Curious if anyones experimented with what makes more power (at the same boost level).. More spark advance, or more static compression ?

Trying to figure out what would make more power. My S-trim on a 8.66:1 alum head motor with tons of timing, or a 9.5:1 alum head motor with less timing.

(10-12psi either way).


-- Joe

 

I'd say it depends on how much timing the head design needs. If it likes the most possible timing before detonation, then run low comp pistons and max out the timing. If it makes the most power at a lower timing setting, run the highest compression you can get away with.

Are the heads old school or a fast burn chamber design? Fast burn style generally requires less timing.

 

Hrmm.. Now that is truely a good question!

Here is a picture from summit. Any idea?

 

Within the bounds of sanity, timing beats compression every time. If you have a motor with compression that's a little too low but can take full best-power spark advance it will make more power than a motor with a little too much compression that has to have the spark pulled back to stay out of detonation (all else being equal, obviously).

 

that would be a fast burn type