1991 Ford Mustang X302 Crate Engine Install - Uncrate & Barrel - Ford Racing X302 Install
Dropping In An X302 Crate Engine Gets An Old Fox Up To Speed
From the December, 2010 issue of 5.0 Mustang & Super Fords
By Tom Wilson
Photography by Tom Wilson
This is a crate engine story that talks about everything except the crate engine. We did that last month when we detailed our new M-6007-X302 engine.
Just in case you missed it, the X302 is Ford Racing's affordable stock-block small-block. At a competitive $3,495, it's ideal for real-world projects, either fuel-injected, such as our '91 5.0 LX hatchback, or carbureted. Under best conditions, it's rated at 340 hp and has a rumpty-rump E303-cam persona.
This month we address everything else surrounding a crate-engine install. That's because it's natural to get excited about the crate motor and the intake or blower you're going to put on it, but oh-too-easy to overlook the mundane, such as engine mounts, fan clutches, and radiator hoses. It sounds pedantic, but you must have a plan. An engine change is relatively easy work-a collection of many small, easy steps-but the key word is "many." Not thinking it through is begging for frustration and disappointment.
Slipping in Ford Racing's...
Slipping in Ford Racing's X302 crate motor has invigorated our '91 LX to no end. The process is straightforward, but considering the lifting tools required and the numerous steps involved, it's a pro job for all but experienced enthusiasts. For someone wanting to step up their wrenching game, however, it's a great first "big" project, as long as you have some experienced help.
On its second time around,...
On its second time around, an odometer like this means your old Fox is going to need more than just a new crate motor. Consider all supporting systems, such as cooling and fuel supply, when penciling your plans.
When ordering a crate engine,...
When ordering a crate engine, it's best to have it shipped right to where the engine installation will take place. If not, then it's good to have friends with a forklift. Tom Aberle got our X302 into our F-350 shop truck for us, and he eventually filled the bed with the engine, transmission, driveshaft and boxes of small parts. There's a lot of stuff involved.
The first step is setting the scope of the work. Are you changing just a blown engine in an otherwise great-running car? Or, like us, are you making the pivotal improvement on a high-mileage daily driver? Obviously, you need to set a budget.
As you think through where you want to be at the end of the project, we think you'll be surprised at how many parts you want to change besides the core engine. Don't be surprised when your simple crate-engine job turns into a full-car restoration. That's what happened to us.
Our case is hyper-typical. Our '91 LX hatchback had 198,062 miles when it's original engine came out. As a daily driver, the car was up and running, but it was used up in so many mechanical ways. The valve covers and oil pan had never been off, nor had we changed the ignition wires or upgraded the stock exhaust manifolds. The radiator had who knows how much gunk in its tubes, the power steering pump was grrrring a little, the engine mounts had sagged. Furthermore, the clutch was unknown, the transmission noisy, and the U-joints were likely original.
We opted to change everything. Along with recent upholstery and other interior work, plus cutting and polishing the paint, a new set of mechanicals would give us a fairly new Fox-and no new car payments, big insurance, or registration bills.
GTR Performance did our engine...
GTR Performance did our engine installation, and they had all sorts of tricks to ease the job. GTR main man Ricardo Topete started by wrapping the front of our 5.0 with packing plastic. The material sticks enough to stay, doesn't hurt the paint, leaves no residue, and kept all sorts of nasty chemicals off our fenders.
It won't be long before people...
It won't be long before people will be searching for vintage 5.0 speed parts, so keep your eyes open. As we were undoing the EGR hose tanglement on the passenger side, we noticed our old plug wires were marked "Motorsport." The new ones are marked "Ford Racing." We think the old ones are worthy souvenirs. You'll want the wiring separators and standoffs, too.
Aftermarket fuel rails are...
Aftermarket fuel rails are not necessary for the X302 crate engine, so plan on re-using your stocker. The chrome finish cleans easily and we also re-used our existing Aeromotive adjustable fuel pressure regulator. These 19-lb/hr injectors were swapped for FRPP 24-lb/hr units, however.
We're covering most of our parts details in the photos and captions, but in general overview, consider the following. You need a place to work. Do you have a home shop? Great. If not, go with a local shop. We chose GTR Performance, and the staff not only did the work, but provided indispensible knowledge and support services (receiving, research, and bargaining with suppliers).
