100 octane in a 58 Imp ????

[William Parker <parkerw@xxxxxxxxxxxxxxxxxxxxxx>]

I can't speak about an early hemi, not having driven one. 
My '65 Imperial would have flat top pistons and the closed
combustion chambers.  More recent research and experience as
touted in magazine articles seems to indicate that having a
"squish" area (such as between a flat top piston and the
corresponding flat area of the combustion chamber) enables
running higher compression for the same octane, or lower
octane for the same compression, than having a completely
open combustion chamber.  I've never had the heads off, so
they may have a fair amount of carbon to help produce ping. 
In running regular gas as I usually do, its fine unless I do
put a load on such as accelerating up a hill, then I do get
some ping.  


-- 
Bill Parker, South Central Indiana
'62 Plymouth Max Wedge; '65 Imperial; '65 Barracuda \6
(Kathi's car); '68 Hemi Roadrunner
'68 Barracuda Fastback 383-S; '69 Barracuda Fastback now 360
(20 y.o. son's car); '72 Cuda 340