Tommy Cookers wrote: ↑28 Apr 2022, 13:48
comparisons of 4 stroke vs 2 stroke are utterly false unless cylinder sizes are equal ... because by geometry ....
the 2 stroke benefits disproportionately (in effective port area) from smaller cylinder sizes .....and ....
the 2 stroke loses disproportionately (in effective port area) from larger cylinder sizes
the last-attempt 500cc twin cylinder 2 strokes had 'only' c.140 hp NA because of this
(peakiness ? - both 4 and 2 cylinder GP bikes had 6 speed gearboxes)
also ....
wall-ported engines (2 stroke) cannot benefit in rpm from a high bore:stroke ratio as head-ported engines (4 stroke) can...
T-C, c'mon now, these kinds of ideas simply do not stand scrutiny, look at Ducati, which pushed its
short-stroke/big-bore high rpm V-twin superbike engine architecture to the nth degree, with saucer
sized pistons & huge poppet valves, plus revving well over 10,000rpm, but even they had to abandon
their decades-long trade-mark twins to compete with smaller 1000cc 4T 4-cylinder superbikes...
Not that MotoGP prototype 4-stroke 1000cc bikes have yet managed to match the (softly tuned, in fact)
Honda NRV500 twin 2T G.P. bike in specific output, over a 1/4 century later..
As for the 'blind alley' of (spiralled up to prohibitive) costs which cruelled atmo F1 from reaching up
to stratospheric rpm chasing marginal returns in time/area breathing & exponential friction/pumping
losses, well, that's hardly a grand story, given they still couldn't match the ~15 bar BMEP of G.P. 2Ts..
(Honda could've made this plain of course, but corporate ethos/pride - pig-headed/purblind notions
- precluded this, naturally.)..