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This paper describes the new measuring method dealing with the contact pressure of a multi-layer cylinder head gasket for a diesel engine with the displacement of 3 liters. This method uses the electrodeposited copper foil with the thickness of 26 μm as a gauge. The foil surface has small irregularities and the surface appearance corresponds to the applied pressure. Using the foil gauge, the pressure measurement was performed on two kinds of gaskets, i.e., wire type and bead type. The measurement was also performed on wire type by the methods of strain gauge and Fuji Prescale. Furthermore, FEM analysis was performed on two types. Based on the results obtained, the validity of the present method was discussed.

Hydrogen can be readily used in spark-ignition engines as a clean alternative to fossil fuels. However, a larger burning velocity and a shorter quenching distance for hydrogen as compared with hydrocarbons bring a larger cooling loss from burning gas to the combustion-chamber wall. Because of the large cooling loss, the thermal efficiency of a hydrogen-fueled engine is sometimes lower than that of a conventionally fueled engine. Therefore, the reduction of the cooling loss is very important for improving the thermal efficiency in hydrogen-combustion engines. On the other hand, the direct-injection stratified charge can suppress knocking in spark-ignition engines at near stoichiometric overall mixture conditions. Because this is attributed to a leaner end gas, the stratification can lead to a lowered temperature of burning gas around the wall and a reduced cooling loss.