressure drop across the filtering media? Conversely, are some filters less restrictive, provide "increased" oil pressure, yet are not able to "filter" as well?

The bottom line...is switching to an oil filter that provides increased gauge oil pressure a GOOD thing? :rolleyes:

Food for thought.

65 Post

29th-October-2005, 07:44 AM

Here's my advice on oil filters. FRAM (edit). I've run AC for years. My friend talked me into running a Fram. Low oil pressure, oil pressure goes away after burnout, and in shutdown area. Pulled filter off and NO oil ran down my hand. What's wrong with this picture? Looked in filter, it was half filled with oil. Can you say BYPASS? Tossed the filter, and put my trusty AC1218 back on. Pressure went up, problems went away. I only run AC or Systems 1. That's my .02 on oil filters. By the way, same friend called me about his oil pressure being around 40lbs. Told him to yank the Fram and go get an AC at K-Mart. He did and pressure went up to 65lbs. Dave

Carathers Nova

29th-November-2005, 09:27 PM

the oil pressure is at 60 psi when driving and then drops to 30 psi at idle is this something to worry about?

I just dont know for sure,

thanks,
chris

Mike Goble

29th-November-2005, 09:46 PM

It's nothing to worry about, that's normal operation.

Carathers Nova

29th-November-2005, 10:15 PM

thats what i thought but someone made me second guess it, so i wanted a third party to answer it.

thanks

SSBowtie65

19th-February-2006, 02:14 AM

4door64

19th-February-2006, 02:19 AM

Mine runs at 40psi at 3,000Rpm and about 20psi at idle so idk but a friend of mines Mustang idles at like 7psi and about 23 at 2,000Rpm but thats a Mustang and his rings are fried so idk man

hotrodssnova

19th-February-2006, 08:38 AM

have you tried a differnt gauge? also i have seen the high volume oil pumps suck a 5qt pan dry and it gets ugly. i have an eight qt milodon with scraper andjust run the high pressure. there is a rule like 10 pounds per 1000 rpm or something like that. anybody...
my 2 cents
eric

69NovaSS

19th-February-2006, 09:04 AM

Anything above 9psi at idle is safe.(5 or 6psi in drive at idle is not safe IMO)..since your last rebuild was not that long ago possibly the mains might have too much clearance (not trying to insult your engine building skills here) but loose bearing clearances will cause low oil pressure...

What weight oil are you running? If your running a 10 weight or less you could try running a heavier weight oil as that will increase your pressure...but if you are already running like 20 weight oil and this is the pressure you have I would be very concerned. I agree a high volume oil pump can pump a pan empty but I would think that would be at a higher rpm level not at idle.

BTW trying a second guage is a good idea too...sometimes guages can be wrong...

this is just my 2cents on this.....good luck:)

69NovaSS

19th-February-2006, 09:06 AM

there is a rule like 10 pounds per 1000 rpm or something like that. anybody...

Yep it is something like 1psi per 100rpms is a good safe working oil pressure...;)

Mike Goble

19th-February-2006, 09:28 AM

65 Post

19th-February-2006, 12:23 PM

What was the oil pressure when it was fresh? If the pressure was good when it was fresh, maybe something like silicone got sucked into the oil pump pickup or something. Something else could be that the oil pump came loose and there is a gap between the pump and cap. Dave

69NovaSS

19th-February-2006, 01:32 PM

How does the pan get sucked dry? Where does the oil go?

As you know Mike, and maybe the SBC doesnt have this issue, but sometimes oil can be pumped faster from the pan than it can return which can lead to issues of low or zero oil pressure...however this is normally only an issue at high RPMs, ie above 5000rpms, the olds 455 is a perfect example of this...staying above 5000rpm with that motor for any length of time will likely cause this situation to happen..:)

Mike Goble

19th-February-2006, 02:38 PM

I would have a hard time believing that you can suspend a gallon of oil inside the crankcase for any period of time. If I have a high volume pump and 50# of oil pressure, will the pump be pushing more oil through the galleys then a standard volume pump at 50#?
I would be more likely to believe that a high volume pump aerates the oil a lot more at high rpm, causing a loss in oil pressure. This same effect is observed by overfilling the sump and letting the crank churn up the oil. Oil also gets thinner as you work the engine harder, and the oil pressure will drop.

staying above 5000rpm with that motor for any length of time will likely cause this situation to happen..

Why isn't the effect apparent immediately?

novaboy009

19th-February-2006, 02:47 PM

Very interesting explanation Mike! Thanks!

Kev

Maxturbo

19th-February-2006, 02:51 PM

Sometimes the engine may become starved for oil at higher rpms because the oil isn’t returning quickly enough to the crankcase. The underlying cause here is usually severe varnish buildup that restricts the oil return holes in the head.

Additional causes here...

http://www.aa1car.com/library/us1097.htm

bowtie0069

19th-February-2006, 06:57 PM

How does the pan get sucked dry? Where does the oil go?

I ran a high volume pump with a stock pan and it would lose pressure driving at freeway speeds for a couple miles--I believe it wasn't returning to the pan fast enough.
The ONLY pump I will run anymore is Moroso's standard pressure/standard volume unit. In my sloppy, worn out junk it idles at about 10-15 hot and might go to 65-70 at 7500+. It's all I need for a sbc.

One change you might try to pick up some pressure is a different filter. After reading about several instances of low pressure with standard Fram and 'parts store' filters, I switched to a K&N and pressure came up a few lbs.

Deluga10

19th-February-2006, 07:24 PM

The only thing I know is what my machine shop told me. NEVER!!! Install a high volume oil pump with a stock oil pan. I recently bought a Nova that was just rebuilt by a " True Chevy Pro", who apparently didn't know his --- from a hole in the ground. He did just that and guess what? It cost me . I had to rebuild the rebuilt engine that had only 20 hours on it. :(

bowtie0069

19th-February-2006, 09:53 PM

I had to rebuild the rebuilt engine that had only 20 hours on it.

You had a lot more than an oil pump volume problem--I ran my starved for oil repeatedly( I like to push things to the edge) and it never failed. I would cross the finish line with the gauge reading 20lbs. or less for years. Small block Chevy's just don't need a lot of oil pressure.

Maxturbo

20th-February-2006, 07:18 AM

Paul Wright

20th-February-2006, 08:33 AM

I tend to agree that high volume oil pumps are fine for stock and mildly modified / driven engine combinations, and something ELSE is the reason for the low oil pressure.

I've been running a high volume oil pump (Melling or TRW, can't remember) since rebuilding my SB over 150K miles ago, with no engine issues what so ever. The only other mods from stock during the rebuild was the addition of a mild Isky cam and TRW forged pistons. Neither one of which should effect lack of oil pressure concerns mentioned thus far.

Look at how many professional engine builders install them on a routine basis, or the parts houses that include them in their "kits"! :)

The last line is an example of backwards logic. It's like saying because many performance cams have a lumpy idle, then a lumpy idle must be good for performance.

The REAL reason that High volume pumps are frequently used is because MANY people think high volume pumps are better for the engine than the standard volume pump.
Manufacturers sell what people buy, and engine builders install what the people buy.

All a high volume pump does is waste energy trying to pump more oil volume through the bearings. Once you hit the oil pressure relief PSI, the excess is dumped back in the pan.

If you build engines for a living you can call yourself a "professional", but that does not automatically mean you are an expert. Installing a high volume pump in an engine that doesn't need it probably means you don't trust your engine to last on normal volume. Not exactly the confidence of an expert.

