Key to any engine's performance...
Key to any engine's performance personality is the cylinder head, and the X302 has plenty of charm thanks to the nice X306 aluminum assembly. This is the latest development of FRPP's bolt-on GT-40 head, often referred to as the GT-40X or Turbo Swirl. It's designed to give maximum performance in a durable, bolt-on architecture, and compares well with other bolt-on heads. At 22 pounds per assembled head, a pair of these shaves 50 pounds off the nose of your Fox.
Because camming has so much to do with an engine's personality, a closer look at the E303 should prove helpful. As the chart shows, it's a definite step up-or two-from the most common stock 5.0 H.O. cam, the E8ZE-CA:
If it's a hot-rod presence you're looking for, the E303 will deliver. On the other hand, if you're still trying to sneak home at night, or if smoothness and the last word in driveability are requirements, the X302 crate motor is too choppy. In that case, simply get the X302 and re-cam it with a stocker. It's not that much work considering the engine arrives on a pallet and you only need to loosen the rocker arms, set the pushrods to one side, pull the damper, and remove the front cover and timing chain to change the cam.
Two items normally associated with crate engines are not supplied with the X302. There is no flywheel or flexplate. This is both to keep the advertised cost low as well as allow the buyer to fit their own. A pilot bearing is fitted so there's no worry for manual transmission owners.
The intake ports on the GT-40X...
The intake ports on the GT-40X are tall and wide, measuring 178 cc in volume. The require a corresponding intake gasket, which FRPP offers as the M-9439-A50. No intake gasket is supplied with either the X302 crate engine or any intake manifold, so you must remember to order them separately.
At the other end of the engine, the water pump isn't supplied either. This is mainly because the X302 sells almost equally to Fox owners who need a reverse-rotation water pump and earlier Ford buyers using V-belt drives and standard-rotation water pumps. FRPP offers both styles of water pump separately- M-8501-G351 for standard rotation and, more likely for 5.0&SF readers, the reverse-rotation M-8501-C50. If you have a '94-'95 Mustang, then the short-nose M-8501-A50 water pump is what you need.
Of course, the X302 is sold sans intake manifold, so buyers must supply their own. That doesn't mean re-using the stocker. Its ports are far too small and we doubt the gasket would even line up. In any case, the result would be a doggy mess of an engine.
The large-port GT-40 heads and big cam need plenty of airflow to work at anything above putt-putt rpm, and the stock intake would be a deadly choke. Same goes for the stock throttle body and EGR spacer. Much better are any of the bolt-on street intakes. FRPP could supply their Cobra intake. Also the street-legal Edelbrock Performer or Trick Flow Street Heat castings are two good matches. A 70mm throttle body, 24-lb/hr injectors, and matching mass air meter are other needed accessories to get what the X302 has to offer.
We'll thoroughly cover installation of an X302 in our own project '91 hatchback next month, but for now understand that crate engines are not complete engines. They are the basic engines and feature all the major moving, wearable parts, but they are designed only to replace the core of an existing engine. In other words, there is a seemingly endless number of small items, such as stud bolts, brackets, pumps, compressors, manifolds, gaskets, ignition wiring, and on and on, that are not included in a crate engine. The idea is for you to supply new bits, or remove many items from the old engine and fit them to the new one.
This is a good system and works well for almost everyone. However, if you're interested in keeping your original engine intact for future restoration, or if you're starting with an engine-less project car, understand that you'll likely do best by having a complete donor engine for the small parts-it's that or be willing to use a large number of aftermarket bits for things such as the distributor, ignition wiring stand-offs, or vacuum hose attachments.
Ford Racing Performance Parts backs the X302 with its usual crate engine warranty. The term is 12 months or 12,000 miles. A power adder is not only not recommended but it voids the warranty. If you want a blower, turbo, or nitrous, FRPP recommends the X302B or X302E crate engines. They feature the stronger Boss block.
Assuming you add the short-tube headers of your choice and one of the intakes mentioned above, we expect the X302 to make maybe 300 hp to the tire, which is plenty of snort to reinvigorate a tired old friend. We'll find out for sure next month when we share the dyno results from our own X302 installation.
Even without dyno data, if you're coming from a stock-cammed 5.0, expect the X302 to be rev-happier up high and a touch soft off idle. Again, the idle has some chop or stutter to it and you'll likely find an elevated 900-rpm idle speed helpful, so brace yourself for some hot-rod vibes with the X302.
See you next month with our real-world results.
For the X302 engine, Ford...
For the X302 engine, Ford uses the 64cc combustion chamber version of the GT-40X head. This gives a nominal 9.0:1 compression ratio and seems to allow running on rot-gut 87-octane-if you have the ignition timing set at 10 degrees and keep your foot out of it on really hot days. The stainless steel valve package measures 1.94x1.54 inches.
Ford Racing dresses the X302...
Ford Racing dresses the X302 crate engine in these handsome and desirable-read more expensive-polished-aluminum valve covers. Also available separate as M-6000-K302R covers, they clear most EFI intakes. If they don't match your underhood scheme, they are easily traded or sold. That said, a little effort spraying your trim color between the ribs and leaving the rest polished could really set off an engine compartment.