5.0 Mustang & Super FordsHow To Engine
Fox Lake P-51 Intake Manifold - Flying High Again
Fox Lake's New P-51 4.6 Intake Flies At The Top Of The Tach, But It Doesn't Give It All Up Down Low
Fox Lake main man Ron Robart staked his company's name on its cylinder-head porting packages, particularly those on the original Trick Flow Street Heat heads. How did he gain insight into making these heads sing? Well, Ron once worked as a head porter at Trick Flow before it became part of Summit Racing Equipment.
We have long complained that the aftermarket has taken its sweet time addressing the major hard parts necessary to take the 4.6 modular engines to the next level of performance. Yes, we are spoiled by the myriad products available for the pushrod 5.0, but we would like at least a few choices from outside the factory to push modular performance. Well, the good news is, that's beginning to change. We've seen Reichard's high-rpm, sheetmetal intake, and a flood of upper intake elbows for the stock plastic intake. Now there's a new intake that seems to work well on stock and modified 4.6s-and it's from noted head and intake porting shop, Fox Lake Power Products.
The man behind Fox Lake is Ron Robart. Ron was working at Trick Flow in the late '80s when the 5.0 craze achieved critical mass. Since those days, he's been making it on his own by grinding more airflow out of all manner of aftermarket heads and intakes for the 5.0 crowd, as well as a popular line of ported PI heads for the 4.6 Two-Valve crowd. Of course, Ron has seen what the 5.0s could do with all those available aftermarket pieces, so he knew there was a place for a 4.6 manifold that could service the street and street/ strip crowds.
So, Ron came up with the concept of creating a cross-ram-style intake for the 4.6 Two-Valve engine. The benefits of a cross-ram arrangement are attributed to its split personality. By using tuned equal-length runners, low-end torque is promoted, and that's a plus when you have only 281 ci. Moreover, these same runners are kept relatively straight, so at high rpm those same runners create a ram effect that actually tries to overfill the cylinders. Naturally, when you're talking about a high-revving, overhead-cam motor, this high-rpm power is a plus.
When you're trying to have your cake and eat it too, there's usually a catch, and when it comes to intake manifolds, that catch is getting it to fit under a stock hood. To help achieve this, Ron contacted his old friend and former Trick Flow co-owner and idea man behind the original Super Ford 5.0 Shootout, Rick Smith, who now runs a company appropriately named SpeedSmith [(330) 682-6167]. With Ron's design mission in mind, Rick and his crew took the critical measurements of a '99-up 4.6 Two-Valve engine. From there, the manifold was virtually created in computer-aided design software. Using those measurements, the drawing of the manifold could be virtually fit on the engine.
From there, a version was created in wood to test fit on the engine. Ron says that first version was fairly close. He was actually able to hook up all the hoses, sensors, and even the throttle cable to the wood model. It turned out the only significant change was to angle the front of the manifold down a bit to clear the hood. Once the minor corrections were programmed into the CAD software, a real prototype was cut from a solid chunk of billet aluminum. This is the unit Ron has been testing, and the one he brought for us to run on the AFM dyno. The real P-51 versions you can buy will, of course, be cast aluminum. Ron's predicting they'll take flight by mid-March.
Our baseline combination includes all the parts mentioned in the captions, but it's important to note that Rick Anderson says the Dragon Performance intake elbow was good for 9 hp and 5 lb-ft of torque over the stock elbow on this combo. Both the baseline and P-51 pulls were run at exactly 196 degrees of engine temperature to maintain consistency. As you can see, the P-51 did give up a little power and torque down low, but it definitely pulled harder from the midrange to the top of the tach. That's fairly impressive on a car modified to the level of the AFM test car. When Fox Lake did its own testing on a bone-stock 4.6, it was said to pick up power and torque peaks by 17 hp and 21 lb-ft, respectively. Better yet, it improved power across the board on the stocker.