# 400 ci 4 bolt main torque specs



## Shake-N-Bake (Jun 16, 2015)

Are the inner and outer main cap bolts torqued to the same spec? My book says that #1-4 cap bolts are torqued to 80 ft/lbs but it shows a 2 bolt block in the example. I am working on a 4 bolt block and the inner bolts look different then the outer bolts so I am wondering if they get a different torque value. They are the same wrench size so I assume they all get 80 ft/lbs but I wanted to ask the question to be sure.

Thanks


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## Pinion head (Jan 3, 2015)

Yes, same torque value, only rear main cap takes a higher torque amt.


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## Goat Roper (Oct 28, 2014)

Pinion head said:


> Yes, same torque value, only rear main cap takes a higher torque amt.


Should a freshly rebuilt engine be re torqued after it has been run to break in the cam?
My engine was shipped back with a cracked balancer hub, rusted oil pan and other problems and I have torn it back down to a long block.
I don't see any mention of a higher torque value for the rear main cap, do you have that value?


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## PontiacJim (Dec 29, 2012)

Goat Roper said:


> Should a freshly rebuilt engine be re torqued after it has been run to break in the cam?
> My engine was shipped back with a cracked balancer hub, rusted oil pan and other problems and I have torn it back down to a long block.
> I don't see any mention of a higher torque value for the rear main cap, do you have that value?




Shouldn't need to be re-torqued, but it may be good insurance to check the torque. Some heads require re-torquing, but it depends on type of gasket. Most are good to go.

Rear main cap using factory bolts is torqued to 120 ft lbs while the others are 100 ft lbs.


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## Goat Roper (Oct 28, 2014)

PontiacJim said:


> Shouldn't need to be re-torqued, but it may be good insurance to check the torque. Some heads require re-torquing, but it depends on type of gasket. Most are good to go.
> 
> Rear main cap using factory bolts is torqued to 120 ft lbs while the others are 100 ft lbs.


Thanks for the info PJ, my motors manual doesn't specify this only all of them @ 100.
Since it is torn down to a long block I am going to go over everything tomorrow and start assembly, Ames sent me the wrong exhaust manifold bolts so the correct ones will be here the 30th.
Everything else is done so I will be able to get it all back together and see how it runs the first week of Dec.


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## Shake-N-Bake (Jun 16, 2015)

Pinion head said:


> Yes, same torque value, only rear main cap takes a higher torque amt.


Great. Thanks.
I show 120 ft/lbs for #5 which appears to be correct.
Judging from the other responses....the other cap bolts get torqued to 100 ft/lbs. The book I have that is written by Don Keefe says 80 ft/lbs so I went through a few more books and found the 100 ft/lb value in my Pete McCarthy/John Angeles book. Plus you guys say 100 ft/lbs as well......so I'll go with that figure. I suppose the 80 figure might be a misprint?

Thanks for the help!
Happy Thanksgiving! atriot:


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## Goat Roper (Oct 28, 2014)

Shake-N-Bake said:


> Great. Thanks.
> I show 120 ft/lbs for #5 which appears to be correct.
> Judging from the other responses....the other cap bolts get torqued to 100 ft/lbs. The book I have that is written by Don Keefe says 80 ft/lbs so I went through a few more books and found the 100 ft/lb value in my Pete McCarthy/John Angeles book. Plus you guys say 100 ft/lbs as well......so I'll go with that figure. I suppose the 80 figure might be a misprint?
> 
> ...


Here is a cheat sheet I found from Wallace Racing that shows the 120 ft. lbs. for the rear main cap as well as 100 for the others.

Wallace Racing - Pontiac Bolt Torque Values

I just printed this out to take to the shop tomorrow.


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## Shake-N-Bake (Jun 16, 2015)

Goat Roper said:


> Here is a cheat sheet I found from Wallace Racing that shows the 120 ft. lbs. for the rear main cap as well as 100 for the others.
> 
> Wallace Racing - Pontiac Bolt Torque Values
> 
> I just printed this out to take to the shop tomorrow.


