Ford Windsor engine

Overview

The small-block engine that was identified as the Windsor engine was introduced in the 1962 Ford Fairlane. Displacing 221 cu in (3.6 L), it was designed to save weight, using thin-wall casting with a block that does not extend below the centerline of the crankshaft. The engine uses a separate aluminum timing chain cover, which differentiates it from the later 335-series Cleveland engines that use an integrated timing cover. All Windsor engines use two-valve-per-cylinder heads, with "2V" and "4V" designations indicating the number of barrels (or venturi) in the carburetor. The valves are in-line and use straight six-bolt valve covers. Coolant is routed into the block by the intake manifold.

The design was soon bored to 260 cu in (4.3 L) and again to 289 cu in (4.7 L), then stroked to 302 cu in (4.9 L), settling on the most common displacement offered until the engine’s retirement in 2001, nearly 40 years after the basic block design debuted. Two additional displacements were produced during the engine’s history. A 351 cu in (5.8 L) model (stroked from the 302) was offered beginning in 1969 and continuing until 1996. The 351W (so identified to distinguish from the 335-series Cleveland 351C) uses a taller block than the other engines in the series to avoid excessively short connecting rods. Additionally, briefly in the early 1980s, a debored 4.2 L displacement engine was produced as Ford struggled with emissions and fuel economy.

In response to the Chevrolet Camaro's success in the SCCA Trans-Am series, Ford engineers developed a new racing engine from the Windsor series small block. The first attempt mated a tunnel-port head to a 289 cu in block, but the displacement proved to be too small to deliver the desired power. The next iteration of the engine mated an improved head design to the 302 cu in block, producing the famous "Boss 302". The heads from the Boss 302 became the production heads on the 335-series Cleveland engines, which used the same bore spacing and head bolt configuration as the Windsor engines.

As the 1980s drew to a close, Ford begin the design of a new small-block V8 to replace the venerable Windsor design. The Modular 4.6L OHC V8 debuted in the 1991 Lincoln Town Car, signaling the eventual demise of the Windsor. Through the rest of the decade, Ford gradually shifted V8 applications to the Modular engine, with the Mustang transitioning in 1996. Even as the Windsor neared the end of its life, development continued, with new cylinder heads introduced for the Ford Explorer in 1997. Sale in new vehicles ended with the 2001 Ford Explorer, but the engine continued to be offered for sale as a crate engine from Ford Racing and Performance Parts.

221

The first engine of this family, introduced for the 1962 model year as an option on the Fairlane and Meteor, had a displacement of 221 cu in (3.6 L), from a 3.5 in (89 mm) bore and 2.87 in (72.9 mm) stroke, with wedge combustion chambers for excellent breathing. An advanced, compact, thinwall-casting design, it was 24 in wide, 29 in long, and 27.5 in tall (610 mm × 737 mm × 699 mm). It weighed only 470 lb (210 kg) dry despite its cast iron construction, making it one of the lightest and most compact V8 engines of its class. The 221 Ford was possibly one of the lightest iron V8 engines ever produced.

All of the July 1961 through August 1964 221-260-289 engines used a five-bolt bell housing, with all 221s and 260s being of this configuration, but the 289 changed to the six-bolt arrangement at this time - the change was made due to transmission utilization issues i.e. the need for larger-diameter clutches, for example. The block mount pads and the cylinder wall contour of the 221 and 260 engines changed in January–February 1963 with the introduction of the 289 variant – all 221 and 260 engine blocks up to this time featured 'corrugated wall' construction with two freeze plugs on the side of each bank and engine mount hole pitch distances of 6 inch. All three block variants from this point on featured the straight wall method of construction, three freeze plugs and an engine mount hole pitch distance of seven inches. The corrugated wall method of block construction had caused cleaning difficulties in the foundry from day one and a change was phased in.

In stock form, it used a two-barrel carburetor and a compression ratio of 8.7:1, allowing the use of regular (rather than premium) gasoline. Valve diameters were 1.59 in (40.4 mm) (intake) and 1.388 in (35.3 mm) (exhaust). Rated power and torque (SAE gross) were 145 hp (108 kW) at 4,400 rpm and 216 lb·ft (293 N·m) at 2,200 rpm.

