Abstract: A pump supplies pressurized lubricant to an internal combustion engine from an external reservoir through a closed loop system. Delivery channels extending through the crankshaft, connecting rod and other components, supply the pressurized lubricant to the several areas of relative movement. Return channels, extending through the components, conduct lubricant from the several areas to the reservoir. Fuel-air mixture from a carburetor enters the crankcase through the open end of the crankshaft and moves through ports within the several cylinders to the respective combustion chambers. Selected ports are sequentially closed by a valve plate carried by the crankshaft. Incomplete products of combustion are exhausted into an auxiliary exhaust outlet for recycling with the fuel-air mixture. Retainer members engaging the spark plugs assist in dissipating heat therefrom.