The cam sensor is reinstalled...
The cam sensor is reinstalled on the driver side, and the computer wire is hooked up to it. If you leave it unplugged, the car will idle but will act funny when you rev it. The hesitation and misfire are unmistakable.
Dez grabbed the PMS handheld tuner from the passenger seat and added some fuel. This resulted in the peak torque coming back to our baseline, but the powerband was broader and more aggressive in the upper rpm. This jumped peak power by 47 hp and torque by a few lb-ft. Dez went back into the PMS and added 2 degrees of timing-"a change that only takes a few minutes," he says. He also said that with the stock cams, you could run only a max of 12 degrees of timing. But with new cams he could safely bump it up to 14 degrees without the fear of detonation.
The result was an outstanding 59.33 peak horsepower increase at the rear tires. Torque was up a few lb-ft, but once again the curve appeared more aggressive. One major point to remember is this car still had a stock throttle body. If there had been a 75mm throttle body, the results might have been even better.
The power difference occurs in the midrange, so around-town driving will have a similar "feel" as with the stock camshafts. "At 4,300 and above is where you are going to see the gains in drag racing," Dez says. With rpm rarely dropping below the 4.300-rpm range in drag racing applications, we have no doubt these cams will be the hot ticket in the quarter-mile.
Romeo vs. Windsor Modular Engines
If you are new to modular powerplants, there are a few facts you need to know before tackling a cam swap. The first is that there are two types of Two-Valve mod motors-Romeo and Windsor. The designation comes from the factory in which the engine was built. Rick Anderson says one way to tell which engine you have is to check the VIN. The eighth number/letter will tell which engine combination is in your Stang. If there is a "W" in the eighth spot, it is a Romeo (who thought of that one?). A Windsor-equipped Stang has an "X" designation in the VIN code. Many aftermarket-ported Two-Valve heads are bought from Ford Racing. If that's the case with your car, as it is with our test Stang, then all Ford Racing heads are of the Romeo no fear, the differences do not affect the performance of your ponycar.
Romeo-style engines have 11-bolt valve covers, and that is the only outside indication to which heads are on your mod mill. There's also a bridge between the cam caps, or as we call them, "cages." The front engine cover is fastened to the block using 8mm bolts. The OEM camshafts in Romeo-style engines use a non-removable cam sprocket. So, installation of the AFM F-42 cams would be different than what we have done in this article. But the Stang we used for the story does have Romeo heads because the owner bought them from Total Engine Airflow, and that company started with Ford Racing castings. That means the Stang in our story featured Romeo heads with cams that had removable sprockets. Confused yet? If not, we will continue.
The Windsor engines have cylinder heads that use 14 bolts on the valve covers. The cams are secured into place using caps. They look a lot like main caps on the bottom of an engine block. Be careful not mix them up, otherwise there will be some wearing issues with the cam journals. The front engine cover uses 10mm bolts. The Windsor engines also have the removable cam sprockets. It is on these types of engines where the AFM cam-change tool saves a lot of time.
"We have seen almost all '02-up [Two-Valve] Mustangs having removable cam gears," Anderson says. Identify which style engine is in your Stang before picking up the phone and ordering camshafts for it. The performance gains from a camshaft swap will be the same regardless of the type of cam sprockets.
With the cam lubed up, it...
With the cam lubed up, it is ready to install. Remove the collar on the front of the OEM camshaft and install it on the new one.
The cam is laid into place,...
The cam is laid into place, the cam sprocket is bolted on, and the cages are screwed down. The cam sprocket is attached using a larger bolt, which AFM supplies. The cages and cam sprocket need to be torqued down, so tighten them only slightly and then use the proper tools for torquing the bolts.
The cages are torqued down...
The cages are torqued down using 100 in/lb. This must be done before the camshaft sprocket is torqued into place.
All AFM modular camshafts...
All AFM modular camshafts have provisions in the middle of the cam to hold it still with a wrench.
Dez holds the cam while Mochie...
Dez holds the cam while Mochie torques the sprocket bolt to 90 ft-lb.
With the driver side complete,...
With the driver side complete, we turned our attention to the passenger side. The only difference between the two is the AFM cam-changing tool fits a little tighter. This is because the passenger-side camshaft sits closer to the front engine cover.
Once both cams are installed...
Once both cams are installed and everything is torqued down, pop the cam followers into place. Mochie has a technique that seems to work well, but it still took almost as long to get the followers in place than it did to the swap the cams.
The valve covers were cleaned,...
The valve covers were cleaned, and fresh OEM gaskets were set in place.