Rotax 256 powerplant?

[swedenturbo]

Seen some attempts here to use a snowmobile engine in a snowbike.
The problem seems to be that the enginge with cvt clutch will be too wide. There is also an issue where to place footpegs in order to get the right riding position.
Seen some photos of the Rotax 256 engine. Dont know anyting about this engine. 256 cc? Prototype race engine?
A 500 cc with this layout and E-start would look really nice snowbike engine. Maybe a purpose built snowbike will have this kind of layout?

 

[portgrinder]

very neat idea

problem i see is rotary valve engines are very peaky. my lil 340RV makes 16 hp at 5000 rpm and around 80@9k. not ideal for shifting gears

a 500 2 stroke bike has almost a flat tq curve making it easy to stay in the meat of the power

 

[jrusher]

This is a kawasaki 800 twin we use in our jetskis for racing,, with a good pipe 100 hp @ 7250 rpm with no ther mods.. There light and fairly compact, e start, direct drive

 

[SnoFro]

bump

 

[swedenturbo]

Have done some research:


The 2 stroke dual crank tandem layout was developed by Rotax during 80:s
This was a racing engine mainly for carting.
A quite low decplacement engine with high peak power. Probably not suitable for snowbikes.
The Danish company PVP have continued development of this design.
You can buy these engines from PVP. Looks like its a limited production and they are super expensive, $12.600!
http://www.pvpkart.com/PRICES%20LIST%202015.htm

My point is that engines on snowbikes have to be narrow, lots of torque and hp.
Current 2T 500 singles have no E-start and heavy vibrations.
An inline twin 500-700 would be a slim and narrow solution.
80-100 hp target would be quite easy to reach.

 

[more snow]

Would be great if they would develop something based on the Yamaha 350 twin cylinder Banshee motor. Anyone attempting to stuff one of these in their snowbike yet?

 

[madmax]

Would be great if they would develop something based on the Yamaha 350 twin cylinder Banshee motor. Anyone attempting to stuff one of these in their snowbike yet?

My thoughts exactly. With a big bore you can get some serious power outta the 350 twin

 

[Hawkster]

What does it run for rpm , one would think it's some pretty good numbers coming from a rotax ?

 

[Grr]

Not to give out all my secrets, but my build for next year will be the shiznit.

Engine is the best option for a bike IMO which is the 2-stroke Polaris 400 liquid cooled single, found in the scrambler 400 and Xpress 400 4 wheelers. This engine is very small and light, uses a snowmobile clutch instead of a transmission.
Also with common pipe and porting it makes about 50hp, but also can add a 440cc big bore kit and high compression head makes around 70-75hp.

Total engine weight without clutch is around 35#, also has electric start. You should really look into it.

 

[moparmadman40]

Banshee twin

I have a 2003 ktm that i've put a banshee engine in for my timbersled kit. 4 mill stroker, ported .030 over stock cylinders. Here are the problems so far, no room for two carbs or pipes so it is a custom 2 to 1 setup on both sides. Works fine but leaves some power on the table over a normal setup. Also the engine vibrates like crazy at certain rpms, this is why all twins seem to be rubber mounted vs solid on bikes. I have a smartcarb on it that I just haven't got tuned right but when I had a regular carb it made great power on the pipe and turns 10-11k rpm. Forum won't upload my pictures...

 

[jethro450]

This is a kawasaki 800 twin we use in our jetskis for racing,, with a good pipe 100 hp @ 7250 rpm with no ther mods.. There light and fairly compact, e start, direct drive

And that is what i'm hoping to see in the near future in a purpose built snow bike!

 

[powdermuncher]

Yamaha should realy put a gearbox on the Phazer 4 stroke engine small light good torque and revs out to 11000 rpm
80 hp proven designe .
4 stroke pipe can be build into small spaces -- Heck I want one in a small lightweight Adventure bike and one in a snowbike.