The two-stroke motorcycle has long been replaced by the four-stroke. Now, Ilmore Engineering appears to have come up with a five-stroke engine. Ilmore does a lot of stuff in Indy Car, Formula 1, and MotoGP, so they aren’t some fly-by-night firm with a wild idea.
Although, it is a wild idea.
With dual camshafts and an asymetrical three-cylinder configuration, the Ilmor is more than intriguing with its design, and promises to bring real benefits both to the race track, and to road-use. Most notably is a 10% increased fuel efficiency, and 20% weight reduction in power-plant weight.
With its 700cc, turbocharged, prototype motor, Ilmor is able to extract 130hp and 122 lbs•ft of torque. To achieve this, the motor employs two overhead camshafts. One is a “high pressure” camshaft, which turns at half the crank speed, while the other shaft is a “low pressure” camshaft, which turns at the same speed as the crankshaft.
Yes, you read that right. A 700cc motor with 130HP and 122lb-ft of torque. Those are…interesting numbers. That’s what I call a real “Speed Triple”. You’d need to put a second mortgage on your house to pay off your tire bill, assuming you don’t just wheelie right over and turn turtle, killing yourself.
But, assuming those difficulties can be overcome, it sounds like a neat idea.
I‘ve been seeing this pop up for the last few days. Oberdan Bezzi is an Italian motorcycle designer. Sometimes his notions of what a future bike model would look like are just that: notions. But, he is a guy who has some hooks into the major bike shops in Europe, so, sometimes, he’s spot on.
In this particular case, the rumor is that BMW is working on a 12500cc successor to the current 1200cc boxer in their R-Series bikes. It would give the bike maybe, what, 10-15 more ponies, and an extra lb-ft or two? And, it would keep in tradition with past incremental shifts for the R-Bikes, from the 110 to 1150, to 1200. maybe it;s shave a few punds of weight off, too. I dunno.
If I was BMW, though, I’m not sure why I would. Instead, I think the move towards the HP2 boxer engine, with the dual overhead cams would be a better move. They already get 130HP out of that engine.
Of course, if you bumped up that engine to 1250cc, you’d probably get to 140+ HP out of it in the HP2 series.
And, lets’ not forget my previous trip down BMW rumor lane, which is that there will be a 1300cc HP2 boxer, and it will go into the RT and GS.