The cylinder head is a one-piece cylinder head in aluminium alloy and silicone.The two valves per cylinder, which are parallel and vertical, are fitted in their own valve guides and controlled by a single camshaft whose cams act on mechanical tappets.The valve guides are an interference fit in the cylinder head seats. A special reamer is used to produce the correct inner diameter after fitting.Unlike cylinder heads with prechamber, the entire combustion process takes place in the combustion chamber on the piston.The gasket between cylinder head and crankcase is metal and the head does not require retightening throughout the life of the engine.
The nylon tappet cover incorporates the oil vapour separate and closes off the cylinder head at the top and an intervening gasket assures a seal.
