428 Cobra Jet Engine Specs

Ford Motor Co. introduced the first V-8 engine in a low-cost car in 1932. The Ford FE-type V-8 engine was introduced in 1958 so that Ford buyers would have the option of powering their cars with a larger, more powerful engine. The original FE engine displaced 332 cubic inches. The 428-cubic-inch version of this engine was introduced in 1966 and was optional in full-sized Ford cars and Thunderbirds. Beginning in 1968, performance buffs wanting even more horsepower than the standard 428 engine produced could opt for the 428 Cobra Jet engine. The 428 Cobra Jet engine was available in certain Ford cars from 1968 to 1970.

Engine Specifications

  • The 428 CJ engine displaced 428 cubic inches and had a 90-degree V-8 cylinder configuration. The valves were located in the detachable heads and were operated by hydraulic lifters. The horsepower output of this engine was 335 at 5,400 rpm, while the torque rating was 440 feet-pounds at 3200 rpm. The bore and stroke was 4.132 by 3.984 inches and the compression ratio was 10.6-to-1 in 1968 and 1969 models and 11-to-1 in 1970 models.

Unique Cobra Jet Specifications

  • The Cobra Jet had four-bolt main bearing caps. Standard 428 engines had only two-bolt main bearing caps. The Cobra Jet also had high-efficiency cast iron intake and exhaust manifolds. A Holley 4150 four-barrel carburetor was used for fuel delivery and had an automatic choke in 1968 and 1969 models and a manual choke in 1970 models. The 428 CJ had a different crankshaft than other 428 engines, and was externally balanced by a harmonic balancer mounted on the end of the crankshaft at the front of the engine block.

Tune-Up Specifications

  • The 1968 and 1969 models used a single-point distributor, while the 1970 models used a dual-point setup. All points should be set at a .2-inch gap. The dwell angle should be checked with a dwell meter and set to between 30 and 33 degrees. The ignition timing should be set to 6 degrees behind top dead center. The cylinder firing order for the 428 CJ is 1-5-4-2-6-3-7-8. The idle speed should be set to 725 rpm on cars with manual transmission, and to 675 rpm for cars with automatic transmission.