Investigations on wear and friction in the SI engine valvetrain

Abstract

The engine valvetrain system operating under insufficient oil lubrication conditions, caused by an incorrect installation of the gasket between the block and the head, was tested. The aim of the analysis was to determine the wear intensity and resistance to motion in camshaft bearings. A model including a camshaft, bearings, tappet-valve-spring subassemblies and a part of the lubrication system was developed. It was used to determine the bearing loads and the amount of oil supplied. The volumetric wear of the camshaft journals and bearing covers was measured. For the estimated engine run, the wear rate and resistance to motion were compared for the cases of the engine with correct and incorrect lubrication.

The Measurement of the Wear of Tie Rod End Components

“…The latter is affected by two parameters: factor k and pressure exponent x. The latter varies usually in a range of <1, 2> [19] and [20]. Such two parameters are functions of material properties, geometrical characteristics of surfaces, etc.…”

“…An experimental determination of these parameters is described in [21]. Some values of parameter k for various tribological contacts were given in [20] and [22].…”