All 2 bolt, 4 bolt, 4 splayed cap, studs, align boring Q's (Merged)

[Ed's68]

I have a 1975 nova 350 and would like to know if any came with a 4 bolt main. I looked up the casting numbers and they said 2 or 4 bolt main:confused: Any one have a clue on what is under the oil pan:D Thanks ( it had a factory 2 barrel carb)

[DriveWFO]

Any one have a clue on what is under the oil pan

Umm....oil :confused: LOL, drop the pan down and take a peek in there!

[Rich_66]

Most were a 2 bolt! But the only way to be sure is to drop the pan!!

[Paul Wright]

No factory 4 bolt main 75 novas. All 4th gen's were two bolt main. If you find one it was swapped in. Check the block numbers to see if they even match the model year. If they do it's 2 bolt.

[robs65nova]

whatr u guys talking about when u say 2 or 4 bolt main sorry im new to motors

[Scooter]

It means the main caps that keep the crankshaft into the engine block are held down by four bolts each ( a 4-bolt) or two bolts each ( a two bolt). Four bolts are better usually, unless you want to get a two bolt and make it four bolt with aftermarket main caps. Hope that makes sense.

-Aaron

[Paul Wright]

Here's a picture of the different types of center main bearing caps.
(from right to left)
2 bolt
4 bolt
4 bolt splayed (outer bolts are at an angle)

Material varies from cast iron to billet steel.

Main caps are machined in place and can't be interchanged. If you convert a block to 4 bolt or have to replace a cap the cap has to be fitted to the block.

[Nova_Guy]

Another point is small block chevys only have 4 bolts in the center 3 main caps. Big block chevys have 4 bolts in each main cap on 4 bolt blocks. Some other style engines have cross bolted mains where the bolts come in through the block pan rails and bolt into the side of the caps. Some Ford FE series engines used those. There are lots of different configurations used.

[Ed's68]

Oh well there gose my big money dreams of selling a 4 bolt main motor :rolleyes: Hey do any of you need a low mile 2 bolt main:D

[NIGHTSHADE]

Here's a picture of the different types of center main bearing caps.
(from right to left)
2 bolt
4 bolt
4 bolt splayed (outer bolts are at an angle)

Material varies from cast iron to billet steel.

Main caps are machined in place and can't be interchanged. If you convert a block to 4 bolt or have to replace a cap the cap has to be fitted to the block.


Um........Paul, wouldn't it be better if your block had matching main caps??:D

[DriveWFO]

The oil pan package I'm looking at includes a windage tray. The windage tray looks like it mounts on main studs. Do I need to have the mains honed to switch to studs from bolts?

[Real McCoy]

Nope............

[the FLYER]

i believe ARP, Milodon etc recommend align boring or honing on all applications of main studs... whether it's actually needed... that i dunno. every job i saw come in for stud install... the mains were honed or bored. never saw one NOT have it done.

[Nova_Guy]

A girl once told me she wanted to switch from a dolt to a stud. I don't know what she meant:confused:

[DriveWFO]

If the mains checked out good and there's new bearings and a new crankshaft, would it still need to be honed or align honed then?

[the FLYER]

Dave, some (or most) of these guys are smarter than i am... but according to the manufacturer... it's needed. check with yer guy who's doing the work. i'd wager he'll insist on it.

[DriveWFO]

Dave, some (or most) of these guys are smarter than i am... but according to the manufacturer... it's needed. check with yer guy who's doing the work. i'd wager he'll insist on it.

I'll check with the shop and ARP.

[Real McCoy]

Why do you think installing a stud rather than using a bolt would require honing the mains? I have installed many main studs in many motors and never alighn honed any of them because of adding studs. Also not one ARP stud kit ever suggested that be done. Maybe I'm just a lucky guy?????? LOL

[Ironman]

Quit monkeying around and get that ride back together Dave. The showdown is on.:eek: :D

[the FLYER]

Why do you think installing a stud rather than using a bolt would require honing the mains? I have installed many main studs in many motors and never alighn honed any of them because of adding studs. Also not one ARP stud kit ever suggested that be done. Maybe I'm just a lucky guy?????? LOL



RM, you may be right... i have no real proof it's needed other than from what i was told years ago... i know my APR studs came with a sheet that said it was required... maybe it's BS, i dunno... Milodon recommends it too...


maybe it's to ensure main bores are straight so there's no legality issues from a blown block (guys blaming the studs fer an outta whack block)... know what i mean ???


i'm relearning and learning every day...

[Dan_Lebherz]

Dave,
If I'm not mistaken, there are special bolts that can be used to mount the windage tray. that may solve your problem.

[Ron Slabaugh]

Bolts are available with the standoffs to mount a windage tray.

I installed ARP main studs and did not line hone/bore. I checked the main line with a dial bore gauge with the caps torqued up and it was perfect.

[DriveWFO]

I'll double-check with Canton Racing tomorrow to see if the windage tray mounts to the main bolts/studs or the pan itself.

[Real McCoy]

I went out in the shop to empty the de humidifier and looked and found an old ARP stud set for a BBC in the cabinet. All the sheet says is 190,000 PSI stud kit, hand tighten studs do not use force or bottom out and use no sealent on threads. No mention of alighn honing. This is an old box with used studs in it but that's all it says. RM

[the FLYER]

RM, i openly acknowledge yer being more knowledgable than i in these matters...


here's my instruction sheet. check the footnotes...

http://i7.photobucket.com/albums/y258/64Flyer/ARPinstructions.jpg

[Real McCoy]

Well I wonder why mine don't say that? Your sheet is yellow and mine is white. Wonder if they added that to the newer stuff? As for not being as knowledgable that just ain't so. I learn every day. I have been doing this stuff for a long time but that doesn't mean much really. Nothing stays the same, always changing, so I appreciate everyone ideas and knowledge. I don't plan to start honing mains when I do studs because I've never had a problem but I'll be sure to check them closer. I just took two blocks to Arden, NC to get steel caps installed Friday and I plan to ask the brains up at Precision about it when I go to pick them up, if I can remember.......LOL. RM

[the FLYER]

the guy where i was had seen lots that didn't need the align boring but it was soo close in measurement, it might have been fine... but a little off and have it come back wasn't worth the headache, so on all installs he did, the bore was recommended. yer a smart guy and i recognize this... yer in there looking at your own blocks and seeing the layout, ok they were fine without the bore. but you checked it. for a recommendation to someone else, not actually seeing their block, the recommendation might be different if you actually saw their block. so without my seeing Dave's block, not knowing how exact the caps come down in the registers to bore alignment... i'd say save the possibility and bore it. if i saw Dave's block, if i was good enough ta check it (heck i'm a counterguy, not a machinist, i can't do it) IF i was good enough, then ya never know, Dave's block might be fine too... but i'm in Cali and he's in PA


i'd recommend the a-bore from here.
i mean all due respect, not tryin' ta sound like i know anything, just what i thought i knew... or heard. i been gone from all this since 89-90 and just tryin' ta remember now in '06.. things do change.



