Building a rotary-powered bike??

[imdying]

rotors "sweep"

I thought they would've 'rotated'

[James Deuce]

I thought they would've 'rotated'

Pistons work through a "stroke" in operation and rotors "sweep" the area the rotate through, gathering charge, combusting, and exhausting, hence the phrase swept volume when describing the cc rating of a rotary.

[imdying]

Heh, I just thought it would go well with the rotating smiley

[stanko]

The term "Rotary piston" is derived from Drehkolbnmotor the german term for Rotary piston motor. The first such engine the DKM-54 first ran under its own power on 1 Feb 1957 . DKM is an abbreviation for Drehkolbnmotor. So the term was coined by Felix Wankel, pretty hard to argue with that.!

[James Deuce]

Who built the last German rotary powered car and how long ago? You're looking at 40 years ago and they only spent about 8 years developing and building rotary powered cars culminating the NSU Ro80. Norton's rotary has been developed and in production longer than anything the Germans did and Norton is now a distributor for pocket bikes in the US. The Japanese have been building rotary engines for 40 years, still do, and call the rotary "piston" a rotor.

I go with the guys that know more about rotaries than old Dr Wankel ever did.

[Mr. Peanut]

I like engines period.

[toymachine]

Why the fullstop after saying period?

I'd like to hear this bike...

[imdying]

pretty hard to argue with that.!

Must be something lost in the translation.

[aerobubb1]

Saw this thread and thought Id better put my 5c worth in for what its worth, there seems to be a bit of confusion about the sachs engines and wankel engines in general, alot of people make comments on them not fully understanding the engine or actually knowing anything about them at all and as there are not many people out there who do fully understand them who is going to know! You can say whatever you like!
Anyway I am going to clear a few things up on this subject, for every rotation of the shaft it fires once (not 3 times as many think) and the amount of gas compressed and burned for that 1 fireing say the engine is 125cc so you can virtually directly compare them to a 125cc two stroke engine, where it gets confusing for alot of people is where you bring the rotor into the picture, the rotor is only doing 1 third of crankshaft speed not 3 times crank speed (another urban myth), so you need 3 complete crank (e-shaft) rotations to get the engine to fire on all 3 sides of the rotor.

So heres where it gets even more confusing because the rotor is only doing 1 third engine speed the efective crank angle of the engine ends up being around 270 degrees of crank rotation so when you compare this with an ordinary 2 stroke engine with an effective crankangle of around 120 degrees its a big difference. This extra effective crank angle makes the wankel a very smooth running engine when you also concider nothing in the engine is changing direction, I have had people try and tell me that "rotary engines do go up and down thats why they have a figure of 8 chamber if they went round and round they would have a round chamber" this is not the case it is just an optical illusion created by the spirograph effect of the rotary engine if you don't beleave me go to http://en.wikipedia.org/wiki/Image:W...n_nojitter.gif and have a good long hard look eventually you will see its an illusion
So you might ask with an effective crank angle more double that of the 2 stroke engine why are they not more powerful than a 2 stroke engine of the same capacity? Well the biggest factor in this is torque,
The stroke of the wankel is minimal compared to that of a 2 stroke engine so where the wankel makes up for a long effective crank angle it looses out on stroke, but all said and done a 125cc two stroke and a 125cc wankel should be fairly closely matched in power, the 2 stroke would probably win due to more development no one except norton ever built successful wankel race bikes, to see the norton wankels in action go to
http://www.youtube.com/watch?v=kBg86...feature=relate

Anyway back to the forum I have been working on my own turbo wankel bike a honda mb100 chasis, with honda mb100 gearbox with mb5 internals, the engine is a periphial ported km3 110cc lawmower engine and I have only had the engine running NA at the moment and have not bothered tuning it as I will be turbocharging it as soon as the turbo turns up from japan, you can see it running at
http://www.youtube.com/watch?v=dOsCUtEE_W8
Alot more work to do on it will hopefully have it done by the end of the year

[honda929]

Ive got a john player special sitting in my shed, Shipped it over from australia,all it needs is new rotor seals and then