All crate engines come bare from at least the valve covers on up. Select the intake manifold, throttle body, and cold-air intake that work with your heads and cam. We chose Edelbrock's Performer RPM II because it's a good power maker and has an E.O. number.
What about your front-of-engine accessories? The alternator, water pump, power steering, and so on are normally changed as-needed, but you might want to upgrade now to reset the clock on high-mileage units and gain shiny new parts to match your new engine.
Interestingly, we swapped what we thought was a noisy but still working power steering pump against Ricardo Topete's recommendation at GTR. He was right. Our zillion-mile PS pump was much quieter than the one we got from NAPA. Water pumps we would change no questions asked, but alternators, air pumps, and so on we'd clean and re-use.
If the original radiator is old or you're stepping up the power with the new crate engine, then a new radiator is smart; ditto for the fuel system. Old in-tank fuel pumps, tired filters, and new injectors don't mix.
First time out after 19 years...
First time out after 19 years and 198,062 miles, it was a big moment when our engine lifted out. As the engine hangs from the hoist is a good time to strip off the parts you'll reuse. It is not necessary to remove the hood if you tie it back, nearly upright.
Two chronic problems in this...
Two chronic problems in this era of tired 5.0s show here-wasted engine mounts and leaking oil-level senders. New engine mounts are absolutely mandatory with a crate engine. Urethane mounts are likely best as they are extremely durable and offer a minimal increase in NVH. The obvious oil washing from the oil-level sender is one issue you won't have with the X302 crate engine, because its oil pan doesn't have the sender or a hole to put it in. You can simply tape off the electrical leads to this sender and remember to check the dipstick occasionally.
Looking humble but still in...
Looking humble but still in the chase is our viscous fan clutch. Unless it's leaked or offers zero resistance when spun, you can likely reuse the fan clutch as they've proven durable. Cadmium plating makes them easy to clean, too. We washed this one and put it on our new engine.
Which brings up injectors-are they properly sized for the crate motor you're installing? You need new engine mounts unless you already have aftermarket mounts. We recommend urethane mounts as they hardly affect vibration but are vastly more durable than rubber. Don't forget to change the transmission mount, too.
Moving beyond the engine compartment, consider the clutch, transmission, and driveshaft, dealing with each as necessary. Unless you just installed a new clutch, plan on a new one with the new engine. Transmissions are typically OK and most Mustang transmissions are easy enough to change on their own, so they need not be changed automatically along with the engine.
Driveshafts are forever, but U-joints aren't. Replace them as necessary is the fiscally responsible advice; we swapped in an FRPP aluminum driveshaft to easily gain new U-joints and lose a few pounds.
And what about the rest of the car? Are the tires good? Do you need a brake upgrade to match your new power? The cost must be factored into the budget and the parts acquired before grabbing the wrenches.
One of the best deals going...
One of the best deals going is FRPP's M-6052-B silicone hose kit. Durable as sin, these seemingly indestructible hoses will outlast any engine and are an excellent upgrade. Developed for police-pursuit Foxes, these molded hoses offer a perfect OEM fit. Well ... Ricardo finds trimming a quarter-inch off the small 90-degree thermostat bypass hose makes it easier to install.
Everyone has their own clean...
Everyone has their own clean quotient, but don't forget that when the engine is out there's no better time to clean from the firewall forward. It's possible to spend days on this-we dedicated over 15 hours on the job-so plan generous downtime in your schedule if you're looking to impress. We found Simple Green Max Degreaser from a gallon jug, diluted 50-50 with water and put in squirt bottles, was amazingly effective yet didn't hurt the paint.
Our X302 came on a wooden...
Our X302 came on a wooden pallet closed with cardboard. Stripping back the cardboard left the engine nicely exposed, supported, and easy to dress. Because the oil pan rails hold the engine, almost everything could be bolted to the engine, including the engine mounts, flywheel, clutch, headers, and so on. With a Mustang-friendly double-sump pan, the X302 is ready-to-go in that respect. However, it comes with an SN-95 dipstick; we substituted our existing Fox dipstick, which works fine.