Johnny (at least get it checked after stud install) :rolleyes: :D :D :D


hey RM, the caps, if aftermarket steel, generally have extra meat in them and the caps/block will need the bore... if you were to be studding a stocker set up (caps to block) then yeah, i could see where ya may not have needed it. but then again... you were checking it out... if ya noticed a problem, ya woulda dealt with it accordingly ;)

respectfully... :D

[DriveWFO]

Talked to the oil pan company and the windage tray is attached to the pan and not the main cap fasteners. I'm sticking with my bolts.

[stock z/28]

Hi,

I have to agree with John. Its mostly a safety issue. I think ARP suggests align hone if you even change bolts.

I have done quite a few and they were fine with no machining, but I measured them carefully.

One thing I always look at is how the crankshaft spins as you torque the caps. If it binds a bit at say 20lbs, about the same at say 40, a little better at 60, and then is fine at 75 or 80, in my opinion the main webbing on this particular block is stressed or possibly a bit weak, probably since it was new. A block like this is fairly common and seems to preform fine in moderate performance use, but I question it for severe use, and I think a block that has these characteristics may be distorted by changing clamping loads on the caps.

A block that the cranks spins freely in no matter what point the torque sequence is in is in my opinion the best as far as main webbing is concerned.


A trick that I use that seems to really show how a crank fits in the mains is that I have several different size thrust bearings that I have machined the thrust flange off of (I use them for a very specific purpose but they work great for this). I install them in place of the actual thrust brg and torque the crank to specs. Then spin the crank and more importantly (to me anyway) you can drastically move the crank laterally in the block. If it slides freely back and forth Im reasonably sure the main bores are about perfect.

I know this sounds crazy but it doesnt really take that long to do and its a fairly accurate indicator.


Just my depraved opinions guys

Good luck

Jeff

[69NovaSS]

at what point (RPM usage, HP output, etc) would studs be a good idea to use instead of bolts?:)

[66 II]

Would the outter bolts on splayed caps hit water if drilled to deep? The engine is a two-bolt 400.

Todd

[GrandmaGold]

Yes it would. There is water undernieth the pan rail. I had a 400 bolt that had gone too far with the outer bolt and it hit water. I just put some silicone on the threads of the bolts and it never leaked.

[NEVER FINISHED64]

One of mine were mistakenly cut just a hair to deep so I measured the depth of the hole vs how far the bolt would go in and placed silicone in the hole just above that point, torqing down the bolt I assumed pushed a tad bit of silicone out but formed a plug under the bolt. I also used blue lock tite.
I know it held becuase I pulled the pan and main cap.
My problem was the head bolts leaked.
Also be carefull with pan clearance and the splayed main caps. Mine interfered by offsetting the pan and I had to grind a taste off the ends of the caps.

[big dog ss]

i would just stud your 2 bolt block and go. the money for the 4bolt splayed caps and machine work isnt going to get you that much more strengh then a studded 2 bolt. unless the motor is going to be living at high RPM's all the extra's of doing the 4 bolt splayed isnt worth it. IMHO

[Real McCoy]

Cast SBC caps break when you bring the HP up. On the round track motors the stock 4 bolt caps can fail at about 450 HP. With steel straps they live to about 500. This is at 7000 RPMs or a tad more. I have a buddy in Ohio who was running a stock 4 bolt SBC block with cast caps at about 700 HP in a blown nostalgia FED on alcohol. It lasted 2 yrs but when it broke it killed a high dollar rotating assembly completely and messed up everything else. On a BBC Fulton told me I could go to 900 HP with a 2 bolt motor with studs. So far I know 750 plus works fine for many years. JMO. RM

[KenDog]

I have a 97' vortec 350 block, two bolt, roller cam, 1pc rear main seal, that has spun all the main bearings. The machine shop told me it was to bad to fix, My ? is, is it possible to open the mains up to 400 size, use an adapter for a 2pc rear main seal, and use a 400 crank to build a 383? Maybe install billet 4 bolt caps at the same time?

Thanks,
KenDog

[nova10sec]

The fix is to mill the block side of the mains, you will then need a shorter timing chain, (they are made). My suggestion on the 4 bolt conversion... Just use 2 bolt with studs, unless you are spinning past 8000 rpm there is no need to convert.

[L78 Nova]

They aren't that hard to find.. why spend so much $$ on machine work.

I think I would find a better core.

[jolietjake]

I inherited a "74" 350 two bolt main engine in need of rebuilding. In the past I have went with four bolt blocks. My rebuilder tells me that the two bolt will work fine up to and just over the 450 hp range using main cap studs instead of bolts. Does anyone have good or bad stories using two bolt blocks in performance applications? I've even heard of circle track guys running them with no problem. If I use this block I'm turning it into a 383 stroker.
Opinions?

[MuscleDreams]

I inherited a "74" 350 two bolt main engine in need of rebuilding. In the past I have went with four bolt blocks. My rebuilder tells me that the two bolt will work fine up to and just over the 450 hp range using main cap studs instead of bolts. Does anyone have good or bad stories using two bolt blocks in performance applications? I've even heard of circle track guys running them with no problem. If I use this block I'm turning it into a 383 stroker.
Opinions?

