The 302 engine was introduced in 1968. That year a high performance 302 was not offered in the production cars. Ford was looking for a higher output small block though. The first attempt with the 302 was the "tunnel port". Copied from the 427 NASCAR heads, the intake push rods ran through a small tube in the head, surrounded by huge intake ports and valves. The motors were used in the Trans Am/Series II racing with mild success. The gains just weren't there from those exotic heads.
The next year, 1969, Ford came back with a better designed head. This head design had canted-valves, placed at an angle, allowing for larger intake and exhaust valves. It also created a semi-hemispherical combustion chamber. A special block was used with the heads. Ford called it the Boss 302. In addition to the heads the Boss 302 had:
- Four bolt mains
- Forged rods
- 10.5:1 compression
- A special windage tray in the oil pan
- Dual point distributor
- 290 degree duration solid lifter cam
- Aluminum intake manifold
- Huge 780 cfm Holley four barrel carb
And Boss it was. The Boss 302 was a close as you could come to buying a racing engine in a street car.
After winning the Manufacturers Trophy in 1966 & 1967, the Ford team had some stronger competition for 1968. Chevrolet was about to get involved in a very big way. Vince Piggins at Chevrolet saw the great potential for sales of Camaros by racing in the Trans Am series. He committed to SCCA that Chevrolet would support the series.
The 302 Camaros had a clear horse power advantage over the Mustangs. The ports and valves in the 289 heads were too small to produce the horsepower needed. The best head available was the high performance heads with small valves and ports. The new Ford 302 would be ideal for Trans-Am racing since it was under the 305 cid limit of class limit, but the hi-po heads would be too restrictive on the longer stroke of the 302 block. Ford started a crash development program to fix the problem at Ford Engine and Development during 1967. This effort would lead to development of the Boss 302 in 1969. It was also during this development time that the famous Ford "tunnel port head" came about. There was a "pull out the stops" effort to maximize the flow of the heads. The Ford engineers developed a brand new head with straight intake ports and the pushrod tubes running through the port. In the past the ports would twist around the pushrods. The intake valves were a huge 2.12" compared to 1.77" for the 289. The exhaust valves were 1.54" versus 1.44". Each port feed an individual cylinder. These heads became known as "tunnel ports." On paper this combination of the head design with the new 4 bolt main 302, looked unbeatable. The overhead valve pushrod engines competed for space with the intake ports. Conventional design places the pushrods along side a rectangular shaped intake port. These ports also steer around the pushrods. The Ford tunnel-port design runs the pushrod through the center of a round intake port, within a thin wall tube. The ports flow better due to their round shape and straight path. This design was first used on the 427, and then in 1968 on a special 302.
These round intake ports were 3.8 sq. in. in area at the intake manifold face. The Tunnel Port 302 cylinder heads feature 2.12" intake and 1.54" exhaust valves. By comparison, the 289 High Performance engine used 1.78" intake and 1.44" exhaust. These large valves completely filled the wedge shaped combustion chamber. The exhaust ports were larger than normal 289 & 302 heads. Two 540 cfm Holley's sat on a high-rise aluminum manifold. Two Autolite 4300 carburetors were used on the street version.
The race version featured domed pistons, yielding a compression ratio of 12.5:1, a solid lifter camshaft and forged steel crankshaft. The nodular cast iron rocker arms were shaft mounted, similar to those used on the Y-block V-8. Lubrication for these shaft mounted rockers required a special block with revised oil passages. Also used was a special road racing style 8-quart oil pan. Some used an early transistorized ignition.
The street version used flat-top piston, for 10.5:1 compression, and a hydraulic camshaft. The engine was complete with thermactor emissions control hardware, 289 Hi-Po style exhaust manifolds, and a thermostatic clutch radiator fan. SCCA rules required 1,000 engines in production for 1968 Trans Am homologation. As used in Trans Am competition the engines produced approximately 420 bhp with an 8,500 rpm redline
You have to finish races to win them, though. The tunnel port engines just didn't have lasting power. Engine failure after engine failure keep the Mustangs from finishing the races. Penske's Camaros dominated the 1968 Trans-Am racing.
