1972 Demon 340 engine mods

nm9stheham said

Yes the whole ignition system needed a rework. Keep that cap if it works; the brass terminals look nice. Hope it does not have any cracks.

20 psi in the cylinders? Yes, that is a whole point increase in CR! That will sure make it run harder down in the low RPM's.

BTW, at first I read the above as using 20 psi turbo boost....I wondered how THAT got started LOL

Click to expand...

Cap looks like this after serious brushing with wire brush on dremel. This cap looked really bad.
I will give it a shot but the other side needs work also.

Yes 20psi jump was expected after going to 63cc heads from stock J heads.
Test just confirmed that all is good in this area.
It’s probably around 9.5:1 now.

Shame we did not use thinner head gasket, 10:1 would be perfect.