AMC Straight 6 engine

The American Motors Corporation (AMC) straight-6 family of engines was used in AMC passenger cars and Jeep vehicles from 1964 through 2006.

American Motors' first straight-six engine was the 195.6 cu in (3.2 L). It was produced from 1952 through 1965 in both overhead valve (OHV) and flathead (L-head) side-valve versions.

Sometimes referred to as the 196 engine, this engine was originally designed by Nash and introduced in the 1941 Nash Ambassador 600 model. It featured only four main bearings, unlike the 7-main-bearing 234 flathead engine it replaced. It was a flathead design displacing 172.6 cu in (2.8 L). It was later enlarged to 184 cu in (3.0 L), and finally to 195.6 cu in (3.2 L). It was redesigned as an OHV engine in 1956. The flathead version was discontinued for 1956–1957, but reemerged in 1958 as the economy engine for the "new" Rambler American. When the engine was changed to an OHV configuration the water pump was moved from the left side of the engine (driven by a shaft extending from the back of the generator) to the front above the timing chain. When the flathead model was reintroduced it also received the new water pump. Equipped with such high quality parts as forged crankshafts and connecting rods, these engines earned a reputation for remarkable durability. The flathead, however, was prone to the typical flathead problem of overheating under sustained heavy load. This was from the hot exhaust traveling through the cylinder block to the exhaust manifold.

American Motors introduced a die-cast aluminum block version of the OHV 195.6 cu in (3.2 L) engine in 1961. It was produced through 1964. This engine used cast-iron cylinder liners and a cast-iron head. The cylinder heads for the two types of block (aluminum and cast iron) are of similar design, but are not interchangeable. The cylinder head for the aluminum block is roughly 1/8" wider than that for the cast iron block and uses a slightly different head bolt pattern.

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