[6pack] TOO MUCH COMPRESSION?

[Sally or Dick Taylor]

John Mc---You could be right on the fringe of detonation with the 10:1 CR.  So it would be best to use the highest octane pump gas you can get. If you're on the East coast, this could be the 94 at Sunoco stations. There are scattered stations across the country that I've seen that carry this higher octane, but don't recall which States.

It is not a good idea to try stacking head gaskets, as this method wouldn't last too long before blowing. There are thicker copper gaskets available that are said to be of some value. I think Morty Dunst sells them.
He may also have the gaskets for the overbore. Sorry, I don't know how to contact him.

You could try the engine as is, listening carefully for the distinct rattle of detonation under load. Reduce the ignition timing as far as practical to see if you can stop the rattle. If you retard too far, you'll lose some of the power you were after to begin with. You'll want to have at least 26 deg. BTDC when the timing is "all in".

Some boosters in a can will up the octane numbers a little. The "104+ Super Octane" is one of the better ones. Expect the spark plugs to look a little strange, if you do use this. Everything here is a trade off.
 
If you are using a cam with a large valve overlap, like the S2, this will help bleed off some of the cylinder pressure at lower rpm. As you may know, it's a combo of many things that allows one to get away with the higher CRs.
Cooler air, knock sensors, forged pistons, and the like.

Dick