Talk:W engine

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In the Dutch version of this article it is stated that a V-engine with two crankshafts (one for each bank of cilinders) is also known as a W-engine, applied by Yamaha and Cagiva in their racing bikes for the Supersport and/or Superbike class. Before I add this third type of W-engine to this article, can anyone confirm that these types of engines exist and are indeed called W-engines? I am not certain whether the Dutch article is correct. Waldorf 12:55, 21 Mar 2005 (UTC)

The only auto engine I have ever heard of with two crankshafts was Bugatti's U engine. That's the only name I've heard that type called. --SFoskett 19:31, Mar 21, 2005 (UTC)

I have already figured it out: see the article. Thanks for your input. Waldorf 19:41, 21 Mar 2005 (UTC)

MotoGP motorbikes are now equipped with 4-stroke 1000cc engines!!!

Under the motorcycle section it says: There are two major advantages of these engines over the more traditional straight-4 or V4 engines. The first is the width of the engine: a V4 engine will be narrower than a straight-4 engine with the same displacement, but a W4 with its two crankshafts will be even smaller. The second advantage is that the W4 lacks the need for a balance shaft; it will run smoothly if the two crankshafts rotate in opposite directions. This is a weight advantage over the V4 engine, which will need a balance shaft.

However: The actual reason for the two crankshafts in these motorcycles (and others of the same era) was to provide individual crankcases for each cylinder because they are crankcase charged two-stroke engines, a single crank V wouldn't work.

Also its unlikely that the weight imposed by the addtition of a crankshaft would be less than that required for a balancer shaft. The reason for the V4 (I don't understand why its a W4) configuration was purely to make a more compact engine and consequently a more compact motorcycle. It was logical for the two crankshafts to be geared together, therefor the counter-rotation was easily accomodated and probably also reduced vibration though this would have been a secondary consideration. jaf