Ford Y-block engine

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Ford Y-block V8
Manufacturer Ford Motor Company
Production 1954-1964,1980 South America
Combustion chamber
Configuration Small-block OHV V8
Predecessor Flathead V8
Successor Ford Windsor engine
Ford 335 Cleveland V8

The Y-block engine is a family of overhead valve V8 automobile engines produced by Ford Motor Company. It was introduced in 1954 on Ford trucks and cars to replace the side-valved Ford Flathead V8, and replaced by the Ford FE engine (on medium cars) and the Ford Windsor engine (on small cars) in 1962, and lasted until 1964 in Ford trucks.

Lincoln introduced a very different and larger Y-block engine, the Lincoln V8, in 1952 for use on large cars and Ford heavy duty trucks.


The first Y-block on Ford automobiles was the 1954 239 in³ (3.9 L) Ford engine, known for its deep skirting, which causes the engine block to resemble a Y. Rated at 130 hp (97 kW) and 193 ft-lbs of torque at 2200rpm, it replaced the 106 hp (79 kW) 239 in³ (3.9 L) flathead. The Y-block was considered a major advancement over the flathead. It is known for having oiling problems in the rocker shafts because the oil first went to the crankshaft bearing, then to the camshaft bearings, then to the rocker shafts.[citation needed] This problem plagued the entire Y-block family and could be remedied by running a copper line from the oil pump to the rocker shafts.[citation needed]

The oiling problem was caused by the passage from the center cam bearing to the cylinder head being offset by an inch and too small. The motor oils of the era were low in detergents, but high in petroleum coke; when combined with short trips and infrequent oil changes, this led to blockage of this passage.[citation needed] This left the lower end with ample oil while the rocker shaft assemblies literally burned up. The external oiler kit essentially provided oil to the rocker shafts from the oil pressure port on the outside of the engine.[citation needed]


The original Mercury Y-block, introduced for the 1954 model year, displaced 256 in³ (4.2 L). Advertised as the "V-161" engine, it ran a bore and stroke of 3-5/8 X 3-3/32 in. The compression ratio was 7.5:1, and the rated power was 161 hp (120 kW) at 4400 rpm. Torque was 238 lb·ft (323 N·m) at 2200 rpm. The engine breathed through a Holley model 2140 (4V) carburetor.


The 272 in³ (4.5 L) version was introduced in 1955. Most standard Fords used this engine.

Ford Australia released this V8 motor as its only option in the four-door Customline sedan from 1955-1959 (based on the Canadian Mercury), and its coupé utility, based on the same styling as the Customline, called a Mainline. It was introduced in passenger cars in July 1955, and in the redesigned truck lineup one month later.[1]

This engine, as well as the 292 version starting in 1956, was also produced by Ford of Brazil at its São Paulo plant facility (Ipiranga plant). A new building was opened on November 21, 1958, by the Brazilian President, Juscelino Kubitschek de Oliveira, to produce the first Ford engine in South America. The 272 version was used on Brazilian F-series trucks until 1977 and on the Brazilian Galaxie 500, launched in April 1967.


A 292 Y-block engine in a 1955 Ford Crown Victoria Skyliner

The 292 cu in (4.8 L) was also introduced in 1955. The bore and stroke are 3.75 and 3.30 in (95.25 and 83.82 mm), respectively, for a total displacement of 291.6 cu in (4,778 cc). It was used in the Ford Thunderbird, Mercury, and some high-end Ford cars. In 1956, it was an optional engine for Ford cars, was commonly used in high-end models, and called the "Thunderbird V8" (the optional larger 312 cu in engine was called the "Thunderbird Special V8"). The 292 cu in was also used in Ford trucks, namely the F-100, through 1964. The 292 forged steel crankshaft was popular with motor enthusiasts in increasing the performance potential of the 312. With some machine work, this part was used to upstroke the 312 V8 to 340 cu in in combination with custom-made pistons and a .040 inch overbore (4.040 in. x 3.3 in.).

This particular version of the Y-block engine was used in Argentina in the F-100 pick-up well into the 1960s, and was known as Fase I (Phase I). In 1971, the engine was modified to accept a new-style cylinder head with a different valve arrangement (E-I-E-I-E-I-E-I versus E-I-I-E-E-I-I-E), new intake and exhaust manifolds and was renamed Fase II (Phase II). In this form, the 292 Fase II continued into the 1980s in the F-100, and was also used in the Argentine Ford Fairlane (built from 1969–1982, and based heavily on the U.S. 1968 model). All Argentine versions of this engine feature a cast crankshaft rather than the forged example that equipped US heavy-duty engines. The 292 version was also produced by Ford of Brazil and equipped the Brazilian LTD starting in 1969. Both the 272 and 292 engines were replaced on Brazilian cars by the 302 engine starting on 1976 model year.


The 312 cu in (5.1 L) engine came out for the 1956 model year and was again used in high-end Ford and Mercury cars, including the Thunderbird.

Bore and stroke dimensions of the 312 V8 were 3.80" X 3.44".

Depending on model year and application, the 312 was available with a single two- or four-barrel carburetor, two four-barrel carburetors, and with or without a McCulloch (Paxton) supercharger (1957 only).

All 1956 U.S. Mercury models were powered by the 312 cu in (5.1 L) V8 breathing through a four-barrel carburetor. At the beginning of the model year, a 210-horsepower version with 8.0:1 compression ratio powered Mercury cars with manual transmissions (including three-speed plus overdrive), while a 225-horsepower version powered cars with automatic transmissions. The 225-horsepower version had an 8.4:1 compression ratio. Later in the model year, a 235-horsepower version with 9.0:1 compression ratio became available. All 1956 Mercury engines had gold-painted blocks and heads. The 210-horsepower version had red valve covers and air cleaner, while the 225-horsepower version had blue valve covers and air cleaner. The 235-horsepower version had argent silver valve covers and air cleaner. A dealer-installed "M 260" engine kit was released in January 1956. The kit consisted of a hotter camshaft, revised cylinder heads, and an intake manifold mounting two four-barrel carburetors. The kit was advertised as boosting the Mercury 312 V8 to 260 horsepower.

The last regular application of the 312 V8 in the U.S. was for certain 1960 Mercury models. Though considered to be a high-performance engine in 1956 and 1957, it was downgraded to an "economy" engine with low compression and two-barrel carburetor by 1960.


The Y-block was ultimately superseded because of its inherent displacement limit. A quick reference to the engine specifications for 1955-57 shows the Ford V8s ahead of the Chevrolet counterparts in displacement, horsepower, and torque. However, the original architecture was very small and tight. The ever-increasing size and weight of the standard passenger car, the added parasitic losses for accessories (power steering, power brakes and air conditioning), cheap gasoline, and the horsepower race all caused Ford to outgrow its first OHV V8 engine.

Even with the benefit of today's technology (aftermarket rods and stroker cranks), the real limit of a Y-block is about 348 cu in (5.7 L), while the Chevrolet could be modified well past the factory limit of 400 cu in (6.6 L). The result was the introduction in 1958 of the "big block" Ford FE engine on medium cars – which ultimately grew to 428 in³ – and the Ford Windsor engine – which began at 221 cu in (3.6 L) but grew to 351 cu in (5.8 L) and saw numerous high-performance versions – on small cars in 1962.


  1. ^ "V-8 overhead valve engines for new Ford trucks". The Farmer and Settler. Sydney, NSW. 26 August 1955. p. 37. Retrieved 18 January 2015. 

External links[edit]