2 bolt blocks are good for more than 450 hp IMo if you use good bolts "ARP" and aren't revving them to 10 grand.

I'm also running a 2 bolt block on my 468. My engine builder who works for John Medlen told me that big block chevy 2 bolt blocks would really take alot of punishment and that if I wasn't supercharging or running tons of NOS then "don't worry about it"

[Real McCoy]

I run 2 bolt main BBC all the time at about 750 HP and they are normally OK up to 900 HP but the SBC caps are no where near as strong as the BBC. On the round track SB motors we strap the 4 bolt caps with steel straps and they usually live at just over 500 HP. The straps save the motor if the caps do fail. There is a preferred SB block we always try and use. It is what we call a 010 clock block. They are a decent block with minimal core shift and have more nickle in them. SBs are not near as stout as the BBs in the bottom in my opinion and some SBs have terrible core shift issues which are easy to see on the front cam boss area. Just my opinions. RM

[CDJr]

Id say itd be safe unless you really build it up, jake. Since youre gonna have it worked over anyways, you could always get the shop to drill it for splayed caps. They say a 2-bolt converted to a 4-bolt is much stronger than a stock 4-bolt. And like RM said, if its an 010 or 020 block, then its definitely stronger. They have tin and nickel in them and are stouter than others.

[1963DUCE100]

get it drilled and tapped for splayed four bolts with STEEL main caps and you will have one stout bottom end

[veno]

I inherited a "74" 350 two bolt main engine in need of rebuilding. In the past I have went with four bolt blocks. My rebuilder tells me that the two bolt will work fine up to and just over the 450 hp range using main cap studs instead of bolts. Does anyone have good or bad stories using two bolt blocks in performance applications? I've even heard of circle track guys running them with no problem. If I use this block I'm turning it into a 383 stroker.
Opinions?

The 383/2bolt main is the same as the 400 2bolt main. same stroke, different bore. all 2bolt blocks were built with low rpm in mind. correct? well think about all those 327/375 327/365 327/340 HP motors that spin to the stratosphere with 2bolt mains. the difference is stroke and side loading of the cylinders from the longer stroke.

If you build a Mild 383 with ARP Bolts in stead of studs you will be fine. If you go with Studs you have to line hone, If you line hone then why not spend the little extra and get some 4 bolt billet splayed caps the cost will not be that much more and you will have one bad bottom end!

[Mike Goble]

How much difference does the stroke make on the cylinder wall side loading?

[bowtie0069]

I wouldn't waste the money; if you're not building an engine to run 9000 rpm all day, only your wallet will know. How many thousands of 2 bolt 383's do you think are out there living long happy lives?

[veno]

How much difference does the stroke make on the cylinder wall side loading?


As stroke go up. Rod angle increases and piston length is reduced due to greater stroke creating greater piston rock. the greater the radi the higher the rod angle and more acute the angle to the piston bore. the more acute the angle the higher the side load. you can reduce this angular loading by using longer rods thats why the 5.7/6 inch rod 383 is so popular. but still piston length is sacrificed by longer than stock rods. only higher deck hight can bring all the variables back in to alignment.


Just my .02

[jolietjake]

My intended use is cruising around town and a trip to Daytona twice a year and probably never seeing the drag strip again. But like everone, I love the hp feel. The reality is I'm looking at 350 to 400 hp output max. so from what I'm reading here, I can trust my builder and use what I have instead of starting over with another block. No nitrous and no 6000 rpm hole shots for me.

[Real McCoy]

All those killer old SBs had small journal steel cranks and I think the caps were thicker at the bottom plus I'd think the blocks were better material. The next thing is they didn't make alot of HP per cubic inch really. The stuff today easily does 1.75 HP per cubic inch. Back then 1.25 HP per cube was pretty good. The factory HP was a rated HP and sometimes didn't always reflect actual brake HP at the crank. Then they sometimes lied low too, like the Hemis and killer 454s which had more HP than rated. Just more ramblings of a grouchy old guy who is cold this morning.........LOL. RM

[Deuceisloose]

My last motor was a tunnel ram'd 383 2 bolt that was 525hp and continually saw 6500 rpm and never talked back to me. Like Mike said, only your wallet will ever know the difference.

My current blown 383 has splayed 4 bolt caps, but only because of the blower...and it didn't cost me anything (friends).

[Pro-touring72]

If you line hone then why not spend the little extra and get some 4 bolt billet splayed caps the cost will not be that much more and you will have one bad bottom end!


Line Honeing costs about $130 And adding spayed mains cost well over $600 How in that "A little extra"

Amazing


Use the 2 bolt block if your plans do not excceed 500 HP and no NOS. If you plan to stud it and have it line honed Add a $130 main girdle.

A buddy of mine (he is also the son of Real McCoys buddy) Beat the crap out of his 2 bolt main block for years. He exsploded t-10s M-21s and 1 GodzillaGlide that he had hanging off the back of it but no motor damage.
He also drove it on the free way with 4;56s keeping up with traffic to and from the track 1 hour each way.

And thats with stock bolts also.
2 kids and a wife happened so now the car is rusting on blocks but the motor is still together on a stand

[veno]

Line Honeing costs about $130 And adding spayed mains cost well over $600 How in that "A little extra"

Amazing


Use the 2 bolt block if your plans do not excceed 500 HP and no NOS. If you plan to stud it and have it line honed Add a $130 main girdle.



the Eagle caps are 75.00 the machine shop I use is 150 to install and 125 to hone. so thats 75+125+150=350.

I am unlucky when it comes to trying to do things on the cheap. and have paid the penalty a few times. so I try as best I can to never cheap out on motors. I will wait a year or more to save to get the best I can afford.

I am not buying a Winburg crank, or a some other 2000.00 crank or 2000.00 rods. but I will go with 4340 I beam rods, a 4130, or cast steel crank I am not in class racing or super comp or super stock class so every little thing costs a mint and you squeeze every .25hp you can. I am a street rodder and X street racer. So longevity is very important to me as I am just a School employee, and we all know what they make..

