Cylinder Head Gasketing Problems in Bi-Metallic Engines 840189
There has been and continues to be a growing trend in world engines towards the use of ‘Bi-Metallic’ constructions, ie. engines which feature head and block castings of different materials. The use of aluminium cylinder heads with cast iron cylinder blocks is a typical arrangement.
Figure 1 indicates some of the significant differences in the physical properties of cast iron and aluminium. As can be seen, aluminium offers a number of advantages from an engine design viewpoint, notably weight saving and heat transfer efficiency.
The use of aluminium can, however, result in a number of potential difficulties in terms of its effect on cylinder head gasket performance.
This paper considers these difficulties with particular reference to ‘fluid sealing’.