The 221 was phased out in April 1963 due to a lack of demand after about 270,000 had been produced. Ford engineers knew straight away that the engine was not quite powerful enough for these cars equipped with the two-speed automatic transmission, which led to the introduction of a larger-displacement version.

260

The second version of the Fairlane V8, introduced during the middle of the 1962 model year (March 1962), had a larger bore of 3.80 in (96.5 mm), increasing displacement to 260 cu in (4.3 L). Compression ratio was raised fractionally to 8.8:1. The engine was slightly heavier than the 221, at 482 lb (219 kg). Rated power (still SAE gross) rose to 164 hp (122 kW) @ 4400 rpm, with a peak torque of 258 lb·ft (350 N·m) @ 2200 rpm.

For the 1962 and 1963 car model years, the valve diameters remained the same as the 221, but for the 1964 car model year, they were enlarged to 1.67 in (42.4 mm) (intake) and 1.45 in (36.8 mm) (exhaust) – this was an economy measure so that both 260 and 289 engines could use the same valves. Rated power was not changed.

In 1963, the 260 became the base engine on full-sized Ford sedans. Later in the model year, its availability was expanded to the Ford Falcon and Mercury Comet. The early "1964½" Ford Mustang also offered the 260, although it was dropped at the end of the 1964 car model year. The 1964–1966 Sunbeam Tiger Mk I used the 260. The 1967 Sunbeam Tiger Mk II used the 289 ci in V8 when stocks of the 260 ran out.

The special rally version of the Falcon and Comet and early AC Cobra sports cars used a high-performance version of the 260 with higher compression, hotter camshaft timing, and a four-barrel carburetor. This engine was rated (SAE gross) 260 hp (194 kW) @ 5800 rpm and 269 lb·ft (365 N·m) @ 4800 rpm. This engine was termed the HP-260 by Ford and was specifically made for Carroll Shelby – about 100 were made.

Ford dropped the 260 after the 1964 model year with roughly 600,000 having been made.

289

The 289 cu in (4.7 L) was also introduced in April 1963. Bore was expanded to 4.00 in (101.6 mm), becoming the standard bore for most Windsor engines. Stroke remained at 2.87 inches. The 289 weighed 506 lb (230 kg).

The Windsor 289 had nothing in common with the older Studebaker-designed and manufactured 289 OHV V8 (3.5625 bore X 3.625 stroke, 7.8:1 compression ratio, 190 hp (2V) or 210 hp (4V), and a whopping weight of 695 lb!). The Studebaker 289 was introduced in 1956, a full seven years before the Windsor 289 was available, and was manufactured in Studebaker's foundry in South Bend, Indiana, for various Studebaker cars and trucks from 1956 through 1964. The design of the Studebaker 289 was based on Studebaker's thick-walled 232 OHV V8 introduced in late 1950 for the 1951 model year. Though Studebaker struggled for survival during the 1950s and 1960s, at no time were new Ford engines purchased for installation in new Studebaker cars or trucks in the Studebaker factories. If a Ford engine is seen in a Studebaker car or truck today, it simply means that, at some point after the car left a Studebaker factory, someone removed the Studebaker engine, made the necessary modifications, and installed a Ford engine.

In 1963, the 289 was available in two forms. The base version came with a two-barrel carburetor and 8.7:1 compression; it was rated at 195 hp (145 kW) (SAE gross) at 4,400 rpm and 258 lb·ft (350 N·m) at 2,200 rpm. The two-barrel 289 replaced the 260 as the base V8 for full-sized Fords. As a performance option, the "HiPo" or "K-code" engine was offered; the K-code is discussed more below. In 1963, it was available only in the Fairlane.

In 1964, an intermediate performance version of the engine was introduced with a four-barrel carburetor and 9.0:1 compression, rated at 210 hp (157 kW) at 4,400 rpm and 300 lb·ft (407 N·m) at 2,800 rpm. The engine was an option on both the initial 1964 1/2 Ford Mustang and the Mercury Comet. The engine was known as the "D-code" from the letter code used to identify the engine in the VIN. The D-code engine is relatively rare, as it was only offered as an optional engine in the latter half of the 1964 model year.

