Analysis of Load in the Cylinder Head Bolts of an Internal Combustion Engine

Abstract

In this paper, the relationship between the ignition pressure and the increment of axial force in the cylinder-head bolts is analysed theoretically and experimentally, considering the thermal stress which is generated in the steel bolts fastening the aluminium alloy cylinder head of an internal combustion engine. As a result, the following are made clear; the increment of axial force in the cylinder head bolts due to the ignition pressure is very small, but a relatively high thermal stress is generated in the bolt, and the preload loss caused by the permanent set of a new gasket cannot be neglected.