> Anybody on the list have experieince with timing on a naturally aspirated,
> gas burning Chev big block? I ran with 36 total advance but several other
> racers told me that a BB likes more advance than that.
Dick,
Several things influence correct timing of an engine. Compression ratio,
A/F mixture, and combustion chamber design are important ones. How well
the engine breaths (altitude affects this) is also important. I have not
run a big block Chevy, but I will relay what Earl Wooden told me about his
first big block engine. He had run up against the clock on time to prepare
for Bonneville. He had planned to run 36 degrees, but conditions kept him
from running. After he dynoed the engine, he was glad he didn't get to
run. The engine didn't want anything over 32 degrees and I believe he ran
it at 28 or 30 degrees. I know of another case here locally, where the
dynoing of a big block surprised the builder. It also did not improve in
power over 32 degrees.
I don't really care how someone else sets up their engine. Each engine has
its own comfort zone. When chosing the correct timing for my engine, I
start out with a conservative setting and advance it until it doesn't
improve in performance, then I back it up a couple of degrees, lock it
down and start massaging something else. I have run as high as 52 degrees
with the 23 degree head motor with success. This was because the engine
didn't breath well. After I got good heads on the motor, 42 to 44 dergrees
at Bonneville was the correct number. Better heads would have dropped the
nmumber even more I suspect. With the present motor (18 deg heads) I run
38 degrees on gasoline at Bonneville. Lee Gustafson (Seth Hammond's engine
guru) told me that they burnt an engine down at 36 degrees. They run 32
degrees, I believe.
Bottom line...it helps to listen to others, but chances are your setting
will be different. Whatever works for you is the correct setting.
Tom, Redding CA - #216 D/FCC
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