RE: Ignition timing.
I agree. What is odd about my Echo "stroker" engines is that they want the later timing, even though the combustion chamber, squish/quench distance, etc. is all the same as the non stroker versions of the engine. (I mechanically set the squish distance to be the same with a custom cylinder spacer.) The increase in swept volume via the stroker crank is only 1.4cc. That of course would slightly raise the static compression ratio, but so little that I can't believe it would be enough of a raise to warrant needing four degrees less timing advance. I think that there is more at work in this case, and it is interesting.
AV8TOR