Читать книгу Ford Small-Block Engine Parts Interchange - George Reid - Страница 6

INTRODUCTION

At the cusp of the 1960s, Ford turned its product planning and engineering attentions to a new lightweight gray iron V-8 displacing 221 and 260 ci designed for the all-new unit-body 1962 Ford Fair-lane intermediate. Known as the “90-degree Fairlane V-8,” the 221/260 grew quickly to 289 ci in 1963. The Fairlane V-8 became known among enthusiasts as the small-block Ford and remains so today.

When the Fairlane V-8 arrived, it had a bore size of 3.500 inches and a 2.870-inch stroke. The short stroke reduced piston speed and frictional issues coupled with high-revving capability. Yet the larger bore, which grew larger in time to 4.000 inches, allowed for generous valve sizing and breathing. What made the Fairlane V-8 different was the absence of a traditional block skirt and rail to support the crankshaft, which reduced weight.

Few can dispute the runaway success of Ford’s small-block V-8. It went to dozens of racing venues around the world with great success and continues to be campaigned successfully more than a half century later. Ford’s first shot at a high-performance small-block was the 289 High Performance V-8 introduced for 1963 in the Fairlane car line. At 271 hp at 6,000 rpm it allowed the 289 to prove its worth as a factory high-performance V-8. Carroll Shelby showed the competition what this engine could do in the new Mustang in the following years. Ford ultimately stroked the 221/260/289 to 3.000 inches and topped the 302-ci with large-port poly-angle-valve heads to create the high-revving Boss 302 small-block for SCCA Trans-Am competition in 1969–1970.

It was the misfortune of the 302 Tunnel Port on the track in 1968 that led Ford engineers to develop the Boss 302 engine in the first place. The short-lived 302 Tunnel Port head made power at very high-RPM ranges, but caused catastrophic engine failure and unacceptable losses during the 1968 SCCA racing season. Racers had to spin the Tunnel Port well above the 8,000-rpm mark, which caused these engines to scatter themselves all over racetracks from coast to coast. Befuddled by failure after failure, Ford engineers looked to the new large-port poly-angle-valve 351C wedge head, which enabled the 302 to make more horsepower at lower RPM ranges. The deep-breathing, high-revving Boss 302 engine had what it took to win thanks to great cylinder heads, a four-bolt main block, and a steel crank with heavy-duty C3AE Boss rods. The Boss 302 was the ultimate evolution of those first petite 221-inch Fairlane V-8s.

For 1969, Ford capitalized on the small-block’s proven architecture by adding 1.28 inches of block deck and 1/2 inch of stroke to the basic 289/302 block to get 351 ci. The 351-ci Windsor small-block with 3.500 inches of stroke on a 4.000-inch bore was a quick response to Chevrolet’s 327- and 350-ci small-blocks as well as Chrysler’s 318/340/360 and AMC’s 343/360/390. It was the mid-size engine Ford needed and didn’t have prior to 1969. It made abundant torque, which is exactly what Ford’s product line needed to attract buyers.

The 351W engine has been very successful in its own right, especially considering its production life span has far outpaced the long-defunct 351C, 351M, and 400. However, did you know the Cleveland engine family was allegedly a replacement for the small-block and big-block? It has been said that Ford’s plan at the time was to have one V-8 engine family: the 335-series Cleveland displacing 302, 351, and 400+ ci. For reasons unknown today, Ford didn’t drop the small-block Fairlane V-8. Instead, 302 and 351W engine production continued and the 335-series engine family faded away in North America.

Because of the big move to go metric in the 1970s, Ford went from using cubic inches to measure displacement to liters and centimeters. In 1978 the 302 became known as the 5.0L V-8 and remained such until production ended in 2001. The short-lived 255-ci, a small-bore 302 with 3.000-inch stroke, was employed in 1980–1981 as a means to fuel economy.

The 351 Cleveland that arrived in 1970 quickly developed a performance image for itself thanks to large-port heads, wedge chambers, and rugged block architecture. The downside to the 351C on the street was its large ports, which delivered lackluster low- to mid-range torque, yet came on strong at high RPM. The 335-series block was an overweight design with an inadequate oiling system, which begs the question why use it at all if you have the option of a 351W-based engine? There is also a strong loyalty to the 335-series block, which has inspired the aftermarket to get on board with a couple of different blocks with great strength and better oiling systems.

Ford Australia did more with the Cleveland than did Ford’s North American Operations. It improved the Cleveland block’s shortcomings and created just the right combination of port size and combustion chamber design, building a far better 351-ci middle-block than Ford North America ever did. We will probably never know the entire story of why Ford did a parallel family of 351-ci engines.

It has been said that the 351 Cleveland came as a result of former General Motors boss Semon E. “Bunkie” Knudsen’s brief presidency at Ford Motor Company during the late 1960s. Because the 351C has poly-angle valves like a big-block Chevy and block architecture resembling Oldsmobile’s Rocket V-8s of the era, it is logical to assume Knudsen brought these nuances with him from General Motors via the engineering staff that followed him. However, it remains unknown as to how or why this engine became a reality.

The 351C had abundant torque at high RPM; it was a small-block Ford with the attitude of a big-block. Production of the 351C ended in 1974 in North America and in the 1980s in Australia. This leads us to the 351M and 400 middle-block V-8s. The 400 was a raised-deck version of the 351C introduced in 1972 to replace the FE-series 390 in passenger cars and ultimately in trucks. To improve manufacturing efficiency, Ford destroked the 400 to create the 351M in 1975, which enabled Ford to use a single block casting for both displacements. When the 351C was discontinued, it was replaced by the 351M. Externally, the 351M and 400 are identical in appearance. This makes the 351M a poor choice for an engine build. You might as well take advantage of the 400’s displacement because there’s virtually no difference in weight and size.

Although a lot folks call the 400 the “400M,” it was never so designated by Ford. It was introduced and recognized as the 400 in 1972. The 351M uses the “M” designation to differentiate it from the 351C, which is a different block. The debate continues as to whether Ford called it Midland or Modified.

The small-block Ford’s production history spans nearly 40 years.