[Ironman]

I got in over 100 runs this year at the strip running mid to low 12's, drive to and from. I launch around 2K and shift 5800-6200 so I'm not spinning it too high. It is still in one piece and I plan to run it another full year. The only thing that is not stock in the bottom end is the cam/pistons and I had good rod bolts installed...cast crank, rods, +.030 bore.

With quality machine work a 2 bolt block will be more than fine for your application.

[Pro-touring72]

the Eagle caps are 75.00 the machine shop I use is 150 to install and 125 to hone. so thats 75+125+150=350.


You forgot the required align bore of mains.

[Real McCoy]

Pro touring, Who exactly were you referring to in my buddies son? This kid here? looks a little young to be driving to me.......LOL. Whats he about 5 or 6 ? RM
http://i112.photobucket.com/albums/n187/RealMcCoy099/Nicky.jpg

[Mike Goble]

As stroke go up. Rod angle increases and piston length is reduced due to greater stroke creating greater piston rock. the greater the radi the higher the rod angle and more acute the angle to the piston bore. the more acute the angle the higher the side load. you can reduce this angular loading by using longer rods thats why the 5.7/6 inch rod 383 is so popular. but still piston length is sacrificed by longer than stock rods. only higher deck hight can bring all the variables back in to alignment.


Just my .02

You're confusing me with your geometry explanation. An acute angle is an angle less than 90°. What does 'more acute' mean? If I had a 3.48" stroke crank and a 5.7" rod, what would the maximum rod-bore angle be? If I stroke it to 3.75" and keep the 5.7" rods, what would the maximum rod-bore angle be? How long would a rod need to be to establish the same relative geometry with a 3.75" stroke crank when compared to a 3.48" stroke/5.7" rod setup?

Are there any benefits to side loading a piston? If I could design a connecting rod that pushed directly down the bore at all times would you see a difference in performance?

[Pro-touring72]

Pro touring, Who exactly were you referring to in my buddies son? This kid here? looks a little young to be driving to me.......LOL. Whats he about 5 or 6 ? RM
http://i112.photobucket.com/albums/n187/RealMcCoy099/Nicky.jpg


my lord. he looks like his nephew in that pic

[veno]

You're confusing me with your geometry explanation. An acute angle is an angle less than 90°. What does 'more acute' mean? If I had a 3.48" stroke crank and a 5.7" rod, what would the maximum rod-bore angle be? If I stroke it to 3.75" and keep the 5.7" rods, what would the maximum rod-bore angle be? How long would a rod need to be to establish the same relative geometry with a 3.75" stroke crank when compared to a 3.48" stroke/5.7" rod setup?

Are there any benefits to side loading a piston? If I could design a connecting rod that pushed directly down the bore at all times would you see a difference in performance?

acute:

1. Having a sharp point or tip.
2. Keenly perceptive or discerning: "a raw, chilling and psychologically acute novel of human passions reduced to their deadliest essence" Literary Guild Magazine. See Synonyms at sharp.
3. Reacting readily to stimuli or impressions; sensitive: His hearing was unusually acute.
4. Of great importance or consequence; crucial: an acute lack of research funds.
5. Extremely sharp or severe; intense: acute pain; acute relief.
6. Medicine
a. Having a rapid onset and following a short but severe course: acute disease.
b. Afflicted by a disease exhibiting a rapid onset followed by a short, severe course: acute patients.
7. Music High in pitch; shrill.
8. Geometry Having an acute angle: an acute triangle.

severe angle.....

or greater or approaching line of perpendicular but not reaching perpendicular to the side wall of the cylinder bore in relation to rod angle at the apex of rotation of greatest force as seen in relation to cylinder bore from crank rotation. Higher rod angle is always seen as stroke increases.

I am not going to toss words with other smarter than me.

[Paul Wright]

My 2 cents on bottom end durabilty in regards to 2 bolts or 4 bolt main caps:

You'll often see people asking or telling about HP limits for either, but it's not that simple. A block doesn't automatically fail when it exceeds a certain arbitary power level. Failures can be the result of fatigue (stress/strains over time) or strains that exceed material limits.

"Normal" cap loading comes in 90 degree increments of crank rotation with peak forces being when the piston is at peak cylinder pressure after TDC. This causes pulses in the crank but each cap is only loaded by "Horsepower" induced forces once every 720 degrees and in normal rotation. The rod is not straight up and down at maximum cylinder pressure so most of the forces are used turning the crankshaft.
Normally, this is distributed evenly and if high enough may reduce longevity over time but shouldn't cause a sudden failure unless it spikes from heavy doses of Nitrous or boost induced pressure.
What really strains the caps, bolts and webs is detonation. Cylinder pressure far exceeds normal cylinder pressure AND it occurs before TDC which imparts extreme forces counter to normal rotation.

Any vertical strain on the caps is ultimately shouldered by the main bolts which are anchored to the web. Stretching these bolts can cause the cap to pinch inward at the parting line. The main bore goes from round O to oval 0 This can reduce bearing clearance and fail bearings even though the cap, bolt or block does not break.

Many a spun main bearing was not caused by a failure of the main cap or oil pump, but by the root cause of inaudible detonation.

Another factor is vibration induced forces. These forces impart stray pulses in radial directions from the crankshaft centerline. Imbalances get dramatically worse as RPM increases so RPM is another factor.

Because there are many contributors to failure, you can't predict durabilty by horsepower alone.

A 400 horspower 4 bolt main engine that has too much spark timing, revved too high and wasn't balanced, is not going to be as durable as a 450 hp 2 bolt main that was built and tuned right.

Because of all the variables, there are wide gray areas where durability becomes a crap shoot, but certainly at some point the production OEM block is clearly inadequate no matter what you do to it and an aftermarket block is required.

[Real McCoy]

Then to all that you have the Chit Happens Factor. It too is incalculable. Did I spell that right? RM

[Rifleman]

My son's circle track car used to have a 355 with 2 bolt mains in it. He ran the crap out of it for two seasons, turning 7200 to 7600 rpm depending on the track. He got lucky after the end of the second season, he pulled the motor and found one main cap cracked. It would not have lasted another race. He ran his engine much harder than you are planning to. I know your doing a 383, not a 350, but if you keep the rpm's at about 6000, it should last a long time.

