Certainly with a high compression engine maximum efficiency (which delivers
both best performance when you are using the power and best economy when you
aren't) is governed by the onset of pinking - ideally the timing should be
just short of pinking right across the throttle/load/revs range. Changing any
one of those factors moves the point at which pinking starts, and the
centrifugal and vacuum advance mechanisms are intended to take account of
them. However they are mechanical and relatively crude, so in practice you
can only get an approximation. Another huge factor is fuel octane, and as
modern fuel has come down in octane and changed in formulation it has tended
to make engine pink when they wouldn't before, so you have to retard the
timing if you can't get high-octane, and this has to be the rule of thumb
these days and not any hard and fast number in a book from 30 years ago. With
low compression it is less clear-cut, you may not get pinking, and if you
start advancing the timing too much to try and get more power *that* will
cause high running temps, and in extreme cases can stall the starter. The
last pointer the notch passes is TDC, the notches before that are BTDC,
usually 5 and 15 degrees being smaller than 10 and 20.
Whether you have electronic ignition or not makes no change to the above. As
another has said if you can't exceed 3k (and I'd add in *any* gear) on the
flat there is something very wrong.
PaulH.
----- Original Message -----
How can I maximize performance by adjusting the timing? I have an
electronic ignition. The car doesn't run bad, but won't achieve high rpm
(say
>3000). Is this normal?
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