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
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.
well that's pretty interesting.... :dunno_black: I can't imagine it could make that much more power....tell us how it goes if you actually do this!
2 stroke?
Quote from: ecpreston on April 13, 2009, 08:01:30 PM
well that's pretty interesting.... :dunno_black: 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.
Turbocharging a supercharged engine?
Quote from: qwertydude on April 26, 2009, 10:02:50 AM
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/
An amazingly complex engine that only gets 32.7 mpg, I'll pass.
Quote from: qwertydude on April 26, 2009, 10:02:50 AM
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. :icon_mrgreen:
I didn't know it was possible to supercharge a 2 stroke
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.
Thats what i was thinking....
Quote from: qwertydude on April 26, 2009, 03:52:46 PM
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.
Quote from: qwertydude on April 26, 2009, 03:52:46 PM
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
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.
QuoteI 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
Poppet valves are the true term for standard engine valves.
Quote from: Weston on April 26, 2009, 12:54:03 PM
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
OK that means 5K rpm redline with the stock GS valves and springs.
Cool.
Buddha.
Quote from: The Buddha on April 29, 2009, 06:15:35 AM
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?
Put in stiffer springs in and you automagically accelerate the valve seat and valve back wear ... it slams into it harder right.
It also will run hotter because valves lose heat by dissipating it into the head at point of contact. That usually happens 3 cycles out of 4. @ 6000 rpm, you're spinning 100 revs a second, aka 50 cycles, and it spends approximately .75 second sitting @ the seat. It takes in heat worth 50 cyles and spends .75 seconds losing it @ steady state. If you were to make it run 200 revs a second, you would still spend .75 second sitting but take in a 100 cycles worth of heat. Agreed its not linear ... but still it will take in more heat.
Stiffer springs will turn the valve into a tulip if you make it stiff enough to run 20K rpm. Lighter valves are a must, so is springs and so is valves that shed heat better ... dunno the answer man, just saying it gotta shed heat, retain shape under very high seat pressures and be overall in possible to make and use unless you're a formula 1 team.
Cool.
Buddha.
Quote from: machg on April 13, 2009, 06:24:09 PM
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.
Sounds pretty similar to the Scuderi Split Cycle engine: http://en.wikipedia.org/wiki/Scuderi_Engine
Is your built yet? Or just a design so far?
Quote from: VSG on May 05, 2009, 01:51:32 PM
Quote from: machg on April 13, 2009, 06:24:09 PM
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.
Sounds pretty similar to the Scuderi Split Cycle engine: http://en.wikipedia.org/wiki/Scuderi_Engine
Is your built yet? Or just a design so far?
Yeah, it looks very similar to the Scuderi engine, but this is based on an existing engine design. I have done design and provisional patent only at this stage. An attempt at building will require the sourcing of a cheap engine, hence my membership and posting on here. Pnuematic valves would be the ultimate answer to high rpm reliability, but way too costly and complex. To help with heat dissipation of the active cylinder head I was thinking of using a SACS type system as fitted to early GSXRs (using an oil bath around the head, a RGV radiator as an oil radiator {or cooler}, and an upgraded or additional oil pump). In any case; heat might be less of a problem as I would only be running intake valves, all the exhaust heat would be leaving via exhaust ports low in the cylinder wall. Initial build would ignore issues such as valve bounce etc. just getting it running would be a challenge. If I could get it running, performance extraction would be the next priority.
So would you have a larger, higher compression cylinder feeding the power cylinder?