John K

[jolietjake]

WOW,
I knew I would get great advice by asking my question here, thanks so much for that advice. I will stick with my 2 bolt and build a fine 383 to power my 62.

Gassers rule! :cool:
62 Chevy II, 300 series two door sedan
small block, Muncie, 12-bolt posi, narrowed 65 Chevy van straight axle
Honduras Maroon

http://www.cardomain.com/ride/2506897

[stock z/28]

Hi Guys,

As usual this gets kinda complicated> I really agree with Paul about many kinds of failure, and its usually not just related to power levels. I see more failures that are related to detonation than just about anything. Oh well, kind a busy today.

But, I kinda disagree about the 350 2 bolt (383) and 400 2 bolt main strength. The 400 uses a wider register than the the 350 and this does seem to add strength. I usually mill the 2 bolt 350s to the wider register when I add caps.

The other thing Im curious about is this added nickel thing. I would really like to know more detail on this. I have checked a lot of blocks and I really havent seen a lot of diff in hardness in the 010 (020 under the timing cover is an issue as well) and other blocks. Some of the 010s out of HD use (60 series truck- police-taxi) sometimes do seem better, but they are generally easy to spot by eye.

Thanks

Jeff

[shaggy]

The other thing Im curious about is this added nickel thing. I would really like to know more detail on this. I have checked a lot of blocks and I really havent seen a lot of diff in hardness in the 010 (020 under the timing cover is an issue as well) and other blocks. Some of the 010s out of HD use (60 series truck- police-taxi) sometimes do seem better, but they are generally easy to spot by eye.

Thanks

Jeff

Im curious about this as well as I read this was a long going myth and GM only did this in a few selective years. I dont want to start an argument because I could care less either way but out of curiosity has anyone put one of these high nickel blocks in a rockwell tester to test the myth.

[DriveWFO]

I got in over 100 runs this year at the strip running mid to low 12's, drive to and from. I launch around 2K and shift 5800-6200 so I'm not spinning it too high. It is still in one piece and I plan to run it another full year. The only thing that is not stock in the bottom end is the cam/pistons and I had good rod bolts installed...cast crank, rods, +.030 bore.

With quality machine work a 2 bolt block will be more than fine for your application.

I beat my 2-bolt 350 for 2 seasons at the track, shifting at 6000-6200 rpm. Stock crank, rods and pistons :eek: Sprayed it with nitrous too! You will be fine with your block.

Tom, you DID hit 7500 in the water box last week :D

[jolietjake]

What I'm taking away from this now is, when it comes right down to it, does it really matter? low nickel/high nickel? 2 bolt/4 bolt? the bottom line appears to be, if you run a blower or nitrous, and/or hi rev the damn thing and race the crap out of it, you might want to have a 4 bolt block, otherwise, a 2 bolt is just fine for most all applications. I was raised old school, it had to be a 4 bolt or nothing, I guess it's a gear head thing. As I said I'm going with the 2 bolt.

[CDJr]

Excellent info, Paul! ;)
jake, I think youre makin the right decision. As long as the blocks in good shape and you dont get too radical with building it up, it should be fine. Im planning on doin something similar with a 2-bolt thats presently outside holding my shop floor down and as long as the blocks OK (I havent even had it tested yet) itll be about the same as what youre planning ;)

[stock z/28]

Hi.

Ive rockwelled a lot of them and thats why Im curious where this came from.

Jeff

[Real McCoy]

If my old friend was still alive I could ask him about it but he is gone. What I do know is when he was building motors he always looked for the 010 clock blocks. He told me they were better blocks with more nickle and less core shift. Now where he learned this I can't say but he was very good friends with all the NASCAR motor builders in the 60s/70s and 80s. Not sure if they told him that or what. His son who now owns the engine shop follows the old mans policies as do I. RM

[CDJr]

Thats right, RM...010 = 1% Nickel and 020 = 2% Nickel. They are harder, stronger, and last much longer than regular iron blocks.

[shaggy]

Is it possible that not every block got this special nickel content even though they had the markings? Im just trying to understand how stock z/28 tested blocks showed no difference. The general myth was that GM stopped producing these block after the 60s/70s hotrod muscle car era.

[Nova_Guy]

One of the benefits of the higher nickel content is resistance to rust. A friend of mine had a GM performance BB high nickel block. The engine blew up and ruined the block; it laid outside for several months without rusting.

[stock z/28]

Hello.

CDjr, I guess what Im asking is where did this info come from. I have seen a lot of blocks cast with 010 and my understanding was that it applied to the molds as did the 020 - the inner mold?

I just check one of the hardest blocks I have found and it has -020-509-010 on one side and 512-592-g5 0n the other side - all under thew timing cover.


I have actually seen very little difference in standard production style blocks. Im certainly no expert at this but in my experience a drastically harder block really shows up when its being honed (im referring to after boring).

Got to run for now-- Im not trying to argue this just really interests me a lot.

Thanks

Jeff

[veno]

If I recall right, the 1970's GM power manual stated so. I have read it in hot rod mag and a few other rag sheets as well from the seventys and eightys. But I do seem to recall with a certan recolection that the Power manual stated the 010 block as well as the 020 block were higher nickle than other blocks with the 020 block having double the nickle of 010 block.

But alass I am now showing signs of Old timer Illness, and memory is darkening with the passage of time. If any one has one of the 70's power manuals I am kinda, purdy, maybe, thinkin you'll find it in there.

[Pick]

I can't answer the 010 and 020 mysteries (though both of my small blocks are 010's) but I have a question about the 2 bolt 4 bolt mains. Why did a cost conscious company like GM decide to spend the extra money on 4 bolt mains in so many relatively low performance truck motors? The general concensus here seems to be that 2 bolt will safely handle 6000 rpm and 450 or so hp, yet GM made zillions of 200-250hp 350's that were 4 bolt? What was the percieved benefit to GM that would cause them to spend the extra $$?

