Kendall---The only price to be paid after you've increased the
compression ratio from 7.5:1 to 9.X:1 is the likelihood that you won't
be able to run the lower octane fuel that you can now. The lower comp.
ratio wasn't done so that owners could use a lower octane, but to
satisfy the Feds and environmental/emissions people. Apparantly the
higher compression affects one of the smog-producing elements that car
manufacturers had to reduce. I think it was oxides of nitrogen, or
something like that. If you keep the ignition curve to less than 28
degrees total advance, you should be able to keep detonation at bay with
the highest pump octane, which is 92, here in Ca. If you go over 9.0:1
compression, you'll need a camshaft with more than stock overlap, to
bleed off some of this compression,.... or have to retard the spark so
much you'll defeat the purpose of the higher compression.
Dick Taylor
'73
L.A.
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