Head Gasket thickness?
Thread Starter
Registered User
Joined: May 2000
Posts: 210
From: Salisbury, NC, USA
Head Gasket thickness?
Does anyone know off hand what the thickness of a stock alum. head LT1 head gasket? How about Iron head? Also some aftermarket gaskets.
I am looking for another couple of cc's (like 10-12) I am going to try to keep the amount I deck the block to a minimum, and I am going to try to get rid of as much in the head as I can and still have them safe and performing well. Figured this is my next place.
Thaks
I am looking for another couple of cc's (like 10-12) I am going to try to keep the amount I deck the block to a minimum, and I am going to try to get rid of as much in the head as I can and still have them safe and performing well. Figured this is my next place.
Thaks
Registered User
Joined: Oct 2002
Posts: 2,168
From: AACO, MD
Originally posted by ibanez6rg
Fel-Pro replacements are .039, no?
Fel-Pro replacements are .039, no?
What are you trying to lower compression for?
If you zero-deck it with that .059 gasket you're gonna have a really ****ty quench/squish area...
Do a google or a search on here on 'quench' to see what I'm talking about, it can explain it better than I can.
Basically most sources say you want to keep it between .035-.040" piston-to-head clearance.
You didn't mention what piston/crank/rods you are going with, but the 383 combo that I bought has a 9.000" 1/2 stroke + rod length + compression height. The block deck is 9.025", so you're already .025 in the hole, add a .059" head gasket and you have .084" piston-head clearance...hello detonation.
Last edited by Dave88LX; Apr 18, 2004 at 12:22 AM.
Registered User
Joined: Aug 2003
Posts: 515
From: jacksonville, FL
stock is .039". Impala or b-body gaskets are .029". I went with the Impy gaskets to reduce quench. The only negative I've HEARD of regarding the Impala gaskets is they are meant for a iron block/iron head combo so they don't have the lifespan the other ones have. I think that's just a myth though.
Registered User
Joined: Apr 2000
Posts: 510
From: Victoria, BC, Canada
Compressed thicknes of available head gaskets
0.028" - Impalla SS (12553160) *some claim 0.029"*
0.039" - Fel-Pro (1074 LT1/LT4)
0.043" - LT4 (12551488)
0.050" - LT1 (10168457) *some claim 0.049"*
Ideal quench is in the .04"-.05" range
Stock deck height is .025" so stock quench is ~.075" crappy but it does work
As mentioned impy gaskets are ment for iron and from all I've seen they seem to have a higher number of blown gaskets than the felpro ones. Not to say you would have problems with them.
I'm just completing a rebuild and kept stock deck height and went with the felpro's on ~11.0 CR motor.
0.028" - Impalla SS (12553160) *some claim 0.029"*
0.039" - Fel-Pro (1074 LT1/LT4)
0.043" - LT4 (12551488)
0.050" - LT1 (10168457) *some claim 0.049"*
Ideal quench is in the .04"-.05" range
Stock deck height is .025" so stock quench is ~.075" crappy but it does work
As mentioned impy gaskets are ment for iron and from all I've seen they seem to have a higher number of blown gaskets than the felpro ones. Not to say you would have problems with them.
I'm just completing a rebuild and kept stock deck height and went with the felpro's on ~11.0 CR motor.
Registered User
Joined: Apr 2000
Posts: 510
From: Victoria, BC, Canada
From my reading 0.035" is an absolute minimum as one has to allow for heat expansion.
so .04" seems to be a realistic minimum .
of course it will also depend on the materials used in the pistons and valves.
so .04" seems to be a realistic minimum .
of course it will also depend on the materials used in the pistons and valves.
Registered User
Joined: Aug 1998
Posts: 823
From: houston, tx
Originally posted by Sunsceamer
what will the compresion change to by changing just the gasket?
what will the compresion change to by changing just the gasket?
Then find the compression ratio calculator and plug in your numbers.
