How do I Identify a Detroit Diesel 8V71?

by Richard Rowe

Detroit Diesel (as a division of General motors) hit the American diesel market in a big way when it debuted with the Series 71. These engines came in several inline (one, two three, four and six cylinder) and "V" (six, eight, twelve, sixteen and twenty-four cylinder) configurations, all united by one oddly obscure factor: the displacement of the cylinder on each engine was 71 cubic inches. This is how the 8V-71 gets its name as it has eight cylinders, V-configuration and 71 cubic inches per cylinder.

Identifying the Engine


Note the configuration. The 8V-71 was one of the very few diesels ever produced in a V8 configuration; the only other large-truck V8 diesel you're likely to see is the 71's larger cousin, the Series 92.


Look at the induction system. Although many diesels today come with turbochargers, very few come with superchargers. The 71 series engines have both; the turbocharger sits off to one side of the engine and feeds into a supercharger mounted on top. This is the easiest way to distinguish the 71 from the 92, which (because of its larger displacement) doesn't require a supercharger for low-end torque.


Find the external water manifold. The 71's smaller cousin, the Series 53, doesn't use an external water manifold for the cylinder head. A series 53 will have a flat plate over the exhaust port on each head, whereas a series 71 will have a water manifold attached there. Follow the radiator hose to the thermostat housing, which integral to the water manifold.


Read the plate on the driver's side valve cover; the serial number on it should begin with "8VA.". These plates can be difficult to read, covered in years of oil and road grime and may not be visible when opening the hood. If you can see the plate, then a quick blast of carburetor or brake cleaner and a rag should make quick work of any obscuring grime.

About the Author

Richard Rowe has been writing professionally since 2007, specializing in automotive topics. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. Rowe studied engineering, philosophy and American literature at Central Florida Community College.

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