ArKay99

iTrader: (1)

Anyone know who makes a .042" or .043" compressed head gasket for a 99 LS1? I'm putting a set of milled AFR's on soon. I have a set of .052" compressed stock gaskets for installation. What I would like to do is put together the h/c package assembled and check my p/v clearance and if adequate install a .042" or .043", and if not stay with the .052" gaskets. Right now I have the heads milled .010" and with the .052" gasket I should be close to a 63cc combustion chamber vol. I'm using a 224/228 .581/.588 112+2 or +4 cam (I'll check for best fit then set the advance). I'd like to get the tightest quench but unfortunately can't keep the car where the lift is for more than a few days so I don't have time to assemble, check, remove, disassemble, re-mill, and reassemble. I also have the Isky piston notchers but I really, really don't want to go there unless I absolutely have to (inadequate p/v with .052" gaskets).

PREDATOR-Z

Cometics .043 + .030 (62cc) = ~11:1 CR as per Tony Mamo (AFR)

ArKay99

iTrader: (1)

I'm looking around and AFR recommends these. Fel-Pro#1041, Cometic #6847 Cometic #6846. I can't find the Cometic gaskets, but I have found the Fel-Pro. It's a .041" that fits my requirement. However, the bore size is 4.135" and I have a stock bore that 'should' use a 3.910" gasket. Is AFR telling me I can use the bigger bore gasket? My knee-jerk reaction is to not use it.

PREDATOR-Z

You are correct!! I goofed

This is part of the PM he sent me:

So felpro would be good.

ArKay99

iTrader: (1)

But what about the bore size? The part# 1041 states a 4.135 bore, clearly not a stock bore. I haven't been able to find a Fel-Pro with a 3.910 bore...

PREDATOR-Z

On another thread, Tony mentionned having thin cometic gaskets in stock.
From the AFR site it mentions "Cometic AFR # 6846".
This might be the one.
Call Tony and find out.

ArKay99

iTrader: (1)

I'll check that out. I'll give AFR a call tomorrow.

PREDATOR-Z

BTW, I'm going with AFR's too. Could you post if that are the gaskets needed? It would be good info to have on the forum's data banks.

ArKay99

iTrader: (1)

No problem. I've emailed Tony and will post his suggestion when I see it.

z-ya

iTrader: (1)

felpro 9284pt for stock bore.

ArKay99

iTrader: (1)

Here is what I discussed with Tony@AFR. Optimum head mill is .024 for 62cc combustion chamber for 11:1 c/r using a .040 gasket. One thing to keep in mind is this is on the hairy edge for detonation. They are using a Cometic gasket that is a custom MLS with 3.910 bore and .040 compressed thickness. The cam that was used was a 224/228 .581/.588 @114. I didn't ask about the advance. With that mill and gasket thickness p/v was as close as could be reliable. I'm using a 112lsa+2 and will try a +4 install but I may be close due the tighter ICL of the 112@+4. So I'm leaving the .010 mill and checking p/v and if I have the room I'll mill them the extra .014. If not I should only leave ~5hp on the table. I'll be running 64.34cc combustion chambers and quench should still be good with that gasket.

jrp

iTrader: (16)

im running a cometic .043 gasket 3.905 bore, 5.7 heads milled .020, and pistons out the hole .010; quench is .033. my SCR is a little higher then 11.1 though

John B

iTrader: (10)

This is pushing it a bit much. Any decent racer's shortblock assembly handbook will typically spec out a minimum 0.035" - 0.045" for use with good aftermarket connecting rods because your stockers will stretch too much at high RPM! Might want to think twice about this one

jrp

iTrader: (16)

its on a forged 347 w/ arp bolts and studs through out.

ArKay99

iTrader: (1)

pistons out the hole... That's my unknown until I get the heads off and mic them. That is definitely going to be a factor with stock decks. Are yours .010 out due to cleanup/squareing? BTW, I heard that cam you are running. Lot's of overlap there... DCR much different than SCR

jrp

iTrader: (16)

shortblock:

stock treated crank
eagle 6.125 rods
custom diamond pistons; 3.905 bore 1.309 CH w/ .927 pin
stock deck (9.240)
ect.

ArKay99

iTrader: (1)

There was a sound byte about 2 weeks ago that you posted of a scarey sounding cam. I thought that is what you are running.

jrp

iTrader: (16)

nah, that wasnt mine, it was an old T1 through a cutout.

my DCR should come out to ~9.1

KJ

iTrader: (1)

Just wanted to let everyone know that we are a stocking dealer for Cometic! I have 0.030" & 0.040" (3.910 bore) in stock ready to ship. $63.75 per side is what they go for. Let me know if I can help!!

SideStep

What is the compressed thickness of this gasket???

Where would I get it????



***EDIT***

I found Felpro's tech line number... it is .054 compressed, .060 uncompressed....