Overhead cam shaft for unit injectors and internal combustion engine therewith

摘要

The present invention provides an internal combustion engine drive train actuating assembly which includes a dual overhead cam shaft arrangement wherein a pair of cam shafts is supported in the head section of the engine. One cam shaft is positioned to actuate the intake and exhaust valves. The other cam shaft is dedicated to actuating only the unit fuel injectors and is positioned relative to the injector actuating rocker levers to contact only these rocker levers during engine operation. The rocker lever-contacting lobes on the dedicated injector-actuating cam shaft are dimensionally wider than has heretofore been possible, which allows the high fuel injection pressures required to achieve optimum fuel economy and emissions while minimizing hertz stresses on the cam shaft. <IMAGE>