Function

The four stroke three-cylinder in-line engine features an decisively improved mass balance as compared to the two-cylinder. There are only three, each 60° crank angle long, empty strokes. Construction expenditure, internal friction (fuel consumption) and length are lower and make the engine with rising cubic capacity interesting as a substitute for four cylinder engines. Though its crankshaft is shorter, it has headers in three levels. The two-stroke three-cylinder was compared earlier to the six-cylinder four-stroke engine because its power strokes overlap similarly. This is not valid of course for the mass balance. Designers of motorcycles prefer the three-cylinder because of its compact design. It can reach total displacements of more than 2 litres.

How it works

Every piston has its own crankshaft header. The pistons go through their strokes at different times. The ignition interval is 240°. The three-cylinder four-stroke engine works precisely like half a six-cylinder engine. The less favourable mass balance is most often improved by an additional equalizer shaft. 05/08