The American Motors Corporation (AMC) straight-6 family of engines was used in AMC passenger cars and Jeep vehicles from 1964 through 2006. 195.6 American Motors' first straight-six engine was the . Sometimes referred to as the 196 engine, it was produced from 1952 through 1965 in both overhead valve (OHV) and flathead (L-head) side-valve versions. The 196 was originally designed to be an economy engine by Nash Motors, the company that merged with Hudson to form AMC in 1954. This engine was introduced in the 1941 Nash Ambassador 600 model. The intake and exhaust manifolds were integrated into the cylinder block casting to reduce both weight and cost. It had four main bearings, unlike the 7-main-bearing 234 flathead engine it replaced. The new flathead design had a smaller displacement, and was initially rated at . The engine combined with the new Ambassador's advanced "unitized" construction design provided better than . Using the same the same bore, this engine was enlarged 1950 to for the Nash Statesman, and finally to by using different strokes, an unusual practice given that changing forging is more expensive than changing the block casting. This engine was redesigned as an OHV for the 1956 model year. The flathead version was discontinued during 1956 and 1957, but reemerged in 1958 as the economy engine for the "new" Rambler American and was available through 1965. The new OHV configuration for 1956 continued with the water pump mounted the left side of the engine (driven by a shaft extending from the back of the generator). This was changed for 1957 with the water pump mounted on the front of the engine above the timing chain. When the flathead model was reintroduced it also received a new water pump. Featuring high-quality parts as forged crankshafts and connecting rods, these engines earned a reputation for 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 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