Page:General Motors single cylinder diesel engine Model 1-53x3 installation and tests. (IA generalmotorssin00mcco).pdf/29

 located on the front panel of the engine frame in a gear train case. The fuel injection is accomplished by a unit injector which meters and times injection after positioning of the throttle which controls the injector rack and plunger.

The exhaust valves and injector are operated by rocker arms and pushrods from their respective camshafts.

The camshafts are located symmetrically on each side of the engine.

Cam profiles have been taken of each camshaft for reference use in making timing changes. Fig,1 is the displacement diagram for the injector cam and Fig.2 is the displacement diagram for the exhaust valve camshaft. Up to about 6 degrees of injector timing change can be obtained by using injector timing gauges (adjusting the plunger position). Fig.3 shows the timing possible by this means. Fig.4 shows the theoretical injector performance for the normal injector timing position which is 1.484 inches. 3