loud motor = happy motor?

[PMDRACER at aol.com]

In a message dated 11/3/98 1:41:07 AM Pacific Standard Time,
am018 at post.almac.co.uk writes:

<< As a general rule as taught to me by my grandfather who was setting
 ignitions by ear at the start of this century an over advanced ignition
 always sounds more powerful -- this could be partially explained (I think)
 by the fact that it will pick up revs more quickly when reved out of gear.
 On few cars I have come across (Lotus Elans which had only 20 crank
 degrees of mechanical advance) retarded ignition has caused pinking ---- I
 suspect due to hot spots forming from excess rejected heat.
  >>
Well, to be truthful, you will never see full advance curves on a motor revved
out of gear. You simply cannot achieve any sort of vacuum to run the advance,
so in reality, you are revving the motor with retarded timing. Ignition timing
is a factor dictated by today's gasoline. You simply cannot run the amount of
ignition advance today that you used to 10 to 20 years ago. The "more is
better" rule also does not apply. You can easily go too far, and lose
performance (and the motor, under extreme conditions). The idea of ignition
timing is to start the ignited fuel's flame front early enough so that the
largest explosive force occurs when the piston/rod combination is on it's way
down on the combustion stroke. If ignition timing is retarded, (closer to Top
Dead Center), the maximum flame front will occur too late, and a loss of
potential power will occur. If the ignition timing is too far advanced,
(farther before TDC), the maximum flame front will occur too early, and the
piston will actually fight the flame front on it's travel upward, causing a
pressure spike, and that pressure causing the actual secondary ignition (and
flame front) of the remaining fuel. As the two flame fronts meet in the
cylinder, a harmonic clashing occurs (audible ping), and instead of the one
flame front propagating throughout the cylinder, and creating power, both
flame fronts collapse, and power diminishes, along with the real possibility
of extensive engine damage! 
You must also keep in mind that all engines are different. For example, a
stock Chevy small block will run with a static timing of 4 deg. advance, and a
total of 40 to 44 deg advance at full power. A Pontiac engine, on the other
hand, runs with a static timing of 12 to 16 degrees, and 36 to 38 deg of
advance at full power. Also keep in mind that if you change an engine's
combination of parts (a new cam, heads, etc.) the ignition timing demands will
change. Other things that will change an engine's demand for more or less
timing is ambient air temp. and density, altitude, humidity, gas quality, load
(towing, etc.), and state of tune.
Hope this answers your question!
PMDRACER at aol.com