Cylinder Head Gaskets for Bi-Metal Engines and Techniques for Optimizing the Method of Clamping

THIS PAPER WILL DESCRIBE THE PROBLEMS associated with cylinder head gaskets in bimetal engines. To expand on this theme, the consequences for the gasket material, the gasket thickness and the method of torquing the cylinder head bolts will be traced in detail.

Recommendations aimed at increasing sealing reliability will be made regarding the choice of gasket thickness, that is, the choice of cylinder head gaskets of greater installed thickness, since, in that way, an even distribution of pressure is achieved and the range to the minimum required surface pressure can be increased. On the other hand - mainly in connection with the requirement for cylinder head gasket non-retorquability - the recommendation will be made that angle torquing of the head bolts should be introduced. The technique and its advantages over the traditional wrench torquing technique will be explained.

A thermal shock test program for evaluating the functional efficiency of the cylinder head gasket will be presented and explained in detail. The increased loading on the cylinder head gasket especially during the engine hot running phase can be simulated with this program.