Abstract: Disclosed herein is an internal combustion engine including first and second adjacent oppositely acting crankcases defined, in part, by a wall intermediate the first and second crankcases, a passageway through the wall and including a central portion and end portions which extends in opposite directions from the central portion, which are outwardly divergent, and which communicate with the first and second crankcases, whereby the central portion acts as a venturi consequent to air passage through the passageway between the crankcases incident to the pressure differential between the crankcases, and a conduit communicating with the central portion of the passageway for alternately supplying lubricating oil to the crankcases.

Abstract: Disclosed herein is an internal combustion engine including first and second adjacent oppositely acting crankcases defined, in part, by a wall intermediate the first and second crankcases, a passageway through the wall and including a central portion and end portions which extends in opposite directions from the central portion, which are outwardly divergent, and which communicate with the first and second crankcases, whereby the central portion acts as a venturi consequent to air passage through the passageway between the crankcases incident to the pressure differential between the crankcases, and a conduit communicating with the central portion of the passageway for alternately supplying lubricating oil to the crankcases.

Abstract: An internal combustion engine including an engine block defining first and second cylinders with first and second crankcases associated with the first and second cylinders. An oil passageway communicates with each of the crankcases and a conduit is connected to the oil passageway to supply oil to the crankcases. A check valve is located in either the oil passageway or the conduit.

Abstract: A powered device has a center of gravity and includes an engine comprising a block member, a crankshaft having opposite first and second end portions, and generally spaced supports on the block member for supporting the crankshaft for rotation with the first end portion extending toward the center of gravity and the second end portion extending beyond the supports. A piston is located in the block member for reciprocative movement, and a connecting rod has a first end portion pivotally connected with the piston and a rotationally balanced second end portion rotationally connected with the crankshaft intermediate the supports for converting the reciprocative movement of the piston into rotation of the crankshaft about its axis.