The American Motors Corporation (AMC) used V8, straight-6, V6, and straight-4 engines in various passenger automobiles and Jeep vehicles from 1954 onward. American Motors designed some of its engines; others were inherited from its constituents. The company bought other engines or engine designs from other manufacturers. Four cylinder engines American Motors used several four-cylinder engine designs. Air-cooled 108 The is an AMC designed air-cooled V4 engine that was used in AMC's lightweight aluminium-bodied M422 'Mighty Mite' military vehicle, built from January 1960 to January 1963 as an air transportable (by the helicopters of the time) Jeep for the U.S. Marine Corps. This engine was unsuitable for regular passenger car use mainly due to its relatively small displacement and power output. Bore and stroke: Compression: 7.5:1 Horsepower: @ 3,600 rpm Torque: @ 2,500 rpm Audi/VW 121 The was an advanced design overhead camshaft four-cylinder EA831 engine bought from Audi/Volkswagen 1977 through 1979. Though a small engine, its advanced design created reasonable power for its size and due to being an OHC engine, it had a high redline. This engine was also used in the Audi 100, Volkswagen LT van, and Porsche 924. The engine was assembled to AMC specs in the US at a specifically purchased AMC assembly plant. Specifications are different from the Audi/VW/Porsche assembled engine. AMC used a carburetor and standard points ignition as well as slightly larger clearances. The original agreement was for AMC to buy the design, eventually moving manufacturing to the United States and selling the engines back to VW and Audi. American Motors bought a plant specifically to build the engine, but never sold enough to move complete manufacturing. The AMC engines were assembled in the U.S. from major castings supplied by VW, hence the different assembly clearances. As part of the agreement, AMC was not to use the VW or Audi names when referring to the engine. Everyone familiar with the design knew they were virtually identical, and the automotive press commonly referred to them as Audi or VW engines. VW/Audi/Porsche U.S. spec engines produced in mid-1977; earlier models produced -- more than the AMC version. Bore × stroke 3.406" × 3.323" (86.5mm x 84.4mm) Compression ratio 8.1:1 Horsepower (net) @ 5,000 rpm Torque (net) @ 2,800 rpm It was used in the AMC Gremlin, AMC Spirit, and AMC Concord, The only Jeep this engine was used in was the 1979 Jeep DJ (Dispatcher