Another performance advantage is gained as a result of the better optimised port configurations made possible with overhead camshaft designs.

The main improvement was the implementation of overhead camshaft design which replaced the M136's lateral camshaft layout.

It was an advanced four-stroke single-cylinder unit construction double overhead camshaft design of 500cc.

Some overhead camshaft designs still have rocker arms; this facilitates adjustment of mechanical clearances.

The overhead camshaft design meant that the head could be flowed and ported to allow the engine to run at high speeds.

This is primarily due to the C90's camshaft design.

It was an overhead camshaft design, and superseded the older two-stroke 2G1 series.

To reduce inertia and improve performance the valve gear was changed from sidevalves to an overhead camshaft design.

The new engine's overhead camshaft design was only one of the advanced features offered for the first time in a U.S.-designed and mass-produced engine.

It had an aluminium sump, block and cylinder head, and is an overhead camshaft design with two valves per cylinder.