Both 1963 and 1964 versions had a five-bolt bell housing pattern that was different from later six-bolt units (Mustangs switched bolt patterns around August 3, 1964). The engines switched from a generator to an alternator in the latter part of the 1964 model year.

For 1965, the compression ratio of the base 289 was raised to 9.3:1, increasing power and torque to 200 hp (149 kW) at 4,400 rpm and 282 lb·ft (382 N·m) at 2,400 rpm. The four-barrel version was increased to 10.0:1 compression, and was rated at 225 hp (168 kW) at 4,800 rpm and 305 lb·ft (414 N·m) at 3,200 rpm. The HiPo engine specifications were not changed.

Engine specifications were unchanged for 1966 and 1967. In 1968, the four-barrel 225 hp (168 kW) engine was dropped, leaving only the two-barrel – now reduced to 195 hp (145 kW). The HiPo engine was also dropped, making room for the new-for-1968 302 V8; 1968 was the last year of production for the 289 in the U.S.

The 289-4V was also the engine for the first Australian Ford Falcon GT, the XR Falcon GT. Around 3,500,000 289-2V and 289-4V engines were made at CEP1 in 1963-1967 and 800,000 289-2V at WEP1.

289 HiPo (K-code)

A high-performance version of the 289 engine was introduced late in the 1963 model year as a special order for Ford Fairlanes. The engine is informally known as the HiPo or the K-code' (after the engine letter used in the VIN of cars so equipped). Oddly, this engine was introduced in 1963 as the only 289 engine available in the intermediate Fairlanes. Lesser-powered cars had the 260 engine in that year. Starting in June 1964, it became an option for the Mustang. K-code Mercury Comets were the 210 HP 4V engine, not the same HiPo engine as the K-code Fords.

The HiPo engine was engineered to increase performance and high-RPM reliability over standard 289 fare. It had solid lifters with hotter cam timing; 10.5:1 compression; a dual point, centrifugal advance distributor; smaller combustion chamber heads with cast spring cups and screw-in studs; low-restriction exhaust manifolds; and a bigger, manual-choke 595 CFM carburetor (the standard 289-4V was 480 CFM). The water pump, fuel pump, and alternator/generator pulleys were altered, fewer vanes, extra spring, and larger diameter, respectively; to help handle the higher engine speeds. Even the HiPo’s fan was unique. Bottom-end improvements included a flaw-free selected standard block, thicker main bearing caps and crankshaft damper/balancer, larger-diameter rod bolts, a crankshaft made from 80% "nodular iron" as opposed to the regular items at 40%, all were checked for correct 'nodularity' by polishing an area of the rear counterweight and comparing that surface using a magnification arrangement against a picture datum, increased crankshaft counterweighting to compensate for the heavier connecting rod big ends, the increased external counter weighting at the front was split between the crankshaft damper and a supplementary counterweight place adjacent to the front main bearing journal (all designed to reduce the 'bending moment' in the crankshaft at high-rpm), all for high-rpm reliability. The HiPo carried SAE gross ratings of 271 hp (202 kW) at 6,000 rpm and 312 lb·ft (423 N·m) at 3,400 rpm. About 25,000 were manufactured at CEP1 between March 1963 and June 1967.

The HiPo engine was used in modified form by Carroll Shelby for the 1965–1967 Shelby GT350, raising rated power to 306 hp (228 kW) at 6,000 rpm through use of special exhaust headers, an aluminum intake manifold, and a larger carburetor. The Shelby engine also had a larger oil pan with baffles to reduce oil starvation in hard cornering. Shelby also replaced the internal front press-in oil gallery plugs with a screw-in type plug to reduce chances of failure.

From 1966 to 1968, Shelby offered an optional Paxton supercharger for the 289, raising its power (on Shelby GT350s) to around 390 hp (291 kW).

The K-code HiPo engine was an expensive option and its popularity was greatly diminished after the 390 and 428 big-block engines became available in the Mustang and Fairlane lines, which offered similar power (at the expense of greater weight) for far less cost.