1968 Tunnel Port 302 Cylinder Head Casting number C8FE- 6090-A
The Boss 302
After a very disappointing 1968 racing season Ford designed a new engine specifically for F.I.A. Trans Am competition in 1969, the Boss 302. The engine was introduced on April 17, 1969. About 8,600 Boss 302 engines were built.The Boss 302 block was essentially the next generation of 289 High Performance hardware, but features a forged steel crankshaft, 4-bolt main caps, and screw-in freeze plugs. These modifications were developed as part of the 302 Tunnel Port design. Street versions used connecting rods similar to the 289 Hi-Po while the Trans Am version used heavier 7/16" bolts.
The real magic of the Boss engines came from the canted-valve Cleveland cylinder heads. While the Boss 302 was normally considered a 302 with 351 Cleveland heads, these canted-valve heads were used first on the Boss before the rest of the Cleveland was developed. As fitted to the Boss, the heads feature steel spring seats, screw-in rocker studs, pushrod guide plates, and adjustable rocker arms. The Boss 302 and 351C-4V head casting were the same except for a minor difference in water passages. Camshafts were quite similar to the 289 Hi-Po. Due to the larger Cleveland-style heads, the Boss 302 weighs somewhat more than the normal 302, tipping the scales at 500 lbs.
The street version was conservatively rated at 290 HP @ 5800 RPM. During the '69 Trans Am season the racing engines were putting out 470 bhp at a 9,000 rpm redline.
Designed for the road racing environment, the engines featured a scraper style windage tray. This tray attached to four special main cap bolts with small threaded holes in their heads.
Exp 232/507
302 "F" 2V
1968-1973
1968-1973
302 "J" 4V
1968
1968
302 "G" 8V
1968
Tunnel Port
1968
Tunnel Port
302 "G" 4V
1969-71#
Boss
1969-71#
Boss
Engine Type
8 cylinder
90 degree,
Overhead Valves (OHV)
90 degree,
Overhead Valves (OHV)
8 cylinder
90 degree,
Overhead Valves (OHV)
90 degree,
Overhead Valves (OHV)
8 cylinder
90 degree,
Overhead Valves (OHV)
90 degree,
Overhead Valves (OHV)
8 cylinder
90 degree,
Overhead Valves (OHV)
90 degree,
Overhead Valves (OHV)
Displacement
302 cu.inches (CID)
302 cu.inches (CID)
302 cu.inches (CID)
302 cu.inches (CID)
Maximum torque
310 lbs./ft. @ 2,800 RPM
(1968)
295 lbs./ft. @ 2,600 RPM
(1969-71)
242 lbs./ft. @ 2,000 RPM
(1972-73)
310 lbs./ft. @ 2,800 RPM
310 lbs./ft. @ 2,800 RPM
290 lbs./ft. @4,300 RPM
Maximum Horsepower
210 BHP @ 4,400
(1968)
210 BHP @ 4,600 RPM
(1969-70)
210 BHP @ 4,600 RPM
(1971)
141 BHP @ 4,000 RPM
(1972-73)
(1968)
210 BHP @ 4,600 RPM
(1969-70)
210 BHP @ 4,600 RPM
(1971)
141 BHP @ 4,000 RPM
(1972-73)
230 BHP @ 4,800 RPM
250 BHP @ 4,800 RPM
(Shelby Cobra GT 350 only)
250 BHP @ 4,800 RPM
(Shelby Cobra GT 350 only)
240 BHP @ 5,000 RPM
420 BHP @ 8,000 RPM
(Trans Am Version)
290 BHP @ 5,800 RPM
470 BHP @ 9,000 RPM
(Trans Am Racing Version)
470 BHP @ 9,000 RPM
(Trans Am Racing Version)
Firing Order
1-5-4-2-6-3-7-8
(Number 1 cylinder on right bank, nearest radiator)
