Chevy Nova Forum banner

21 - 40 of 236 Posts

·
Premium Member
Joined
·
8,405 Posts
Here's pictures of the broken plastic collar in my 1/4 million mile '78 Caprice tow wagon:
Broken HV Pump photo's


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!
 

·
Registered
Joined
·
801 Posts
arp oil pump rod

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
 

·
Registered
Joined
·
429 Posts
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
 

·
Premium Member
Joined
·
14,614 Posts
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.
 

·
Premium Member
Joined
·
8,405 Posts
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
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.
 

·
Super Moderator
Joined
·
9,776 Posts
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.
 

·
Premium Member
Joined
·
8,405 Posts
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.
 

·
Registered
Joined
·
801 Posts
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.
 

·
Premium Member
Joined
·
2,354 Posts
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
 

·
Registered
Joined
·
801 Posts
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
 

·
Premium Member
Joined
·
14,614 Posts
66IISS said:
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.
 

·
Registered
Joined
·
1,400 Posts
oiling problem

@ 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
 

·
Moderator
Joined
·
4,534 Posts
What weight oil are you running?

Miles :D
 

·
Registered
Joined
·
1,400 Posts
oil problems

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????
 

·
Premium Member
Joined
·
8,478 Posts
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
 

·
Premium Member
Joined
·
3,361 Posts
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.
 

·
Registered
Joined
·
1,400 Posts
oil probs

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
 

·
Registered
Joined
·
135 Posts
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.
 
21 - 40 of 236 Posts
Top