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Old 01 September 2014, 10:09   #1
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Future four strokes lighter than twos?



Could this also apply to two strokes by computer controlling the opening and closing of the ports?
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Old 01 September 2014, 11:37   #2
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I dont think so because on a two stroke as the piston moves up/down it exposes the ports in the cylinder. These being just static holes in the side of the cylinder.

There are already some 2 Stroke engines with ports that are raised / lowered mechanically as the revs increase. Ive had a few Kawasaki motorcycles that used this sort of technology, way back in the 90's.

However, the idea of individually operated valves that can utilise a square profile is a good idea. Obviously they could alter the profile to suit whatever was needed - so altering the whole angle per cylinder / rev range. Big improvement over the already available variable cam timing some engines have, like my Suzuki 175's for example.

Removes the mechanical limitations of valve actuation, bounce, profiles, valve overlap etc.

But I do wonder what sort of pump is needed to control them opening / closing. That must be some pretty good pump. That may negate any weight saving you get by removing the camshaft.

I may be wrong though
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