A System for the Static and Dynamic Measurement of Cylinder Head to Block Separation in Operating Engines

Measurement of the separation between cylinder head and block at discrete points across the gasket provides information to the designer which can be crucial in determining the properties of the gasket required to ensure complete sealing over all engine operating conditions, particularly during deep thermal shock testing. This paper describes the development of a measurement system which uses capacitive displacement transducers combined with high speed charge amplifiers to allow real time static and dynamic measurements of head to block displacement at discrete points across the gasket over a complete range of engine operating conditions. Typical data obtained from use of the system in a four cylinder gasoline engine running a mild thermal shock cycle is presented and discussed.