Mustang Engine History: 1979-1995 Ford Small-Blocks
Late-model Mustang Powerplant Timeline: Charting the evolution of pony powerplants starting with 5 liters of fury
Ford Motor Company has led the industry in V-8 engine development since it introduced the flathead back in 1932. The mass-produced flathead gave customers excellent power and reliability (for the era). Ford’s Flathead was somewhat complex with its Vee configuration, which placed the camshaft above the crankshaft and used a common intake manifold to feed both banks. It became a favorite with hot rodders and racers who incorporated aftermarket parts and go-fast tuning tricks; flatheads are still used today.
The flathead was produced until 1953, when it was succeeded by the Y-Block V-8. The Y-block came during a time when both gasoline and steel were very inexpensive, so vehicle size and engine displacement grew rapidly. Next came the FE series of engines, which took displacement to a whopping 428 ci. This included the popular 427 with dual quads and the awesome 428 Cobra Jet. Ford also developed the 385-series big-block engines, such as the 429 and 460.
Still, there remained a need for smaller V-8s that were powerful and efficient. So engineers developed the Windsor small-block Ford, which lasted 40 years. The Windsor was introduced in 1962 as a 221ci V-8, originally produced by Ford’s Windsor Engine Plant in Windsor, Ontario, Canada. There are of course other small-blocks, such as the 351 Cleveland, but here in Part 1 of this series we focus on the Windsor family of engines—specifically those installed in 1979-1995 Mustangs.
A Touch of History
Designed for midsize Ford and Mercury vehicles, the 221 V-8 produced 145 hp and was a lightweight engine that incorporated a thin-wall block casting, wedge-style heads with inline valves, and a two-barrel carb. Needing more power, Ford increased displacement to 260, 289, and then to 302 ci with an 8.2-inch deck height. Later, Ford engineered a tall-deck block (9.2 inches) to accept a larger stroke. Using a 4.0-inch bore and a 3.50-inch stroke produced 351 ci, 1 more inch than the popular small-block Chevrolet. This 351 variant is commonly called a “Windsor,” while the other engines in the family are simply called small-blocks.
While most performance cars died in the early 1970s when insurance skyrocketed and America faced an energy crisis, it was revitalized almost 10 years later, when Ford, Chrylser, and GM got back into the performance game. At this time the 5.0 made its triumphant return. Chrysler had the 2.2 Turbo; GM went with a 305, a 350, and a turbocharged V-6; and Ford went to war with a 2.3L Turbo and the venerable 5.0. Needless to say, the new-era horsepower race was on!
Ford’s pony in the race was the Fox-body Mustang, which debuted in 1979. A far cry from the Mustang II, the Fox was based off the Fairmont platform and sported a lightweight unibody and nice lines. Enthusiasts clearly fell in love. Sales jumped from 192,410 units sold in 1978 (the final year for the Mustang II) to 369,936 in 1979.
Engine options in 1979 included the 2.3L four-cylinder, 2.8L V6, and 302-cube V-8, which Ford now called the 5.0 (five point oh). Using two-barrel carburetion, the V-8 packed a 140hp punch. This engine was basically a carryover from 1978. Ford also offered a 2.3L turbo (1979-1981), which was produced at the Lima, Ohio, engine plant. These engines produced roughly 130 hp.
Though power was nothing like it was in the 1960s and early 1970s, the new 5.0 V-8 was architecturally the same as earlier 302 small-block Ford engines, utilizing a 4-inch bore, a 3-inch stroke, 10 head bolts to retain the cylinder heads, and the common 8.2-inch deck height. Even the bosses for the engine mounts were the same. The V-8 option in 1979 cost $514, and quarter-mile times for the 1979 V-8 Mustang was in the mid-16s at 84 mph.
But as quick as it came, the 5.0 was gone. Only the most hardcore Mustang fans know that the 5.0 was not available in the 1980 and 1981 model years. Ford’s only V-8 option was the smaller 4.2L (255ci) mill. The 4.2L was a small-bore version of the 5.0—and with just 8.8:1 compression, 118 hp, and 193 lb-ft of torque, it didn’t perform very well. Like all the 1979-1984 engines, the valvetrain consisted of a standard hydraulic cam with 1.6:1 stamped-steel rockers. It also had 1.68- and 1.46- intake and exhaust valves. Ford was on the hunt for improved fuel economy, hence the smaller engine size, but the Mustang needed more power.
1982: Return of the GT
With performance on the rise, Ford reintroduced the Mustang GT along with an all-new 302—er, 5.0—engine. The new 5.0 H.O. now sported 157 hp and 240 lb-ft of torque with just 8.3:1 compression. Up top it wore a dual-snorkel air cleaner that fed a Motorcraft carburetor flowing about 360 cfm. Still, the 1982 GT had a nice look and Ford fans saw evolution.