More on the subject of oil pressure in Best of Tech.

As far as the original question, make sure your oil pressure line isn't crimped under the ferrule.
Take a knowngood gauge (and line) and verify the reading is correct at the port

Maxturbo

20th-February-2006, 08:57 AM

a high volume pump does is waste energy trying to pump more oil volume through the bearings. Once you hit the oil pressure relief PSI, the excess is dumped back in the pan. Which is no different than a stock oil pump in function.

Well, you are certainly entitled to your opinion, but not all are in agreement.

http://www.melling.com/support/bulletins/bulletin-3rd.htm
http://www.chevyhiperformance.com/techarticles/148_0506_how/

FunkyNova66

20th-February-2006, 10:33 AM

I have about 10-12 PSI at idle (600-700 RPMs). As soon as I bump the throttle the pressure jumps to 40PSI and under hard acceleration is around 50-60 PSI.

Looks like I'm good to go.:D

FunkyNova66

20th-February-2006, 10:45 AM

What sould my oil pressure be at idle. Its a 327 with vortec heads. Probably like 700 miles on my engine. I have a milidon 5 or 6 quart pan with a high volume pump. Oil level is fine. When I am at running temp in nuetral my oil pressure is 10. When I put in drive it drops to around 5 or 6. At 2000 rpm it at around 35. My line is hooked up in the rear of the block right behind the manifold. HELP!!!!!!!!!!

SSbowtie65,

If you car is:
holding 10PSI when in nuetral (1000 RPM I assume?)
holding 5-6 PSI when the car is in drive and the foot brake on (500-600RPMs I assume?)
holding 35 PSI when the car is revving 2000 RPM.

To everyone on this thread,

Isn't the general rule?:
1 PSI per 100RPM?
10 PSI per 1000RPM?

yet say he has an issue with his oil pressure?

It seems to me to be a contradiction or am I missing something here. Unless the 1PSI per 100RPM doesn't apply to idle PSI ???? I don't know......Someone please enlighten me.

67Chevelleguy

20th-February-2006, 10:50 AM

I run a high-volume pump on my Chevelle. Its rebuilt 396 BB, but mosly stock with a mild cam. I get 40+psi cold and 25+psi hot, around 15-20Psi on the highway. I don't have any problems with my high-volume pump and I would buy one again.

Maxturbo

20th-February-2006, 11:22 AM

It seems to me to be a contradiction or am I missing something here. Unless the 1PSI per 100RPM doesn't apply to idle PSI ???? I don't know......Someone please enlighten me.
When I put in drive it drops to around 5 or 6
THAT's pretty low, especially on a fresh rebuild. It's even below the typical oil pressure idiot light setting of 7-9.

I understand your thoughts on deriving the 1 psi per 100 RPM, but that's sorta' splitting hairs at the idle end of things (I think) when probably 95% of us routinely see 10 psi PLUS at idle. Know what I mean? ;)

Now with a tired engine, loose fit-up new bearing job, pump problems or an inaccurate gauge, MAYBE numbers that low.

Paul Wright

20th-February-2006, 04:54 PM

Which is no different than a stock oil pump in function.

Well, you are certainly entitled to your opinion, but not all are in agreement.

http://www.melling.com/support/bulletins/bulletin-3rd.htm
http://www.chevyhiperformance.com/techarticles/148_0506_how/

Melling sells a lot of High volume pumps. People are spending more for a warm fuzzy feeling rather than a true need. Melling is all too glad to sell parts to people that worry. They aren't cheating anyone. Everything they say is basically accurate but if you read it closely they refute the need for a high volume pump except in some cases.
High volume pumps can be a big advantage if used where needed. If installed in an engine that does not need the additional volume, they will not create a problem. The additional flow will be recirculated within the pump.
People often refute my position saying they never have a problem with HV pumps. There's one problem they might not be aware of. It wastes energy to pump and dump extra volume.
If you doubt that an oil pump takes power to turn, watch what happens to a drill motor during the initial phase of oil pump priming.

Simply put a standard pump provides enough oil and wastes less energy doing it. Melling goes on in another tech tip about using a HV pump when it's not necessary or to cover up low oil pressure from loose bearings:

The high volume pump does increase the flow so you will have some increase in pressure. However, you still have the original problem of a leak or worn out. The high volume pump just delays fixing the real problem. High volume pumps are for increased demands on the oil system such as higher RPM usage, racing, remote filters and or coolers, etc.
That seems to confirm what I'm saying. You only need a HV pump if you need it. Most people don't need it. I only agree with the usages in bold. Here's why:

It takes 8-9 gallons per minute to run a small block 7,500 rpm and the stock pump can do that easily..... Most stock pumps will get the job done to 7,000 rpm with just a bigger pickup and more pressure relief spring without anything else

The rule of thumb for pressure was originated by Smokey Yunick and has been parroted without question by almost everyone since.

However what they don't know is later Smokey noted that smart engine builders were ignoring his rule of thumb (Sounds like something he would do himself):

It takes 10 hp or more at 7,000 RPM to turn the oil pump. The more pressure you run, the more horsepower you lose. Some Winston Cuppers drop the oil pressure to 50 psi when they qualify.

Later more and more people broke away from conventional wisdom (who would have thought Smokey Yunick's ideas would become old school thinking.

Here's a quote from Gary Penn at GMPP (that name sounds familiar)

The advanced quality of oils on the market means the old rule of thumb that you need 10 pounds of pressure for every 1,000 rpm is not valid anymore

I realize that a lot of people who've read all the books from the 70's will never be convinced of any of this and continue to waste money on "high volume" pumps.

Keep this in mind. 10 un-conventional tricks that are worth "only" 1-5 hp each give me a 25-30 hp advantage over conventional wisdom engines.

69NovaSS

21st-February-2006, 07:59 AM

It takes 10 hp or more at 7,000 RPM to turn the oil pump. The more pressure you run, the more horsepower you lose. Some Winston Cuppers drop the oil pressure to 50 psi when they qualify.

Paul..just one quick question about these Winston Cup Racers that lower oil pressure-down to 50psi during qualifications would their idle pressure be as low as 5-6psi that this guys car is at? 5-6psi of idle oil pressure seems really low in a motor with only 700miles on it. An ya even though based on the old out of touch rule of thumb of 1psi per 100rpm the 5-6pis is about right on target IF his idle speed was not more than 600rpm(how many of us have a 600rpm or less idle?) but with that said 5-6psi just seems low to me...like Max said most oil pressure idiot lights would be on already as they are normally regulated in the 7-9psi ball park.

Also the thing about the Winston cup racers it sounds like when they need their motor to last longer then 2 all out laps they increase the oil pressure to help longevity...or at least that could be read into Smokey's quote.

Now with all of that said I am not advocating the use of a HV oil pump...If your bearing clearances are kept on the low side of the recomended tolerance there should be no need to have a HV pump in most motors. Now for those that are running street cars and just for their own peace of mind want to run an HV pump IMO it likely causes them no real ill effect as they are likely not too worried about the 7+HP that the pump is eating at 7000 RPM cause their motor will never see that rpm anyway......just my 2 cents. ;)

Maxturbo

21st-February-2006, 08:10 AM

I realize that a lot of people who've read all the books from the 70's will never be convinced of any of this and continue to waste money on "high volume" pumps. I hear ya', but your theory is not compelling enough (to a lot of us) to deter us from taking advantage of the attributes of a little additional oil volume and pressure, at little or no cost. ;) Call it peace of mind if you want. It's a price I'd gladly pay.

