2000cc 2 stroke Engine - Check this out

[Guest ozzie]

The Suzuki F750 motor developed from the 'Water-bottle', (that shredded Barry Sheene at Daytona..) developed, from memory, about 145 HP. I have the porting dimensions tucked away somewhere; almost the only other change was the titanium Mikuni flat-slide carbies, for weight purposes, and very trick pipes..A bog-standard Squeeky 750 was a stone-axe reliable tourer, with no nasty 'on-the-pipe' characteristics (unlike the Kwacka Mach III 500 triple!). The Kwacka engine was stuffed into a frame that was called 'benign, when parked with the engine turned off' but was generally accepted as being psychotically homicidal if moving.

 

A water-cooled, twin-spark 750 - 1000cc two-stroke, with porting and exhaust tuned for the limited rev range required of an aircraft, could well be a viable concept. However, I suspect that by the time you have added the PSRU, the cooling set-up, and taken allowance for the higher fuel consumption in terms of MTOW/endurance, the advantages become very slim.

 

Of all the manufacturers on the planet, Rotax has probably the greatest depth of data for both 2-stroke and 4-stroke engines across its range. Had it been a lay-down misere for 2-strokes, the 912 series (and derivatives) would not have been created. As it is, the 91X has many design characteristics common with lawn mower engines... but not the lack of valves.

Between the little group of friends I rode with in the Seventies we had the whole range of Kawasaki triples. I had a blue model 750, a real point and shoot machine and with a little work it could be made to handle reasonably well but could never keep the front wheel down thru the first 4 gear changes. Both the 750 and 500 sorted out the four stokes a couple times at the Castrol 6 Hour. Lotsa fun back then, shame the cops could follow the blue two stroke haze home.

 

The Suzi 750 was a dream to ride, a lot smother and quieter,stayed in tune longer, a little top heavy but you arrived less fatigued on a long trip.

 

Wish i never sold them, they will bring over 20 grand today for a good example.

 

 

[Nobody]

The WAM 3-cylinder is pretty comparable with the Jab. 3300 for output. But it weighs 131 kgs installed, vs 83.5 for the 3300. ( prop hub forward excluded for both.)

I think you will find that the WAN numbers include the weight of the prop and oil so the difference is not as big but yes the diesel is heavier. On the other had it produces a little more power than the jabiru under standard sea level conditions (125 vs 120) and being turbocharged produces more power at higher density altitude, Eg at 100 feet and 35 degrees Celsius the jabiru will be down 10% while the diesel will still be at 100%.

 

 

[Oscar]

Somewhat strangely, the GS 850 shaftie reminded me strongly of the Water Bottle for riding character, but of the two, I preferred the 750. It had a 'lope along all day, no worries' sort of feel.

 

 

[Old Koreelah]

Between the little group of friends I rode with in the Seventies we had the whole range of Kawasaki triples. I had a blue model 750, a real point and shoot machine and with a little work it could be made to handle reasonably well but could never keep the front wheel down thru the first 4 gear changes. Both the 750 and 500 sorted out the four stokes a couple times at the Castrol 6 Hour...

Lethal weapon the Mach III, but not the fastest all-round bike. I watched a televised production race of 500cc bikes during that era. The camera was concentrating on close dicing between a Yamaha DOHC twin and a Mach III; way out in front was a pushrod V-twin Honda CX-500.

 

 

[Oscar]

Aha, now I had a CX500 'sports' for a little while and it was a real sleeper, never seemed to be trying at all but got rid of the clicks with unexpected rapidity. My CB 400/4F was huge fun wringing its neck but frustrating on the highway, the CX500 wasn't really 'fun' but connected the distances in less time than you'd figured, and reasonably plush ride to boot.. Mind you, the Viffer 750 is in another place entirely...

 

 

[bexrbetter]

Reed intake bex?...easiest I guess...I haven't looked too hard at the Rotax 582 but I guess it fires 180 degrees apart? (2 carbs)

 

Separate crankcases but one rotary valve. Is that right?

 

Going to get one heck of a pulse firing together but the stroke would smooth it out somewhat?

Reed is easiest by far and variable timing by nature. The disc setup by Rotax is quite clever, about the only bit of the otherwise antiquated design. Neither here nor there but I used to race a 1976 CanAm with a 250 disc valve Bombardier (Rotax) engine, 36hps worth stock and the most powerful engine of it's time, so good it was still competitive until the early 1980's in the same spec in CanAm MX models.

 

The strength or not of the firing pulse is not relevant as it would be a flat twin and the forces oppose each other, even more so than a 4 stroke where alternate sides fire causing some rocking.