(Number 1 cylinder on right bank, nearest radiator)
1-5-4-2-6-3-7-8
(Number 1 cylinder on right bank, nearest radiator)
(Number 1 cylinder on right bank, nearest radiator)
1-5-4-2-6-3-7-8
(Number 1 cylinder on right bank, nearest radiator)
(Number 1 cylinder on right bank, nearest radiator)
1-5-4-2-6-3-7-8
(Number 1 cylinder on right bank, nearest radiator)
(Number 1 cylinder on right bank, nearest radiator)
Bore & Stroke
4.004" X 3.0028"
(101.6 mm X 76.0 mm)
(101.6 mm X 76.0 mm)
4.004" X 3.0028"
(101.6 mm X 76.0 mm)
(101.6 mm X 76.0 mm)
4.004" x 3.0028"
(101.6 mm X 76.0 mm)
(101.6 mm X 76.0 mm)
4.004" x 3.0028"
(101.6 mm X 76.0 mm)
(101.6 mm X 76.0 mm)
Compression Ratio
9.01:1
(pre 2/68)
9.51:1
(2/68 to 1970)
9.01:1
(1971)
8.5:1
(1972-73)
(pre 2/68)
9.51:1
(2/68 to 1970)
9.01:1
(1971)
8.5:1
(1972-73)
10.1:1
10.5:1
10.5:1 (1969-70)
Compression Pressure
130-170 psi
Oil Pressure (hot)
35 to 60 lbf/in2
35 to 60 lbf/in2
35 to 60 lbf/in2
35 to 60 lbf/in2
Mains
2-bolt
2-bolt
4-bolt
cross bolted
Carburetor
Autolite 2300-A (2V)
automatic choke
Autolite 4300 (4V)
automatic choke
automatic choke
Autolite 4300-A (2x4V)
automatic choke
Holley 4160 (2x4V)
manual choke
Holley 4150-C (4V)
manual choke
manual choke
Size of Carburetor
Autolite 435x2 CFM
Holley 540x2 CFM
Holley 540x2 CFM
Fuel
regular gas
premium gas
premium gas
premium gas
Intake Manifold
cast iron
cast iron
aluminum
(Shelby Cobra only)
aluminum
(Shelby Cobra only)
special aluminum with pushrods in intake
aluminum
Valve train
hydraulic lifters
hydraulic lifters
hydraulic lifters
solid adjustable lifters
Intake
1.773"-1.788"
1.773"-1.788"
2.01"
2.225" -2.375"
(1969)
2.185"-2.195"
(1970-71)
(1969)
2.185"-2.195"
(1970-71)
Exhaust
1.442"-1.457"
1.442"-1.457"
1.53"
1.647"-1.662"
(early 1969)
1.7075"-1.7125"
(1969-70)
1.7045-1.7145"
(1971)
(early 1969)
1.7075"-1.7125"
(1969-70)
1.7045-1.7145"
(1971)
Distributor
single point
vacuum advance
vacuum advance
single point
vacuum advance
vacuum advance
single point
vacuum advance
vacuum advance
dual point
vacuum advance
RPM limits
5,950-6,050
(1969)
6,050-6,150
(1970)
vacuum advance
RPM limits
5,950-6,050
(1969)
6,050-6,150
(1970)
Point Gap
.017"-.021"
.017" for IMCO
.021" for Themactor
.021" for Themactor
.020" both sets
Initial Ignition Timing
6 degrees
6 degrees
16 degrees
Dwell @ idle RPM
24-29 (manual)
26-31 (automatic)
26-31 (automatic)
26-31 for IMCO
24-29 for Thermactor
24-29 for Thermactor
30-33
Spark Plugs
Autolite BF-42
(1968-70)
Autolite BRF-42
(1971-73)
(1968-70)
Autolite BRF-42
(1971-73)
Autolite BF-42
Autolite BF-42
Autolite AF-32
(1969-70)
Autolite ARF-32
(1971)
(1969-70)
Autolite ARF-32
(1971)
Plug Gap
.032"-.036"
.032"-.036"
.035"
Long Block Weight
in lbs.
in lbs.
475
475
475
500
Tunnel Port 302
After winning the Manufacturers Trophy in 1966 & 1967, the Ford team had some stronger competition for 1968. Chevrolet was about to get involved in a very big way. Vince Piggins at Chevrolet saw the great potential for sales of Camaros by racing in the Trans Am series. He committed to SCCA that Chevrolet would support the series.
