5.0 Mustang & Super FordsHow To Engine
Fox Lake CNC-Ported Modular Heads - Ports Improved
Fox Lake Shows Us How To Maximize 4.6 Two-Valve Heads For A 70-Horse Gain
If you're thinking about adding an intake and cams to complement a set of Fox Lake CNC-ported modular heads, you're in luck. Fox Lake and Mod Max are teaming up to design their own intake casting, and cams are already available. Of course, the Bullitt intake will suffice while you wait for the trick stuff to get off the design table.
So, you have a '99-'02 Mus-tang GT, and it's fast. You can kick a Camaro's rump and still have enough left for any ricer dumb enough to mess with a pumped-up, small-block Ford. You've done the gears, the sticky tires, the pulleys, the exhaust, the cold-air kit-man, you have everything. The problem is, you've spent all your loot on bolt-on parts and entrance fees to the local Wednesday night drags. You don't have the scratch to do that street blower you want so bad, but you still want to go faster. So, you put some nitrous to the old girl, get a couple 11-second timeslips, and really start to impress your friends. But what now? Where do you up the ante on this nasty, little overhead-cam wonder? Don't worry, we've got you covered!
Fox Lake Power Products has expanded its menu of CNC-ported 5.0 and 5.8 pushrod heads (of all castings, varieties, and flavors) to include Ford's modular cylinder heads. As with all Ron Robart's cylinder heads, his CNC port job originates from his own hand-cut design. After months of experimentation with the '99-and-newer P.I. castings (see Head Name Games sidebar), Ron developed a port configuration that offered enhanced air speed and volume without killing power, especially in the lower lift numbers.
A look at the Go with the Flow sidebar shows the heads peak at 210-212 cfm at 0.500 inch lift. That's up from 160 cfm with a stock P.I. casting. The stainless valve combination will get you up to 225 cfm at 0.500 inch lift. As a side note, the head is done after 0.500 inch lift. No amount of modifications, as tested at the time of this writing, will get the head to work at higher lift numbers. Now, if you're a dedicated 5.0&SF reader, you're saying, "Wait a minute. Those are typical numbers that you would see from a set of iron GT-40 heads for a 5.0." Well, you're right-and wrong. The flow numbers are the same, but the castings with the modular motors are what make the difference.
As Ron puts it, "The small, 281ci motor is the major difference. What looks like a small amount of airflow is really a huge difference because of the proportional difference (in engine size)."
Ron also explained to us that the P.I. head is efficient because it's a better overall design. It has a better taper angle from the intake manifold face to the valve-throat area. It has a high-speed port designed to direct the air to the cylinder, while the valve stops the combustion from going backward through the intake. And the P.I. heads are taller than a typical pushrod head, allowing for a much more direct angle of intake-charge flow.