And how DARE you besmirch the legacy of Smokey Yunick! :eek:

Real McCoy

21st-February-2006, 08:55 AM

Everyone has their opinions on oiling, pressures and pumps so here's mine. I never use a HV pump anymore and quit using them about 20 yrs ago when I bought a dial bore gauge and was taught how to check clearances with it. I found the standard Melling pump will produce enough pressure to keep the motor happy and oil pressure is usually above 15 PSI hot at idle. When I stopped using the HV pumps I found my timing chains and distributor gears quit wearing out so fast which told me the HV pump was tough to turn. Someone mentioned the NASCAR guys and oil pressures. Not to forget they are dry sump motors, run alot of sump vacuum, alot of coated internal parts,they don't idle much at all, and are clearanced alot differently have a street motor. Ever notice the heaters and recirculators they have hooked up before testing, qualifying and the race? JMHO, RM

Maxturbo

21st-February-2006, 09:01 AM

When I stopped using the HV pumps I found my timing chains and distributor gears quit wearing out so fast which told me the HV pump was tough to turn. My guess is that you had OTHER problem areas of concern. Case in point? My experience...150K on my SB Nova and just under 100K on my truck's 327 and I haven't touched the timing chain nor dist gearing. Both engines have HV pumps installed by me. Go figure! ;)

Side note: my Nova's stock nylon coated timing sprocket went south at 105K with the stock oil pump FWIW. Both my engines had dual-roller chain assy's installed after that.

Bottom line? (which I share with Melling)

High volume pumps can be a big advantage if used where needed. If installed in an engine that does not need the additional volume, they will not create a problem. The additional flow will be recirculated within the pump.
Works for me!:)

Real McCoy

21st-February-2006, 09:54 AM

Maxturbo, I don't do stock type or mild street motors much so when you refer to 100,000 miles and no wear I refer to 10 or 15 races and worn out with less than 500 actual miles. Like I said everyone has an opinion and they are never going to be the same. I wasn't trying to convince you about anything, just expressing my opinion based on my experiences. If the HV pump works for you with no problems I'd stay with it too. They just don't work well for what I do so I don't use them. RM

Maxturbo

21st-February-2006, 10:00 AM

Maxturbo, I don't do stock type or mild street motors much so when you refer to 100,000 miles and no wear I refer to 10 or 15 races and worn out with less than 500 actual miles. I understand. Dif application. ;)

We've been touting the HV in stock and mild performance scenarios. I appreciate your input.

It's all good. :)

You going to the spring Charlotte Auto Fair?

69NovaSS

21st-February-2006, 10:15 AM

When I stopped using the HV pumps I found my timing chains and distributor gears quit wearing out so fast which told me the HV pump was tough to turn.

this is interesting info....did you notice if your timing was more stable after the switch away from the HV pump...I have heard that high oil pressures can, in certain cases, cause your timming to be sliightly retarded I believe it is due to the high drag load placed on the distributor by the oil pump:confused:

Nova_Guy

21st-February-2006, 10:41 AM

69NovaSS

21st-February-2006, 10:44 AM

For the ignition timming to change wouldn't the camshaft twist over it's length? That would throw off valve timing front to rear along the entire engine. I have heard this happens with extreme valve spring tension.

well the timming I suspect could change a bit due to timing chain stretch which would be caused by the drag created by the pump...I dunno just asking...there must have been added drag for the dist gear and timming chains to wear out faster and this could cause the timming to be slightly off I suspect...I dunno whadda ya think?:confused:

Maxturbo

21st-February-2006, 10:45 AM

69NovaSS

21st-February-2006, 10:53 AM

I was just going to go there Nova_Guy after thinking about the Real McCoy's probs.

Valve trane...radical spring rates, rockers and cam grinds. They place a significant additional strain on the timing gearing as well. ;)

ok I agree these put extra strain on the valve train but I think that one of the symptons of a worn timing chain...even in a total stock car is timing that bounces around a bit...due to slop in the timming chain...could this slop also not be created by excessive drag created by an HV oil pump? Besides on RM's situation the excessive gear and chain wear went away after removing the HV pump...possibly removing any one of these factors(high spring rates, HV pump, rockers, etc) could have reduced gear and chain wear ..but in his case the HV pump did and because it is a race car the other factors were needed to be successful....Just wondering is all guys I'm not trying to convince anyone of anything I'm just trying to understand:)

Maxturbo

21st-February-2006, 11:00 AM

could this slop also not be created by excessive drag created by an HV oil pump? Not according to Melling.

3. It will not wear out distributor gears. The load on the gear is directly related to the resistance to flow. Oil pressure is the measure of resistance to flow. The Ford 427 FE "side oiler" used a pump with relief valve set at 125 psi and it used a standard distributor gear. Distributor gear failures are usually caused by a worn gear on a new cam gear and/or worn bearings allowing misalignment.

5. It will not cause spark scatter. Because of the pump pressure there is a load on the distributor gear. The number of teeth on the oil pump gears determine the number of impulses per revolution of the pump. In a SB Chevy there are seven teeth on each gear giving 14 impulses per revolution. At 6000 RPM the oil pump is turning 3000 RPM or 50 revolutions per second. To have an effect on the distributor, these impulses would have to vibrate the distributor gear through an intermediate shaft that has loose connections at both ends. Spark scatter is usually caused by weak springs in the points or dust inside the distributor cap.

Real McCoy

21st-February-2006, 11:11 AM

In my opinion everything mentioned adds stress to the timing chain. The belt system helps alot if you can use it. Many racing classes don't allow the belt though. Crank triggers fix that if they are allowed and the type racing you do will tolerate them. Dirt guys can't use the dry belts or triggers for obvious reasons. NASCAR guys use to have problems breaking cams with the small diameters partially due to excessive stress. Only two things wear out the distributor gear though. On our applications this problem went away when we got away from the HV pumps though. I also spend some time polishing up the dump pistons in the oil pumps to be sure they are free. Melling is the only oil pump I use also. Had mixed results from other make pumps so all I use is Melling now. We inspect the pumps on a engine freshen up but I don't change one unless it is hurt or I have a concern with it. I just have better results from certain stuff while other people seem to get by with anything.......LOL. If my way was the best and only good way then I'd always win so since that's not true there are other ways to do things and get good results too. That's why I read all these posts.......LOL. RM

Paul Wright

21st-February-2006, 12:29 PM

Paul..just one quick question about these Winston Cup Racers that lower oil pressure-down to 50psi during qualifications would their idle pressure be as low as 5-6psi that this guys car is at? 5-6psi of idle oil pressure seems really low in a motor with only 700miles on it. An ya even though based on the old out of touch rule of thumb of 1psi per 100rpm the 5-6pis is about right on target IF his idle speed was not more than 600rpm(how many of us have a 600rpm or less idle?) but with that said 5-6psi just seems low to me...like Max said most oil pressure idiot lights would be on already as they are normally regulated in the 7-9psi ball park.

Also the thing about the Winston cup racers it sounds like when they need their motor to last longer then 2 all out laps they increase the oil pressure to help longevity...or at least that could be read into Smokey's quote.

Now with all of that said I am not advocating the use of a HV oil pump...If your bearing clearances are kept on the low side of the recomended tolerance there should be no need to have a HV pump in most motors. Now for those that are running street cars and just for their own peace of mind want to run an HV pump IMO it likely causes them no real ill effect as they are likely not too worried about the 7+HP that the pump is eating at 7000 RPM cause their motor will never see that rpm anyway......just my 2 cents. ;)

5-6 psi is too low and indicates a problem. Somewhere there is an internal pressure leak.

