I was reading about the new Rotax 800R engine in the last issue, both the dyno run and the info on the 3-D RAVE valves. The way I read this, the 800 R is fitted with â€œvariable valve timingâ€. Correct?
I suppose you could make that claim about any of the power valve systems, as the exhaust port timing is varied by the position of the exhaust valve. In the case of the 800R it isn’t a matter of being simply â€œopenâ€ or â€œclosedâ€, there is the intermediate position allowed by the use of a main valve and the smaller â€œfingersâ€ controlling the sub ports, independently.
So the 800R’s three-position valve control is closer to what we could call â€œtrueâ€ variable valve timing. Some riders think the electronically-controlled valves are capable of infinite positioning, but as far as I know they all operate on an â€œopenâ€ or â€œclosedâ€ basis, none of them utilize an intermediate positioning. Not even the servo-motor configurations. Why not? We’ll find out!