Billet Caps and ET

[Detomaso71]

Building a new engine, stroker/forged etc.

How low ETs can I hit if I have a good tune before the billet caps start to want to leave the block? I was gonna use 3 billets, possibly 4 and I am aware a girdle would be cheaper than the 3 caps.

Its a street strip car so I am tryin to avoid the girdle due to all the leaks ad horror stories. I am sure a few people will say "mine doesnt ever leak" but almost everyone I talk to says theirs leaves puddles on the ground.

Thanks

 

[howdies86]

I ran 10.80 @125 w/25# boost, stock crank,rods, main caps with no problems. I never tried more boost for this reason and had "no" detonation or knock retard.

 

[Mike Licht]

A properly done main cap motor with a proper tune up can run in the 9's without issue

 

[49-blues]

How did you figure that a girdled block is cheaper to build than a billet capped block? Did you account for all the machine work neccessary?

 

[Detomaso71]

Billet Cap $

Four billet caps and the machine work needed for caps is a few hundred dollars more than a girdled block.
Both need machine work and cap number four costs half as much as a girdle itself, not to mention the other three.

Pretty sure 4 billet caps and machine work will be around 200 more total but I'm new to engine work.

I plan for low tens and occasional high nines, we will see if they fall out I guess.

 

[Mike Licht]

IMO the rear cap is a waste of money.
Mike

 

[hemi8]

The center 2 are all thats required, the forged crank will not flex in the middle like the stock piece. Forged crank, center billet caps, no detonation and your weak point will shift to the block webbing, which is why they made the Stage 2 block.
Mike

 

[Mike Licht]

I agree with what Mike posted about the center 2 being most important but the cost to add the front is very small considering you are already paying for the machine work so I usually add that in too. Steel cranks do not twist like stockers and the twist is what breaks the main caps.
ML

 

[49-blues]

i would prefer just to do the three front caps-should be plenty of support.

 

[williambavila]

i would prefer just to do the three front caps-should be plenty of support.

three caps will work fine i am running low 11,s with stock bottom end and stock caps.lotsa boost with alky

 

[machinegun]

I would not worry about the number 4 cap.

1, 2, 3 billet and machine work are cheaper than a girdle and we have been low low 10.0's with no issues. High nines have been had with this and a forged crank.

 

[gnxtc2]

The center 2 are all thats required, the forged crank will not flex in the middle like the stock piece. Forged crank, center billet caps, no detonation and your weak point will shift to the block webbing, which is why they made the Stage 2 block.
Mike

Bingo..... the crank flexing destroys the main webbing. Billet caps and/or girdle is not going to help a crank flexing. Throw a forged/billet crank in there and most of your flex problems are over with.

Billy T.
gnxtc2@aol.com

 

[buickboy]

I agree with the stock crank flex in the center. I just went through a new rebuild for that reason. Std/Std factory turbo crank, 2 center caps and it cracked the crank on the 2 center journals and ate up the bearings. Now, steel crank with 2 center caps. Yet to test the new motor.

Mitch