LT4 Thinner head gasket
Thread Starter
Race Director
Joined: Feb 2008
Posts: 19,691
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From: Alexandria VA
LT4 Thinner head gasket
Was planning on running the MR. Gasket 5716G on my LT4. From my understanding this should bump my compression a bit. Block is stock deck but heads were shaved .010" for flatness. Am i to the point i should be concerned with valve clearance? (stock cam btw) Thanks!
Burning Brakes
Joined: Apr 2014
Posts: 829
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The compression on an LT4 is already high enough. If anything, I’d use a thicker gasket to compensate for the milling work.
BTW, milled heads in combination with thinner head gaskets might cause trouble with the intake manifold fitting properly.
BTW, milled heads in combination with thinner head gaskets might cause trouble with the intake manifold fitting properly.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
The .010 off the head shouldn't hurt anything provided they haven't already been milled. Decking block is a different matter. The piston should be below the deck probably .015 or more at TDC. 0 decking reduces deck height until it is equal to piston height a TDC. Head gasket actually sets the clearance between head and piston. There should be enough clearance that piston wouldn't contact heads at high RPM. You can measure piston to deck distance add to crushed head gasket thickness spec. You should have atleast .040.
The piston to valve clearance is also dependent on piston eye browe depth along with the cam valve lift. .550 or less is probably ok. If in doubt I'm certain YouTube has a how to video; to check piston to valve clearance.
The piston to valve clearance is also dependent on piston eye browe depth along with the cam valve lift. .550 or less is probably ok. If in doubt I'm certain YouTube has a how to video; to check piston to valve clearance.
Last edited by Kevova; Jun 3, 2021 at 02:39 PM.
Thread Starter
Race Director
Joined: Feb 2008
Posts: 19,691
Likes: 322
From: Alexandria VA
The .010 off the head shouldn't hurt anything provided they haven't already been milled. Decking block is a different matter. The piston should be below the deck probably .015 or more at TDC. 0 decking reduces deck height until it is equal to piston height a TDC. Head gasket actually sets the clearance between head and piston. There should be enough clearance that piston wouldn't contact heads at high RPM. You can measure piston to deck distance add to crushed head gasket thickness spec. You should have atleast .040.
The piston to valve clearance is also dependent on piston eye browe depth along with the cam valve lift. .550 or less is probably ok. If in doubt I'm certain YouTube has a how to video; to check piston to valve clearance.
The piston to valve clearance is also dependent on piston eye browe depth along with the cam valve lift. .550 or less is probably ok. If in doubt I'm certain YouTube has a how to video; to check piston to valve clearance.
Edit: just measured. Pistons .041" in the hole.
Last edited by RandomTask; Jun 3, 2021 at 08:09 PM.