Making the Swap
We don't have the room here to detail an engine change step-by-step, but in general, it's best to unhook the original engine enough to lift it out of the car, then strip it as necessary while it's out on the ground. At the same time, the new crate engine can be dressed with as much as you can get away with-headers are a joy to install out of the car-then put into the car.
Remove the vulnerable radiator before the engine, and you'll find pulling the transmission makes handling the engine that much easier. You might want to support the rear of the engine with a floor jack or stand once the transmission is out, especially if the engine mounts are shot.
Obviously you need some large tools, such as an engine hoist. A transmission jack and muffler stand (if you're lucky enough to work on a hoist) are nice, but not absolutely necessary. A suitable concrete floor is a must, and it's best to plan on having the car down for a week, typically because last-minute parts are required. A helper or two are mandatory in spots as well. For these reasons, most folks opt for pro installation, but if you have the tools, go for it.
Air conditioning turned out to be the least of our installation worries. By unbolting the compressor from the engine and laying it over a fender, it was possible to swap engines without breaking into the air conditioning system. That means no trip to an AC shop to have the system discharged and refilled later. You have to work around the bulky AC hoses and compressor, but it's still the best option.
Another small, easily over-looked...
Another small, easily over-looked part is the oil-pressure sending unit. We washed our old one and threaded it into the new engine. The chrome fuel-pump block-off plate is stock on the X302; a fuel-pump eccentric is too, so carbureted applications require simply bolting on the engine-driven fuel pump. The FRPP oil filter is included with the engine; a water pump is not. We ordered FRPP's M-8501-C50 reverse-rotation aluminum pump, which fits all '86-'93 Mustangs.
Ford Racing fits its top-of-the-line...
Ford Racing fits its top-of-the-line polished valve covers to the X302, and they look great. We wanted to stay with a black theme in our black Fox, however, so we ordered a black Edelbrock intake manifold. While dressing the engine at GTR, we lucked out when another customer wanted to trade their black valve covers for our polished set, giving us an all-black top end. It was another way choosing our local shop paid off.
Ricardo told us not to but...
Ricardo told us not to but we insisted on fitting a new power steering pump, just to reset the clock on what was rapidly becoming a "new" 5.0. That meant pulling the taper fit pulley off the old PS pump, which Ricardo is getting ready to do here. We should have listened, as the new pump is way louder than the old one we removed! "Typical!" said Ricardo. Stick with your existing pump if it's quiet and doesn't leak. Rebuilding your stock pump is a good option as well.
Because we wanted functioning EGR, we wanted to use the stock threaded fittings at rear of each head. These came blocked with steel fittings on the X302, and sealed with red Loctite. They wouldn't unscrew, so Ricardo drilled them to form an air passage. Greasing the drill bit and fishing for leftover chips with a magnet got the job done. As there is no gasket at this head-to-EGR-pipe connection, Ricardo used copper ultra-high-temp RTV silicone as a gasket.
If you have stock rubber heater hoses sticking out of the firewall, carefully remove them. Slitting them lengthwise first is smart as the heater-core nipples have a tendency to rot and pull out now that Fox heater cores are 20 years old. This begs the smart decision to replace the heater core-a hateful under-dash job you just might have to put off for a few more paychecks. If so, and your Fox already has silicone hoses, just leave 'em. The hoses might be slightly stained, but they can be safely reused, thus avoiding a wrestling match with a weakened heater core.
Finally, consider what to do with your old engine. Most people are happy enough to donate the old hulk to the install shop. Also, a used T-5 transmission that isn't beat to death is trade-worthy, so you might inquire if your core parts have any value to the shop.
With the GT-40X cylinder head's...
With the GT-40X cylinder head's larger-than-stock exhaust ports, the stock crimped-tube manifolds are choked. This restriction makes using a proper 15/8-inch, mandrel-bent, short-tube header a must. FRPP has just the part in these M-9430-P50 stainless steel short-tubes, which fit great and are built to last. As a bonus, there's never an easier header installation than when the engine is out of the car. As a caution, we didn't like the fit of the supplied gaskets (bolt hole misalignment) and stock gaskets have under-sized port openings, so we used Fel-Pro 1415 gaskets, which fit in all dimensions, were thicker, and obviously of high Fel-Pro quality.
