The Windsor engine is a 90-degree small-block V8 from Ford Motor Company. It was introduced in 1962, replacing the old Ford Y-block engine. Though not all of the engines in this family were produced at the Windsor, Ontario engine plant (all Ford small blocks came from Cleveland, Ohio until 1966), the name stuck. The mid-sized 335 "Cleveland" V8, introduced in 1970, was to replace the larger Windsors, but this design ended up outliving its replacement. In 1991, the Windsor engine began to be phased out and replaced with Ford's new 4.6 L modular V8 engine, which was disliked by many because of the overhead cam valvetrain as opposed to the more traditional "muscle car-ish" pushrod V8 with overhead valves that Chevy stuck with in their GM LS engine line. In 1996, Ford replaced the popular 5.0 L pushrod V8 with the 4.6 L in their flagship vehicle, the Ford Mustang. Its use in production vehicles continued until 1997 in the F-150 and until 2001 in the Ford Explorer. As of 2008 the Windsor engines including the 351 and 302 are still being produced by Ford, available as complete crate motors, from Ford Racing and Performance Parts.
Another simple differentiator between the Windsor and Cleveland series is the location of the radiator hose — the Windsor routed coolant through the intake manifold, with the hose protruding horizontally, while the Cleveland had the radiator hose connecting vertically to the engine block. The Cleveland and later "Modified" engines used a canted valve design, allowing for larger valves within the same 4" bore. Something worth noting was the fact that the Ford Engineers designed the Cleveland heads with the same bore spacing and head bolt configuration making it possible (with some light machine work) to bolt Cleveland heads to the Windsor block and in 1969 they did just that creating the Boss 302.
The oil routing in the engine block is unique in that a third passage is drilled parallel to the tappet passages. This passage insures that oil reaches the main and cam bearings before the tappets, reducing the likelihood of lubricant starvation of the bearings (unlike the 351 Cleveland and the 385 series). The tappets are fed from an inverted 'V' passage cast in the rear under the intake manifold that connects with this passage and is sealed with a steel cap. The third oil passage is visible from the rear of the block with the transmission components removed. It is under and slightly right of the right bank tappet passage. The tappets on the left bank are the farthest from the oil pump and are last to be pressurized by oil upon a dry start. This gives an impression that there is insufficient lubrication, but this is normal and the noise ceases after several seconds of operation.
With the exception of the 289 HiPo, Boss 302 and 351W, all connecting rods use the same 5/16 in. dia. bolts which tend to fail under high RPM operation. It is possible to machine the bolt holes to accept 11/32 inch rod bolts used in the pre-1968 Chevrolet small V8 engines (265, 283, 327) as a remedy. The rod forgings had undergone some changes throughout its history. The 221, 260 and early 289 (C2OZ-A and C3AE-D) rods used an oil squirt hole to lubricate the piston pin and rings. The oil squirt hole was discontinued in 1964. The same forging continued to be used up to 1967 and all were the same length (5.155 in.). The 302 used a shorter beam (C8OE-A 5.090 in.) but used the same cap up to 1970. In 1971 the cap design was changed from flanged to flat (D1OE-A). This was changed back to the flange design in 1988 due to fatigue failures from increased power output of fuel injection and continued until the end of production. The 289 HiPo and Boss 302 were the same length (5.155 in) used heavier beam and cap forgings and 3/8 in bolts but were machined differently. The former used square head bolts and square cut and the latter were spot faced for 'football head' bolts.
The first engine of this family, introduced for the 1962 model year as an option on the Ford Fairlane and Mercury Meteor, had a displacement of , 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 day.
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 @ 4400 rpm and @ 2200 rpm.
The 221 was dropped after the 1963 model year.
The second version of the Windsor, introduced during the middle of the 1962 model year, had a wider bore of 3.80 in (96.5 mm), increasing displacement to . 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 @ 4400 rpm, with a peak torque of @ 2200 rpm.
In 1962 and 1963 valve diameters remained the same as the 221, but starting in 1964 they were enlarged to 1.67 in. (42.4 mm) (intake) and 1.45 in (36.8 mm) (exhaust). Rated power was not changed.
In 1963 the 260 became the base engine on full-size 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 by mid-year, as did the 1964-1966 Sunbeam Tiger. The 1967 Sunbeam Tiger Mk II used the 289 CID V8 (see 289).
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) @ 5800 rpm and @ 4800 rpm.
Ford dropped the 260 after the 1964 model year.
The Windsor was also introduced in 1963. Bore was expanded to 4.0 in (102 mm), becoming the standard bore for most factory Windsor engines. The 289 weighed 506 lb (230 kg).
In 1963 the 289 was available in two forms: with a two-barrel carburetor and 8.7:1 compression, (SAE gross) rated at @ 4400 rpm and @ 2200 rpm, and with a four-barrel carburetor and 9.0:1 compression, rated at @ 4400 rpm and @ 2800 rpm. The two-barrel 289 replaced the 260 as the base V8 for full-sized Fords.
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).
For 1965 the compression ratio of the base 289 was raised to 9.3:1, increasing power and torque to @ 4400 rpm and @ 2400 rpm. The four-barrel version was increased to 10.0:1 compression, and was rated at @ 4800 rpm and @ 3200 rpm.