I think it should be pointed out that Nextel cup racers don't use a "stock" oiling system, but they do minimize un-necessary oil flinging around creating windage problems.

I spent many hours in dyno cell working on oil system development. Some surprising data changed my mind about what is still conventional wisdom.

The race engines have good oil pressure even at idle. In fact my 245,000 mile std bore,std crank 350 in my tow wagon has minimum of 25 psi hot and up to 60 psi cold at idle with a standard volume pump.

If you recall I once had a HV pump in the wagon because that's what came in the re build kit. I used the OEM pump shaft and after 60,000 miles of pumping too much oil it snapped. There's a picture of it in this thread.
I realize that buying a HV pump is a peace of mind issue for some, however I sleep much better with the standard volume pump in my car.

SSBowtie65

22nd-February-2006, 12:41 AM

Jegs sells a high pressure spring is it worth trying???

Real McCoy

22nd-February-2006, 07:54 AM

A heavier spring will allow you more oil pressure before the dump valve opens. If you have 60 lbs of oil pressure max a heavier spring would let you go 80 lbs. max if you thought you wanted that. It's not going to improve oil pressure but only allow you to increase the max pressure you can get. I remember when I was a kid people bragging about having over 100 PSI of oil pressure. Back then we had small journal cranks, junk bearings, little knowledge, no tools, so we killed alot of bearings and thought the high pressure would solve that problem. RM

Sedanman527

22nd-February-2006, 08:01 PM

Heys guys !
I drive NHRA SS/CM (not that it matters..) and have used a N/A 324ci. (4.040x3.16) 0.0025 bearing clearance that is at 9300 rpm each pass using a melling standard oil pump, while using the same pump for 9 years of updating and servicing the engine and inspecting the pump. Appr. 20 psi at idle and 50 psi at rpm/hot (Mobil 1 5w40 fully Senthetic), Stefs full length oil pan that is 9" deep x 9" wide at bottom x 13" wide at top , using 5 qts oil... running 9.20-40´s 1/4 at 2970 pounds.
Bearings are beautiful after each season of HARD work. Using this pump was after consulting with Nickens Bros and Jake from Stefs. (I was also recommeneded a used one for the maximum hp per/ci that i was/is looking for)

Pump chatter has been addressed but not much said about "bearing wash" from high oil pressure .
Jake from Stefs has talked about to much oil pressure will not hold its load or support the crank / also bearings that are worn down from the high volume "wash".
What about the loss of thermal transfer from the bearing to the oil when using a high volume pump .....? the high pressure will make more heat too ?

Acouple years back it became legal for SS/xM cars to use a vacum pump, so for the 2005 season i installed a Pettersons `WetVac´ , a combined vacum pump/exteranal oil pump that makes for easy oil pressure adjustments. Great ! I now have the hot psi at rpm about 45-48 psi . The bearings are beautiful and its running faster than ever.

To each there own... not trying to convert anyone into using a standard pump, but just stating why i like one .

Back to the first post .. .. did you use anything to seal the fitting ? like plumbers tape. .. if so maybe a small piece is in the line to the gauge ?

SSBowtie65

23rd-February-2006, 02:20 PM

I took the gauge out and tested it and it works fine. I took the line out and blew air through it with the air compressor and tried again.Still low at idle when its warm. I guess this means pulling the engine out again:D!!!! (It will only be like the 10th time hahaha) Oh well I guess i can paint my subframe how I want it now and change the color of my engine. Its black and I think I wanna go silver then maybe I can find my leaks :)

63SLEEPER

14th-May-2006, 12:56 PM

Talk about frustrating,
I switched to a rear sump system on my 63. I had an unused melling m55hv pump in my garage for 10 years. I poped it in with the new pan and the oil guage read 65 at idle and swung off the guage at 100psi when reeved high. So I figured it was a bad pump maybe from sitting for so long. I bought a new one threw it in with the same results. I wrote an email to tech support at melling explaining the situation. They though I had bad luck and got two bad pumps in a row. They sent me a third and tested it first. They said it was 41 at idle and 65 relief. So, I just installed it and it reads the same as the two previous pumps. I bought a new guage thinking mine could be bad, but still too much pressure. What do I do next? Should I try a stock pump rather than the high volume variety? It's my understanding that the hv pumps should not increase the oil pressure?
How much clearance should I had between the pickup and pan? I have about 3/4 of an inch. The folks at Canton who I bought the pickup from said that I can go as low as 1/4 inch of clearance. So I should be fine right? The motor is a 327 that had no problems prior to the pump/pan swap. My pressure with the Nova specific pump was 35 - 75 psi.
I'll probably end up going back to the old setup b/c this is driving me nuts.

Thanks for any suggestions

Hawk1

14th-May-2006, 03:22 PM

I would be thinking tight bearing clearances.

bowtie0069

14th-May-2006, 06:21 PM

Other than the pan and pickup, what has changed? How much pressure did you have before?
The best pump I've ever found is Moroso's standard pressure/standard volume piece. It's a Chevy, it doesn't need any more than that!
Now if you had a F**D or Buick, or Olds..................they need all the help they can get!

63SLEEPER

14th-May-2006, 06:25 PM

Nothing has changed besides the pump pan and pickup. Before, I had 35-75 psi

Bill's II

15th-May-2006, 01:07 AM

Hey Now, At what engine temperature? cold, hot, I know that some with tighter bearing clearance will have higher pressure on cold start and not drop down until engine temp is above 185 degrees. This is with the high volumn pumps. Another option is to replace the oil pump by pass spring with a stock GM, not the White spring its the high pressure bypass spring. Respectfully, "Bill's" II :cool:

69NovaSS

15th-May-2006, 07:01 AM

This is JMO here but if your main bearing tolerances are where they should be a HV pump will likely increase your oil pressure as its trying to pump a larger volumn of oil through the oiling system and since the bearings are not bleeding off some of this volume the oil pressure HAS to go up. On the other hand if your main bearing tolerances are on the loose side a HV pump might not effect your oil pressure at all as it is losing some of the excess volume it pumps due to the internal leaks caused by the loose fitting main bearings...I think we have had other threads on here about this subject...possibly do a search for them....I'm not sure that a spring change in the pump will effect the presures you are seeing as its the pump gears themselves that are larger in a HV pump (they are normally longer then a regular oil pump) that is how it pumps more volume so even with a spring change it will still try to pump just as much oil....Since it appears that your main bearing clearances might be right where they should be possibly a standard oil pump NOT a HV pump would be a better choice...just my 2 cents;)

Tom Griffin

15th-May-2006, 07:44 AM

So maybe a different angle here. You had 35-75 psi with a stock front sump setup? That seems awefully high to me with a stock CII oilpump. What weight oil were you using with your original setup?
Tg

69NovaSS

15th-May-2006, 07:47 AM

So maybe a different angle here. You had 35-75 psi with a stock front sump setup? That seems awefully high to me with a stock CII oilpump. What weight oil were you using with your original setup?
Tg

Very good question Tom, possibly he is running 20 or 30 weight dino oil....which would also explain the high pressure:)

63SLEEPER

15th-May-2006, 09:26 AM

69NovaSS

15th-May-2006, 09:35 AM

I was running 20/50 oil with the front sump setup. There's 10/30 in it now. What are the dangers with running at the high oil pressure? Should I just go back to the old setup or should I try a stock pump with the rear sump? Also, what should the pickup to pan clearance be?

