The Y-block engine is a V8 automobile piston engine from Ford Motor Company. It was introduced in 1954 to replace the Ford L-Head engine and was replaced by the Ford FE engine (on larger cars) and the Ford Windsor engine (on smaller cars) in 1962, and lasted until 1964 in Ford trucks.
Note that Lincoln introduced its own Y-block in 1952. That engine lasted until the 1958 introduction of the MEL.
The first Y-block was the 1954 239 (3.9 liter) Ford engine. Known for its deep skirting to make the engine resemble a Y. Rated at 130hp, (replacing the 239ci Flathead, 106hp) was considered a major advancement over the flathead. Known for having oiling problems in the rocker shafts due to the fact the oil first went to the crankshaft bearing, then the camshaft bearings, then to the rocker shafts. This problem plagued the entire Y-block family and could be remedied by running a copper line from the oil pump and then to the rocker shafts. This series of engines also lacked the breathing abilities compared to the Chevy 265 small block, thus could not develop the same power.
The Mercury Y-block was the 256 (4.2 liter).
The 272 (4.5 liter) version was introduced in 1955. Most standard Fords used this engine.
The 292 (4.8 liter) was also introduced in 1955. It was used in the Ford Thunderbird, and some high-end Ford and Mercury cars.
This engine was also used in Ford trucks, namely the F-100, thru 1963
The 312 (5.1 liter) engine came out in 1956 and was again used in high-end Ford and Mercury cars, including the Thunderbird.