Ford 428 Cobra Jet V8 (1969–1970 Mach 1)
The 7.0-litre FE-series big-block that placed the early Mach 1 near the top of the Mustang performance range.
Overview
Ford’s 428 Cobra Jet combined the large displacement of the FE-series big-block with cylinder heads, induction and exhaust components selected for stronger production-car performance. Introduced in the Mustang during 1968, it became one of the headline engine choices for the new Mach 1 in 1969 and remained available for 1970.
Ford advertised the engine at 335 horsepower and 440 pound-feet of torque. The rating placed it close to other Ford big-blocks on paper, but its broad torque delivery, large-port heads and four-barrel induction gave the Cobra Jet a strong reputation in road tests and drag racing.
Architecture
The 428 was a 90-degree overhead-valve V8 with a cast-iron block and cylinder heads. A 4.13-inch bore and 3.98-inch stroke produced 428 cubic inches, or approximately 7.0 litres. Hydraulic valve lifters and a single four-barrel carburettor made it more tractable for road use than a specialised competition engine.
The Cobra Jet specification used freer-flowing heads, an iron intake manifold and less restrictive exhaust manifolds. Mustangs ordered with functional ram-air induction fed the carburettor through a sealed bonnet scoop and carried the R engine code; non-ram-air cars used the Q code.
Cobra Jet and Super Cobra Jet
The standard 428 Cobra Jet could be paired with manual or automatic transmissions. Ordering the Drag Pack or Super Drag Pack created the 428 Super Cobra Jet specification, which added stronger rotating components and an external engine-oil cooler for repeated high-load operation. Ford retained the same advertised power rating despite the durability changes.
Both versions were available in the Mach 1 during 1969 and 1970. The 1971 Mustang’s engine range replaced the 428 with the newer 429 Cobra Jet family, closing the FE-powered Mach 1 period.
Key specifications
- Configuration: 90-degree, naturally aspirated overhead-valve V8
- Engine family: Ford FE
- Displacement: 428 cu in (approximately 7.0 litres)
- Bore × stroke: 4.13 × 3.98 in
- Induction: Single four-barrel carburettor; optional functional ram air
- Valve gear: Pushrod-operated overhead valves with hydraulic lifters
- Compression ratio: 10.6:1
- Advertised output: 335 hp at 5,200 rpm
- Advertised torque: 440 lb-ft at 3,400 rpm
- Mach 1 application: 1969–1970