This summary comparison of major 428 engine components was prepared by Bill Barr, Principal Engineer for the 428 Cobra Jet engine development program at Ford Motor Company. Unless specifically noted this comparison does not include the parts that are unique to the 428 Super Cobra Jet engine.
Component | Tasca KR-8 (estimated) | 428 Police Interceptor | 428 Cobra Jet |
---|---|---|---|
Cylinder Heads | C3AE-6049-H | C7AE-6049-D (Production 390 - 410 - 428 - 428 PI) | C8OE-6049-N Similar to earlier C4AE-H but with enlarged intake and exhaust ports, valve seat throat clearance cutter, and improved water jacket core print |
Intake Manifold | Aluminum PI | Aluminum PI | Cast iron, similar to PI with revised carburetor bore risers, relocated carburetor pad, and radiused riser to upper and lower logs to improve fuel/air distribution |
Exhaust Manifolds | Exhaust headers | Production 390 GT cast iron light car manifolds | Redesigned high flow, low restriction unique to the 428 CJ |
Air Cleaner | Unknown | Light car 390 GT | Redesigned dual inlet with hot/cold start-up system. Upgrade available to low restriction ram air (seal to hood) and "shaker" hood with hot/cold start-up system |
Thermactor Secondary Air System | None | Air inlet to exhaust manifolds | Air inlet to exhaust ports |
Carburetor | 635 or 650 CFM Holley 1.6875" x 1.6875" primary and secondary bores | Ford P&E 600 CFM 4V | Holley 735 CFM 4V (780 CFM modified with FT (Ford Truck) booster nozzles for improved atomization and emissions) 1.75" x 1.75" primary and secondary bores |
Crankshaft | Production 428 PI | Production 428 PI | Production 428 PI (Note that Bill's original notes used for this page said "Special 50% nodularity for improved strength", but we can't find any evidence that suggests that the original CJ crank was anything other than the same crank used with the 428 PI) |
Connecting Rods | Production 428 PI | Production 428 PI | Larger bolts; SCJ had material added to outside of big end |
Crankshaft Mass Balance | Production 428 PI | Production 428 PI | Rebalanced special crankshaft |
Crankshaft Damper | Production 428 PI | Production 428 PI | Retuned damper for strengthened crankshaft |
Camshaft | 390 GT | 390 GT | 390 GT |
Valve Springs and Valve Toss Speed | Production 428 PI (6000 RPM) | Production 428 PI (6000 RPM) | Revised valve springs for higher valve toss speed (6700 RPM) |
Intake Valves | Regular Production | Production 428 PI | Improved material with modified, polished backside fillet radius |
Exhaust Valves | Regular Production | Production 428 PI | Improved material with modified, polished backside fillet radius |
Oil Filter Adapter | Production 428 PI | Production 428 PI | Unique adapter with oil in and oil out provisions for external oil cooler (SCJ only) |
Flywheel and Clutch | Production 428 PI | Production 428 PI | Unique high (90%+) nodular iron with 10,000 RPM burst strength; high RPM clutch assembly |
Oil Pump and Oil Pressure | Production 428 PI | Production 428 PI | Higher relief valve pressure, unique oil filter adapter, and external oil cooling (SCJ only) |
Transmission | Automatic only | Automatic and manual transmission available | Automatic and manual transmission available. Upgraded C6 with higher shift speed and modified clutch packs |
Exhaust System | Unknown | Standard 390 GT Mustang | New 6" HG with miminal exhaust restriction mufflers and pipes |
Rear Shock Absorber Mounts | Production 1967 Mustang | Production 1967 - 1968 Mustang | Revised for staggered shock absorbers to eliminate reverse gear tramping |
Power Output | Unknown | ≈ 295 "B" Curve HP and 395 ft-lb Torque | ≈ 340 "B" Curve HP/420 ft-lb Torque |
The engine engineering personnel who worked for me on the 428 program were Paul Lampela, Frank Gondoly, Bob Snider, and Matt Hecht.