The two-stroke motorcycle has long been replaced by the four-stroke.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.