Ford Boss 302 engine
|Ford Boss 302 V8 (1969-70 Version)|
|Manufacturer||Ford Motor Company|
|Displacement||302 cu in (4.9 L)|
|Cylinder bore||4 in (102 mm)|
|Piston stroke||3 in (76 mm)|
|Fuel system||Normally aspirated|
|Power output||Rated at 290 hp (216 kW) @ 5900 rpm|
|Torque output||290 lb·ft (393 N·m) @ 4300 rpm|
|Successor||Ford Boss 351 V8|
Two generations of Boss 302 Mustang sports cars—the 1969-1970 original and the 2012-2013 reintroduction—have been produced and, while their model-specific engines (the 1969-70 Cleveland-Boss variant and 2012-13 Coyote-Boss variant respectively) share their 302 cubic inch (5 liter) displacement and "race engine for the street" personalities, they also show how advances in engineering and manufacturing techniques have made possible modern "muscle cars" that greatly outperform the American-made muscle cars produced in the era 1965-1970. This is exemplified by the 2012-13 Boss 302 Mustangs, which, powered by the Coyote-Boss engines Ford Modular engine#Boss 302 (Road Runner) Variant, have 50% more power and torque than their 1969-70 ancestors, while simultaneously enjoying superior fuel economy and exhaust emissions performance.
In spite of the advance in performance seen in the most recent generation of Boss 302 engines, the original Cleveland-Boss engine had striking performance for its time, and even today would afford ample power in high-performance automotive applications. Because of its historical significance and its ongoing appeal (the Cleveland-Boss engine remains highly sought after, as are the 1969-70 Boss 302 cars, in the enthusiast marketplace), the balance of this article will explore the original Boss 302 engine of 1969-70 in depth, and it will be referred to as the Boss 302 engine. For details about the modern Coyote-Boss engine, see the Wikipedia article "Ford Modular engine".
The Boss 302 engine is a high-performance small-block V8 from Ford Motor Company. This engine powered the Boss 302 Mustang of 1969-70, but new engines of identical displacement and valvetrain design—and higher output—are available (see below).
The Boss 302 engine was a hybrid of small-block Ford V8s: it used the block of the small Ford Windsor engine and the heads of the larger Ford Cleveland engine. It was created for the SCCA's Trans-Am road racing series, and was fitted to the factory-made Boss 302 Mustangs of 1969-70.
The high nickel content block has a thicker deck, cylinder walls and beefy 4-bolt main caps. It is identified by screw in freeze plugs on the side of the block, pent roof valve covers, wide heads and a wide intake manifold. A Boss 302 has 8 valve cover bolts (because of the Cleveland heads) as opposed to the standard 302 having 6. The connecting rods are heavy, high strength steel forgings made for high rpm use. The crankshaft is a cross drilled high strength steel forging. The cam and lifters are high lift solid mechanical units.
The wide and large port Cleveland-style heads with staggered valve placement give the Boss 302 high power capabilities. Early units were typically characterized by very large intake and exhaust valves sitting in a small quench style combustion chamber.
The motor has a unique sound as a result of its solid lifter configuration. At idle, properly tuned, the engine has a great deal of 'chatter.'
The original designer, Larry Shinoda, came up with the Boss moniker as a way to pay homage to Bunkie Knudsen, the CEO at Ford and an outspoken proponent of the car's development. He just called him "Boss," he didn't call him "Mr. Knudsen," he was the Boss. So when he told his designers, "I want to design a car that's the coolest mustang out there. I don't want somebody else's name on it, like a Shelby, " so they call it the Boss Mustang, because they designed it for the new boss.
This engine was also available on a limited basis in the Mercury Cougar Eliminator & 1993 Cobra R.
Ford Racing Performance Parts BOSS 302 (2007-)
Ford Racing offers a "Boss 302" crate engine with displacement between 4.9 L (302 cu in) to 5.9 L (363 cu in). Entry level engines feature Ford Racing GT-40X Xtra Performance Turbo Swirl aluminum heads to retain stock exhaust locations and are rated at 340 and 345 hp (257 kW). Higher performance versions include Ford Racing's Z-head equipped 302 and 5.7 L (347 cu in) engines rated between 360 and 450 hp (336 kW), depending on configuration. The highest power version is a 5.4 L (331 cu in) rated 500 hp (373 kW). The double overhead cam, variable valvetiming Coyote-Boss engine is also available as a crate engine from Ford Racing. It is rated at 444 hp (331 kW) in 2012-13 Boss 302 street tune, though it is substantially more costly than the pushrod valvetrain crate engines.
The engine went on sale in 2007.
BOSS 302 was unveiled in 2006 SEMA show.
In 2006 SEMA, 4 builders used the 4.9 L (302 cu in) version of BOSS 302 engines:
- Dan Web – It was a 1933 Ford 3-window coupe with 390 hp (291 kW) BOSS engine.
- Galpin Ford – It was based on 2007 Ford Mustang featuring a 360 hp (268 kW) BOSS engine.
- Chip Foose – It was a 1970 Ford Mustang from the show Overhaulin'.
- Hotrods and Horsepower – It was a commemorative vehicle for the 2006 SEMA show with a 360 hp (268 kW) BOSS engine.
- "Boss 302 Engine and Boss 302 Mustang History and Specifications". 302w.com. Retrieved 2010-07-15.
- "Ford Racing brings the boss back with new line of BOSS 302 Crate Engines". Tuningnews.net. Retrieved 2010-07-15.