LT4 head gasket
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,295
Likes: 14
From: Grand Sport #82
LT4 head gasket
I am pulling the heads to get a crossed plug thread fixed.
Should install the 5716, (026 in. Compressed Thickness) head gasket when I am in there anyway?
The car has the following mods:
Hotcam, Headers, testpipes, CORSA
Becool Rad, 160 T stat, PCM4LESS tune, Fidanza FW
Is there any downsides doing this? And is there any gain at all?
Do I need a retune when increasing the CR by this amount?
Should install the 5716, (026 in. Compressed Thickness) head gasket when I am in there anyway?
The car has the following mods:
Hotcam, Headers, testpipes, CORSA
Becool Rad, 160 T stat, PCM4LESS tune, Fidanza FW
Is there any downsides doing this? And is there any gain at all?
Do I need a retune when increasing the CR by this amount?
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
Changing from the .043 LT4 gasket to the .026 gasket -
It will bump your SCR from 10.8 to 11.3
With the Lt4 Hot Cam your DCR is 9.08 (v/s 8.66 DCR stock)
You already have the sensitive knock sensor... The big alum radiator and 160 stat with re-programed fans helps a bunch. As does the headers and no cats...
I'd recommend you get a new dyno tune - it'll be fine - but with a mail order tune your near the edge for an LTX at 9.0 DCR.
Keep in mind Victor Reinz also sells a very good .026 GENII head gasket (PN 5898) for about $18.00 each.
Will
It will bump your SCR from 10.8 to 11.3
With the Lt4 Hot Cam your DCR is 9.08 (v/s 8.66 DCR stock)
You already have the sensitive knock sensor... The big alum radiator and 160 stat with re-programed fans helps a bunch. As does the headers and no cats...
I'd recommend you get a new dyno tune - it'll be fine - but with a mail order tune your near the edge for an LTX at 9.0 DCR.
Keep in mind Victor Reinz also sells a very good .026 GENII head gasket (PN 5898) for about $18.00 each.
Will
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
I ran the Impala SS head gaskets and HOT Cam for a long time... .026 compressed. Bumps compression a couple tenths to a bit over 11:1 and it'll pick you up a few hp.
I experienced no downside. There's always the risk of seeing some knock retard, but that can be addressed via tuning if it occurs.
I experienced no downside. There's always the risk of seeing some knock retard, but that can be addressed via tuning if it occurs.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,295
Likes: 14
From: Grand Sport #82
Changing from the .043 LT4 gasket to the .026 gasket -
It will bump your SCR from 10.8 to 11.3
With the Lt4 Hot Cam your DCR is 9.08 (v/s 8.66 DCR stock)
You already have the sensitive knock sensor... The big alum radiator and 160 stat with re-programed fans helps a bunch. As does the headers and no cats...
I'd recommend you get a new dyno tune - it'll be fine - but with a mail order tune your near the edge for an LTX at 9.0 DCR.
Keep in mind Victor Reinz also sells a very good .026 GENII head gasket (PN 5898) for about $18.00 each.
Will
It will bump your SCR from 10.8 to 11.3
With the Lt4 Hot Cam your DCR is 9.08 (v/s 8.66 DCR stock)
You already have the sensitive knock sensor... The big alum radiator and 160 stat with re-programed fans helps a bunch. As does the headers and no cats...
I'd recommend you get a new dyno tune - it'll be fine - but with a mail order tune your near the edge for an LTX at 9.0 DCR.
Keep in mind Victor Reinz also sells a very good .026 GENII head gasket (PN 5898) for about $18.00 each.
Will
I will propperly run it on the mail Tune I got now. A Dyno re-tune is not really possible here.
Melting Slicks
Joined: Jan 2009
Posts: 3,482
Likes: 196
From: folsom california
I'm not familiar with those head gaskets, but a couple of caveats:
make sure the head gasket is designed for (soft) aluminum heads; some gaskets, especially thin ones, work best in a cast iron block, cast iron head with its equal expansion rates, harder material, and tolerance for much higher clamping loads; and,
if labor is an issue, does the gasket need to be retorqued, or can it be installed, torqued once, and forgotten (as a Fel Pro Permatorque for example) ?
make sure the head gasket is designed for (soft) aluminum heads; some gaskets, especially thin ones, work best in a cast iron block, cast iron head with its equal expansion rates, harder material, and tolerance for much higher clamping loads; and,
if labor is an issue, does the gasket need to be retorqued, or can it be installed, torqued once, and forgotten (as a Fel Pro Permatorque for example) ?
