I don't understand what you just said. I ran a 420 Husqvarna with a short stroke big bore in my outlaw cart some 30 years ago and found major power when widening the exhaust and transfer and intake ports to where the ring gaps had very little bore surface. Ran right with the big boys CR 500 and KTM 550,senglertracing wrote: ↑Thu Jun 03, 2021 2:36 pmYou can't widen it enough to make up the difference.af2 wrote: ↑Wed Jun 02, 2021 9:14 pmUntil you widen it..englertracing wrote: ↑Wed Jun 02, 2021 2:00 am Manufacturer Ducati
Engine Liquid cooled 90° 1,285 cc (78.4 cu in) L-twin,
4-valve/cyl desmodromic
Bore / stroke 116 mm × 60.8 mm (4.57 in × 2.39 in)
Compression ratio 12.6:1
Power 205 hp (150.8 kW) @ 10,500 rpm (claimed)
The bore and stroke have less to do with how Streetable an engine is than the port velocity and cam characteristics.
Also
Back to 2 strokes, the way cylinder ports work, the port area is smaller on a big bore short stroke than a small bore long stroke.
That's why you'll see 20,000rpm ica kart engines are undersquare and 45,000 rpm rc engines also undersquare.
There are some square and oversquare 2 strokes but non of them are outstanding.
Port width is limited to a percent bore size, and does not take advantage of any 3.14 trickery.
Again I don't understand?