Editing Ford small block engine (section)

==351W==<!-- This section is linked from [[Ford Mustang]] -->
[[File:1969 Ford Mustang Mach 1 351 Windsor engine.JPG|thumb|A 351 Windsor V8 in a 1969 Ford Mustang]]

The 351W (Windsor) made its debut in 1969; it is often confused with the Ford 351 Cleveland, a different engine of nearly identical displacement that also began production in 1969. The {{cvt|5766|cc|cuin L cc|1|order=out}} Windsor featured a {{cvt|32.5|mm|1|order=flip}} taller deck height than the 289/302, allowing a stroke of {{cvt|3.5|in|mm|1}}. It was initially rated (SAE gross) at {{cvt|250|hp|kW|0}} with a two-barrel carburetor (referred to as "2V" in engine designations) or {{cvt|290|hp|kW|0}} with a four-barrel (designated "4V"). Emissions compliance led to a compression drop in 1971. When Ford switched to net power ratings in 1972 power ratings had fallen to {{cvt|153|HP|kW}} from {{cvt|161|hp|kW}}.

The 289, 302, and 351W all share the same bellhousing, motor mounts, and other small parts. The [[distributor]] is slightly different, to accommodate a larger [[oil pump (internal combustion engine)|oil pump]] shaft and larger oil pump. Some years had threaded dipstick tubes. The 351W had larger main bearing caps, thicker and longer connecting rods. The firing order was changed to 1-3-7-2-6-5-4-8 from the usual 1-5-4-2-6-3-7-8 to move the "noise" of the consecutively-firing adjacent front cylinders to the sturdier rear part of the engine block while reducing excessive main bearing load. The changes added some {{cvt|25|lb|kg|0}} to the engine's dry weight.

The head castings and valve head sizes from 1969 to 1976 were different, notably in passages for air injection and spark plug diameters (1969–1974 18&nbsp;mm, 1975 and up 14&nbsp;mm). From 1977 onward, the 351W shared the same head casting as the 302, differing only in bolt hole diameters (7/16&nbsp;inch for the 302, 1/2&nbsp;inch for the 351W). Early blocks (casting ID C9OE-6015-B) had enough metal on bearing saddles 2, 3, and 4 for four-bolt mains, and as with all small-block Fords, were superior in strength to most late-model, lightweight castings. Generally, the 1969 to 1974 blocks are considered to be stronger than the later blocks, making these early units some of the most desirable in the small block or 335-series. During the 1980s, a four-barrel version (intake manifold casting ID E6TE-9425-B) was reintroduced for use in light trucks and vans. In 1988, [[fuel injection]] replaced the four-barrel carburetor. Roller camshaft/lifters were introduced in 1994.

The original connecting rod beam ([[Forge|forging]] ID C9OE-A) featured drilled oil squirt bosses to lubricate the piston pin and cylinder bore and rectangular-head rod bolts mounted on broached shoulders. A number of [[Fatigue (material)|fatigue failures]] were attributed to the machining of the part, so the bolt head area was spot-faced to retain metal in the critical area, requiring the use of 'football head' bolts. In 1975, the beam forging (D6OE-AA) was updated with more metal in the bolt-head area. The oil squirt bosses were drilled for use in export engines, where the quality of accessible lubricants was questionable. The rod cap forging remained the same on both units (part ID C9OE-A). In 1982, the [[Ford Essex V6 engine (Canadian)|Essex V6 engine]] used a version of the 351W connecting rod (E2AE-A) machined in [[SI units|metric]] units, while the V8 part was machined with [[Society of Automotive Engineers|SAE]] units. The cap featured a longer boss for balancing than the original design.

In 1971 the block deck height was raised from {{cvt|9.480 to 9.503|in|mm}} (casting D1AE-6015-DA) to lower the compression ratio to reduce {{NOx|link=yes}} emissions without the need to change piston or cylinder-head design. In 1974, a boss was added on the front of the right cylinder bank to mount the [[secondary air injection#Pumped air injection|air injection pump]] (casting D4AE-A). In 1974, the oil dipstick tube moved from the timing case to the skirt under the left cylinder bank near the rear of the casting. In 1984, the rear main seal was changed from a two-piece to a one-piece design.

Around 8.6 million 351W engines were manufactured between 1969 and 1996 at the Windsor Engine Plant Number One.

Applications:
*1969–1974 [[Ford Galaxie]]
*1969–1970 [[Ford Mustang]]
*1969–1971 [[Mercury Cougar]]
*1969–1991 [[Ford Country Squire]]
*1969–1970 [[Ford Fairlane (Americas)]]
*1970–1976 [[Ford Torino]]
*1974–1976 [[Ford Elite]]
*1975–1976 [[Bricklin SV-1]]
*1975–1996 [[Ford E series]]
*1977–1979 [[Ford LTD II]]
*1977–1979 [[Ford Thunderbird]]
*1979–1996 [[Ford Bronco]]
*1979–1982 [[Ford LTD (Americas)]]
*1979–1991 [[Ford LTD Crown Victoria]] (after 1982, this engine would only be sold for police sales in the U.S.)
*1983–1997 [[Ford F-Series]]
*1977–1979 [[Mercury Cougar]] (station wagons only)
*1978, 1986–1991 [[Mercury Colony Park]]
*1978–1982 [[Mercury Marquis]]
*1986–1991 [[Mercury Grand Marquis]]
*1980 [[Lincoln Continental Mark VI|Continental Mark VI]]
*1995 [[Ford Mustang SVT Cobra#Cobra R (1995)|Ford Mustang SVT Cobra R]]

===Marine 351===
From the late 1960s through the early to mid-1990s, the 351 Windsor had a long history of being [[marinized]] by Holman Moody Marine, Redline of Lewiston, ID (now defunct), Pleasure Craft Marine (PCM), and Indmar for use in several makes of recreational boat, including; Correct Craft, Ski Supreme, [[Hydrodyne]], MasterCraft, and Supra inboard competition ski boats. The early marinized engines were rated at {{cvt|220|hp|kW|0}}. Most PCM and Indmar marinized 351s were rated at {{cvt|240|hp|kW|0}}. In the early 1990s, a {{cvt|260|hp|kW|0}} version and a high-output version that used GT40 heads and the Holley 4160 marine carburetor was rated at {{cvt|285|hp|kW|0}}. A few 351 GT40/HO engines were marinized equipped with throttle-body fuel injection (TBI) and were rated at {{cvt|310|hp|kW|0}}. The marine industry's relationship with the 351W platform ended when Ford was unable or unwilling to compete with GM's production of TBI- and MPI-equipped engines in mass quantity. During that time, the recreational marine community's small-block V8 platform of choice shifted to the {{cvt|350|cuin|L|1}} [[Chevrolet small-block engine (first- and second-generation)|Chevrolet L31 (Vortec 5700)]] engine series.