GS500 Superstroke Engine

[machg]

Hey all, this could also be in the "wanted" section. I have put a provisional patent in for an engine design based on the mighty GS500 engine. The design runs as a two-stroke on 1 cylinder only, with the other cylinder supplying compressed air for scavenging duties. Target power output will be 60-70hp! If anyone in Australia has an old or damaged GS500 engine lying around, let me know. I am pretty broke ATM, but I am chasing some support from educational institutions. Obviously, if the idea works, it will have big benefits to all GS500 owners who are chasing improved engine performance. My long term plan (if it works) is to develop a "bolt-on" kit for GS 500 engines, with money raised from selling the kits to be used for developing the idea for other applications. Oh yeah, I wouldn't mind getting hold of a complete rear wheel assembly either!

Sincerely,

Mark

[Kurlon]

There is a frenchman who has done a similar conversion to a Ducati V-Twin.  One cylinder is used as a pump, which dumps it's output into an accumulator.  That pressure is fed into the airbox as boost to feed the remaining cylinder, providing extra umph at WOT.

[ecpreston]

well that's pretty interesting....  I can't imagine it could make that much more power....tell us how it goes if you actually do this!

[Weston]

2 stroke?

[machg]

well that's pretty interesting....  I can't imagine it could make that much more power....tell us how it goes if you actually do this!

O.K. yes, would be using only half the capacity (1/2 the power) BUT engine will be two stroke (double the 1/2 = same power as stock) then If the supercharging effect is good enough; double that = twice the horsepower. It is quite common for turbo engines to double the power output of their natrakky aspirated brethren. I would also have the option of turbo charging with this design if I am short on power.

[qwertydude]

Turbocharging a supercharged engine?

[sledge]

Turbocharging a supercharged engine?

VW launched one over 3 years ago.

http://www.autobloggreen.com/2006/05/10/volkswagen-twincharger-tsi-wins-best-new-engine-of-2006/

[qwertydude]

An amazingly complex engine that only gets 32.7 mpg, I'll pass.

[GeeP]

Turbocharging a supercharged engine?

EMD 16-645

Two Roots blowers, two turbochargers, 4,000HP continuous.

Then, they changed to super-turbochargers.  Below notch 5, a sprag clutch remains engaged with the turbocharger shaft, acting as a centrifugal blower.  Above notch 5, the sprag clutch disengages and the turbo shaft is able to freewheel, thus becoming a turbocharger.  They fail spectacularly every now and then.   

[Weston]

I didn't know it was possible to supercharge a 2 stroke

[qwertydude]

It is only possible to supercharge or turbocharge a poppet valved 2 stroke engine, trying to blow a sleeve ported one is pointless since both the intake and exhaust are open at the same time, you'll just blow most of your fuel-air out the exaust.

[Weston]

Thats what i was thinking....

[The Buddha]

It is only possible to supercharge or turbocharge a poppet valved 2 stroke engine, trying to blow a sleeve ported one is pointless since both the intake and exhaust are open at the same time, you'll just blow most of your fuel-air out the exaust.

Poppet valve ? is that a rotary disc valve ?
Cool.
Buddha.

[sledge]

It is only possible to supercharge or turbocharge a poppet valved 2 stroke engine

Or an Opposed-Piston engine.

http://en.wikipedia.org/wiki/Napier_Deltic

[The Buddha]

That was one time done to a ducati super mono I wanna say.
The lower one was like 750CC 1 cyl, and the upper was a 500 or so and that top one basically pumped mix into the lower one. i think it had cams that spun at engine speed or some such BS ... it was 750 CC of combustion, and 1350 CC of total volume.
2 stroke power with 4 stroke emmissions and reliability.
BFD I say ... sheite that is made to break, by incomprehensible Italian engineers should not be allowed to see the light of day ...
Cool.
Buddha.

[Beelzeboss]

I wouldn't mind getting hold of a complete rear wheel assembly either!

I've got a complete rear wheel assembly, just missing the rear disc.
If you're interested PM me with an offer.

Andrew

[qwertydude]

Poppet valves are the true term for standard engine valves.

[machg]

I didn't know it was possible to supercharge a 2 stroke

Because modern two-strokes utilise their cranck case and use transfer ports, its nearly impossible to get it to work. Toyota (and Subaru as well) have made prototype 2 stroke engines that run conventional valves and supercharging for scanvenging. My understanding of early two-strokes that ran poppet valves is that they had no cams, just very light valve springs, so the valve would self open under vaccuum. I think this design worked well for low revs, but not for high performance due to poor valve control. I was thinking of using this in my design, but I think just doubling the camshaft spped will be a better/more reliable option. How do you all think it will go with the camshaft spinning at the same maximum RPM as the engine, not half speed as in the conventional engine?

Cheers,

Mark

[The Buddha]

OK that means 5K rpm redline with the stock GS valves and springs.
Cool.
Buddha.

[machg]

OK that means 5K rpm redline with the stock GS valves and springs.
Cool.
Buddha.

It would want to rev to 10K rpm  to be any fun (and make decent HP), so I'd need stiffer valve springs? Budget probably wouldn't stretch to lightweigt valves, unless there is a cheap source of suitable ones. Anyone?