How to Build a Cheap Drag Racing 302 Ford Motorby Richard Rowe
Ford's seminal 302 engine (later re-dubbed the 5.0) has been popular with budget-minded hot rodders for decades. Part of this reason is due to its inherent strength and simplicity, but a lot of it has to do with how little Ford has changed it over the years. As with Chevrolet's small-block engine, the aftermarket has had dozens of years to expand the range and reduce the cost of the parts they offer for this engine. When combined with modern power-makers, such as nitrous, the 302 is more than capable of producing 400+ horsepower for little more than the cost of a stock engine rebuild.
Start with any 302 block, but try to find one from 1985 and up since it will already have provisions for a roller camshaft.
Purchase a set of flat top pistons (from Ford Motorsport, TRW or Keith Black) with machined valve reliefs and designed to provide 10:1 compression with a 59 to 60 cc combustion chamber cylinder head. Stock 1989 5.0L HO pistons will work if you can find them.
Assemble the rotating assembly with a stock 5.0L crankshaft, a set of 5.0L rods and the specified pistons with stock-type rings. Take the assembly to a machine shop to have it balanced and install it in the block. Install a Ford Motorsport E303, X303 or F303 cam, or any of the similar units from Indy, Lunati or your favorite manufacturer.
Long Block and Breathing
Install a set of GT-40P cylinder heads from a late 1990's Ford Explorer or a set of GT40 heads from an early 1990's Mustang 5.0L. These are some of the best castings Ford ever produced for this engine, and are still fairly cheap and available used. Install a set of 1.7:1 roller-tipped rocker arms on the heads.
Purchase any used aftermarket manifold for the 302 that is designed to function in the 3,500 to 6,500 power band. The Edelbrock Performer RPM is a good choice, but Holley, Weiand and Ford Motorsport also have similar offerings.
Install a used set of 5.0L Mustang "shorty" headers, generally available at auto swap meets for a reasonable price. Aftermarket headers, such as those made by Hooker, BBK and Competition Engineering, are better and are just as easy, if somewhat more expensive, to procure used.
Add a distributor designed for a carbureted 302 but make sure to install the correct distributor gear for your cam. The newer camshaft is designed for use with a soft bronze distributor gear, not the hardened steel gear used for older camshafts.
Install a "wet" nitrous plate system (which carries both nitrous and fuel) onto the intake manifold and jet it conservatively for a 100 horsepower shot. You should be able to get away with a 150 to 200 horsepower shot later, but it's best to start out small and work up.
- This combination should be good for about 400 horsepower and as much as 500 if you opt to use the stronger aftermarket pistons. Aside from the cost of the nitrous itself, this setup should cost you little more than a stock rebuild using all brand new parts.
- Consider having the head's intake ports matched to the intake manifold gasket. This modification will help your late-model GT40P heads work better with the old-school carbureted intake setup.
Items you will need
- dragster engine image by Robert Young from Fotolia.com