Wilksch WAM series

Wilksch WAM series
Type	Diesel piston aero engine
National origin	United Kingdom
Manufacturer	Wilksch Airmotive

The Wilksch WAM series is a family of aero-engines for light and general aviation aircraft. WAM series engines are produced by Wilksch Airmotive in Gloucestershire, England. The engine outputs range between 100 hp (75 kW) and 190 hp (142 kW), and are suitable for both tractor and pusher configurations. Initially intended for homebuilt aircraft, the WAM engines may become certified for use on factory-built aircraft.

Wilksch engines are compression ignition engines which burn Diesel fuel or jet fuel. Aero-diesels are more efficient than the avgas engines more commonly found in general aviation aircraft. Kerosene jet fuel is ideal for jet turbines, but it lacks the lubricity of Diesel fuel. Accordingly, Diesel aero-engines that use jet fuel must have sufficient lubrication to compensate.

The WAM unit is a direct-drive two-stroke inverted inline triple with wet-sump, liquid cooling, supercharger, turbocharger and intercooler. Compression boost at startup comes via a supercharger, but once the engine is running, a turbocharger provides additional boost. Being inverted, the engine has its crankshaft at the top directly driving the propeller, and a camshaft at the bottom, immersed in sump oil. Charged air for combustion is introduced under pressure through a gallery of small ports, and exhaust gases are later expelled through a poppet valve in the cylinder head.

The intake ports are small enough to ensure that piston rings do not need to be pegged. Instead of using a gudgeon pin, each piston is connected to its connecting rod via a ball and socket joint, to enable the piston to rotate. This feature may be abandoned in favour of conventional gudgeon pins.

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