I believe that too much pressure can cause a drag on the dist that can possibly cause spark scatter. Also it can cause the oil pump drive shaft to fail....not saying any of these things will happen just that they can happen when you have too much oil pressure. There should be roughly, based on the book "step by step guide to engine blueprinting", 1/4" to 3/8" of pickup to pan clearance :)

Mike Feudo

15th-May-2006, 09:58 AM

You have no need of the HP-HV pump unless something is out of wack with your oil system. Put the std 55 pump in with the higher pressure spring and it will be just fine.

wskaiser

15th-May-2006, 10:28 AM

I have to agree with Tom Griffin, those pressures with a stock front sump pump see awfully high. The bearing clearances must be very tight and stock pressure hot is usually 35-40 psi at 3000rpm with the stock oil pump. If the bearing clearances are that tight I can easilly see having excess pressures with the high volume pump since the bleed off is limited. I don't know what bypass spring is in the new pump but those pressures seem unusually high and I would be worried about washing the bearings as well as distributor gear wear.

stock z/28

15th-May-2006, 01:09 PM

Hi,

I agree it seems like a lot of oil pressure, especially with 10/30.

You can probably modify the bypass passage in the pump to help the problem.
Its fairly simple.

How many miles are on this?

Jeff

markss327

15th-May-2006, 01:59 PM

My fresh 406 has 60lbs at cold start, with 10-30. I can rev it to 3000rpm, and it'll bury the gage - 100lbs. Granted, this is COLD. Once warm, it idles at 40, and will go to 80 at 3000rpm and above. Back in 1995, my previous engine, a 327 had the same characteristics. Pretty much what you have now. Even the rear sump.

To answer your question, 100lbs of oil psi, is a lot. We both are running the High Volume pump.
IMO, this is the problem.
The pressure relief orifice can only pass so much oil. It's being overwhelmed. I belive switching back to a standard volume pump, will return your oil pressure back to 'normal'.

Just my $.02

63SLEEPER

15th-May-2006, 02:35 PM

I guess i'll try a non hv pump with the rear sump setup. This better work. It will be the 4th time lying on my back with my eyes full of oil. The FAQ's on the melling site says that an HV pump should not increase the oil pressure, but who knows. I've been in contact with their tech support, but the haven't offered much of an explanation.

Thanks,

-Christian

63SLEEPER

7th-June-2006, 05:06 PM

Well, I installed my 4th oil pump, a standard volume one this time. The pressure came down a bit, but I would still consider it high. 65 idle,
90 - 100+ at 6500rpm. I also changed to a deeper pickup that sits 1/4 inch from the bottom just to be safe. I guess I'm going to live with the high oil pressure and hope it doesn't cause any problems. Wish me luck!

-Christian

wskaiser

7th-June-2006, 05:57 PM

I sure would like to know what the bearing clearances are on that motor. They have to be tight. How many miles on the engine?

Bucs01

8th-June-2006, 08:36 AM

Ya, with the stock front sump set up from Chevy 2 Only I am running about 14 when engine is HOT idling at 900 rpm then about 25-30 at 2,000 and 35-40 at 3,000. 20/50 oil since I only drive in the summer 65-100 degree weather.

With my old rear sump HV pump it was around 30-40 at 900 rpm idle HOT and stayed around 60 or so at 3,000 rpm's with 10/40 oil.

71SS454

8th-June-2006, 10:45 AM

Just my .02cents, but could the cam bearings be installed incorrectly blocking some oil flow and creating a restriction? What about a galley plug somewhere installed too deep doing the same thing? Or bearing clearances also? Has this engine been rebuilt or is it stock assembled? You definatley have something too tight or a restriction in the oil system somewhere that dosen't sound too good to me. If the engine was rebuilt, did the machine shop measure the rod ends and main caps witht he undersized bearings in place and tell the crank grinder what to grind the journals to or was the crank ground and assembled with undersized bearings according to what the grinder said the crank was ground to? If the later, you may have a big clearance problem that I personally (IMO) wouldn't just ride out and hope nothing goes wrong. Good luck.

63SLEEPER

8th-June-2006, 11:55 AM

Thanks for the input. I ran this motor for about 9 years with the front sump. From what i read here, the front sump delivers pretty low pressure. Mine was high at about 75 max. Now with with the rear sump i'm at 90 - 100+ max. I don't doubt that there is something wrong, tight bearings, a blockage, who knows! However, at this point, I can't see tearing anything apart. It is what it is. I've been beating the crap out of this motor for a long time and it hasn't given me any problems.

Thanks guys.

novaboy009

8th-June-2006, 12:02 PM

I've got quite a few trophy blown up engine pieces to show for with thinking like that...:eek:

Kev

IgnitionMan

8th-June-2006, 12:41 PM

On rear sump small blocks, I ALWAYS use a dead stock Melling replacement pump for 1966 427/425 horsepower engine. Same pump I run for big blocks.

Pickup to bottom of pan, between 1/4th to 3/8ths of an inche clearance is just right.

Too much oil pressure will wash the cam, main and rod bearings out.

What oil filter are you using, and is the standard bypass valve in place in the block, above the filter, and operating, on the filter adapter? Some "race" engine builders will insist on blocking the filter bypass valve, which is a drag race only thing, not for a real daily driver situation. With the bypass valve blocked, warming the engine before winging it is vitally essential, as the oil needs to be thinned so it doesn't blow the filter off the engine from excessive oil pressure.

Just more info, Buick small block engines have a lubrication system that is volume based, not pressure. Those engines go for decades with 10 psi at idle, and 33 psi at full rpms. Higher volume setups on those engines only make for more issues and problems. My 239,000 mile dead stock 4.3 V6 in my Safari van uses straight 30 wgt oil, works at 20 psi at idle, 40 psi at rpms.

stock z/28

8th-June-2006, 02:05 PM

Hi,

That a real strange situation, especially with with 10/30 oil. Is that racing oil or standard oil?

With 9 years of operation you would think if something was wrong internally it would have showed up by now.

With that much pressure I would be concerned about distributor and cam wear.

As far as the filter bypass is concerned I have never seen where pluging this causes a significant problem as 1) its primarilly a differential type bypass and filter restriction would have to be very high to cause a problem and 2) most filters have an internal bypass in them so plugging the adapter really causes no significant gain in filtration, although some filters are available without the internal bypass.

The bypass orifice inside the oil pump itself can be enlarged to "dump" more oil in the bypass mode. Some "race" aftermarket pumps offer this modification. You can usually spot them by looking at the pump cover, if it has a small "freeze" plug its probably a stock size. If its a threaded type plug its "usually" been modified.

In my opinion you should not need any of these modifications anyway, thats why this is so puzzling to me

Is it possible that something got into the oil passage (like silicone sealer) when you changed pumps? Just a thought.

Good luck

Jeff

JBimmolate

8th-June-2006, 05:12 PM

Is it a manual gauge or electric? It could be a bad oil pressure sensor/sending unit if it's electrical.

Just a thought
Miles:D

63SLEEPER

9th-June-2006, 09:17 AM

I would agree that after nine years of use, a problem would have appeared by now, that's why this is so strange.

-Regular castrol 10w30

-engine is 1965 327 this engine builds it's power very high. it regularly sees 6500-7000rpms

-oil filter is fram ford ph8a or something like that. I have an adapter to be able to use the spin on filter and it only fits the ford filters.

-My guage is a mechanical autoguage. I tried an electronic autometer, but it read the same.

