If you've been reading Muscle Mustangs & Fast Fords for a while, you may have seen our subject notchback, dubbed the Little Juice Coupe, in numerous articles as we have taken the AOD-equipped slug and transformed it into a true street fighter.
Since the last installment "The Last Stand" (Oct. '08), we have swapped out the TCI torque converter for one with a slightly higher stall speed. The car responded with a best-ever motor-only pass of 13.34 at 102 mph. Sixty-foot times dropped nearly a tenth of a second on the motor. The higher stall speed converter really helped the car on nitrous, as it allowed the engine to rev to the window switches set point of 3,000 rpm right at the launch. Short times dropped to 1.75 seconds, and we set a new best elapsed time of 11.78 at 117 mph. In addition to the new and faster quarter-mile e.t.'s, we were able to drive the car an hour and a half to and from the track, while recording 20-22 mpg.
As much as we were happy with the way our Pony was performing, there was still something missing from the package. The Flowmaster exhaust let's you know this Mustang is modified, but the stock sounding idle just screamed mundane. To that end, we decided to swap in a high-performance camshaft to give the idle some spunk. There are currently tons of camshafts available for the 5.0L Mustang, and they offer a price range that is just as broad as the cam selection. Our main goal was for the car to sound good, and if we picked up a few ponies along the way, that was cool too.
Ford Racing Performance Parts was one of the first companies to offer high-performance camshafts for the 5.0L, and they are still popular today, both for the increased performance they offer, as well as the relatively minimal cash outlay that it requires. Probably the most popular of the FRPP grinds is the E303 camshaft. Part number M-6250-E303 is a hydraulic roller camshaft that offers an advertised duration of 282 degrees on both the intake and exhaust sides, and it will lift the valves .498-inches off the seat. The cam is the only FRPP camshaft that is 50-state legal and it carries its own CARB E.O. number to prove it.
Another one of Ford Racing's performance camshafts that we considered was the B303 cam. Offering 284 degrees of advertised duration and .480 inches of lift, the B303 (PN M-6250-B303) is actually better suited for use with nitrous thanks to its extended duration. After talking with the folks at the Ford Racing Performance Parts tech line, we opted for the E303, as the B303 drops a bit of bottom-end torque in exchange for a higher powerband. We wanted that torque since the car spends far more time running on the motor than it does on the bottle. Either cam would work well with our GT40X Turboswirl cylinder heads and Cobra intake manifold, and piston-to-valve clearance wouldn't be a problem with the 1.94 intake valves that the heads featured.
Prior to the camshaft swap, we were running FRPP 1.7:1 bolt-down roller rockers along with the stock cam. This combination offers .472-inch lift versus the stock .444-inch measurement, and while it produced good power for our coupe, it just didn't sound aggressive enough. After choosing to go with the E303 camshaft, we employed FRPP's 1.6:1 bolt-down roller rockers, and installed a new timing chain (PN M-6268-F302) set along with a hardened cam thrust plate.
Installation is a bit involved, and if you've never opened up your 5.0L before, this might not be the best time to do so. We had the job knocked out in about eight hours, taking our time as we went. The Little Juice Coupe fired right up, and after we set the timing, it crackled just like we had hoped. After the swap, we took the car back to HP Performance in Orange Park, Florida, for a little dyno testing and saw that horsepower increased from 4,300 rpm upward, and recorded a peak horsepower increase from 265 to 273 at the wheels. Torque stayed relatively the same.
No, we're not doing a 4.6L...
No, we're not doing a 4.6L Modular cam swap. Ford Racing sent us both its E303 and B303 camshafts to choose from. We also procured a set of 1.6:1 roller rocker arms and a timing chain for our cam swap.
After you disconnect the battery,...
After you disconnect the battery, you can unplug the various harnesses, lines, and cables from the upper intake manifold and remove it.
Drain the coolant, and then...
Drain the coolant, and then remove the radiator and fan assemblies.
Next, unplug the distributor...
Next, unplug the distributor harness and remove the cap. Then pull the distributor. We didn't bother to mark it, as we set the engine to top dead center on the balancer and planned to install the cam straight up. We'll then adjust the timing once everything is buttoned up.
All of the front accessories...
All of the front accessories need to come off the engine, with the exception of the power steering pump.
Rather than have the A/C discharged...
Rather than have the A/C discharged and then refilled, we simply pivoted the A/C compressor and condenser over to the side of the car. Just be careful as you do this because you can cause a leak if you bend or twist them harshly.
You can get the Ford Racing 5.0L cams most anywhere these days, and smart shoppers can find them for about $169. The roller rockers are a bit more at $269, but they are optional. Some may say that's a good bit of money to spend just for the sound and a few horsepower, but you'll pay far more for that particular exhaust system that floats your boat. At that point, the camshaft is a bargain. Thumpity thump, thump. Thumpity thump, thump, look at your Mustang go.
You don't have to remove the...
You don't have to remove the water pump, but you do have to remove the timing cover to which it is attached. For now, remove the thermostat housing coolant hoses up front, as well as the heater hoses at the back of the lower intake manifold. Then unbolt the lower intake and remove that too.
Time to clean up the mating...
Time to clean up the mating surfaces. We filled the head ports with rags and paper towels, and the lifter valley with an old shirt. Once you're finished cleaning, remove the rags from the ports and then carefully remove the shirt from the lifter valley.
Though ours didn't come from...
Though ours didn't come from there, you can rent a balancer puller from your local AutoZone for just a few dollars.
After jacking up the car,...
After jacking up the car, we drained the oil and then removed all of the oil pan bolts except for the rear four. This will allow the pan to tilt downward so you can remove the timing cover.
The timing cover hangs on...
The timing cover hangs on the front of the block thanks to a pair of dowel pins. You'll need to make sure the oil pan is low enough to clear the timing cover, and then wiggle the cover off. Be gentle as it is made out of aluminum and you have to buy them through mail order if you break it.
The stock timing chain and...
The stock timing chain and gears are next to come off the engine.
Use a long 3/8-inch thread...
Use a long 3/8-inch thread bolt to remove the camshaft and install the new one. Take care in removing and installing the cams, as you don't want to nick the cam bearings.
The timing cover ridge is...
The timing cover ridge is cleaned and a new gasket is applied using gasket sealer on the block. Most 5.0L come from the factory with a cork oil pan gasket, and in some cases, you can just add some gasket sealer to it and put the timing cover back on. In other cases, you end up ripping the cork, in which case you need to cut it cleanly at the block, and use gasket sealer along the front end of the pan. Our car had been previously fitted with a rubber, one-piece oil pan gasket, so we just dabbed a little sealer at the block/pan/cover joint and buttoned it back up.
On the HP Performance dynamometer,...
On the HP Performance dynamometer, we saw power improve here and there along the power band, and it really took off from 4,300 rpm upwards. Peak horsepower was up from 265 to 273, though torque remained largely unchanged.
Ford Racing's new timing chain...
Ford Racing's new timing chain and sprocket set (PN M-6268-F302) features a multi-index setup to change the cam timing. We installed the E303 stick straight up, which means the cam pin on the cam sprocket is pointing dead south. The crank sprocket in the new FRPP chain set features a large flat section on its inside. This should be pointing at six o'clock as well. You need to use FRPP's hardened cam thrust plate (PN M-6269-A351) with this timing chain as well.
Once the car was put back...
Once the car was put back together, we topped off the fluids with some Peak Antifreeze and Roush Racing's new synthetic motor oil. A Ford Racing filter makes sure the oil stays clean.