The 302 Camaros had a clear horse power advantage over the Mustangs. The ports and valves in the 289 heads were too small to produce the horsepower needed. The best head available was the high performance heads with small valves and ports. The new Ford 302 would be ideal for Trans-Am racing since it was under the 305 cid limit of class limit, but the hi-po heads would be too restrictive on the longer stroke of the 302 block. Ford started a crash development program to fix the problem at Ford Engine and Development during 1967. This effort would lead to development of the Boss 302 in 1969. It was also during this development time that the famous Ford "tunnel port head" came about. There was a "pull out the stops" effort to maximize the flow of the heads. The Ford engineers developed a brand new head with straight intake ports and the pushrod tubes running through the port. In the past the ports would twist around the pushrods. The intake valves were a huge 2.12" compared to 1.77" for the 289. The exhaust valves were 1.54" versus 1.44". Each port feed an individual cylinder. These heads became known as "tunnel ports." On paper this combination of the head design with the new 4 bolt main 302, looked unbeatable. The overhead valve pushrod engines competed for space with the intake ports. Conventional design places the pushrods along side a rectangular shaped intake port. These ports also steer around the pushrods. The Ford tunnel-port design runs the pushrod through the center of a round intake port, within a thin wall tube. The ports flow better due to their round shape and straight path. This design was first used on the 427, and then in 1968 on a special 302.
These round intake ports were 3.8 sq. in. in area at the intake manifold face. The Tunnel Port 302 cylinder heads feature 2.12" intake and 1.54" exhaust valves. By comparison, the 289 High Performance engine used 1.78" intake and 1.44" exhaust. These large valves completely filled the wedge shaped combustion chamber. The exhaust ports were larger than normal 289 & 302 heads. Two 540 cfm Holley's sat on a high-rise aluminum manifold. Two Autolite 4300 carburetors were used on the street version.
The race version featured domed pistons, yielding a compression ratio of 12.5:1, a solid lifter camshaft and forged steel crankshaft. The nodular cast iron rocker arms were shaft mounted, similar to those used on the Y-block V-8. Lubrication for these shaft mounted rockers required a special block with revised oil passages. Also used was a special road racing style 8-quart oil pan. Some used an early transistorized ignition.
The street version used flat-top piston, for 10.5:1 compression, and a hydraulic camshaft. The engine was complete with thermactor emissions control hardware, 289 Hi-Po style exhaust manifolds, and a thermostatic clutch radiator fan. SCCA rules required 1,000 engines in production for 1968 Trans Am homologation. As used in Trans Am competition the engines produced approximately 420 bhp with an 8,500 rpm redline
You have to finish races to win them, though. The tunnel port engines just didn't have lasting power. Engine failure after engine failure keep the Mustangs from finishing the races. Penske's Camaros dominated the 1968 Trans-Am racing.
The Boss 302 block was essentially the next generation of 289 High Performance hardware, but features a forged steel crankshaft, 4-bolt main caps, and screw-in freeze plugs. These modifications were developed as part of the 302 Tunnel Port design. Street versions used connecting rods similar to the 289 Hi-Po while the Trans Am version used heavier 7/16" bolts.
The real magic of the Boss engines came from the canted-valve Cleveland cylinder heads. While the Boss 302 was normally considered a 302 with 351 Cleveland heads, these canted-valve heads were used first on the Boss before the rest of the Cleveland was developed. As fitted to the Boss, the heads feature steel spring seats, screw-in rocker studs, pushrod guide plates, and adjustable rocker arms. The Boss 302 and 351C-4V head casting were the same except for a minor difference in water passages. Camshafts were quite similar to the 289 Hi-Po. Due to the larger Cleveland-style heads, the Boss 302 weighs somewhat more than the normal 302, tipping the scales at 500 lbs.
The street version was conservatively rated at 290 HP @ 5800 RPM. During the '69 Trans Am season the racing engines were putting out 470 bhp at a 9,000 rpm redline.
Designed for the road racing environment, the engines featured a scraper style windage tray. This tray attached to four special main cap bolts with small threaded holes in their heads.
After winning the Manufacturers Trophy in 1966 & 1967, the Ford team had some stronger competition for 1968. Chevrolet was about to get involved in a very big way. Vince Piggins at Chevrolet saw the great potential for sales of Camaros by racing in the Trans Am series. He committed to SCCA that Chevrolet would support the series.