69NovaSS

9th-June-2006, 09:21 AM

run 5w30 dino or 0w30 (or there abouts) synthetic and call it a day....seems you have an unsual and elusive situation to figure out:)

DriveWFO

9th-June-2006, 09:34 AM

The whole problem could be caused by the bearing clearances (as stated earlier). So, you gotta either live with it or check the clearances I suppose :confused:

Dan_Lebherz

9th-June-2006, 09:38 AM

If its not too much trouble, I'd try running without the Ford adapter and see if that makes a difference. Probably easier than removing the pan again.

Bucs01

9th-June-2006, 10:32 AM

63 sleeper said- I ran this motor for about 9 years with the front sump. From what i read here, the front sump delivers pretty low pressure.

The pressure is low (compared to various other options), but unless you're racing and running high rpm's it's all you need for the street. 14 at idle at operating temp and 30-35 at 3,000 rpm's hot, is plenty for the street from all that I have read on this site over the past 3 years. ;)

IgnitionMan

9th-June-2006, 12:19 PM

I am set against using Fram anything.

At this point, I'd suggest one more test, may not prove anything, but...try a Wix, CarQuest, NAPA oil filter. Maybe a problem with the relief valving in the Fram filter. Usually, I see a REDUCTION of oil pressure when a Fram oil filter is used. It's a reach, but please consider trying it.

stock z/28

9th-June-2006, 12:36 PM

Hi,

I agree, Im not a big fan of Fram filters either. There is an adapter available for the older blocks that use a standard Chev. style spin on filter. That's the one I generally use. NAPA is about the only source for a filter that doesnt use a drain back valve locally. I wont use a current filter that has such a valve in a high perf application.

I may be wrong but I dont think that type of filter adapter is used with the stock Chev. bypass assembly. The other one I mentioned is, and you still have the use of the filter differential bypass.

Its still quite a mystery to me. If your block has an 1/8" pipe plug in the front above the timing cover, maybe you could take pressure Reading there as well.
It would seem if the main oil passage was blocked (unless it just happened) the engine would have had failure before now, but the would verify that the main oil supply gallery was not restricted.

Got to run

Good luck

Jeff

63SLEEPER

9th-June-2006, 02:35 PM

I'm a little confused with the responses. The only one that makes since is to try a different location for the sender. could the adapter i'm using be the problem? I've always wondered why is takes a ford filter. I'll take a picture tonight and post it.

Thanks as always

-Christian

Paul Wright

9th-June-2006, 05:08 PM

They all make sense to me. I don't understand why you changed 4 oil pumps!

You get Pressure when the Exit volume of oil is less than the Input volume.

The exit volume is a function of all the restrictions in the engine, bearing clearances, passageways, lifters, etc.

As oil moves through your oil system it lubricates parts then goes back to the pan. The sum of all these leak paths is your total exit volume.
The oil pump has a pressure relief spring that should open when the oil pressure exceeds the spring pressure.

If you have excessive pressure with a stock volume/pressure pump it means that you might have too much restriction in the oil system.

Igosplut

10th-June-2006, 06:49 AM

I HAVE seen aftermarket spin-on filter adapters make the pressure go out of sight with hi-volume oil pumps. I'd change out that adapter before you do anything else. Make sure the one you try has a factory-style bypass...

L78 Nova

10th-June-2006, 01:37 PM

Sounds like the filter adapter may be the culprit!. The factory filter adapters have a relief valve built in to them to allow excess oil volume to bypass the filter. I've seen problems with these before that caused HUGE oil pressure.

Gary

kceb10

10th-June-2006, 03:24 PM

I have also seen them to cause low oil pressure

63SLEEPER

12th-June-2006, 10:29 AM

OK, I'm going to try a new filter adapter

How about this one?

http://store.summitracing.com/partdetail.asp?autofilter=1&part=NAL%2D3952301&N=115&autoview=sku

stock z/28

12th-June-2006, 04:15 PM

The adapter in the wont work on a 65 block. It will only work on 68 up engines. AC used to sell the best kit(in my opinion), but you will still need to come up with a original style adapter the was available with the canister style filter. It it used in conjunction with the replacement adapter, it is the piece that provides the oil routing and the bypass function.

Jeff

63SLEEPER

13th-June-2006, 04:15 PM

Can someone suggest an adapter to try?

Thanks,

-Christian

63SLEEPER

15th-June-2006, 05:50 PM

Guys,

I think we may have something with the oil filter adapter. I would really appreciate some advice on what to buy as a replacement.

Thanks again

-Christian

Paul Wright

24th-August-2006, 09:35 PM

This was my answer to a question about putting a M77HV Big block pump on a SBC:

Seriously, how many gallons of oil per minute does your engine need? The BBC pump produces 12 GPM. You can only pump so much through the thin space between the bearings before it just bypasses the excess. 8 GPM is plenty and a blueprinted SBC pump can deliver 9 GPM.The loosest small block assembly I've ever seen-one with way too much clearance on the rods, mains and lifters and oil flying all over the place-would only require about 8.0GPM. I can't imagine any small block Chevy-stock or racing-that will ever need more volume than that

Big block pumps on a small block are old, old school "bigger is always better" thinking. There are some who believe the 12 tooth BBC pump has less "spark scatter" than the 6 tooth SBC but Smokey Yunick says the BBC pump uses a lot more power to drive than the SBC pump. That's more strain on the pump drive not less. It's only real advantage is the larger pickup. You can get SBC pumps with bigger pickups.

The Rat motor pump is identified by the five bolts used to retain the pump cover. This pump uses large gears with a larger pump inlet opening for more volume. I don't recommend it, and see no reason to use any high volume pump for the small block. The larger pump merely creates more problems while offering no benefits and requires more power to turn!

Even Bill Jenkins in his 1976 book, "The Chevrolet Racing Engine" recommended using the std 4 bolt SBC pump with hot oil pressure 50-60 psi and plugging the bypass on the adapter.

What more credible references do you need?

Paul Wright

26th-August-2006, 02:05 PM

Guys,

I think we may have something with the oil filter adapter. I would really appreciate some advice on what to buy as a replacement.

Thanks again

-Christian

The production oil filter adapter is PN 3952301. Aftermarket filter "no bypass" adapters are available or you can tap and plug the production part.
See Best of Tech, 'Oil Filter Bypass Thoughts' (http://www.stevesnovasite.com/forums/showthread.php?t=43477) thread for more discussion and info.

JTW

11th-November-2006, 11:56 AM

I know the topic of high volume vs. std. oil pumps has been argued before, but my question is how much oil pressure do you really need at idle? My engine builder believed that high volume pumps were usually unnecessary so we stuck with a stock volume pump in my 383. I have plenty of oil pressure above idle, but only about 15 psi with the engine hot at about 900rpm. Cruising down the highway in 5th gear at about 2000 rpm the oil pressure is 40-50psi, so I haven't been too concerned. But at idle, is 15psi a safe pressure?

Mike Goble

11th-November-2006, 12:07 PM

It'll be just fine at 15 psi.

Bscman

11th-November-2006, 12:21 PM

Interesting how two different engines with stock pumps can behave differently. When mine is warmed up I'm idling at 850rpm with about 25psi, and anything about about 1500 I'm sitting between 50 and 55psi.

You should be fine at 15psi. As a general rule I've heard several times, 10psi for every 1,000rpm.

taz3

11th-November-2006, 12:49 PM

Bearing clearance as well as cross drilled cranks will reduce idle pressure.The biggest thing that will get hurt at low idle is the cam.GM's lubes from bottom up.Alot of guys I know keep the idle a little on the high side,but most of these cars have stall converters or are stick cars to keep the top end well lubricated.