We’d hardly call a 157hp engine High Output, but it was OK for the times. The engine sported carryover heads from the 4.2L with stiffer valve springs, cast iron exhaust manifolds, and sharp-looking finned valve covers. Down below, the block was slightly revised and a larger camshaft was installed, as was a double-roller timing chain.
1983-1984: Four Eyes and Four Barrels
The 1983 GT took on a new look with a pointier nose designed to reduce drag, but the big news for enthusiasts was the four-barrel carburetor. While the long-block carried over from 1982, Ford added a 600-cfm Holley/Motorcraft carburetor and set it atop a dual-plane aluminum manifold. This gave the Mustang a much-needed punch, increasing output to 175 hp and 245 lb-ft of torque.
In 1984 Ford introduced CFI (central fuel injection), a throttle-body injection system used on automatic-equipped Mustangs sold in 1984-1985. Computer controlled EFI was in its infancy, and this model only made 165 hp. In fact, it gave Mustang enthusiasts a bad taste when it came to EFI. They feared it would be impossible to make performance modifications. The 1984 CFI models are the very first Mustangs to come with an electronic engine management system.
1985: Carbed and cammed
Many agree that the 1985 Mustang took on a muscular yet clean look with the updated front fascia. The quad headlights, enlarged grille opening, and 10-hole (phone-dial) wheels just looked right—and Ford made the top engine available in the LX coupe.
Ford used classic hot rodding tricks for improvements, which included a new hydraulic roller camshaft, tubular shorty headers, and revised cylinder heads (E5AE) with 1.78- and 1.46-inch intake and exhaust valves. This gave the 5.0 a gain of 35 hp (to 210 hp) and 25 lb-ft of torque (270). The block was also updated with raised bosses in the lifter galley used to secure the lifter-retention “spider” devise. The use of the roller cam allowed more aggressive cam timing, which improved efficiency and power.
From the driver’s seat, owners began grinning, as the V-8–equipped Mustangs (and Capri cousins) would blaze the tires and run respectable quarter-mile times. The last carbureted Mustang sported a Motorcraft/Holley 600-cfm four-barrel fitted to the same dual-plane aluminum intake used in 1983-1984. The system also used a dual-snorkel air cleaner, fed by twin fender-mounted tubes. Yes, even stock Mustangs had cold-air induction.
|49-State V-8 Engine Output|
|1979||5.0L||140 @ 3,600||250 @ 1,800|
|1980||4.2L||118 @ 3,800||193 @ 2,200|
|1981||4.2L||118 @ 3,400||195 @ 2,200|
|1982||5.0L*||157 @ 4,200||240 @ 2,400|
|1983-1984||5.0L*||175 @ 4,200||245 @ 2,400|
|1985**||5.0L*||210 @ 4,400||270 @ 3,200|
|1986||5.0L||200 @ 4,000||285 @ 3,000|
|1987-1992||5.0L||225 @ 4,200||300 @ 3,200|
|1993||5.0L||205 @ 4,200||275 @ 3,200|
|1993||5.0L Cobra||235 @ 4,600||380 @ 4,000|
|1994-1995||5.0L||215 @ 4,200||285 @ 3,500|
|1995||5.8L Cobra R||300 @ 4,800||365 @ 3,750|
1986: Enter Port Fuel Injection
The successor to CFI was Ford’s new SEFI (sequential electronic multiport fuel injection) system. This included an advanced (for the time) EEC computer that controlled eight 19-lb/hr injectors and a hall-effect distributor that fed ignition to the 5.0.
Despite providing amazing midrange power and drivability, the initial reaction to EFI was not good. Horsepower on the 5.0L engine was down 10 from 1985 (now rated at 200), which threw enthusiasts into a frenzy. It didn’t matter that the new engine had 15 more lb-ft of torque (285 versus 270); enthusiasts feared the electronics would limit or even kill the ability to modify the engine. But in the end, EFI gave them the tools to achieve today’s insane levels of performance, reliability, and drivability.
Air entered through a fender-mounted airbox and was directed to a 58mm throttle body (which flowed roughly 541 cfm) and into a unique two-piece intake manifold. The intake featured an upper with a common plenum connecting to eight individual runners. The lower intake bolts to the heads and has smallish oval ports that match to the upper. Overall runner length is about 18 inches, which made for amazing cylinder filling efficiency in the 2,800-4,600 rpm window. Unfortunately the small ports limited flow, preventing big power gains in the upper rpm band.
Fuel is fed from injectors directly into the lower intake ports just above each intake valve. The 1986 5.0L also uses a 23-gph in-tank pump with fuel pressure set between 38 and 42 psi.
In addition, the 1986 5.0L also used a one-year-only iron cylinder head with the E6AE casting number. This head used a 62.9cc combustion chamber and a “masked-valve” design that was supposed to promote efficient combustion. The standard 1.78- and 1.46-inch intake and exhaust valve combo was retained, but it didn’t prove to be a winning combination.