The 302 Camaros had a clear horse power advantage over the Mustangs. The ports and valves in the 289 heads were too small to produce the horsepower needed. The best head available was the high performance heads with small valves and ports. The new Ford 302 would be ideal for Trans-Am racing since it was under the 305 cid limit of class limit, but the hi-po heads would be too restrictive on the longer stroke of the 302 block. Ford started a crash development program to fix the problem at Ford Engine and Development during 1967. This effort would lead to development of the Boss 302 in 1969. It was also during this development time that the famous Ford "tunnel port head" came about. There was a "pull out the stops" effort to maximize the flow of the heads. The Ford engineers developed a brand new head with straight intake ports and the pushrod tubes running through the port. In the past the ports would twist around the pushrods. The intake valves were a huge 2.12" compared to 1.77" for the 289. The exhaust valves were 1.54" versus 1.44". Each port feed an individual cylinder. These heads became known as "tunnel ports." On paper this combination of the head design with the new 4 bolt main 302, looked unbeatable. The overhead valve pushrod engines competed for space with the intake ports. Conventional design places the pushrods along side a rectangular shaped intake port. These ports also steer around the pushrods. The Ford tunnel-port design runs the pushrod through the center of a round intake port, within a thin wall tube. The ports flow better due to their round shape and straight path. This design was first used on the 427, and then in 1968 on a special 302.
These round intake ports were 3.8 sq. in. in area at the intake manifold face. The Tunnel Port 302 cylinder heads feature 2.12" intake and 1.54" exhaust valves. By comparison, the 289 High Performance engine used 1.78" intake and 1.44" exhaust. These large valves completely filled the wedge shaped combustion chamber. The exhaust ports were larger than normal 289 & 302 heads. Two 540 cfm Holley's sat on a high-rise aluminum manifold. Two Autolite 4300 carburetors were used on the street version.
The race version featured domed pistons, yielding a compression ratio of 12.5:1, a solid lifter camshaft and forged steel crankshaft. The nodular cast iron rocker arms were shaft mounted, similar to those used on the Y-block V-8. Lubrication for these shaft mounted rockers required a special block with revised oil passages. Also used was a special road racing style 8-quart oil pan. Some used an early transistorized ignition.
The street version used flat-top piston, for 10.5:1 compression, and a hydraulic camshaft. The engine was complete with thermactor emissions control hardware, 289 Hi-Po style exhaust manifolds, and a thermostatic clutch radiator fan. SCCA rules required 1,000 engines in production for 1968 Trans Am homologation. As used in Trans Am competition the engines produced approximately 420 bhp with an 8,500 rpm redline
You have to finish races to win them, though. The tunnel port engines just didn't have lasting power. Engine failure after engine failure keep the Mustangs from finishing the races. Penske's Camaros dominated the 1968 Trans-Am racing.
1968 Tunnel Port 302 Cylinder Head Casting number C8FE- 6090-A
The Boss 302
After a very disappointing 1968 racing season Ford designed a new engine specifically for F.I.A. Trans Am competition in 1969, the Boss 302. The engine was introduced on April 17, 1969. About 8,600 Boss 302 engines were built.The Boss 302 block was essentially the next generation of 289 High Performance hardware, but features a forged steel crankshaft, 4-bolt main caps, and screw-in freeze plugs. These modifications were developed as part of the 302 Tunnel Port design. Street versions used connecting rods similar to the 289 Hi-Po while the Trans Am version used heavier 7/16" bolts.
The real magic of the Boss engines came from the canted-valve Cleveland cylinder heads. While the Boss 302 was normally considered a 302 with 351 Cleveland heads, these canted-valve heads were used first on the Boss before the rest of the Cleveland was developed. As fitted to the Boss, the heads feature steel spring seats, screw-in rocker studs, pushrod guide plates, and adjustable rocker arms. The Boss 302 and 351C-4V head casting were the same except for a minor difference in water passages. Camshafts were quite similar to the 289 Hi-Po. Due to the larger Cleveland-style heads, the Boss 302 weighs somewhat more than the normal 302, tipping the scales at 500 lbs.
The street version was conservatively rated at 290 HP @ 5800 RPM. During the '69 Trans Am season the racing engines were putting out 470 bhp at a 9,000 rpm redline.
Designed for the road racing environment, the engines featured a scraper style windage tray. This tray attached to four special main cap bolts with small threaded holes in their heads.