[Mustangsaly]

what does everyone think of the 1 piece rear main seal 2 & 4 bolt blocks ?
good bad ? I'm talking 350s & 383s 2 bolts to 450hp & 4 bolts to 450hp both n/a






Mustangsaly

[stock z/28]

Hi,

My guess on why the continued to use the 4 bolt in trucks is their perceived lugging potential. The relative low rpm power dissipation under load is what Im referring to. A very high load (say full throttle) with little acceleration potential (think heavy trailer-with little gear multiplication and high weight) and the crank is really being forced away from the block, really trying to pull the the block parting line together--thus the higher clamping potential of the 4 bolt caps (and wider register).

Please understand im no expert and this is just my guess.

Jeff

[stock z/28]

Hi again.

In regard to the one piece seal (which I personally don't like) i would rather have the 4 bolt because of the wider register if you have a choice. I really don't see a drawback to the 4 bolt 350 block. the rat is a different story- the 2 bolt rat may very well be a stronger main webbing block than the 4 bolt block.

[Paul Wright]

I can't answer the 010 and 020 mysteries (though both of my small blocks are 010's) but I have a question about the 2 bolt 4 bolt mains. Why did a cost conscious company like GM decide to spend the extra money on 4 bolt mains in so many relatively low performance truck motors? The general concensus here seems to be that 2 bolt will safely handle 6000 rpm and 45 or so hp, yet GM made zillions of 200-250hp 350's that were 4 bolt? What was the percieved benefit to GM that would cause them to spend the extra $$?

Smokey Yunick mentions why truck blocks are 4 bolt in an old Circle track article. Detonation.
A loaded truck pulling a grade is more likely to detonate and cause warranty problems.
As I mentioned durabilty is not always function of HP.
Same reason why many relatively low (like 220hp) marine crank shafts are forged. The constant loading and unloading of the prop while skittering across the water is hard on cranks.

As far as the 010 nickle thing, I have a 70's Chevy Power book in my boxed up archives.
I'll look for it tomorrow. I did find a mention in Bill Jenkins book that as far as they can tell there has been no change in the metalurgy other than making the blocks as soft as practical to extend tooling life. Hard blocks wear out tooling faster and obviously too soft and the engine wears too fast. They probably have a hardness "sweet spot" spec they shoot for.

[veno]

Thanks Paul.

[Pick]

I've got 6th edition Chevy power book, printed in 1988. I just went through it and there is no mention of the 010 or 020 blocks anywhere. When it talks about block selection, it mentions only checking for a good core based on block condition, cracks, core shift, etc. It then goes on to talk about the benefits of bowtie blocks, or aluminum blocks. The 1988 version makes no distinction between the 010 and any other blocks.

[CDJr]

David Vizard makes note of it in one of his books. If it has both 010 and 020 then its 1% tin and 2% Nickel in the casting, which according to him, the tin helps the actual casting process resulting in a more consistent pour. If it only has 010 or 020 then its 1% or 2% Nickel with no tin. ;) (I had to get out one of my books to refresh my memory about the tin part lol).

[Bluesman]

Boy do I feel dumb!:mad: Torquing the mains on my Gen 2 small block and twisted off one of the bolts. I'm using a torsion-bar wrench (not a clicker) and was going stages up to 80 lbs. One of the bolts on #1 just twisted right off at about 75-78#. Fortunately, I felt it begin to go and was able to back it all out in one piece. I guess I should feel glad that it happened now instead of later when it was running, but dude!! It has been a while (OK...a LONG while) since I last rebuilt an engine, but I like to think I am pretty good at following directions.:(

Am I torquing them too much?? 80# is what the manual I have says to use. Now I am wondering if I should replace just that one or all of them. What do you think??:confused:

I have read that if you change to main studs you should have it align-bored with them in place. Any opinions on that?

Thanks.......bummed:(

Dave

[Real McCoy]

Did you lube the threads and top of the bolts? Using a old beam torque wrench is like using a hatchet for brain surgery.......LOL. Old books say SB mains are 80 but the newer books say 70 for a SB. If it was me I'd go buy a new set of bolts, lube the threads with 30 wt oil and using a good clicker torque wrench torque them at 70 ft lbs. I torque 4 bolt SB mains at 75 and 65. and I use a Snap On clicker. I snug them up then go 40 lbs then torque to spec and don't have any issues. That would be my suggestion. RM

[65prostreet]

Was you using oil or moly lube? the tourque specs are considerly different. I'm no expert by any means,but if the spec was for oil and you used moly lube, I would think that could have been the cause.
If you change over to studs you should have it align honed,the studs distribute the load different than the bolts and could pull things out of round.
Also if you go that route make sure you get a shorter timing set for align honed blocks because that process reduces the distance between the crank and the cam. don't make the same mistake I did,I went with a standard length set(I didn't know) It was borderline when I put it on but I thought it would be alright,after six 1/8 mile passes I put a timing light on it and and you would not believe how much it was moving around! I pulled the cover and the chain had 3 times the slop it had when i put it on. I changed it to a 5 thousanth shorter set and the timing is rock solid.
Gary

[Bluesman]

I was using 30w not moly. Chased the threads and all. I guess I'll spring for a clicker but I honestly thought a beam (old but cared for, and a craftsman at that) was just as good if you knew how to use it.

Thanks for your advice. I'll stay with the bolts and stop at 70# next time.

But seriously, is a clicker better? I have heard they get off over time.:confused:

Dave

[1quik69]

Summit sells an ARP main bolt kit for $27.95 for 4 bolt mains and $17.88 for 2 bolt mains for SB. If you don't feel comfortable with the ones you have that is cheap insurance with the new bolts. Clicker torque wrenches are pretty reliable. I had one checked for calibration after about 15 years and it was only off by an avg of 2 ft lb over the range.

[bowtie0069]

Make sure you always leave it stored at zero! I left mine in the box at 75lbs. between engine builds. While cranking down the rod bolts(small journal) on one of my 391's.....SNAP!! AAARRRGGHH!!!! New rod bolts, re-grind the bolt heads for cam clearance, balance...........Cranking down the head bolts after repairing the other damage.........Pulled the threads out of the block because bolts were too short with new World Products heads AAAARRRRGGGGHHHH!!!!! Heli-coil the block, buy new head bolts..................................

