In Velozeta’s six stroke engine, a four-stroke Honda engine was experimentally altered to build the six stroke engine. The first four strokes of this engine are just like a conventional four stroke engine. The additional two strokes are for better scavenging and cooling of the engine which is provided by a secondary air induction system.
There is only a slight difference between Crower’s six stroke engine and Velozeta’s six stroke engine. In the Crower’s six stroke engine and this engine, the first four stokes are the same as a conventional four stroke engine. In Crowers engine during the fifth stroke water is injected into the cylinder and converted to steam which is used for expansion and the sixth stroke eliminates the expanded vapors through the exhaust manifold. But here the difference is that in the fifth stroke, instead of water, air from an air filter is sucked into the cylinder through a secondary air line provided at the exhaust manifold. In the sixth stroke, a mixture of this air and unburned gases are pushed out through the exhaust valve.
The six stroke engine modification promises dramatic reduction of pollution and fuel consumption of an internal combustion engine. The fuel efficiency of the engine can be increased and also the valve timing can be effectively arranged to extract more work per cycle. Better scavenging is possible as air intake occurs during the fifth stroke and the exhaust during the sixth stroke. Due to more air intake, the cooling system is improved. It enables lower engine temperature and therefore increases in the overall efficiency.