Engine Stroke Diagram. Two stroke engine. As in the 2 stroke engine animationand diagram in this case the cycle would begin at approximately mid stroke when the piston is rising and has covered the transfer port openings.
Generally a two stroke petrol engine works in this principle also for a two stroke diesel engine the working principle is the same but there is one little change and that is a two stroke diesel engine has a fuel injector instead of the spark plug. At b the valves open and suction as well as exhaust take place from b to c. Inlet exhaust valves open and close as well as the firing of fuel in a 4 stroke marine diesel engineit is generally expressed in terms of angular positions of the crankshaft.
Fuel injection starts 5 15 before tdc.
Therefore the complete cycle requires two revolutions of the crankshaft to complete. An engines layout diagram is limited by two constant mean effective pressure mep lines l1 l3 and l2 l4 and by two constant engine speed lines l1 l2 and l3 l4seefig204thel1 pointreferstotheengines nominal maximum continuous rating. Fuel injection stops 15 25 after tdc. The most common designs for engines are two stroke and four stroke.