After nearly 200,000 miles,...
After nearly 200,000 miles, another system we wanted to reset was the ignition. With stock 5.0 distributors rarely needing replacement, we opted for a new harness, cap, and rotor. The wires are especially nice as they are fully built, numbered, and the correct length. Even so, we ended up with a high-rpm miss, so a new coil may be in our future as well...
Also on our hit list was a...
Also on our hit list was a fresh starter. Ford Racing carries the latest Ford corporate mini-starter, PN M-11000-A50. It packs plenty of cranking torque, weighs less than our stock starter, and has OEM reliability. Its modern sound and high-rpm cranking still surprise us every time we hit the key. Installation requires bypassing the fender-mounted starter solenoid, but that's no more than moving a wire from one post to another.
And value is just what the fresh engine will bring to your used 'Stang. If you do the job right, this kind of upgrade should bring years more enjoyment to your classic Mustang.
On The Dyno
The last two miles our 198,062-mile stock engine made were on GTR's chassis dyno. It put out an excellent 207 hp to the tire. Helping factors were underdrive pulleys and precious little internal engine friction. It was, you might say, well broken in.
Don't let the power fool you, however. The old engine burned oil like a steamship smokestack-when it wasn't pouring out of the front crank seal and oil level sender-plus the oil pressure was dangerously low and wavering with rpm. It was surely ready to spin a bearing. Moreover, it was with one part per million from passing its next smog test.
Latemodel Restoration is a...
Latemodel Restoration is a godsend for vintage Fox builds. The company supplied endless parts for our 5.0 interior work; for this engine project, we bought a new engine fan, radiator tank, serpentine belt, and battery cables. Typically 5.0 fans are cracked and ready to fail by now, and the radiator tanks are stained nearly opaque. The belt and cables are maintenance items; we especially wanted stock cables to avoid the bargain-store look of crimping our own cables.
Ford Racing's M-8005-C aluminum...
Ford Racing's M-8005-C aluminum radiator was already on our wish list both to give us a fresh, unclogged heat exchanger, but also extra cooling capacity for both our hot desert climate and higher powered engine. We found it necessary to bend open the radiator support's lower flanges to get the radiator fully seated (a two-minute plier job). FRPP also says to bend the stock upper retention brackets but we used a vastly better Steeda mount instead. Fitting the stock radiator shroud to this radiator is a pure fabrication job. You'll likely drill a couple of small holes in the shroud to relocate its mounting bolts to keep the fan from hitting.
A new crate engine without...
A new crate engine without a fresh flywheel and clutch is like buying shoes with no laces. Again, FRPP has the hot setup in its M-7560-C302N King Cobra clutch kit. A new release arm is typically needed because its throw-out-bearing spring retainers are either broken or too loose to work; because the clutch fork is not part of the clutch kit, you need to order one separately. It's the same with the clutch cable. Use an OEM Ford cable for the later Foxes for maximum durability. Ricardo says the release arm issue is a common "gotcha" on weekend, do-it-yourself clutch jobs, so he keeps them in stock. Something else you absolutely need that no one mentions is an M-6397-A302 dowel-pin kit for the flywheel.
Our new X302 bumped the needle to 270 hp tuned with 13 degrees of initial timing and the fuel ratio leaned to 12.6:1. That seems under-achieving compared to the advertised 340 hp, but not really. Ford rates these engines with a carburetor, short-runner intake manifold, and long-tube headers. At the tire, 340 flywheel horsepower would be 289 rwhp, and you still need to subtract a bunch for the long-tube headers and short-runner intake.
Looking at it the other way, Ricardo says he typically sees 280 rwhp for a street-legal "head, intake, and cam" 5.0 such as ours. Swapping back to our underdrive pulleys would put an additional 10 hp on the clock, plus a couple more for a K&N air filter and cold air intake, and maybe a touch less fuel for 282 rwhp. (We have a paper filter and stock rubber inlet hose.) Either way, that puts our X302 right where it belongs, and it will only get better with more break-in miles.
Speaking of break-in-our X302 had just 603 miles on it when dyno'd. We're sticking with mineral oil until 3,000 miles. That's Ricardo's normal recommendation before switching to synthetic.
