Wet sump

A wet sump offers the advantage of a simple design, using a single pump and no external reservoir.

Early stationary engines employed a small scoop on the extremity of the crankshaft or connecting rod to assist with the lubrication of the cylinder walls by means of a splashing action.

Modern small engines, such as those used in lawnmowers, use a "slinger" (basically a paddle wheel) to perform the same function.

These small engines run on specifically prepared fuel, a mixture of gasoline and two-stroke oil in a ratio recommended by the manufacturer.

Large two-stroke engines do not use crankcase compression; instead they use a mechanical blower or a turbocharger to aspirate air.