The Chrysler A engine is a small-block V8gasoline engine built by Chrysler with polyspherical combustion chambers. It was produced from 1956 until 1967, when it was replaced by the wedge-head LA engine. It is not related to the hemispherical-head Hemi engine of the same era. The A engine was first released in 1956, and was used exclusively in Plymouths until 1958. The cylinder borecenter distance is, larger than the earlier Dodge-based poly engines. The A engine formed the conceptual design basis of its successor, the LA engine.
The 277 was the first A-block engine, produced for 1956 and sharing almost nothing but the basic concepts with other engines built by Chrysler. Bore is and stroke is for a piston displacement of. It was replaced by the 301 in 1957, except for in low-priced Plaza models where it continued to be used during the 1957 model year.
301
The Plymouth 301 replaced the 277 in 1957. Its piston displacement is, owing to its bore. These dimensions are entirely different from the 1955 Chrysler 301.
303
The 1956 Plymouth 303 displaces and uses the same connecting rods as the 277; the bore is and the stroke is. This engine was used in the following vehicles:
1957 standard on all -wheelbase Dodges and Plymouths
313
A version of the A engine called the 313 was produced from 1957 to 1967 primarily for Canadian and export markets. This engine has a bore of and the common stroke, and was used in the following vehicles, amongst others:
The 318 is the most common version of the A engine, produced from 1957 through 1967 when it was replaced in all markets by the LA 318. Only Plymouth used this 318 in 1957 and 1958, but it was shared with the other Chrysler divisions from 1959 on. It displaces and has a bore and the stroke. A special 1957-'58 version called the V-800 used two four-barrel carburetors to produce, making it the highest-output A engine. It was used in the 1957 and 1958 Plymouth Fury, but was also an option on Plymouth models lower in the model range. Bristol Cars introduced the 318 in the Mark II model of their 408 and continued to use it in the succeeding 409 and 410 until 1969. From 1962 until early 1965, Checker used this engine for their Aerobus limousines.
Non-Plymouth
326
The 326 was launched in 1959. Its actual piston displacement is but it was marketed as a 326 to avoid confusion with the Dodge Red Ram 325. The 326 uses the same stroke as the 318, but with the largest bore of any A engine at. It uses hydraulic tappets, unlike the earlier A engines, and was used in the 1959 Dodge Coronet.
