Negative effects of timing advance?

[Mr 5 0]

Timing is controlled by the relationship of the position of the piston to when the spark occurs. If the ignition spark occurs too soon
it can actually push against a piston traveling up the cylinder as it's compressing the fuel/air mixture. This causes detonation, lost power, much higher combustion temperatures as well as higher emissions and early internal engine part failures.

Simple procedure; using 92 (or higher) octane gas, advance by 2 degrees at a time; 12 degrees, then 14 degrees, then 16 degrees.
Test by driving up a hill in fourth or otherwise putting a 'load' on the engine. If it 'pings' (metallic rattle sound, which would be your valves complaining) then back off 2 degrees and test it again.

Hint: Cool weather will diminish the chance of detonation a bit...hot weather increases it.

[This message has been edited by Mr 5 0 (edited 09-18-2001).]