Hirth's most popular engine! The 3203 produces more horsepower and torque per pound than any other engine in its class. The Hirth 3203 is the forerunner in powerplants for the heaviest of ultralight trainers, gyrocopters and light experimentals today. Factory recommended TBO is rated at 1000 Hrs. @ 75% power. 3203 incorporates Al-Nikasil coated cylinders for superior performance and reliability. Al-Nikasil in simple terms is a nickel based material, applied in a paste form, when super heated it becomes part of the cylinder itself. Al-Nikasil provides for a super low coefficient of friction, reducing engine heat and wear. The pistons and cylinders expand at the same rate thus providing for a seizure resistant engine. 3203 crankshaft is 4130 chromemolly steel. Heads, cylinders, rings, block casting, connecting rods and associated components are all of the highest grade alloys available.