Engine specifications were unchanged for 1966 and 1967. In 1968 the four-barrel engine was dropped, leaving the two-barrel — now reduced back to — and the HiPo. 1968 was the last year of production for the 289.
The 289 was also the engine for the first Ford Falcon GT, the XR GT. (Australia)
A high-performance version of the 289 engine was introduced late in the 1963 model year as a special order for Ford Fairlanes and Mercury Comets. The engine is informally known as the "HiPo" or the K-code (after the engine letter used in the VIN of cars so equipped). Starting in June 1964, it became an option for the Mustang.
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 (std 289 4v was 480 CFM). The water pump, fuel pump, and alternator/generator pulley were altered; fewer vanes, extra spring, and larger diameter respectively; to help handle the higher RPMs. Even the HiPo’s fan was unique. Bottom end improvements included thicker main bearing caps and balancer, larger diameter rod bolts, and a hardness tested and counterweighted crankshaft, all for high-rpm reliability. The HiPo carried SAE gross ratings of @ 6000 rpm and @ 3400 rpm.
The HiPo engine was used in modified form by Carroll Shelby for the 1965-1967 Shelby GT350, raising rated power to @ 6000 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.
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.
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 @ 4600 rpm and @ 2600 rpm. Optional was a four-barrel version rated at @ 4800 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 intake and exhaust. It had a longer-duration camshaft, still with hydraulic lifters. The block was a high-strength, higher nickel content design 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 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 HiPO 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 @ 5000 rpm and @ 3800 rpm. The package, which cost $692 (USD) 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. It is considered to be on par and equal in strength to the K-code HP 289 block. The heavy duty Mexican 302 block as it now known was produced for several more years and even showed up on FORD trucks and vans throughout the late 1970's and early 1980's.
Emission regulations saw a progressive reduction in compression ratio for the 302 two-barrel, to 9.0:1 in 1972, reducing SAE gross horsepower to . In that year U.S. automakers began to quote horsepower in SAE net ratings; the 302 two-barrel carried a net rating of . By 1975 its power would drop as low as . Not until fuel injection began to appear in the 1980s would net power ratings rise above .
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 and Capris, equipped first with two-barrel(1982), then later 4-barrel carburetor(1983-85) 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 since 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 replaced by a mass-air type measuring system, with the same manifold. The MAF system continued, with minor revisions, until the retirement of the engine in 2001.
The 302 was also offered for marine applications in both standard and reverse rotation setups.
In the 1980s the 302 became more commonly known as the 5.0 Liter, although its metric displacement (4942 cc) accurately rounds to 4.9 L. It is speculated that ford used the "5.0" moniker to distinguish the 302 from the 300 in³ inline Six, which was known as the 4.9. Despite its advertised displacement, some automotive magazines referred to the 302 – correctly – as a 4.9 liter engine.
The 302 remained a mainstay of various Ford cars and trucks through early 2001, although it was progressively replaced by the 4.6 L Ford Modular engine starting in the early 1990s. The last 5.0 L 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, who installed their last 5.0 engine in a new vehicle in August 2002. The 302/5.0 is still available as a complete crate motor, from Ford Racing and Performance Parts.
Ford Australia also built some stroked, 5.6 L Windsors. With alloy heads and roller rockers they produced and .
The Boss 302 was a performance variant of the Windsor, putting what would become Cleveland heads on a special, heavy duty, 4 bolt main Windsor block to improve rated power to . According to some reports, the canted valve, deep breathing, high revving engine could produce more than , although as delivered, it was equipped with an electrical rev limiter that restricted maximum engine speed to 6150 rpm. A bulletproof bottom end, thicker cylinder walls, steel screw-in freeze plugs, race prepped 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.
The Boss 302 could be built by just about anyone as the Cleveland heads will bolt up to a standard Windsor block. By blocking a coolant passage on the face (combustion side) of the head and opening a passage on the intake side the heads will operate just as a Boss 302 head. A special intake manifold is needed, either one from a Boss 302 or from an aftermarket supplier. At one point there was at least one company making the special intakes in both open and split plenum design.
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. There were a number of fatigue failures attributed to the machining of the part and 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 was 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 1972, The deck height was extended from 9.480 in. to 9.503 in. (casting id D2AE-B) 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 id D4AE-A). In 1979 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 the 1990s the rear main seal was changed from a two-piece component to a one-piece design and provisions for roller tappets were also added.
Introduced in 1969, it was initially rated (SAE gross) at with a two-barrel carburetor or 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.
During the 1990s, motor enthusiasts were modifying 351 Cleveland 2V cylinder heads (by re-routing coolant exit from the block surfaces to the intake manifold surfaces) for use in the 351W resulting in the Clevor (a portmanteau of Cleveland and Windsor). This modification requires the use of custom pistons by reason of differing combustion chamber terrain (canted valves vs. straight valves) and intake manifolds for the Boss 302 was not wide enough and the intake ports were too large. This combination yielded the horsepower potential of the 351C with the ruggedness of the 351W short block. This was possible because more 351C 2V cylinder heads were made than corresponding engine blocks (the 351M and 400 used the same head as the 351C 2V).
In 1980, an urgent need to meet EPA CAFE standards led to the creation of the version, essentially a 302 with the cylinder bores downcored to 3.68 in (93.5 mm). 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. Poorly received thanks to its dismal performance and mediocre fuel economy, it was dropped after the 1982 model year, and is considered one of the worst modern Ford engines.