Mark Houlahan
Tech Editor, Mustang Monthly
September 1, 2003

Horse Sense:
Many modern cams are designed with a few degrees of advance built into them. If you want to advance the cam further or retard it for your application, you'll need an adjustable timing-chain set. For this '89 GT project car, we are installing the Crane 44975-1 billet gear and double-roller chain set, which can advance or retard the installed cam 4 degrees.

A camshaft is often called the heart of an engine. Its specs and design parameters often determine whether or not an engine will make power. While parts such as cylinder heads and exhaust play an important role in the overall power-making process, the camshaft-much like a torque converter in an auto tranny-must be designed to work correctly with all the accompanying speed parts. Otherwise, you're simply wasting your time and money for little or no gain.

Lucky for us 5.0 owners, there's a multitude of camshafts from which to choose. And more than likely there's someone out there who has a combination similar to the one you're considering and who can tell you whether or not the cam worked for them. Of course, today's camshaft manufacturers realize how popular the 5.0 engine has been. These companies have huge databases of their products' test results, along with technical help lines for you to discuss your current parts and future purchases to see if they'll be compatible with a particular cam.

Trust us, no camshaft manufacturer is going to advise you to purchase a cam that's wrong for your application. These companies are in the business of keeping customers, not losing them. Even if you plan major mods in the future that will require a cam change again, their techs will point you in the right direction for what you are working with now. There's nothing worse than having an oversized cam because you "might" build a stroker three years from now.

The featured '89 GT project-owned by Brian Wesche of Lakeland, Florida-has benefited from Crane 1.7 roller rockers, Performance Distributors ignition upgrades, and most recently an Edelbrock Performer 5.0 intake-all basic bolt-on mods that everyone begins with. As the car already has owner-installed headers, an after-cat, an H-pipe, rear gears, and pulleys, the next logical progression in bolt-on power is a cam swap.

Since we'd already bolted on Crane Cobra rockers to the GT, we knew the best cam for it would be Crane's PowerMax 2031. This is the former 2031 CompuCam from the '90s, and it was originally designed as a drop-in replacement cam for '93 Cobras and their OE 1.7 rockers, which were manufactured by Crane. (This same setup was used on yours truly's '90 more than six years ago with great results. Though we never dyno tested that combination, it had great seat-of-the-pants torque and a sweet idle with excellent driveability.) We'll also install a fresh timing-chain set and valvesprings in place of the weak, high-mileage stockers.

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Swapping cams isn't rocket science. You can get by with a parts-store shop manual, such as a Chilton's, or even a performance how-to book on rebuilding small-blocks. The upgrade will require pulling down the front of the engine (water pump, timing cover, accessories), and removing the intake and the valve covers. Usually it's necessary to remove the upper and lower intake, but we're going to save time, labor, and gaskets by using Anderson Ford Motorsport's Tappet Tools. These timesaving tools use powerful magnets at the ends of adjustable pedestals that grab on to and then lift the roller lifters partially out of their bores. Using these tools allows the camshaft to be removed without having to take out the lower intake, the lifter retainer, and the lifters. According to Rick Anderson at AFM,Tappet Tools can save three hours on a cam swap. For only $64, these babies are worth every penny when you consider the cost of intake gaskets and your time.

On the Dyno
When we brought Brian's '89 GT to Lugo's shop for the cam swap, Mario took a look at the odometer (reading 158,000) and asked us if we brought valvesprings. The stock springs, not the best for high rpm to begin with, begin to get soft early and are no match for any aftermarket cam. We actually thought ahead this time and did bring some of Crane's drop-in replacement springs for stock cylinder heads. Mario installed these new springs for us, and while a small amount of the net gains can be attributed to them, you'd be crazy not to install good springs along with the new camshaft, so consider them a package.

Brian's GT picked up quite nicely with nothing more than a mild cam. The 2031's streetable lift (figured with the 1.7s) of 0.513 intake and 0.529 exhaust give the car some nice low-end power. You can see that the peak horsepower, which is now 20 horses stronger, comes in almost 1,000 rpm lower, while the torque increase of 37 lb-ft is a gain you can feel in your khakis. And, the improvements in torque and horsepower all come in below 4,500 rpm-great for the street.

BaselineCrane 2031
RPMTorquePowerTorquePower
3,000205.54116.80216.28126.07
3,100210.04124.10232.84139.21
3,200214.54131.40249.41152.35
3,300212.42133.97252.31157.85
3,400203.69131.83241.57155.71
3,500194.96129.68230.82153.71
3,600206.13141.58242.07165.76
3,700217.30153.48253.31177.94
3,800221.17160.29258.15186.31
3,900217.74162.01256.57190.85
4,000214.31163.73255.00195.39
4,100215.22167.97248.90194.63
4,200216.14172.21242.80193.86
4,300216.97176.92241.46197.43
4,400217.72182.09244.89205.32
4,500218.47187.26248.31213.20
4,600214.39188.11233.25203.99
4,700210.30188.97218.18194.78
4,800203.24186.37213.22194.46
4,900193.18180.31218.37203.05
5,000183.13174.26223.52211.63
5,100188.00182.18217.51210.32
5,200192.86190.11211.50209.01
5,300192.22192.91205.65207.47
5,400186.07190.60199.95205.70
5,500179.92188.29194.26203.92
5,600175.24185.74191.41204.03
5,700170.56183.20188.57204.14
5,800134.57145.54149.71163.36

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