ABSTRACT
Multi-valve gasoline engines rely on two or four overhead camshafts for their high performance and fuel economy. The Sequence V-D test introduced in 1980 used a 2.3-liter single overhead-camshaft engine. In this test, the blow-by rises through the oil drain holes in the cylinder head and exits out the rear end of the rocker cover. The blow-by then passed through an external heat exchanger – maintained at engine coolant temperature – and finally exits through the positive crankcase pressure valve. This engine configuration made it easy to divert the engine blow-by from the camshaft. The gaseous phase of the blow-by was collected and analysed by high resolution mass spectrometry. C. T. West et al. postulated that wear in the V–D test is corrosive. Analysis of high wear parts at the end of the test indicates an abrasive wear mechanism. Lack of the proper wear films probably results in a two–body abrasion.