Edelbrock supplied its excellent...
Edelbrock supplied its excellent Performer RPM II intake and 70mm throttle body and EGR spacer. These are CARB E.O. numbered parts, which is important to us, and prior testing has shown this is a good bolt-on 5.0 intake. The intake is available in light gray/aluminum or black, and you can see how we rolled. You'll need to either reuse your original intake bolts (more parts to clean) or get new ones. The RPM II does not provide a mount for the 5.0's two bulky electric harness connectors as the stock intake does, so stuffing the harness connectors under a rear intake runner and tying them in place is necessary.
Intake manufacturers typically...
Intake manufacturers typically don't supply gaskets with their intakes, so you must obtain these separately. Stock gaskets are trimmed too small to work, and of the aftermarket gaskets, the popular Fel-Pro 1262 just fit the GT-40X's big intake ports. You definitely want to have these gaskets on hand or they'll hold up your installation in a hurry.
With the engine compartment...
With the engine compartment thoroughly cleaned and our X302 dressed with headers, lower intake, thermostat housing, oil sending unit and so on, the big moment arrived. Dress the engine as fully as possible first because it is so much easier than in the car. Note again how we never removed the hood; there's no need, and there's no safer place in the shop for a hood than on the car.
Even at these most conservative numbers, our X302 gained 63 hp over our original stocker-you could say it really gained 73 hp if you account for the underdrive pulleys. Even better, we were expecting to decisively lose bottom-end torque, but really didn't lose that much. The numbers wander back and forth between the two engines below 3,300 rpm, and you can squeak the numbers by playing with ignition timing, so we're calling it nearly a draw to that point as the area under the torque curve about evens out.
Above 3,300 rpm the X302 simply soars away from the old 5.0 in both power and torque. All said, great results for a crate engine that's less expensive than rebuilding the old engine!
Ricardo installed the engine...
Ricardo installed the engine first, then the bellhousing and transmission. It's a great procedure allowing maximum working room. In fact, we might remove the transmission on future engine jobs even if we wouldn't have to otherwise because setting the engine was so easy without the bellhousing and input shaft in the way. Another advantage is the ground strap at the rear of the left cylinder head is dead simple to reach from under the car, as seen here.
There's nothing tricky about...
There's nothing tricky about installing Ford Racing's M-7003-Z transmission, especially when you have a transmission jack! All connections are simple stock hook-ups and take little time. Because the new transmission is supplied without a bellhousing, you'll need to swap on your old one. Bolting the bellhousing to the engine first, then sliding the transmission into the bellhousing worked great for us.
Two quarts of Royal Purple...
Two quarts of Royal Purple synthetic trans fluid went into our gearbox. Ricardo uses Royal Purple, saying the synthetic seems to offer a little easier shifting, especially when cold.
Note: Stock baseline set with 10 degrees ignition timing and underdrive pulleys. The X302 figures reflect 13 degrees ignition timing and stock pulleys. Stock torque would improve with more timing; X302 power would gain with underdrive pulleys.
Because our '91's T-5 gearbox had 198,000 miles on it and was making increasingly more gear whine, we installed Ford Racing's M-7003-Z transmission as a replacement. This is the world-class version of the venerable T-5, a transmission we've come to love for its light shifting and minimal weight.
Easiest of all to install...
Easiest of all to install was our new Ford Racing aluminum driveshaft-just slide it in and bolt it up with the stock bolts. Curious, we first pulled out the bathroom scale and found the stock shaft checked in at 19 pounds, the FRPP aluminum replacement at 14 pounds, so we saved 5 pounds right here. After the driveshaft, the exhaust can be hooked up. Expect a different fit with new headers. We ended up with a small leak our muffler shop cured by cutting and re-clocking the belled end on the right X-pipe-to-header flange. A common fix, says Ricardo.
There are few difficult operations...
There are few difficult operations in a 5.0 engine installation, but a couple of spots might try you patience. Ricardo has found a sawed-off 11/8-inch open-end wrench a big help. It's an easy fit for the water pipe at the intake manifold and the EGR fitting on the passenger-side exhaust.
You'll need the entire front...
