Here's something that's been bugging me.

If you have a non computer controlled car running a centrifugal advance distributor... which is more important, the total final timing, or how fast it comes in?

I've got a lower compression motor I'm trying to dial in the curve on and I'm running into detonation a few degrees before I think is normal. It's an old motor and burns oil, so I figure that's what's causing it.

The motor pings if I set it to 16* base and use one light and one medium advance spring. If I retard the base timing 2*, the ping goes away. However, it ALSO goes away if I switch to two medium springs (bringing the timing in a little slower).

Question is, WHICH solution is best? They're too close to be able to tell by the SOTP-meter which is making more power. Anyone know?

 

Let the timing come in a little slower, and run the more total. Total should be in be 3000 or so anyway, so total definatly has a much larger effect on overall performance. the advancing portion of the curve is just a transition period, there is nothing wrong with the curve being a little slower.