Dan Simons
November 1, 2004

Horse Sense:
We previously mentioned that gas mileage dropped just a little with the 5.4 install, but with the cam swap, we seem to have gone the other direction. We recently recorded a tank of 23 mpg with the 5.4, versus a best of 21.6 with the stock 4.6 and a previous best of 20.6 with the 5.4.

It has been a while since you've seen any updates on our 5.4 SOHC-equipped project car. As do most projects, this one has its time and budget constraints. A complete, "pull up the stakes, pack the wagons, and go" move by the author put a definite dent in any car-related plans for quite some time.

A horsepower junkie can only go so long without a fix, though, so in the interest of preventing any permanent psychological damage, it seemed the only logical thing to do was to install more parts on the car. This particular brand of logic may not be an exact match for the version employed by your significant other, but hey, we're here for technical information, not relationship counseling.

In our last round of testing ("Size Still Matters," Jan. '04, p. 103), we covered all the popular bolt-ons, including an off-road H-pipe, underdrive pulleys, a cold-air inlet, a larger throttle body, and a ported stock upper intake. We also bolted on a Reichard Racing intake manifold. At the end of it all, we had some nice gains, but even with the short runner intake installed, horsepower still peaked at a low 4,800 rpm. At that point, the biggest restriction in the airflow chain was determined to be the smallish stock PI cams, so when it came time to upgrade again it was clear which path to take.

To help with the camshaft selection, we contacted Crane Cams, one of the biggest and most experienced companies in the industry. Crane had recently released six new billet grinds for the 4.6/5.4 modular motors, and we found one that fit our needs perfectly. Part number 379511 has 228 degrees of intake duration and 234 degrees of exhaust duration at 0.050 inch lift, 0.493 inch lift at the valve, and it is ground with 112 degrees of lobe separation. There was a similar grind with higher lift available that may have been worth a few more horsepower, but due to the tight confines of the engine bay, we had no desire to try and swap valvesprings with the motor in the car. The 379511 grind works fine with stock PI valvesprings, so that's what we went with. (See the Cam Specs sidebar for specs on all six grinds available.)

The in-depth details of modular cam swaps have been covered recently and thoroughly, so in this article we'll just point out what was different as far as dealing with the physically larger 5.4 motor. You can find the testing results in the dyno sidebar, and details of the installation in the following photos. Many thanks go out this time around to friend and ASE mechanic Casey Wittmer [anniversarystang@aol.com], who does performance installations in the Twin Cities, Minnesota, area. He made the installation smooth and easy. And thanks to Brian Ebert at Hitech Motorsport who once again handled the dyno testing and tuning tweaks.

Driving A 5.4 Mustang
It really is a shame that Ford never chose to build a 5.4-liter GT. With a well-matched intake manifold and cams, it could easily have given 300 hp with good mileage, excellent driveability, and the kind of torque curve a 4.6 can only dream about. Driving the project car as daily transportation is a blast in a way that only those who have had big torque can appreciate. Acceleration in normal driving is effortless, with a healthy shove in the back just a bit of throttle application away.

On the freeway, you can accelerate briskly to pass slower traffic without the torque converter even unlocking, much less going for a downshift to a lower gear. For all-out acceleration, we still need to beef up the top end of the tach, but for pure driving satisfaction, the combo is well matched the way it sits right now. The future may hold ported heads and perhaps another go 'round with a short-runner intake, but for now a higher stall torque converter and perhaps some 3.73s will ensure we are getting all we can from the current combination. Short, brutal blasts of acceleration-that's the American way to get to work in the morning!

Cam Specs
Crane has the market covered from mild to wild depending on your desires. The first two grinds are intended for the earlier '92-'98 ('96-'98 Mustang) heads, but physically they are interchangeable with cams for the PI heads as long as you have the correct bolt-on cam gears. The earlier cams use a 12mm bolt, whereas the later PI cams (those that don't have press-on gears, as ours did) use a 10mm bolt, so make sure you get the correct part when ordering. We went with the 379511 grinds for our PI heads versus the similar duration 379621 to stay near stock valve lift and to avoid having to swap valvesprings. Here are the full complement of choices.

For '92-up engines with standard cylinder heads:
• PN 379501, 218/228 at 0.050 inch, 0.493/0.493 inch lift, 116 degree centerline, good idle, daily performance, blower, nitrous oxide
• PN 379511, 228/234 at 0.050 inch, 0.493/0.493 inch lift, 112 degree centerline, fair idle, normally aspirated, street performance and bracket racing, computer upgrades required

For '99-up engines with Power Improvement cylinder heads (Crane 37830-16 valvesprings required)
• PN 379601, 212/218 at 0.050 inch, 0.550/0.550 inch lift, 115 degree centerline, smooth idle, daily usage, high torque, towing
• PN 379611, 218/228 at 0.050 inch, 0.550/0.550 inch lift, 116 degree centerline, good idle, daily performance, blower, nitrous oxide
• PN 379621, 228/234 at 0.050 inch, 0.550/0.550 inch lift, 112 degree centerline, fair idle, normally aspirated, street performance and bracket racing with 2,000-plus-rpm converter, computer upgrades required
• PN 379631, 236/242 at 0.050 inch, 0.600/0.600 inch lift, 114 degree centerline, rough idle, increased compression ratio required, street performance and bracket racing with 2,500-plus-rpm converter, computer upgrades required

On the Dyno
2,400310.8142.0302.0138.0 (8.8)(4.0)
2,600311.2154.0302.4149.7 (8.8)(4.3)
3,400339.2219.6334.1216.3 (5.1)(3.3)
3,600338.7232.2337.0231.0 (1.7)(1.2)
3,800332.7240.7334.7242.1 2.0 1.4
4,000322.9245.9329.9251.2 7.0 5.3
4,200311.6249.2323.9259.112.3 9.9
Avg. (from 3,400-5,800)

When it came time to dyno the new setup, we made the usual trek to Hitech Motorsport in Ramsey, Minnesota, where Brian Ebert spun the Dynojet to see how much the cams were worth. During the course of a few pulls, we made a slight fuel change to get the air/fuel ratio back up to 13:1 as it had been previously, and we took out a bit of timing on the high end of the tach that was worth a couple horsepower. As before, all pulls were made with the torque converter locked, so the curves are a true picture of engine output without the converter inflating the lower rpm numbers due to its torque multiplication.

As expected of the greater duration, the new cams shifted the torque curve up the tach, giving up a little down low to gain a lot more up top. When viewed in greater resolution than can be displayed in the chart, the actual peak torque rpm didn't change, as it was 3,480 with both sets of cams. The horsepower peak shifted upward almost 300 rpm, though-a welcome change as the big motor was signing off fairly early. With the way the shape of the new horsepower curve mimics the old one up top, there is definitely another airflow restriction in the motor, as the bigger cams could have been expected to keep gaining more and more as the rpm climbed higher. A high-flow, short-runner intake manifold would certainly be a benefit, but the biggest gains at this point are likely to come from porting the stock heads. As is, though, having more than 300 lb-ft of rear-wheel torque from 2,300 until almost 4,700 rpm makes for a stout powerplant. Five-speed Mustangs typically dyno around 15-20 rear-wheel horsepower and 10 lb-ft of torque higher than with an auto, which would put the peaks more like 280 and 350, and the torque curve would likely be more than 300, from under 2,000 rpm to nearly 5,000 rpm.