Remove the heads and you’ll find a set of flat-top pistons in the 4.0-inch bores. In fact, an old trick was to use a set of later, 1987-up heads on a 1986 short-block to yield higher compression. While more power could be had, this tightened the piston-to-valve clearance, which resulted in bent valves (or worse) when the driver over-revved the engine or missed a gear.
1987-1995: Aero and More Go!
Evolution continued in 1987, as Ford implemented even greater changes to the 5.0L H.O. engine. Output jumped from 200 to 225 hp and from 285 lb-ft of torque to an even 300. In addition, the Mustang received a complete facelift. The “four-eyed” front end was replaced with European “aero” styling, and the basic interior was also revamped with a modern dash, center stack, and seating.
Ford refined the induction to breathe better and make more power. The 1987 still picked up its air in the fender, but it now benefited from a larger 60mm throttle body (flowing 580 cfm), an internally enlarged intake manifold, and new E7TE head castings. The heads were revised for improved flow, and a more-typical combustion chamber was used, one that was similar to the pre-1986 setup. The chamber size was decreased to 60.6 cc, and Ford combined the heads with a short-block featuring an 0.030-inch dish in the forged pistons to arrive at a compression ratio of 9:1.
The 5.0 H.O. retained the shorty headers using 1.5-inch primary tubes, and like the 1986 GT, the exhaust was made up of a true-dual system. And as you know, the 1987 GT used hidden exhaust tips, whereas the LX used stainless pipes.
Notable changes came in 1988 (on California-equipped car) and 1989, as Ford made the move from a speed density (SD) to a mass airflow (MAF) setup. The addition of mass air allowed enthusiasts to dig deep into the 5.0 while maintaining reasonable drivability. The SD system worked well with stock camshaft timing, but cams much larger than stock caused many problems. Owners experienced “hunting” idle, fouled plugs, and inconsistent performance. MAF solved this by metering the incoming airflow. In essence, mass air is a before-the-fact system, while speed density is an after-the-fact system.
The 5.0 H.O. remained virtually unchanged until 1993, when Ford used cast hypereutectic pistons in place of the forged slugs. The same year, horsepower was lowered to 205, although there is no record of mechanical change that would cause this. At the same time, torque was dropped to 275 lb-ft. For 1994 and 1995 Ford utilized a new intake manifold and gave the 5.0 an increase of 10 hp. Many feel this was done to drive sales—and that no real power increase resulted from mechanical changes.
1993-1995 SVT Cobra: Ultimate Fox
Ford produced 107 examples of the 1993 Cobra R.
Owners of the very first SVT Mustang enjoyed real performance thanks to the GT-40 Cobra engine that powered the 1993 Cobra and Cobra R. With 235 hp it was perhaps the hottest Windsor-based 302 ever built by Ford. The GT-40 package consisted of a 65mm throttle body, a cast aluminum Cobra intake that was similar in design to the Ford Racing Performance Parts tubular GT-40 intake (and the later FRPP Cobra intake), and the high-flow GT-40 cast iron cylinder heads. The heads were used on all 1993-1995 Cobras, 1993-1995 SVT Lightning trucks, and the 1995 351-powered Cobra R. Other specific Cobra parts include the 70mm mass airflow sensor, 24-lb/hr injectors, smaller crank, smaller water-pump pulleys, and a recalibrated EEC computer.
Camshaft lift was increased from 0.444 on the 5.0 H.O. to 0.480 with the use of Crane roller rockers, and the valves on the GT-40 heads measure 1.84 and 1.54 inches. And lobe overlap was reduced to better suit the induction. GT-40 heads are easy to spot, as they have three distinct bars cast into the front and rear of the heads. And they have “GT” cast into them as well. GT-40 heads should not be confused with GT-40P, which were used on the Explorer and Mercury Mountaineer. Additionally, GT-40 heads carry casting code “F3ZZ” and “F4ZZ.”
The Cobra engine received a bump in power for 1994 (and 1995) to 240, but the extra output was negated by the extra weight of the new body style. Changes to the engine included a new upper intake with a sharper turn just after the throttle-body, and lower overall height.
1995 SVT Cobra R
Powering the R was a 351 Windsor producing 300 hp and 365 lb-ft of torque. It was a close variant of the F-150 Lightning engine, with a cast intake versus. the tubular version on the Lightning. The Cobra R 351 was a torque monster, but didn’t make amazing high-rpm horsepower because the heads were really designed for the 302.
|1984-1985||2.3L||175 @ 4,400||210 @ 3,000|
|1985.5||2.3L||205 @ 5,000||248 @ 3,200|
|1986||2.3L||200 @ 5,000||240 @ 3,200|
|Windsor Engine Displacement|