How much do composition head gaskets compress?

[travis]

Sbf 4.100” bore composition head gaskets, measured at .051” uncompressed. The felpro catalog says these are .047-.053 compressed??? Seems like a pretty big range to me.

These came with a basic rebuilder gasket set.

[PRH]

For the application at hand...... does it really matter?

Put head on....... barely snug bolts.
If there is an area where there is a gap between the head and block, measure with a feeler gauge.
Torque down head, remeasure..... you have your answer for future reference.

[ProPower engines]

Sbf 4.100” bore composition head gaskets, measured at .051” uncompressed. The felpro catalog says these are .047-.053 compressed??? Seems like a pretty big range to me.

These came with a basic rebuilder gasket set.

I have asked FM tech the same questions and they have no info on the stock replacement gaskets beyond a guess.
Most guys have gaskets hanging up on the wall for this reason so they can consider this issue when doing a build
that will use a stock head gasket.

Here's the thing about SBF head gaskets the 221-302 uses 7/16" head bolts a 351W used 1/2"
Different torque spec for each so the gasket design is different between the two gaskets even though they look the same.
If you use a gasket designed for a 351W on a 302 with the smaller bolts its not going to compress as much as the 1'/2"
So now what are you working with?? I have had issues using a 351W gasket on a 302 with the small bolts. Aluminum heads make it even worse using the small bolts with the W gasket is asking for a leak

[shoedoos]

slightly off subject.....are torque settings different for a composite head gasket from a copper or MLS type head gasket?

[ProPower engines]

slightly off subject.....are torque settings different for a composite head gasket from a copper or MLS type head gasket?

Torque settings are based on fastener being used.
Bolts and studs differ greatly.
7/16" bolt is 70-80 ft lbs depending on length on 302
1/2" bolt is 95-110 depending on length on 351 W
Spec is from AERA Prosis which most shops use as a guide.
Studs are more depending on size and length but not alot but the fine thread allows for a tighter clamp force because
of less friction between threads and better lube is used compared to stock bolts in most cases.