pyrocentric
XS650 Addict
- Messages
- 221
- Reaction score
- 1
- Points
- 18
There's been a lot of news lately about Scuderi's split cycle engine design...most of which is probably bull, granted. http://en.wikipedia.org/wiki/Scuderi_Engine It's basically a refinement of a design that's been around for ages, even on some production bikes like the Sears Twingle scooter in the 50's. Basically, one cylinder compresses the air and another cylinder ignites it, so you end up with a two-stroke machine. The benefit, if built right, is a more complete burn and the ability to store the compressed air during deceleration and deactivate the pumping cylinder when it's not needed.
But it has me thinking about the XS. What would it take to convert it to one of these? We can already split the crank and change the crank angle(to some extent). Stroker cranks exist(the firing piston usually has a longer stroke than the pumping piston to take advantage of the atkinson/miller cycles). punkscalar can chop and re-weld the cams now, although a custom grind would probably be needed. You could reverse flow on one side of the cylinder head...so the carb would be on the front right, pass through the right cylinder, cross over at the rear in a compression tube/tank, then run through the left cylinder and exit in an exhaust header as usual. The pumping cylinder exit valve would need to be replaced with a reed valve or something more complicated to take advantage of regenerative braking. The only major component missing is fuel injection and an optional turbo, which Sky has demonstrated is a massive project on it's own.
Anyway, it's just something I've been thinking about, since I don't have any spare engines sitting around at the moment anyway. Most of the hybrid cars already use atkinson cycle engines. It'll be interesting to see what the major manufacturers can do with split-cycles.
But it has me thinking about the XS. What would it take to convert it to one of these? We can already split the crank and change the crank angle(to some extent). Stroker cranks exist(the firing piston usually has a longer stroke than the pumping piston to take advantage of the atkinson/miller cycles). punkscalar can chop and re-weld the cams now, although a custom grind would probably be needed. You could reverse flow on one side of the cylinder head...so the carb would be on the front right, pass through the right cylinder, cross over at the rear in a compression tube/tank, then run through the left cylinder and exit in an exhaust header as usual. The pumping cylinder exit valve would need to be replaced with a reed valve or something more complicated to take advantage of regenerative braking. The only major component missing is fuel injection and an optional turbo, which Sky has demonstrated is a massive project on it's own.
Anyway, it's just something I've been thinking about, since I don't have any spare engines sitting around at the moment anyway. Most of the hybrid cars already use atkinson cycle engines. It'll be interesting to see what the major manufacturers can do with split-cycles.