[Real McCoy]

A beam torque wrench is reliable but a human isn't. It is hard to see the scale and be accurate and the clicker is a no brainer. The SnapOn torque wrench I use for motors and critical stuff stays in the cabinet. I use a decent Sears and a couple Harbor Freight cheapos for everything else. SnapOn checked and recalibrated mine once. RM

[Mike Goble]

Only some 10% of the applied torque generates preload - and herein lies the cause of most joint problems. Preload is what's left of the tightening torque after friction has absorbed the lion's share, since preload cannot be induced until motion has occurred. Anticipated variations in the coefficient of friction will thus have a marked effect upon the preload, and careful calibration of the torque wrench will do little to improve preload accuracy.

http://www.mech.uwa.edu.au/DANotes/threads/preload/preload.html

http://home.comcast.net/~onovakind67/100px-GroupWlogo.PNG

[stock z/28]

Hello,

I agree with mike that the under head friction is what really throws off proper preload of the fastener when using a torque wrench. If you use the matching lubricant to what the torque spec was created with its generally (at least in my experience) pretty close.

As far as the torque wrenches are concerned, I have a bench mounted tester that I use to check wrenches, and I find a lot of variation in some of the clicker style wrenches. The Craftsman wrenches with the small windows you look through are about the worst, I will not even let any of those in my shop. The snap on wrenches with the adjustment on the side are very reliable as long as you never use them in a counter clock wise direction. If you do it may through the calibration way off. The dial type are generally the most dependable in my experience, but I agree with you that the beam style wrench should have been pretty close, if you can get the correct viewing angle.

It may have just been a defective bolt. I would certainly feel better with a new set. I not sure the ARP (i know this will be controversial) bolts distort the mains as much as is generally feared (studs seem much worse on distortion-but still not generally as much as implied). I have checked a lot of blocks that have been converted to the ARP bolts and (knock on wood) found very little difference in bore concentricity. Im not against align honing the blocks, I just don't think a simple fastener upgrade "always" makes it a "must". I guess this is just my opinions I'm not making a recommendation either way-- you can check the bores with a gage before and after- but it takes a good gage and some time.
Good luck
Jeff

[Nova_Guy]

I was helping my brother put together his LT-1 350 years ago. It used a windage tray and one of his bolts snapped in two torquing them down. The bolt snapped off at about 40lbs on the first round of tightening down. Hw replaced all the bolts before final assembly. I think bolts are like anything else; sometimes you get one thats bad.

[Bluesman]

Well I just ordered a set of ARP bolts and a clicker torque wrench from Summit. That may have been the only bad bolt but for $17 and change it is a no brainer to replace all of them. I know this engine was rebuilt once before I got it and did the machine work on it, so I'm thinking someone may have gotten enthusiastic when they put it back together before. I should have just replaced them to begin with...duh!! I feel d**n lucky that I felt it go and was able to back the whole bolt out of the hole. With these replaced it means every bolt in the engine is a new ARP. Just dumb of me not to replace these when I did all the rest.:(

Thanks for all your advice on this.

Dave

[Paul Wright]

Bolts fatigue over time and repeated loading. Bolts are like very heavy springs. Every time you torque them they stretch (elongation).
Bolts, Springs or paper clips all have a finite life (2) as stress can build up and exceed limits (4). You can stretch them only so many times before they break (5). Prior to breaking the material Yields (3) or doesn't spring back to it's original shape.
http://www.tpub.com/doematerialsci/material%20science_files/image067.jpg
This is when the bolt feels like it's not tightening or the bolt stretches longer than normal.
If you have any bolt that Yields then you should replace ALL of them.

[stock z/28]

Hi Guys,

Not to be down grading tools, but if the clicker torque wrench is an import I would rather use your old beam style. The imports are all over the place, even when brand new. If you dont want to buy a Snap On or Mac etc. (and I dont blame you) SK and the standard style Craftsman seem to be OK.

Im certainly no expert on fasteners (or any thing for that matter), but I think a lot of fasteners (especially automotive) must have a specific amount of elasticity in them at their specified stretch (torque spec?). I have seen several applications where a fastener that had too little elasticity cause failure. An example would be a head bolt where expansion of the head at temperature and load will actually pull the threads in the block because the bolt would not flex with the head.

I personally will not use a fastener higher than a grade 5 on a cast exhaust manifold. I have seen a lot of harder bolts actually break their heads off after a few cycles of heating and cooling. The manifold will expand and basically the bolt wont match it and something has to give.

I really like to leave the design of the bolts up to the experts. I wont even use a couple brands of aftermarket bolts because of what I perceive as poor quality. ARP seems to be about as good as you can get at reasonable money.
Just my opinions

Good Luck
Jeff

[Mike Goble]

Cornwell Quality Tools
667 SEVILLE ROAD
WADSWORTH, OH 44281
TEL: (330) 336-3506
FAX: (330) 336-3337

[Bluesman]

Yesterday the new torque wrench and mains bolts arrived from Summit.

SWEET!!:D I LOOOOVE that wrench!! Micrometer adjustable, so easy to use, what a difference it makes. Followed the ARP instructions, used their lube and torqued the bolts to 65#. Slick!! What a difference a good tool makes!!

Thanks guys!

Dave

[1quik69]

Glad to hear everything came out ok.

[Real McCoy]

I love tools:D If I was a billionaire I'd buy a new tool every day, like drinking a cup of good coffee. :) RM

[Bluesman]

That is so true, Mac!! It just felt like an early Christmas!!:D :D :D

Dave

[slickman]

That's the best money you will ever spend. My last engine build I replaced every bolt with ARP and was glad I did..


Well I just ordered a set of ARP bolts and a clicker torque wrench from Summit. That may have been the only bad bolt but for $17 and change it is a no brainer to replace all of them. I know this engine was rebuilt once before I got it and did the machine work on it, so I'm thinking someone may have gotten enthusiastic when they put it back together before. I should have just replaced them to begin with...duh!! I feel d**n lucky that I felt it go and was able to back the whole bolt out of the hole. With these replaced it means every bolt in the engine is a new ARP. Just dumb of me not to replace these when I did all the rest.:(

Thanks for all your advice on this.

