The Y-block engine is a family of small block overhead valve V8 automobile engines produced by Ford Motor Company. The engine is well known and named for its deep skirting, which causes the engine block to resemble a Y. It was introduced in 1954 as a more modern replacement for the outdated side-valved Ford Flathead V8 and was used in a variety of Ford vehicles through 1964.

Development

By 1948, the famous Ford Flathead V8 had been developed about as far as it could go, and it was antiquated by the early 1950s. Ford was the most conservative of the major automakers, holding onto older designs longer than GM or Chrysler, but market forces pushed Ford to develop new designs in the 1950s. The company had designed the Y-block for a 1953 introduction, but a shortage of nickel due to the Korean War's needs prevented the company from manufacturing the engine in sufficient quantities, again a similar displacement to the Mercury Flathead V8 it replaced, but with 29% more power than the older engine's .

The original Lincoln V8 was also known as a Y-Block. Lincoln introduced their engine in 1952, but it was a different design from the Ford Y-Block, and was used on large cars and Ford heavy-duty trucks.

One of the design qualities of the Y-Block V8 is its deep skirting which makes for a very rigid block for added strength in the bottom end. The drawback to this is it also makes for a heavy cylinder block. This being Ford's first OHV engine, they had to feed oil to the rocker arm shafts through a passage from the center cam bearing. Because of the low detergents in oils of that era these passages would often become clogged giving the Y-Block a reputation for bad oiling to the top end. Ford came up with a stop gap measure for this problem by feeding oil via an external tube directly to the rocker shafts from the main oil gallery. as opposed to the flathead's final at 3,800 rpm, an increase of 18%.

272

By 1955 Chevrolet introduced its small block V8 with ; not to be outdone, Ford increased its displacement to and introduced the Thunderbird with a engine. The standard 1955 U-code featured a two barrel Holley carburetor and was rated at at 4,400 rpm and at 2,400 rpm. The optional "Power Pack" M-code used a four barrel Holley carburetor and was rated at at 4,400 rpm.

In 1956 the U-code was updated to produce at 4,400 rpm and at 2,400 rpm with a manual transmission behind it or at 4,400 rpm and at 2,400 rpm with an automatic transmission. The M-code 272 was dropped altogether in 1956 in favour of a four barrel M-code version of the 292. It featured a two barrel Holley carburetor and was rated at at 4,500 rpm and at 2,700 rpm.

Ford Australia released this V8 motor as its only option in the four-door Customline sedan from 1955 to 1959 (based on the Canadian Meteor), 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. In late 1956 the Australian 272 switched to a four bolt 2 barrel Autolite carburetor.

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.

292

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

The Y-Block was also introduced in 1955. The 292 shared the 3.3 in (83.82 mm) stroke of the 272 but with a larger 3.75 in (95.25 mm) bore.

The Mercury division had two versions of the 292 available in 1955. The standard engine had a 7.6:1 compression ratio and was rated at at 4,400 rpm, with of torque at 2,500 rpm. The top of the range Montclair V8 came with a higher specification version that was rated at 4,400 rpm and at 2,500 rpm. 1955 would be the only model year that Mercury would use the 292 in version of the Y-Block, with it being replaced by the larger 312 in engine for the 1956 model year. whilst the automatic featured an 8.4:1 compression ratio with a rating of at 4,600 rpm and at 2,600 rpm.

All Ford Y-Blocks were up on power for the 1957 model year. The 292 was available as the C-code engine option, once again with a slight difference between the manual transmission and "Fordomatic" automatic transmission. Compression was up to 9.1:1 in manual cars, which were rated at 4,500 rpm and at 2,700 rpm. Automatic vehicles were rated at 4,500 rpm, torque and compression ratio are not listed in the Ford 1957 workshop manual as being any different from the manual car, which seems unlikely given the power difference at the same engine speed.

The 292 would be the longest-lived of the Y-Blocks, carrying on until 1962 in U.S. cars and until 1964 in U.S. trucks.

All 1956 U.S. Mercury models were powered by the V8 breathing through a four-barrel carburetor. At the beginning of the model year, a version with 8.0:1 compression ratio powered Mercury cars with manual transmissions (including three-speed plus overdrive), while a version powered cars with automatic transmissions. The 225-horsepower version had an 8.4:1 compression ratio. Later in the model year, a 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 .

Not generally known, about 40% of these 312s were equipped with vacuum secondary CARTER WCFBs. They are a highly desired version, as the Holleys were cantankerous.

The 312s had no centrifugal timing advance in their distributors until 1957.

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. Ford pickups used the version as late as 1965.

Replacement

When Ford Y-block debuted its power making ability was already hindered by 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, larger CID V8 engines made by Cadillac, Chrysler, Buick, Pontiac and Oldsmobile clearly showed the small CID architecture of the Y-block would need revision in order to keep pace with the other automakers.

Even with the benefit of today's technology (aftermarket rods and stroker cranks), the upper limit of a Y-block is about , while the Chevrolet could be modified well past the factory limit of . The result was the introduction in 1958 of the 332 CID "big block" Ford FE engine which ultimately grew to 428 cu in. Later, in 1962, the Ford Windsor engine – which began at would fully replace the Y-Block and grow to .

References

  • Short descriptions of Ford overhead valve V8 engines
  • Website specializing in the Ford Y-block V8, including a good discussion forum
  • "55 Years of Mercury" by John Gunnell
  • 1956 Mercury sales brochure