 | This article relies largely or entirely on a single source. (November 2024) |
A rocker cover, (UK), or valve cover (elsewhere) is a cover that encloses the rocker arm in an internal combustion engine, bolting with a gasket seal to the engine head. Engines with more than one head (such as a V8) will have multiple rocker covers. On engines without rocker arms, such as some overhead cam and most dual overhead cam types,[1] they are known as rocker boxes in the United Kingdom.
On modern engines without rocker arms they are internationally known as "valve cover" but are sometimes referred to as a "cam cover" or "timing cover" if they also cover the timing gear(s) and belt or chain.
Very large multi-cylinder engines, such as those used in a ship or in aviation, may have one rocker cover for each cylinder, to make removal and installation more manageable.
- ^ Bickford, John H. (1998). Gaskets and Gasketed Joints. CRC Press. ISBN 0-8247-9877-5.[page needed]