All Small Six Compression

[clochard68]

No particular reason, the head is off the block right now for bigger intake valves and I thought I could try to improve my quench distance.

Tighter quench means more compression and I was wondering if the combination could run safely on 91. Gas prices are only going up, so I would prefer using the 91 over the 94...

 

[pmuller9]

No particular reason, the head is off the block right now for bigger intake valves and I thought I could try to improve my quench distance.

Tighter quench means more compression and I was wondering if the combination could run safely on 91. Gas prices are only going up, so I would prefer using the 91 over the 94...

How would you improve quench distance with the cylinder head?
Thinner head gasket?

Reducing quench distance usually requires taking some off the block deck or changing pistons.

 

[clochard68]

Yes, I have a steel shim head gasket. Milling the block is too much work for me, and I only found 1.530 compression height pistons (https://fordsix.com/threads/piston-selection-hypereutectic-vs-cast.79680/) with flat top (too much compression even with .050 head gasket) or a dish so big there would be no usabke quench area on the piston

Also my cranking compression is between 170 and 180psi at the moment, I was planning on getting it up to ~190psi