302

By 1967, the Ford GT40 MKII and GT40 MKIV had dominated the Le Mans 24-Hour Race for two consecutive years, using various versions of the Ford big-block engine. In an attempt to reduce the high speeds (some say to equalize the competition), the organizers of this race capped the engine capacity in 1968. Ford consequently returned to the MKI GT40 (originally using the Windsor 289), but had now increased its capacity to meet the new rules. Since Ford had ruled that the GT40 engines must have a direct link back to its production cars, the 302 was adopted in domestic manufacturing.

So in 1968, the small-block Ford was stroked to 3.0 in (76.2 mm), giving a total displacement of 302 cu in (4,942 cc). The connecting rods were shortened to allow the use of the same pistons as the 289. It replaced the 289 early in the 1968 model year.

The most common form of this engine used a two-barrel carburetor, initially with 9.5:1 compression. It had hydraulic lifters and valves of 1.773 in (45 mm) (intake) and 1.442 in (36.6 mm) (exhaust), and was rated (SAE gross) at 220 hp (164 kW) at 4,600 rpm and 300 lb·ft (407 N·m) at 2,600 rpm. Optional was a four-barrel version rated at 250 hp (186 kW) at 4,800 rpm.

For 1968 only, a special high-performance version of the 302 was offered for the Shelby GT350. Its main features included an angled, high-rise aluminum or iron intake manifold, a larger Holley four-barrel carburetor, and bigger valves of 1.875 in (47.6 mm) intake and 1.6 in (41 mm) exhaust. It had a longer-duration camshaft, still with hydraulic lifters. The block was made in Mexico. "Hecho en Mexico" casting marks are present in the lifter valley, and its main strength was the appearance of much larger and stronger two-bolt main bearing caps on the engine's bottom end - the same as the HP-289, but not made from nodular iron rather Ford's standard material. The heads had special close-tolerance pushrod holes to guide the pushrods without rail rocker arms or stamped steel guide plates. The combustion chambers also featured a smaller quench design for a higher compression ratio and enhanced flow characteristics. Additionally, high-flow cast exhaust manifolds similar to those on the 289 Hi-Po K-code engine further improved output. Heavy-duty connecting rods with high-strength bolts and a nodular iron crankshaft were also included in this package. Rated power (SAE gross) was estimated at 315 hp (235 kW) at 6,000 rpm and 333 lb·ft (451 N·m) at 3,800 rpm. The package, which cost $692 including some other equipment, was not popular and did not return for 1969. This engine was not a factory engine. Rather, like all Shelby Mustang engines, it was modified by Shelby American in their capacity as a vehicle upfitter. This special engine is well documented in the Ford factory engine repair manual for 1968 Mustangs and Fairlanes. This engine block is considered the strongest production 302 block other than the Boss 302 and the Trans Am 302. The Mexican 302 block was produced through to the mid-1990s and even showed up in Ford cars, trucks, and vans throughout the 1970s and early 1980s (Mexican-made 302 engines were often used by the USA car plants when CEP1 could not produce enough engines and many Ford replacement engines were Mexican).

Mexican blocks were not made from a high-nickel content material as is generally thought, but rather Ford's usual ACB specification material. They are a good block but no stronger than any other USA-made component and the bore service life is generally lower due to less wear-resistant South American-sourced iron ore. All Mexican V8 blocks were cast and machined to accept a front engine mount as required for their truck applications.

Emission regulations caused a progressive reduction in compression ratio for the 302 two-barrel, to 9.0:1 in 1972, reducing SAE gross horsepower to 210 hp (157 kW). In that year, U.S. automakers began to quote horsepower in SAE net ratings; the 302 two-barrel carried a net rating of 140 hp (104 kW). By 1975, its power dropped as low as 122 hp (91 kW). Until fuel injection began to appear in the 1980s, net power ratings did not rise above 210 hp (157 kW).

