Tech Tip #81: Identifying the GM 8.1 Liter Industrial Engine

Dr. Diesel
Written by Dr. Diesel

How to identify your engine

The 496 cubic inch GM 8.1 liter engine has quickly found success in the industrial engine market. After all, with the Ford 460 out of production, this is the only V8 gas or natural gas fueled industrial engine of any size now available. This large V8 engine is found powering stand-by generators, many produced by Kohler. We have packaged the GM 8.1 for use in co-generation applications in laundries and correctional facilities. The GM 8.1 engine has also been used in forklifts and other industrial applications. Because it bears more than a passing resemblance to the earlier 7.4-liter GM engine, people often need help identifying it as an 8.1 and which specific 8.1 GM it is when ordering parts. Here is how.

All GM 8.1 industrial engines will have a serial number stamped in on the ear protruding from the rear (i.e., the non-water pump) end of the engine. There are two style 8.1 engines. One has a serial number format that begins as 81L followed by 5 digits. The other, later style 8.1 GM Industrial serial number begins as 8P1L followed by five digits.

This Tech Tip the third in our series on GM Industrial Engines.  Please see

Dr. Diesel
Written by Dr. Diesel
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