Dave

[slickman]

I invested in a 1/2 and 3/8 clicker years ago, one of the best tools in my box.

Yesterday the new torque wrench and mains bolts arrived from Summit.

SWEET!!:D I LOOOOVE that wrench!! Micrometer adjustable, so easy to use, what a difference it makes. Followed the ARP instructions, used their lube and torqued the bolts to 65#. Slick!! What a difference a good tool makes!!

Thanks guys!

Dave

[new2novas]

ditto on cornwell mike...they often sell the exact same stuff as snappy at a reasonable price...only things i have from snap on are all my sockets (chrome and impact) ratchets and wrenches and a few other heres and theres....cornwell is the way to go...

i also did just about every bolt on my engine with arp's....for external bolts (intake, etc...) get the stainless, the black ones rust quickly

[Onlychevy6]

School me oh wise one's. Has anyone ever used a small block 400 block from a truck in there car(s). If not why?

[Mike Goble]

It's the same block. From 1976-80 ( or thereabouts ) all the 400's were in trucks and vans.

[Onlychevy6]

that is what i was thinking. but i wanted to make sure. I have a small block 400 i am thinking about building. Except i think it is a 4 bolt main not 2 bolt. :rolleyes: I guess i will see when i get home. :D

[jason snyder]

It's the same block. From 1976-80 ( or thereabouts ) all the 400's were in trucks and vans.
They were in some large passenger cars as well (monte carlos,caprice for sure)

[Real McCoy]

I remember a guy at work bought a new Impala 4 door and it had a 400 in it. He always complained about bad fuel mileage, that's why I remember it. RM

[bowtie0069]

He always complained about bad fuel mileage, that's why I remember it.

My Grandfather bought a Caprice new in 1972 with a 400; I drove it from Cal. to Illinois that Summer and got between 19-21 mpg staying around 65-70 mph. Surprised the heck out of me.

[Real McCoy]

I think that Impala was like a 72/73 also but it sucked gas bad. I think I looked at it for the guy, he was a good friend and I think I worked on the carb. Don't remember doing it much good though. Been a long time......LOL. RM

[DriveWFO]

The 400 I bought came out of a 74 or 75 Impala (think it was one of those years). It was a "509" 2-bolt block.

[1bad4dr]

very basic question, how do i distinguish between a 2 bolt and 4 bolt main? I have a 350 in my 63 nova it has 2 motor mount bolts, one on each side, is this how i know? I'm fairly new at all this auto mech stuff, thanks for the reply

[1quik69]

you would need to pull the pan to look at the mains. I'm not sure if there is any way you can tell from block #'s or anything. I'm sure someone else will respond if there is a way to tell externally.

[1bad4dr]

maybe this will help, the 350 came out of a 79 z28 camaro

[ProchargedchevyI]

You can try this website for the external casting number method:

http://www.mortec.com/castnum.htm

But the best way is to pull the pan and look at the main caps that cradle the crankshaft. If they have 4 bolts holding them in, then it's a 4 bolt.

[DriveWFO]

What is the casting# on the back of the block (on driver's side where the transmission mates to the block)?

[1bad4dr]

i would have to look, however i need a new oil pan gasket anyways, i will just check when its removed. I just had no idea how to find what it was, a 2 or 4 bolt, thanks for the info and replys guys

[Pwrtrip75]

it doesnt really matter if its a 2 or 4 bolt. On a 4 bolt the main caps are more secure, but a 2 bolt the block is more structualy secure and in both situations unless your turning over 8000 RPMs all day and making over 600hp, going through all the work or effort to use a 4 bolt is pointless.

[Onlychevy6]

ok well i just checked and i do have a "509". 2 bolt block per mortec's website it was made from 74-80. The heads that were with is are the 462624 that was from 75-86. 76cc not sure with valves it has yet. there were 3 options.:rolleyes:

Since i don't have any experience with 400 blocks. What are the possibilities with this one and using those heads(for now)? Looks like it has never been freshened up either. So i am under the impression i have a virgin block.

[Pwrtrip75]

You sure the 624 heads are 76cc chamber? I thought they were small.
Performance wise a stock head is going to be limited in a engine as big as a 400.

I have a 509 block also, it has 2 freeze plugs in the side just like a 350, so its kinda like a sleeper block because the other 400s have 3 freeze plugs on each side.

[Onlychevy6]

according to mortec yes it is a 76cc head. Also is it worth port and polishing these heads? I already know i should just get aftermarket just don't know what i want.

My current block that is supposed to go in the car is being held hostage with the heads, manifold and cam. By the Head guy. Keep getting excuse after excuse and they are paid in full a long time ago. Some of you may know this company. he was based out of Rancho Cucamonga then moved his shop to Nevada.

[Dawg]

The 400's were used in trucks from 1970-1980. Caprice, Impala and Monte Carlo used them 1970-1975-76.

My dad has a 400 out of a 1970 truck in his Camaro. He didn't build it and we're not sure if it's stock or rebuilt, what we do know is it's a 511 casting 4 bolt block, car has an M22 and 3.55's out back. I can take off from a stop light in 1st and let it roll about 25 mph and stomp the pedal and break the tires loose...shift to 2nd and do the same thing, all on dry pavement.

I have a 400 out of a 74 Caprice in my garage awaiting my return from Afghanistan to send it off to the machine shop. Cross your fingers it's not a cracked block.

[DriveWFO]

The 462624 casting heads are boat anchors...period. Don't waste any money on them. They also are very crack-prone.

[Onlychevy6]

The 462624 casting heads are boat anchors...period. Don't waste any money on them. They also are very crack-prone.

Thanks for the heads up...LOL Pun intended:D

[62civa]

Using the casting numbers on the blocks to determine if it's a 2 or 4 bolt main is useless.......thats just my 0.02 worth. The 350 block I have in my garage right now shows up on all the casting number lists as a 4 bolt main....it's not, it's a 2 bolt main. This is also not the first block I have seen that goes against the casting number lists.

[nova656567]

Ditto on the cylinder heads. I just put a set in the scrap iron to haul off. Will be building a 509 block in the near future. Not sure what C.I. it will end of being when we are done.