Ford Boss 302 engine
|Ford Boss 302 V8 (1969-70 Version)|
|Manufacturer||Ford Motor Company|
|Displacement||302 cu in (4.9 L) 5.0 Windsor|
|Cylinder bore||4 in (102 mm)|
|Piston stroke||3 in (76 mm)|
|Fuel system||Normally aspirated|
|Power output||290 hp (216 kW) @ 5900 rpm|
|Torque output||290 lb·ft (393 N·m) @ 4300 rpm|
|Successor||Ford Boss 351 V8|
Sharing the same 302 cu in (4.9 L) displacement, an entirely new Boss 302 engine was introduced for the 2012 Ford Mustang using a variant of Ford's Modular engine.
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. There is a conflict between the actual displacement in cubic inches and the advertised metric displacement.
The high nickel content block has a thicker deck, cylinder walls and 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. The Boss 302 has eight valve cover bolts (because of the Cleveland heads), while the standard 302 has six. The connecting rods are heavy, high strength steel forgings made for high rpm use and featured 3/8 inch bolts with a unique football shaped head. The crankshaft is a cross drilled high strength steel forging. The cam and lifters are high lift solid mechanical units. The cam featured 290 degrees duration and .477 inches of lift.
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 (2.23 inches) and exhaust (1.70 inches) valves sitting in a small quench style combustion chamber. Exhaust valves were sodium-filled to aid cooling. Valve springs were dual units with an inner and outer spring to minimize harmonic resonance at high RPM. Fuel was provided by a Holly 780 cubic foot per minute double pumper carburetor. Ignition was handled by a dual point distributor firing then unique AF 32 Autolite sparkplugs specified for their smaller size (5/8 inch wrench vs. 13/16 inch wrench) so as to fit within the tight confines of the combustion chamber along side the very large valves.
The motor produces a unique sound as a result of its solid lifter configuration. At idle, properly tuned, the engine has a great deal of 'chatter.'
The power output on this engine was a conservative 290 hp at 5,200 RPM with matching torque of 290 foot pounds at the same RPM and competes well with other high performance smallblocks, such as the Chevy 302, the Chrysler 340, and AMC 360. Although the factory specified maximum power at 5,200 RPM the engine was allowed to rev well beyond that to a 6,250 RPM rev limited maximum.
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 optional in the Mercury Cougar Eliminator, with 169 produced in 1969 and 469 produced in 1970.
Ford Racing Performance Parts BOSS 302 (2007-)
In 2007, Ford Racing began marketing new crate engines using the "Boss 302" moniker with displacements between 4951 cc 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 Ford Modular "Coyote-Boss" engine with double overhead cam and variable valve timing 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, and is more expensive than the pushrod valvetrain crate engines.
The new Boss 302 engine was unveiled in 2006 SEMA show.
In 2006 SEMA, four builders used the 4951 cc (5.0 L) version of the new Boss 302 engine:
- Dan Web – a 1933 Ford 3-window coupe with 390 hp (291 kW)
- Galpin Ford – based on a 2007 Ford Mustang featuring a 360 hp (268 kW)
- Chip Foose – a 1970 Ford Mustang from the show Overhaulin'.
- Hotrods and Horsepower – a commemorative vehicle for the 2006 SEMA show with a 360 hp (268 kW)
- "Boss 302 Engine and Boss 302 Mustang History and Specifications". 302w.com. Retrieved 2014-04-19.
- "Ford Racing brings the boss back with new line of BOSS 302 Crate Engines". Tuningnews.net. Retrieved 2010-07-15.