Thank you very much! That is super helpful.


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## PontiacJim (Dec 29, 2012)

I saw the Wallace Racing specs, but when I read 80 ft lbs above, I looked in the '68 Pontiac Service Manual to confirm 100 ft lbs and the 120 ft lbs as being factory specs for *2-bolt main caps*. This would be using oil on the threads. Do not saturate the threads or use excess oil. My machinist says to put oil on the threads and then wipe off so you get a film of oil rather than too much which can drip off the bolts and into the bolt cavity in the block and cause the block to crack when it gets hot and the oil/pressure expands and has no where to go.

Going over to Butler Pontiac, he shows torque specs using moly lube as 95 ft lbs for #1-4 and 115 ft lbs for #5. He also shows the outer bolts of the 4-bolt mains as being 85 ft lbs. Butler Performance


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## Shake-N-Bake (Jun 16, 2015)

PontiacJim said:


> I saw the Wallace Racing specs, but when I read 80 ft lbs above, I looked in the '68 Pontiac Service Manual to confirm 100 ft lbs and the 120 ft lbs as being factory specs for *2-bolt main caps*. This would be using oil on the threads. Do not saturate the threads or use excess oil. My machinist says to put oil on the threads and then wipe off so you get a film of oil rather than too much which can drip off the bolts and into the bolt cavity in the block and cause the block to crack when it gets hot and the oil/pressure expands and has no where to go.
> 
> Going over to Butler Pontiac, he shows torque specs using moly lube as 95 ft lbs for #1-4 and 115 ft lbs for #5. He also shows the outer bolts of the 4-bolt mains as being 85 ft lbs. Butler Performance


Great point about oiling the threads. Must be careful not to fill the blindly tapped hole with any excess oil to avoid hydraulic pressure on the block. Interesting info on the outer bolts on 4 bolt caps. That is exactly the info I was looking for. I am glad I asked....and thankful for the assistance. I will be sure to browse around on the Wallace and Butler site a bit more. What a great resource to have for the hobby.


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## geeteeohguy (Feb 2, 2008)

Also, and not mentioned, torque in stages. Go 30-40 foot pounds, then 70-80, then the final 100/120. And follow any posted sequences, too. Sorry to hear about your disappointment, Eric. Cracked balancer/rusty oil pan. _Sheesh._ Been an uphill battle every step of the way.....


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## Goat Roper (Oct 28, 2014)

geeteeohguy said:


> Also, and not mentioned, torque in stages. Go 30-40 foot pounds, then 70-80, then the final 100/120. And follow any posted sequences, too. Sorry to hear about your disappointment, Eric. Cracked balancer/rusty oil pan. _Sheesh._ Been an uphill battle every step of the way.....


Yeah but I am winning, 
I made the gaskets for the A.I.R manifolds today and the whole front of the engine is together.
I will post pics of the finished engine tomorrow.
Oil pan goes on tomorrow so engine will be competed by the end of the day.
Going to flatbed the car to the shop on Wed. and should have it running by Sunday.
:bannana:


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## Goat Roper (Oct 28, 2014)

Here are some pics, finished the rebuild on the QJet today and the engine is ready to go in as soon as I get the manifold bolts from Ames.


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## geeteeohguy (Feb 2, 2008)

Looking great. Only nit to pick is the PCV line.....you should get the correct Tee and pre-formed hose from AMES, being as the rest of your set-up is so mint!


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## Goat Roper (Oct 28, 2014)

Thanks for being nit picky and the pic, I will put that on the list.
I am trying to put everything back to original but so much has been changed over the years and removed it makes it difficult so details like that are a great help.
I ordered the rail for the wiring harness that was missing and will install that on the new valve covers once the engine is in, I don't want to dent or scratch them so they will go on last.
Put the fuel line on, filled it with oil and ZDDP and ran the pump with a drill today and it is oiling. 
Set the clearance on the starter bendix gear and it cranks.
Flatbed will bring the car over to the shop on Wed., time to get this engine in and put it together.


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