JMO Paul

Wogs64SS

11th-November-2006, 01:34 PM

I've heard that you should have 10 pounds pressure for every 1000 rpms. Anyone know that for sure:)

Mike Goble

11th-November-2006, 02:18 PM

No one knows that for sure. You see many running less oil pressure quite successfully.

1quik69

11th-November-2006, 02:27 PM

My old ramair 442 used to idle at 5-10 psi. Scared me to death when I first saw it. The dealer said that was ok and i even called Joe Mondello about it and he said no probs. He said it had a lot to do with the way the engine was set up. Driving down the road it was always 45-55#.

taz3

11th-November-2006, 02:52 PM

No one knows that for sure. You see many running less oil pressure quite successfully.

I recently read an article about this,that high volume pumps aren't needed,and many racers don't use them cause the cause leaks.

It's been the rule of thumb 10 PSI for every 1000 RPM.

Mike Goble

11th-November-2006, 02:56 PM

We run 7500 rpm with no where near 75 psi of oil pressure, maybe 50-55# max. The 10# rule of thumb comes from a time when oil wasn't as good as you can buy today.

JTW

11th-November-2006, 03:11 PM

I recently read an article about this,that high volume pumps aren't needed,and many racers don't use them cause the cause leaks.

This is the reason my engine builder didn't want to use a hi-vol. pump, he said excessive pressure could cause leaks. I can't keep oil in this motor, but it's not because of leaks. I'm still fighting the problem of oil blowing out through the valve cover breather. I have a new PCV valve in one valve cover and a breather in the other and whenever the engine sees higher rpms it blows oil out through the breather. I put a new grommet in the valve cover under the breather with just a narrow slit in it but the oil still blows through. It's been frustrating.

T. Jerman

11th-November-2006, 04:14 PM

2 black ragtops

11th-November-2006, 05:26 PM

i'm no expert,but a friend( who has forgotten more about s/b chevys than most will ever know !!)suggested running a stock pressure pump.when i asked why,he said "why force your oil through a small oriface causing it to heat up on purpose and wear out prematurely"....."more pressure=more heat in your oil".that's not to say you shouldn't have some oil pressure at idle but excessive pressure may cause other problems.it made sense to me.just my two cents worth.
thx,cj.

Neverdone

11th-November-2006, 05:49 PM

another cause of low idle oil pressure is the bleeding where the dist goes thru the oil gallery. An o-ringed dist body will stop this oil loss and improve the idle oil pres.

Frank(I did it and saw the improvement)

TY70SS

11th-November-2006, 06:54 PM

I have a kinda mild 355 and the oil pressure when it is cold it is 100 at 3000 rpm.When it is warm at about 950 rpm it is at 15 -30 just depends on what day it is.

bowtie0069

11th-November-2006, 08:20 PM

oil pressure when it is cold it is 100 at 3000 rpm

There's a good way to lose an oil filter! I wouldn't touch the throttle til it's completely warmed up--it could get messy! There is no reason to have 100 lbs in a Chevy at any time. An Oldsmobile maybe.............
I usually have 60 cold, and down to 15-20 hot. At 7000+ 55lbs is plenty.

Ron Slabaugh

11th-November-2006, 08:28 PM

I've found oil pressure has a lot to do with oil temperature as well. My 383 will idle 35-40 psi @ 750-800 rpm most the time with 10w-30 oil and a standard Melling pump. However, sustained use in 95° weather, in town, with 200° coolant will drop idle oil pressure to 20 psi.

taz3

11th-November-2006, 09:40 PM

This is the reason my engine builder didn't want to use a hi-vol. pump, he said excessive pressure could cause leaks. I can't keep oil in this motor, but it's not because of leaks. I'm still fighting the problem of oil blowing out through the valve cover breather. I have a new PCV valve in one valve cover and a breather in the other and whenever the engine sees higher rpms it blows oil out through the breather. I put a new grommet in the valve cover under the breather with just a narrow slit in it but the oil still blows through. It's been frustrating.

My dad's S10 w/350 SB did the same thing see T.Jerman's post that's how I fixed his as well,with splash plate.It would suck out all the oil he couldn't figure it out for the longest time he just thought it burned oil.The new valve covers had no baffle to stop the oil from being sucked up through the PCV.

suzukiracing2

11th-November-2006, 11:14 PM

I have a 434 just got back from dyno and it Makes good power and from 3800 - 7300. . . i have 74psi at 3800 and 71 at 7300 . 100 psi at start up thats with 10/40 i use Mobil synthetic motor ran 190 195

63chevytoo

12th-November-2006, 07:30 AM

My 383 runs 40psi at 1100rpm idle
50-60psi on the highway 1500-2500rpm (5th gear)
80psi at 7000rpm
These numbers are when the oil temp. is heat saturated.
I have 70-80psi before heat saturation. (never over 80psi). But I do not run it hard before complete temp. saturation.
I run NAPA straight 40 wt. oil
P.S.
When I let the clutch out on a "granny"/normal start, the rpm drops back to appx. 600 and the oil pressure drops to around 20-25psi momentarily.
I guess if I set the idle to 600rpm I would have somewhere in the 20-25psi range.
Don

Marv D

12th-November-2006, 11:39 AM

Bearing clearance as well as cross drilled cranks will reduce idle pressure.The biggest thing that will get hurt at low idle is the cam.GM's lubes from bottom up.
JMO Paul

I'm no expert on this, but Sorry, but I have to interject a few things here. Not to be argumentative, but... we are talking about a SBC Chevy here.
I agree with the bearing clearance issue being a HUGE factor is oil pressure, BUT, the comment about the GM oiling from the bottom up????
The small block 383 that JWT is talking about,,,, oil is pumped up to the main oil galley where it is fed to the lifters, then DOWN around an annulus around the cam bearings, then down to the mains, where the crank distributes it to the rod bearings. The front main and the #1-2 rod journals are the LAST to see oil. The Chevy small block oils from the top DOWN. Again, not trying to be argumentative, just felt that needed to be clarified. Not taking in account aftermarket blocks here with priority main oiling. We are talking about GM production small blocks. Right?

With that said, We have all heard the internet chatter of the ills of high volume/high pressure oil pumps, exploding oil filters, high pressure causing leaks,,, I'm sorry but I just don't buy into it. There is no pressurized oil in the heads, no pressurized oil under the rocker covers (with the exception of the oil pumped by lifter action up through the pushrods which is then splashed around, but certainally not oil pump pressure), no pressurized oil in the intake manifold, and none under the timing cover. HOW does oil pressure cause leaks!. The only possibility is a loose / cheap garbage oil filter seal, and the rear main seal where the rear main bearing is so close to the rear seal. IF oil pressure were to squirt out of the rear main bearing with such force to push the rear seal out, you have more of a bearing problem than an oil pressure problem. Again, just trying to clarify things, not point fingers at any post. IF you were to have oil leaking out of the rear cam plug, or the oil passage plugs in the block, it's going to leak at 20psi just as well as at 65 or 80psi. Properly installed and sealed block plugs should seal at ANY pressure a oil pump is going to make.

