Thank you for posting that. To answer the question about smaller bores, the competitions have engine cubic inch limits so something has to give. The block dimensions sort of control what rod length to use and the rod length sort of controls the stroke because one is looking for a particular rod/stroke ratio. Kaase is a very savvy engine builder and his winning big block used a sleeved 460 ford block with a long stroke. Then he used the biggest set of heads to get the breathing. the theory is that the shorter rod gets the piston moving sooner so you can really use a big intake port.

The flame travel issue is true, that's one reason 400s are relatively intolerant of bad gas, even with low compression ratios. Smaller bore can be used with higher compression ratios, all other things being equal.

Detonation usually occurs when the fuel in the chamber (but far from the fire so it isn't lit yet) degrades into different compounds that self-ignite because of the heat and pressure in the chamber. Moving the piston away from TDC earlier reduces the pressure and therefore the tendency to knock. I am not completely comfortable with this, but Kaase's results speak for themselves.

R.