An Aspin valve consists of a cone-shaped metal part fitted to the

cylinder head In an internal combustion engine, the cylinder head (often abbreviated to simply "head") sits above the cylinder (engine), cylinders and forms the roof of the combustion chamber. In sidevalve engines, the head is a simple sheet of metal; whereas ...

internal combustion An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal comb ...

. Aspin valves were first patented by Frank Metcalf Aspin in 1939, although the idea was devised before this time. The valve rotates to provide the opening and closing necessary for intake and

exhaust Exhaust, exhaustive, or exhaustion may refer to: Law * Exhaustion of intellectual property rights, limits to intellectual property rights in patent and copyright law ** Exhaustion doctrine, in patent law ** Exhaustion doctrine under U.S. law, i ...

. It is attached to the engine, vertical to the cylinder block, via a shaft at its top; this allows the valve to rotate horizontally above the cylinder and when it turns. The valve is hollow, and has a large cut-out opening in one side. This alternately allows gases into the

combustion chamber A combustion chamber is part of an internal combustion engine in which the fuel/air mix is burned. For steam engines, the term has also been used for an extension of the firebox which is used to allow a more complete combustion process. Intern ...

, and out to the exhaust system by lining up holes in the valve shaft with the cylinder-head ports which allows the gases to pass.

References

External links

Aspin Rotary Valve Engine
Engine valves {{automotive-tech-stub