Green continued to design motorcycle engines too, using cylinders similar to, though smaller than, those on their prize-winning aero-engine, having similar rubber-sealed copper jackets and removable overhead valve mechanisms designed to protect the cylinders from damage by broken valves, and forced lubrication throughout. In 1914, "Motor Cycle" magazine reported on a Zenith motorcycle supplied with the 'new' () V-twin, of bore and stroke. One interesting detail seen on many modern motorcycles was 'the fitting of a glass window in the crank case to show the level of the oil'.