You'll need the entire front engine dress off your original engine, especially the brackets and bolts. It pays to get these parts cleaned as much as possible before installation, and if you're building a looker, you'll want to consider paint, powdercoat, or phosphate wash, etc., as these parts are typically unpainted and a little rusty under the dirt and grease.
Compared to our tired stocker, the M-7003-Z features upgraded synchronizers and bearings; a steel input bearing retainer; more torque capacity at 330 lb-ft; a short-throw shifter (not too short and fun to shift); double-moly second, third, and countershaft cluster gears; carbon-fiber third/fourth blocker rings; and a Cobra-style pocket bearing. The rest is compatible with the stock trans, with a 28-spline output shaft and seven-tooth speedometer drive gear, so it bolts right in.
|T-5 Gear Ratios
To match our 24-lb/hr fuel...
To match our 24-lb/hr fuel injectors, we swapped our mass air electronics into a C&L mass air housing. This is a direct swap, with the C&L housing accepting the stock meter bracket and air inlet tube.
Installing our Edelbrock 70mm...
Installing our Edelbrock 70mm throttle body and EGR spacer was dead simple once we pulled the four long mounting studs from our old upper intake manifold and got them in the new RPM II upper intake. All necessary gaskets are supplied; the final step was setting the TPS voltage with a digital voltmeter.
The thicker Ford Racing radiator...
The thicker Ford Racing radiator causes a mounting issue along its top edge. Ford uses two bolt-down U-stampings for the stock radiator, and the recommendation to bend those clamps wider to accept the radiator violated our sense of aesthetics and mechanical propriety. Steeda has a great answer for this; a simple aluminum piece that bolts into the stock holes and puts a light spring pressure on the radiator. Available in many color and logo combination, we opted for the black version.
As the chart shows, the gear ratios are slightly different. Clearly the taller first gear combined with our crate engine's lower off-idle torque, choppy idle and stock 3.08 rear axle gears means starting from a dead stop is something of a small event, requiring a touch of technique. We stalled the engine numerous times until we ingrained the slight rpm increase and clutch slip required; now it's second nature. Curiously we find the taller first gear handier in parking lots, on super bumpy roads, and so on, but maybe not as brainless in crawling stop-and-go traffic.
Another consideration is speedometer error. Of course, we can ignore the First gear speedo error, Second and Third are close enough to not count, Fourth is identical, leaving only Fifth as an issue which we're probably just going to live with. In the real world, the speedometer is "slow" by about 6 mph at 70 mph in our pacing tests, so we remind ourselves we're going faster than indicated on the freeway. Ssadly, the odometer no longer reflects the exact mileage, but it's close enough for maintenance work.
What is to like about the ratios is the slightly taller Fifth gear makes flying along with the reality of 80-mph freeway traffic easier, plus it's beneficial for fuel economy at less frenetic cruise speeds. What was unexpected on the freeway-and has nothing to do with such minimal gear changes-is the noise level of the exhaust. The only new exhaust bits are the short-tube headers; the sound quality is the same-there's just a bunch more of it.
Our in-tank fuel pump was...
Our in-tank fuel pump was whining like a big dog, so we had GTR fit a new 190-lph pump to ensure our new X302 didn't starve for fuel. As is typical, says Ricardo, the rubber gasket between the fuel tank and filler neck was cracked and disintegrating, so he replaced it. At this age in the LX's life, consider this a normal part of fuel tank service. Ricardo does, and he keeps a ready supply in stock.
It might not seem like part...
It might not seem like part of a crate engine install, but the vital tires and brakes should be considered because you'll be zooming around with more power. Our tires were totally shot, so we fit this set of Continental Extreme Contact DW's in the stock 215/55ZR-16 size. Our brakes didn't require any service, but we assure you, we're using them and these tires much more than with the old engine! The Continentals have proven especially quiet tires-at least as much as we can tell over our suddenly louder exhaust.
After plenty of work, here's...
After plenty of work, here's the finished product. The X302 transformed our mild and tired 5.0 into a real player, complete with stuttering idle and rev-happy power. Cosmetically we'll likely paint the top of the aluminum radiator black to blend it in better, and spend a few minutes with some electrical tape, black cable ties, some ignition wiring separators, and other details to give the cleanest look possible.