What happened to the two-stroke gasoline motor?

[ranger309]

Clean Two-Stroke Motors?

About ten or 15 years ago, after the Gulf War, there was a company out there that was claiming to have invented a two-stroke gasoline motor that was lubricated by internal oil, like a four stoke, and would still meet US smog laws.

Anyone remember that engine design? As I recall, it was produced by an Aussie company, but the name escapes me now, in my old age. :-)

Maybe it met the same fate as the oil leaking, oil burning screaming Jimmy diesels of my youth, but the idea of an engine with no valves, like a rotary engine, seems to be a nice idea.

No camshaft, no pushrods, no valves, no cam-chain, no broken valve springs. Worked great on my old Honda CR 500R dirtbike, I'll tell you !

[pro1driver]

Originally Posted by ranger309

Clean Two-Stroke Motors?

About ten or 15 years ago, after the Gulf War, there was a company out there that was claiming to have invented a two-stroke gasoline motor that was lubricated by internal oil, like a four stoke, and would still meet US smog laws.

Anyone remember that engine design? As I recall, it was produced by an Aussie company, but the name escapes me now, in my old age. :-)

Maybe it met the same fate as the oil leaking, oil burning screaming Jimmy diesels of my youth, but the idea of an engine with no valves, like a rotary engine, seems to be a nice idea.

No camshaft, no pushrods, no valves, no cam-chain, no broken valve springs. Worked great on my old Honda CR 500R dirtbike, I'll tell you !

the only 2 stroke gasoline engines i have are my two snowblowers. as well as some of you are aware of, almost anything garden related.

i cannot remember that particular gasoline engine you speak of, but i can try several searches and post links to what i find.

this didn't take too long, here are some links:

Clean 2-Stroke Engine - Popular Mechanics

here you go...............

http://www.schoellmarine.com/CYCLONE...hoell12203.pdf

[ranger309]

I found it. Its the Orbital corporation in OZ that's been developing this direct injection two stroke motor.I always liked the 2 stroke in dirt bikes as they would blow away a four stroke and you didn't want all that compression braking the 4 strokes had. Of course they were dirty and noisy but winning was all that counts.

[Cerberus_Kelpie]

Mopeds still use 2 stroke engines.
Some 70s Dirt Bikes had a Compression release valve controlled by a smaller handle near the Clutch or front brake handle.
Kawasaki 350 Bighorn for one bike.

How BIG of an engine can be built that is 2 stroke?

When the Wankel engine was introduced and Mazda used it for their cars, it was wonderful as it produced incredible power for such a small encasement.
This engine would be great for trucks yet it would have to be designed not to break down within 60k-100K.

[ranger309]

Originally Posted by Cerberus_Kelpie

Mopeds still use 2 stroke engines.
Some 70s Dirt Bikes had a Compression release valve controlled by a smaller handle near the Clutch or front brake handle.
Kawasaki 350 Bighorn for one bike.

How BIG of an engine can be built that is 2 stroke?

When the Wankel engine was introduced and Mazda used it for their cars, it was wonderful as it produced incredible power for such a small encasement.
This engine would be great for trucks yet it would have to be designed not to break down within 60k-100K.

The old Detriot "Screaming Jimmys" were two strokes, but they would never meet any emission laws at all. They were cheap and light, so lots of truckers used them however.

They leaked oil all over the motor and the rest was burned going up through the piston rings. Adding two gallons of motor oil a day was common and they were noisy as hell. The Wankel was a good idea but they never really solved the rotary seal problem and they had lots of trouble meeting emission controls.

Yeah, I remember the compression release on the old two stroke off road bikes too.

Those were the good old days with 7" suspension travel or less and no disk brakes, unlike todays motocross bikes doing 35 foot jumps with a 50 HP mill under your seat.