Det engelske selskapet Ilmor, som er kjent for å utvikle motorer og teknologi til både F1, NASCAR og selvsagt motoGP har utviklet en ny type tre-sylindret, 5-takters motor.
Den 5-takters prototypen bruker en 700-kubikk turboladet motor som yter 130 Hk ved 7000 omdre og ikke mindre enn 162 Nm ved 5000 omdr. I tillegg er den svært økonomisk i drift.
Her er forklaringen på hvordan motoren fungerer:
The engine uses two overhead camshafts, one is high pressure, the other low pressure. The high pressure camshaft turns at half the crank speed while the low pressure crankshaft rotates at the same speed as the crank.
The highpressure cam works with the outer two cylinders, in the same way a standard 4-stroke engine would, but the low pressure camshaft works with the central larger cylinder gathering exhaust flow from the outer cylinders. The engine is designed to be far more fuel efficient than a traditional four-stroke four-cylinder counterpart.
The advantages of the Ilmor 5-stroke are as follows:
-A secondary cylinder provides an additional expansion process enabling extra work to be extracted, hence increasing thermodynamic efficiency.
-The engine runs an overall expansion ratio approaching that of a diesel engine in the region of 14.5:1
-Minimised pumping work due to the downsizing effect from highly rated firing cylinders.
-The compression ratio can be reduced to delay knock onset without a reduction in performance.
-Because the firing cylinders can be very highly rated, the engine is relatively compact.
-The fuel consumption does not rise as rapidly with increasing BMEP, as retarding rejects more energy into the expansion cylinder.
-The engine uses 100% conventional technology and so requires no new manufacturing techniques.
Kanskje en motor for fremtiden?