Thee Antic

iTrader: (1)

Alright so, 01 LS1 block deck is untouched. I'm using a wiseco flat top forged piston with -3cc valve reliefs and stock stroke. My machinist just milled my 243 heads down to 58cc chambers..he calculated that should give me 11.1:1 using the stock mls gaskets. Now I'm reading about this quench area, saying it's better to use a thinner gasket and mill the head less. Did I just screw myself? Keeping in mind this is going in a strictly DD car.

Thee Antic

iTrader: (1)

Double post.

redtan

iTrader: (5)

You can still use a 0.040 gasket for good quench and be well within the limits of pump gas.

You have the forged pistons and valve reliefs so that gives you plenty of room for PTV.

RezinTexas

What is your piston deck height?

high impact

iTrader: (5)

What he said^^^^^^^

Piston to deck height is the critical number to know to figure out proper quench. Quench is not that critical on a street car anyway. Forged pistons need a little more since they potentially can rock in the bore more. Keep your quench on the safer side. My wisecos ended up .003 in the hole so I used a .036 head gasket for a total of .039 and that's about as perfect as you can get for a street driven engine. I'd only use the stock mls gasket if your pistons are above the deck like stock pistons. The stock gasket is .051

Thee Antic

iTrader: (1)

The block isn't even assembled so I guess I'll be waiting to figure this one out.

So let me get this straight, target quench - piston to deck height = thickness head gasket I should be using? Seems like I'm going to be stuck using a crazy thin gasket..can't imagine what their life span is like..

JakeFusion

iTrader: (7)

Quench is deck height minus head gasket thickness for pistons out of the hole or additive of those numbers if in the hole.

I run .040s with pistons out .006 for a quench around .034". You don't want tighter than .030" and you want to stay in that .035-.045 area.

And quench is very important on a street car trying to push additional ponies.

high impact

iTrader: (5)

Key is "trying to push additional ponies", I Agree with most you say Jake, you even assisted me as I was planning my build....BUT Quench is only extremely important to us ****, crazy, hard core, squeeze everything out of a little street car motor heads. Buts let's face it, most street car guys aren't building a NHRA engine here. And I agree with your target quench of .035-.045. OP, keep doing your homework and you'll have a solid runner, cut no corners.

Thee Antic

iTrader: (1)

Well let's say I end up using the .040 cometics that seem to be so popular. That shouldn't affect compression all that much, at most it might bump it up to 11.2:1. But a motor with 11.2:1 and that's in the proper quench range (.035-.045) should run better/cooler on the street than a motor with 11.1:1 and a quench that's .020 over the target zone right?

I don't mind forking over the extra cash for some cometics if it means a longer lifespan. The high compression on pump gas has me worried enough as it is lol

A.R. Shale Targa

iTrader: (2)

Going from .051 (some claim .054") GM MLS gaskets to the Cometic .040"
is usually closer to 0.35 hike in compression depending on the size of the
engine being built. No worries though as even mid eleven static compression
is still easily pump gas streetable with the correct cam timing events.
Cranking compression or DCR is what the engine truly sees when running
XYZ octane fuel. The tighter the quench helps an engine stave off detonation
and be less octane sensitive. Be careful there as less than .035 quench on an
all aluminum gets really close specially with forged pistons that run looser
piston to wall clearances and rock a bit more in the bore on directional
change.

Thee Antic

iTrader: (1)

I'm not sure if you are talking about the degree the cam is set to or the physical build of the cam..

If it helps I'm using a 228r 112lsa. Small cam for the ultimate in streetability.

LilJayV10

iTrader: (39)

high impact

iTrader: (5)

What's the eye roll for there "mr take one sentence out of context boy?"

LilJayV10

iTrader: (39)

How did I take it out of context "boy"?

LilJayV10

iTrader: (39)

The reason I bolded that sentence out of your whole post because that was the only sentence what was bull ****. That's why.

high impact

iTrader: (5)

You highlighted one sentence with no consideration of what was said in the entire context. A street engine with a little 22* cam doesn't need to run on the ragged edge of quench. Read the rest. I'm not willing to derail the OP's thread for your eye roll anymore then you have already but thanks for your quality contribution anyway.

That sentence isn't bs - he's not building an NHRA engine here.

LilJayV10

iTrader: (39)

But Jake...I read on the internet that quench on a street car isn't important.....

There I go again, quoting one sentence.

LilJayV10

iTrader: (39)

You are right.

There you go.

Thee Antic

iTrader: (1)

Mmhmmm...

A.R could you elaborate?

A.R. Shale Targa

iTrader: (2)

Where the lobes are placed in relation to one another as well as to the crank
can all affect the dynamic compression ratio. Static compression is what you're figuring....mathematically the volume in the hole of the piston at BDC divided by the remaining volume with the piston @ TDC., however the intake valve does NOT close exactly when the piston is @ the bottom but rather when it's already traveling up the bore. It doesn't truly begin to build squeeze until the valves are both closed. Once you decide on the gasket and the 11.xx compression is final....then call TSP and find where that cam should be degreed (w/relation to the crank) so the DCR ends up in the 8.55-8.75 range....depending on whether your area premuim fuel is 90,91, or 93 octane.