Abstract: The two-stroke engine has a plurality of intake passages extending from the external air inlet port through the crankcase, separating the intake air charge from the air and oil vapor within the crankcase. The piston has one or more corresponding inlet tubes depending therefrom that telescope within the crankcase intake passages as the piston reciprocates. All intake air travels through these passages and is separated from the remainder of the crankcase volume. The incoming air charge passes through a concentric poppet valve in the piston crown to enter the combustion chamber. Fuel is provided by conventional direct or port injection and ignition is provided by one or more conventional spark plugs. Diesel operation is achievable when the engine is configured appropriately. Exhaust exits the combustion chamber through a poppet valve in the cylinder head, the poppet valve being actuated by a rocker arm and pushrod from a crankshaft driven cam.