1982/04/07 Caterpillar

All 3200, 3300, and 3400 Series Engines

When the replacement of an engine is made, at times it is not possible to get an engine that is built to the original arrangement. If an engine is used that is built to a different arrangement, there are several differences that must be looked at. Some of these differences are increased when a change is made from engines with direct injection (D.I) to engines with precombustion chambers (P.C.). Remember P.C. and D.I. engines of the same model can have the same serial number prefix, but the engine arrangement number will always be different for a P.C. or D.I. engine.

A few of these differences are given in the list that follows:

... P.C. engines need a larger cooling capacity than D.I. engines because a larger amount of heat is dissipated (taken away). If a P.C. engine is used in an application where the system was designed for a D.I. engine, it is possible that the engine will run too hot. Normally, there is no problem with cooling capacity if a D.I. engine is installed in a P.C. application.

... Some D.I. engines have an orifice or restriction in the outlet coolant lines between the engine and the radiator. This is used to reduce coolant flow and decrease the possibility of water pump cavitation. This orifice or restriction must be removed if a P.C. engine is installed in the application to prevent overheating.

... The rated full load RPM and horsepower can be different from arrangement to arrangement on the same engine model. This difference will change the performance of attachments that get their power from the engine.

Dealers must remember to look at all the engine characteristics before an engine replacement is made. Many times an engine replacement will not have any bad effects on the components or systems, but all components and systems must be carefully checked to make sure they will operate correctly with the new engine.