Throttle-body fuel injection first appeared for the 302 on the Lincoln Continental in 1980, and was made standard on all applications in 1983 except manual-transmission equipped Mustangs, Mercury Capris (equipped first with two-barrel (1982), then later four-barrel carburetor (1983–85)), and F-series trucks. The block was fitted with revised, taller lifter bosses to accept roller lifters, and a steel camshaft in 1985, and electronic sequential fuel injection was introduced in 1986. While sequential injection was used on the Mustang beginning in 1986, many other vehicles, including trucks, continued to use a batch-fire fuel injection system. The speed-density based EFI systems used a large, two-piece, cast-aluminum manifold. It was fitted on all engines through 1988, after which year it was phased out for a mass-air type measuring system in most applications (non-California compliant Panther platform cars retained the speed-density system until the Lincoln Town Car received the Modular V8 for model year 1991, and the Crown Victoria and Grand Marquis for 1992). The same manifold was used in MAF applications, with the addition of the MAF sensor in the air intake tube. The MAF system continued, with minor revisions, until the retirement of the engine in 2001. Ford offered a performance head that was a stock part on 1993–1995 Mustang Cobra models and pre- 1997-1/2 Ford Explorers and Mercury Mountaineers equipped with the 5.0 L engine called the GT-40 head (casting ID F3ZE-AA). In mid-1997, the Explorer and Mountaineer 5.0 L heads were revised and renamed GT40P. The GT40P heads, unlike the GT40 heads, had a very well-developed port shape/design which yielded about 200 cfm on the intake side and 140 cfm on the exhaust side without increasing the size of the ports at all from standard E7TE castings, and without increasing the exhaust valve size. They also had smaller 59-61 cc combustion chambers for added compression, and the combustion chamber shape was revised to put the spark plug tip near the center of the chamber for a more even burn. These GT40P heads are considered by many enthusiasts to be extremely efficient.

The Truck Division instigated a pushrod-operated four-valve-per-cylinder, cylinder head conversion in the early 1990s as a means of modernizing/improving and furthering the service life of the Windsor engine. This work was done for Ford by Roush Industries (for US$1 million) and two 302/5.0L and one 351i/5.8 L variants were built and tested. These engines were highly successful, but upper management refused to allow engines so equipped to go into production, stating that to use a cast iron block in a new car (though the 302 remained an engine option in Explorers through MY2001) was no longer acceptabl . One of the 5.0 L engines is in use in a hot rod. Various aftermarket manufacturers have also produced four-valve heads for the 302, notably Arao Engineering and Dominion Performance.

The 302 was also offered for marine applications in both standard and reverse-rotation setups.

From the 1978 car model year, the 302 became more commonly known as the 5.0 Liter, although its metric displacement is 4.942 L. Ford may have used the "5.0" moniker to distinguish the 302 from their 300 cu in inline six, which was known as the 4.9. Despite its advertised displacement, Car and Driver referred to the 302 as a 4.9-liter engine, though the normal 302 Ford engine enthusiast always referred to it as a "5-Oh, 5-Point-Oh, 5 Liter, or 302".

The 302 remained a mainstay of various Ford cars and trucks through the late '90s, although it was progressively replaced by the 4.6 L Modular engine starting in the early 1990s. The last 302 engine was produced for installation in a production vehicle was at Cleveland Engine Plant #1 in December 2000, as part of a build-ahead to supply Ford of Australia, which installed their last such engine in a new vehicle in August 2002. The 302 is still available as a complete crate motor from Ford Racing Performance Parts.

5.6

In 2001, Ford Australia also built some stroked, 5.6 L (5,605 cc, 342 cu in) Windsors with reworked GT40P heads (featuring larger valves), a unique eight-trumpet inlet manifold, long-throw crank, H-beam rods, and roller rockers. They produced 335 hp (250 kW) at 5,250 rpm and 369 lb·ft (500 N·m) at 4,250 rpm. The 5.6 litres of displacement were reached by lengthening the stroke from 76.2 mm (3.0 in) to 86.4 mm (3.4 in).

