Head Gasket Bore

[khryslerkid]

What should the head gasket bore be for a .040 over cylinder. (4.360 cylinder) 452 heads. I see gasket bore measurements but not any reference to cylinder size. I know too close to the hole can cause detonation. Pistons are .060 in the hole...

 

[lewtot184]

i use the 8519, measures about 4.5. the issue isn't detonation but the fire ring hanging in the chamber and burning out. this can torch the head or block. the 1039 has a large bore but is expensive. the 1009 shouldn't be used on the larger bores, 400 or 440, especially with alum heads.

 

[khryslerkid]

Is there a particular formula for calculating cylinder dia. to gasket bore?

 

[cdr]

the main thing is to lay the gasket on the head & make sure it is not hanging into the chamber.

 

[khryslerkid]

the main thing is to lay the gasket on the head & make sure it is not hanging into the chamber.

I would think that a standard bore gasket would be good on the head side. The heads are factory with no chamber alterations...

 

[lewtot184]

the main thing is to lay the gasket on the head & make sure it is not hanging into the chamber.

this! i try to have the fire ring on the gasket a noticeable distance away from the cylinder and chamber. compression and how hard the engine is worked will have an effect also. i've had to weld up alum heads from bracket engines using the 1009 on the larger bores. there isn't a "formula" that i know of. but, i'd try keep the fire ring about .060", maybe more if possible, away from the cylinder chamfer or chamber wall.

 

[Cranky]

I've seen the combustion chamber of heads over hang the cylinder before and that should be cleaned up to match the bore but the proper gasket bore should be around .020 larger than the cylinder bore chamfer. And large chamfers are not necessary....

 

[khryslerkid]

I've seen the combustion chamber of heads over hang the cylinder before and that should be cleaned up to match the bore but the proper gasket bore should be around .020 larger than the cylinder bore chamfer. And large chamfers are not necessary....

I took notice that the 452 chamber measures .160 smaller than the 4.360 cylinder.