Okay, last little tidbit, also from the Dec. '53 issue of Hot Rod
Magazine, "Ignition Ailments" by W.G.(wasn't he "Racer"?) Brown.
"...many overhead valve engines require as much as 60 degrees before tdc
total advance to obtain maximum power as compared to 16 to 23 degrees
for all Ford V8s and Mercs."(Flatheads) "...an "L" head engine, the
amount of turbulence, or "stirring up" action of the fuel/air mixture,
which is created by the movement of the piston and an irregular
combustion chamber shape, is speeded up which results in a combustion
process that is much faster than an overhead valve engine." "...all
Fords and Mercurys from the smallest V8 "60" to the largest 300-plus
cubic incher operate best between 16 and 18 degrees btdc total spark
advance when gasoline is used and 20 degrees btdc when alcohol and
blends of alcohol and nitromethane or other fuel additives are used."
"...in the vast majority of cases, the connecting rod breaks because of
excessive spark advance."
Now I speculate that the reason people get great results with more
advance on their racing gas Flatheads today is that in '53 premium pump
gas was maybe 80 octane, (Research Octane). Very shortly afterwards
pump gas octane started to jump up as the carmakers wanted higher
compressions, so by '57 I believe you had heavily leaded 100 octane(RO)
premium so your '57 Chrysler 300D Hemi with 10 to 1 compression and
all-iron engine wouldn't "knock" its heads off. BUT, today your race
gas is way up there in octane. VP C14, for example, has a Motor
Octane(lower figure than Research Octane which is not given) of 114,
which would most likely have way more knock-resistance than 100 RO, and
certainly way more than the 80 RO of '53. So this all suggests that a
bit more spark lead is appropriate for today's racing gas in your '53
style Flattie racejob. Bill
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