Expansion Chambers and Development

by Shane
(Canada)

Tim,

Excellent article, but no mention of expansion chambers, which are a large contributor to the way 2-stroke engines develop power.

Would a 2-stroke engine without the expansion chamber develop useful torque over a wider range? Would it have similar peak power to a 4-stroke of the same displacement? (450 2-stroke v.s. 450 4-stroke)

Better yet, with the great peak power that has been achieved with the expansion chamber, why have consumers not seen the development of a variable tuned length expansion chamber. For all the R&D put into 4-strokes over the years, it's hard to believe some simple mechanically or electronically governed device couldn't be developed to control the tuned length of an expansion chamber. Resonance chambers were tinkered with by manufacturers but really did not have the same effect as physically changing the tuned length did they?