What should my target quench be?? What I have is an lq4 pistons .010 out the hole, .015 milled 243s. I also have a set of .040 cometic gaskets. This is an n/a motor that will be sprayed every now and then.
Thanks

 

stock bottem end I belive .60 is good, you always want to go as close as possible, however since you are not running forged internals things will stretch and move a little more i say you are good

 

and the engine will like the closer than stock quench for n20, will help the burn and the n20 likes compression

 

im running flat top pistons with .040 gasket, .030 milled heads at 12 to 1 compression and she runs good on 93

 

INCREASE YOUR QUENCH!

Thats putting you at 0.030 quench. 0.035 is the rule of thumb.

btw, milling has ZERO effect on quench. It's all about head gasket thickness and out of hole.

 

Thanks, I was thinking .030 quench was not enough just couldn't seem to find the info anywhere.

 

When I have built motors I shoot for somewhere between .035" and .040". I try to by the componets/machining that will fall into that range.

 

If you have good valve springs you can run it .025-.030

 

I've seen pistons hit at .030" quench on iron block engines.

Iron blocks don't expand as much as an aluminum block will.

 

The minimum quench we recommend is .035". Anything less then that and you are running a risk of some contact issues.

 

Ran .040 on my lq9 with zero smacking of anything.. But every motors diff..

 

.035 to .040 is close enough to help avoid detonation so you can run a little more timing. I wouldn't go below .035 but that's just me.

Just my $.02

 

Run a stock MLS and call it done.

 

Agreed. A lot cheaper also.

 

EXACTLY !!!!!
It always scares me when I see .040 cometics on a stock LS1 short block.
If the pistons are .006"-.008" OOTH then the quench is brutally tight/close.
Perhaps as Brian just stated the aluminum block helps this but I recently tore
down an aluminum headed iron block stock car engine that had the pistons
.018" out with a .051" gasket and you could see the marks from the pistons
touching the quench pad of the chamber. This was only a 7000 rpm...maybe
525 horsepower application. Luckily it didn't bomb or even pinch the lands
but I am ordering .056" Cometics for it.

 

Not to hijack this thread but is 0.051 quench too much? I have a zero decked ls7, I'd like to run 0.041 head gaskets but I'm afraid that will raise my DCR too high since it has a torquer cam.