Boss 302

The Boss 302 was a chief engineer Bill Gay-inspired and Bill Barr-enacted performance variant of the Windsor, putting what would become Cleveland heads (this engine was still under development at this stage) on Ford's heavy-duty, four-bolt main (center three main caps), racing block (in existence at this specification since 1967 for the GT40 program) to improve rated power to 290 hp (216 kW). According to some reports, the canted-valve, deep-breathing, high-revving engine could produce more than 310 hp (231 kW), although as delivered, it was equipped with an electrical revolution limiter that restricted maximum engine speed to 6150 rpm. A strong bottom end, thicker cylinder walls, steel screw-in freeze plugs, race-prepared crank, special HD connecting rods, and Cleveland-style forged pistons kept the engine together at high speeds. The key to this engine's power was the large-port, large-valve, quench-chambered, free-flowing heads. The Boss 302 Mustang was offered only for the 1969 and 1970 model years. In a January 2010 issue of Hot Rod magazine, a Boss 302 engine built to the exact specifications, settings, and conditions to the original engine was tested. It produced a solid 372 hp @ 6,800rpm and 325 lb-ft of torque @ 4,200rpm.

351W

The 351W is often confused with the 351 Cleveland, which is a different engine of identical displacement. The 351 cu in (5.8 L) Windsor featured a 1.3 in (32.5 mm) taller deck height than the 302, allowing a stroke of 3.5 in (88.9 mm). Although very much related in general configuration to the 289-302 and sharing the same bell housing, motor mounts, and other small parts, the 351W had a unique, tall-deck block, larger main bearing caps, thicker, longer connecting rods, and a distinct firing order (1-3-7-2-6-5-4-8 versus the usual 1-5-4-2-6-3-7-8, a means to move the unacceptable 'noise' of the consecutive firing adjacent front cylinders to the more rigid rear part of the engine block), adding some 25 lb (11 kg) to the engine's dry weight. The distributor is slightly different, so as to accommodate a larger oil pump shaft and larger oil pump. Some years had threaded dipstick tubes. It had a unique head which optimized torque over high-rpm breathing, frequently replaced by enthusiasts with aftermarket heads providing better performance. The early 1969 and 1970 heads had larger valves and ports for better performance. 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 mm, 1975 and up 14 mm). From 1977 onward, the 351W shared the same head casting as the 302, differing only in bolt hole diameters (7/16 inch for 302, 1/2 inch for 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 (SBFs), were superior in strength to most late-model, lightweight castings. Generally, the 1969 to 1974 blocks are considered to be far superior in strength than the later blocks, making these early units some of the strongest and most desirable in the entire SBF engine family including the 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 this engine in 1994.

The original connecting rod beam (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 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 design of the Essex V6 engine used a new version of the 351W connecting rod (E2AE-A), the difference between the two parts was that the V6 and V8 units were machined in metric and SAE units, respectively. The cap featured a longer boss for balancing than the original design.

The block underwent some changes since its inception. In 1971, deck height was extended from 9.480 in to 9.503 in (casting D1AE-6015-DA) to lower the compression ratio to reduce NOx 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 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. These details made swapping older blocks from passenger cars with front sump oil pans to more recent rear-sumped Mustang and LTD/Crown Vic Ford cars more difficult unless an oil pan had the dipstick mounted therein. In 1984, the rear main seal was changed from a two-piece component to a one-piece design.

Introduced in 1969, it was initially rated (SAE gross) at 250 hp (186 kW) with a two-barrel carburetor or 290 hp (216 kW) with a four-barrel. When Ford switched to net power ratings in 1972, it was rated at 153 to 161 hp (114 to 120 kW), although actual, installed horsepower was only fractionally lower than in 1971. Around 8.6 million 351W engines were manufactured between 1969 and 1996 at the Windsor Engine Plant Number One.

During the 1990s, motor enthusiasts were modifying 351 Cleveland 2V cylinder heads (by rerouting the coolant exit from the block surfaces to the intake manifold surfaces) for use in the 351W, resulting in the Clevor (combining Cleveland and Windsor). This modification required the use of custom pistons by reason of differing combustion chamber terrain (canted valves vs. straight valves) and intake manifolds. This combination yielded the horsepower potential of the 351C with the ruggedness of the 351W small block and was possible because more 351C 2V cylinder heads were manufactured than the corresponding engine blocks (the 351M and 400 used the same head as the 351C 2V).