High oil pressure does have it's evils. I'm not saying it doesn't. The energy it takes to spin a pump that is making 80-100psi is wasted horsepower. The stress and wear put on the distributor / cam gear WILL be a significant maintenance issue when your running a bronze distributor gear. And I have witnessed ONE incident where the small rubber gasket around the top of the oil filter was pushed out because of excessive oil pressure. In days of low tech poured babbet bearings high oil pressure would errode the bearing. (not so much an issue with todays bearings, but the theory is the same. If you offer a channel in the bearing for oil to flow, it won't provide a 'film' over the entire bearing surface. THAT'S what our oiling system is supposed to do. Provide an oil film to protect and cool the bearings. Any more than 'enough' is a wast of energy, any LESS and your burning bearings.

Trying not to sound like I'm on a rant here. Where are 99.9% of the cars out there taking the oil pressure reading! At the top back of the block, BEFORE any oil is delivered to ANY bearing or lifter. If you want to scare your self to death.... Most of the small block castings are drilled from the top side of the timing chain housing, down to the annulus around the front cam bearing. Put your oil pressure fitting there (after the oiling system has delivered pressure to the rear 4 main saddles) and see how much you like your low volume/ low pressure pump.

Oil presure and oil temp. Todays oils are formulated for cold flow, and high temp viscosity. In a perfect world those formulas work and we have 30-40 weight oil that cold flows like water! Yeah RIGHT! Not with Dino juice that has a the best additive package. The closest science can get is with synthetics like the 0-40 synthetic racing oils like Amsoil and Royal Purple. Go visit that Bobistheoilguy.com for a bunch of opinions on oils and filters. There is a lot more to oil than just the oil. The additives make the oil and in todays world, the best we can hope for is to start with a good synthetic base stock, and build the additive package to suit the need. Go look around the race track and see what the Comp Eliminator guys are using. No one beats on the oil like these 9500+rpm little monsters. It's amazing that these things stay together with what little oil pressure they run. I know of many that say they keep oil pressure to a max of 50-55psi at 9000+, and if it shows ANY psi at idle it's OK. That OK for a motor that is torn down and inspected / freshened many times a year I guess.

All this rambeling started over oil pressure, what is enough and what is too much. I'm sure if you ask 100 guys you'll get 100 different answers. Just my opinion, but the old 10psi per 1000RPM is fine until you start spinning the snot out of your motor. I have never hurt a crank or bearing spinning my long stroke small block to 8000rpm, and it never sees anything over 70-72psi (oh the wonders of data logging ;) ) I run 0-40 Mobile One synthetic and at 155-170° oil temps it has 40psi at a 1300rpm idle.

But that's just my 2cents, and take it for all that it may be worth. In the end it's your motor and YOU have to make the choices and live with the results. But ,, if it were my motor, I'd dump the straight weight oils and the straight 40 weight and see how oil pressure is with a 10-30 synthetic. I know it would protect your investiment better, and I bet it would stabilize psi on both ends of the temp and rpm spectrum.

littledeuce2

12th-November-2006, 11:43 AM

My little 283 runs 15-20# at a warm idle with 10/30 and no more than 45-50# @4500. Fairly tame engine. Now as long as you have decent oil pressure in the parameters needed, don't you think 40w oil is a little over the top? No? That seems a little too high a pressure. What are your concerns for the way you run your set up 63chevytoo?

gstocker

12th-November-2006, 11:58 AM

In my wife's 305 and my 327 we actually use cut down oil pump relief springs to reduce pressure. At 7500 RPM we have 40 pounds and at idle its about 20 pounds. Thats using 5-30 oil.

Paul Wright

12th-November-2006, 12:07 PM

Oil pressure is a hot topic and I'm sure will always be controversial.

It comes down to two arguements:
1. "high pressure is needed for protection".
2. "high pressure wastes power, increases oil temp and reduces protection by aerating oil"

I used to be in camp 1.
I ran high pressure and thick oil thinking it was "better"....until I spun a main bearing in my V-8 Vega on a cold morning. 50 weight is like sticky molassas when cold, but even with regular weight oil I've personally seen a high volume and pressure pump shaft break from the load.

Later when I worked at a place called Synthetex, I worked on project that put a clear oil pan on an engine on a tilt fixture to study the oiling effects of 4x4 vehicle tilt in off road situations.
This gave me an opportunity to see what actually goes on in an oil pan. Windage is real and eye opening to watch.

Then at Roush I learned the importance of oil pans, oil viscosity and pumping pressure on performance. We would expend great deal of effort on the oil system getting impressive power gains with no loss of durabilty. In fact durability often improved by reducing oil aeration and oil temps.

Even hardcore skeptics are being convinced. I just read a side bar by Dave McClelland in the December issue of Chevy High Performance magazine. On a 441 hp 350 with a high pressure 82 psi spring, gained 7 hp simply by reducing the oil pressure by 10 psi to 73 psi.
"This change really got my attention", he writes. He even goes on to speculate that 55-60 psi is probably better.

Funny, I've been reporting that tip for years here!

Bottom line is to get away from the faulty linear logic where "more is always better".
I wouldn't go to extremes the opposite direction and over reducing the pressure for more power either.
For some things, there's too little, there's too much and there's just right.

Real McCoy

12th-November-2006, 12:20 PM

Marv, When I read the post I figured the motor guys referring to oil leaks and High volumn pumps referred to excessive oil up in the top of the motor not from oil leaks due to the pressure. My personal experiences lead me to beleive oil pressure is an over rated concern on a drag motor. I've had motors with 5 to 10 lb idling and less than 40 at 7500 and they all looked fine on freshen up. I know alot of guys running motors stockers with a couple qts of oil in the pan and the low pressure oil lights burning bright going through the traps setting world records or trying to win a race. Like you said 100 people, 100 replies. Do what makes you feel good. Pressure over 60 or under 10 hot would make me personally unhappy. Anything in between lets me sleep well. JMO. RM

DriveWFO

12th-November-2006, 01:35 PM

Paul, what spring did you put in my new pump? I don't remember the part#.

Paul Wright

12th-November-2006, 01:38 PM

Paul, what spring did you put in my new pump? I don't remember the part#.

It's Super Secret!

DriveWFO

12th-November-2006, 01:50 PM

It's Super Secret!

For all I know, it could've came out of your Tow Wagon of Death!

No, it was brand new a GM ZZ4 spring. I buy 'em in quantity. ~ Paul

JTW

12th-November-2006, 02:17 PM

JTW here is the cure for your problem. My 408 was doing the samething. Grant I do not have baffle in my v/c, do you. Is your PVC plugging from oil being sucked up in there thats what mine was doing and then it would start blowing oil. I fab. some baffle plates that bolt to my poly-locks on my roller rockers. I used the 2 one in on both ends. Removed my allen set screw for the poly-lock and used a 2" long set screw. Do you normal adjusting on rockers and tighten set screw. I used a 3/8 fine thread nut for a spacer because of the rocking motion of the rocker just finger tight on top of poly.
Put my splash plate on and nutted it down. Here is a couple of pictures simple to do and you will not have a problems.
http://i27.photobucket.com/albums/c160/ss66nova/ValvetrainsplashshieldsFab.jpg
Hope these help any question just ask or PM me.
Thanks for the pics and the tip about the PCV possibly being plugged, I'll pull the PCV out today and take a look. I like your deflector setup and I'm certain that would solve my problem. The only reason I had not done that yet is because I know that setup won't fit under my valve covers, but I'm tired of the oil mess so I bought a used set of tall Moroso valve covers on ebay this morning. It looks like it would pretty simple to fab those deflectors, but for $23 I'll probably take the easy route and buy the Moroso kit. Yours looks identical to the Moroso, nice job!

Okay, another question --- what is the purpose of that braided hose with 90* fittings running from the front to the rear of your intake?:confused: