Abstract: (In a Two Stroke engine, there is very little opportunity for scavenging residual exhaust gas, without using impractical exhaust pipe tuning.) Our design utilises momentum air-filling of the cylinder. We use overhead poppet valves, but we have positioned the inlet valve at an angle, and partly recessed it. The angled upstream side of the valve head and the wall of the recess direct airflow. The eminence positioned in the inlet port augments this by a Coanda effect. Air is thus directed alongside and under the exhaust gas, to promote scavenging and optimise volumetric efficiency. This also creates a combustion chamber in the coolest part of the cylinder head, an important consideration. Complex surfaces, liable to overheat, have been avoided. The design is simple and robust.