Billet Main Cap Torque?

[Ttype6]

That is correct, I don't want to disassemble. I'll go to 110.
This will probably come back to bite me anyway. The cap was really stubborn going back in. I'm sure something is jacked up...
If it doesn't leak I'll be amazed.


Sent from my iPhone using Tapatalk

Are you talking about the rear cap specifically?

 

[Nick Micale]

Just my opinion, we use 100 ft-lb's on main studs or bolts. Going to 110 or 120 ft-lbs may not hurt or help?

The weakest part of a production Buick V-6 block is the thin web from the crank mainline to the cam tunnel, and we have seen a couple dozen or more blocks give up there, usually in the threaded holes for the main bolts.

At that point the block is trashed, as even with weld repair, structural integrity is compromised?

Stage blocks and the TA alum block has much more "meat" in that area which helps reliability greatly at increased HP levels, but we still use 100 ft-lbs.

 

[Ttype6]

There is one thing that I believe is most likely to cause main caps to walk, head gaskets to fail,and blocks to crack. The "D" word. Avoid this at all cost and take anyone's advice and you will have the highest chance of success.

I can cause any main cap to walk,any head gasket to explode and any block to split and all of these three events share one common cause.

 

[mtocrs1]

Are you talking about the rear cap specifically?

Yes, it needed more persuasion than normal.


Sent from my iPhone using Tapatalk

 

[juan89]

Use plastic gauge to verify clearances . And adjust torque accordingly .

Juan

 

[Ttype6]

Only a bore gauge will be able to see a difference if there is one.

 

[Nick Micale]

There is one thing that I believe is most likely to cause main caps to walk, head gaskets to fail,and blocks to crack. The "D" word. ........

You are correct with your statement, however there is another factor that will kill a block, and that is Horsepower!

Generally a production block is good to 600 HP with a proper tune, and some give up before that level, and others may live for a while beyond that number.

 

[Ttype6]

however there is another factor that will kill a block, and that is Horsepower!

I would agree that this is the 2nd most likely reason to break a block. Most of us will never break one for this reason and the amount of torque used to clamp the main caps will never be the reason for a cracked block.