The 5.8 L, 351W, was changed during the '90s from speed density to MAF; performance gains were directly affected. Before 1994, the 5.8 L was equipped with speed density. This programmed coding was placed into the vehicle's computer to tell the motor how much air it should be getting, therefore supplying an appropriate amount of fuel. However, if modifications are made to increase air flow, the computer does not provide more fuel, as it is still following the programmed amount of fuel supplied. After 1994, the engine was changed to mass air flow (MAF). This allowed the computer to read how much air the engine was receiving through the help of a sensor in the air intake. Because the computer reads this, it is able to increase the amount of fuel the engine gets when the air flow is increased, thus increasing performance. Without the MAF conversion, the performance of a nonstock to heavily modified 5.8 L, fuel-injected engine will be lacking.

Marinized 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 about every make of recreational boat, including; Correct Craft, Ski Supreme, Hydrodyne and MasterCraft inboard competition ski boats. The early marinized engines were rated at 220 hp (164 kW). Most PCM and Indmar marinized 351s were rated at 240 hp (179 kW). In the early 1990s, a 260 hp (194 kW) version and a high-output version that used GT-40 heads and the Holley 4160 marine carburetor was rated at 285 hp (213 kW). A few 351 GT-40/HO engines were marinized equipped with throttle-body fuel injection (TBI) and were rated at 310 hp (231 kW). 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 350 cu in (5.7L) GM L31 (Vortec 5700) engine series.

Boss 351

The Racing Boss 351' (not to be confused with the Ford 335 engine Cleveland-based Boss 351) is a crate engine from Ford Racing Performance Parts. The block was based on the 351 cu in (5,752 cc) Ford Windsor engine, but uses Cleveland sized 2.75 in (70 mm) main bearing journals. Deck height choices include 9.2 in (234 mm) and 9.5 in (241 mm). Maximum displacements are 4.25 in (108 mm) stroke and 4.125 in (105 mm) bore. The resulting displacement is up to 454.38 cubic inches (7445.9 cc, or 7.4 L).

The uncross-drilled block with increased bore capacity became available from the third quarter of 2009. A 427 cu in (6,997 cc) Boss 351-based crate engine producing 535 hp (399 kW) was available from the first quarter of 2010.

In 2010, the MSRP for the Boss 351 block was US$1,999.

427

The Windsor small-block engine was bored and stroked to 427 cu in (7.0 L) for use in the Saleen S7 (2000-2004) and its competition model S7R (although it used Cleveland style heads). The road going engine was capable of producing 550 bhp (410 kW; 558 PS) at 6400 rpm. The S7's top speed was an estimated 220 mph (354 km/h).

In 2005, Saleen released the S7 twin-turbo version of the engine with two Garrett turbochargers producing 5.5 pounds per square inch (0.4 bar) of boost, increasing the maximum power to 750 bhp (559 kW; 760 PS) at 6300 rpm, and the maximum torque to 700 lb·ft (949 N•m) at 4800 rpm. The top speed of the twin-turbo S7 was 248 mph (399 km/h).

255

In 1980, an urgent need to meet EPA CAFE standards led to the creation of the 255 cu in (4.2 L) version, essentially a 302 with the cylinder bores reduced to 3.68 in (93.5 mm). The 302/5.0 L was going to be phased out and the 255/4.2 L was to be an interim 'new' engine which would last until the new V6 was up and running - the 255/4.2 L was a quick fix. Rated power (SAE net) was 115-122 hp (86-91 kW), depending on year and application. Cylinder heads used smaller combustion chambers and smaller valves, and the intake ports were ovals whereas the others were rectangular. The only externally visible cue was the use of an open-runner intake manifold with a stamped-steel lifter valley cover attached to its underside, giving the appearance of previous-generation engines, such as the Y-block and the MEL. It was optional in Fox-chassis cars including the Mustang and corporate cousin Mercury Capri, Thunderbird, Fairmont, and standard equipment in the Ford LTD. Some variants (i.e. Mercury Grand Marquis) were fitted with a variable-venturi carburetor which were capable of highway fuel economy in excess of 27 MPG. Poorly received due to its dismal overall performance, the 255 was dropped after the 1982 model year with just over 250,000 units being built - 302/5.0 L V8 engine production continued and the plans to phase it out were dropped.