These are tough times--and I'm not talking about the economy. I'm talking about the action on the street and on racetracks from Jersey to L.A. It seems like 11- and 10-second cars are everywhere, roaming late at night and clocking serious numbers on the strip. It takes big horsepower to keep up with blown and nitrous-gulping 5.0s and all those supercharged Cobras that run 12s stock and are just a tweak away from the 11s. For those with a typical bolt-on equipped 5.0 or 4.6 GT, it's easy to get left behind.
We feel your pain, and despite having a Vortech blower, Bullitt intake, and host of other bolt-on parts attached to our '01 GT, we still get smoked from time to time. Just the other day some guy in a white '03 Cobra left me by three cars from a 40-mph roll. And when I reported the news to MM&FF boss Jim Campisano, he was not happy, and decided to do something about it.
Campy ordered up a set of Patriot Performance CNC-ported cylinder heads and set of Comp Cams camshafts to up the power of our stock-block two-cammer. And, with the addition of those parts, we're hoping to take our low 12-second, 118-mph Stang and get it in the 11s on street radials and in the low 11s on slicks.
Patriot Performance is new to the Ford 4.6 market, but they are not new to cylinder head porting. The staff has a lot of experience porting race heads, and they are currently specializing in Ford two-valve 4.6/5.4 and GM LS1 heads.
"We start off with new PI casts that get treated to a full array of modifications," stated Terry Wilkes, project engineer and head porter at Patriot. "We don't claim to be the best or anything like that, or that you'll get more power than anyone else, but we offer a quality product at a great price," Wilkes added.
There are two stages available from Patriot Performance (Stage I and Stage II). Its Stage I package includes full intake and exhaust CNC porting with a custom five- angle valve job. The Stage II heads get Patriot 1.781/1.452-inch valves (with five-angle valve job), Patriot springs, bronze valve guides, and aftermarket retainers. Custom cams and Ferrea valves are available at an additional cost.
"With the Stage II heads, like the ones we sent you, you get larger valves and better springs. Our single beehive springs have 85-pound closed pressure and 185 open, and they work well up to a .570-inch lift. We're working on new springs that will be available shortly, and it will handle .600-inch lift," added Wilkes. As for the price, the Stage I heads retail for $1,095 with a core exchange, and the Stage II heads can be had for $1,295 (with core exchange).
Comp Cams supplied the camshafts (left and right), and they feature .545-inch lift (intake and exhaust) and 234/238 degrees of duration at .050-inch lift. "These are our new Xtreme Energy high-lift lobes," stated Chris Padgitt of Comp Cams. "We've checked quite a few stock cams, and they come with .400-inch lift and 212 degrees duration at the valve. These Xtreme Energy cams are naturally larger and should really do well with the ported heads and the blower on your car."
Padgitt also explained that comparing pushrod cams and overhead cams is like comparing apples and oranges because of the type of rocker, or cam follower, in the case of the SOHC or DOHC engines. "The pushrod engines have one set rocker ratio, whereas the followers in the Modular engine cause the rocker ratio to change as the lobe rolls on the follower. So, you don't need as much lift or duration as you do in a pushrod engine," he explained.
Before ripping the stock parts off, we strapped the Mustang to the DynoJet at JDM Engineering in Freehold, New Jersey. The blown 4.6 spit out 399.8 hp at 5,900 rpm and produced 412 lb-ft of torque at 4,300 rpm. And while we haven't run on slicks, we did shoot to a 12.28 at 118 mph on the strip on Nitto 555 radials.
To ease the installation, the gang at JDM decided it would be best to yank the engine and swap the heads and cams with the engine on a stand. Super technician Shaun Lacko got to work and disconnected the battery, and then drained the coolant from the engine and the supercharger. Next, the exhaust, transmission and main engine harness were disconnected, along with the engine mounts. Lacko then attached the engine hoist and lifted the engine from the bay.
Swapping the heads will entail removing the Bullitt intake, cam covers, front accessories (including the blower), and then, of course, heads. Patriot shipped us the heads assembled, but we'll be installing the Comp Cams camshafts in the shop and swapping over the finger followers and hydraulic lash compensators from the old heads. Downs Ford Motorsport in Toms River, New Jersey, was generous enough to supply the head changing kit (gaskets, head bolts, etc.). Remember, the factory uses torque-to-yield head bolts, so once you remove the stock heads, chuck the bolts in the trash because they are officially used up.
Once the new parts are installed, we'll get the GT back on the dyno and then eventually we'll be testing the combination at the track. Jim D'Amore of JDM explained that the increased cylinder head flow will cause a drop in boost and we may have to decrease the diameter of the blower from the 3.33 inches to one measuring about 3.00 before realizing the potential of the new heads and cams. Nevertheless, we plan to first run the dyno test with the current pulley so we can learn exactly what happens when we go to the smaller pulley.
Before getting busy, we strapped Project Ice Box to the dyno to get some baseline numbers.
At $1,295 (for the Stage II casts) the Patriot Performance heads are competitively priced.
The combustion chambers are cut on the CNC machine, and the size is actually increased fro
Here is a look at the cleaned-up intake port on our Stage II heads. You can see the smooth
The exhaust ports on the Stage II heads flow 193 cfm at .600-inch lift.
Comp Cams supplied us with these camshafts. They feature .545-inch lift and have 234/238 d
We'll be topping off the package with these BBK Performance cast cam covers. The kit inclu
Baseline numbers were achieved on the DynoJet at JDM Engineering.
In its current trim (as shown with a Vortech, ported Bullitt intake and BBK/SLP exhaust) t
Shaun Lacko disconnected the battery, dropped the exhaust and transmission, and then drai
Next, he removed the electric fan and engine accessories, and hooked up the chain to lift
Justin Vashisht and Anthony Giagnacovo helped guide the blown 4.6 from the bay.
Vashisht and Giagnacovo put the engine on a stand. Next month we'll remove the old parts a
|Cylinder Head Flow Data|
|Patriot Performance 4.6 Heads (Flow data by Patriot Superflow 1020 flowbench.) |
|Stage I |
|Lift ||1.752-inch Intake ||1.417-inch Exhaust |
|.100 ||60 ||52 |
|.200 ||107 ||94 |
|.300 ||152 ||130 |
|.400 ||185 ||160 |
|.500 ||209 ||178 |
|.550 ||211 ||185 |
|.600 ||214 ||192 |
|Stage II |
|Lift ||1.781-inch Intake||1.452-inch Exhaust|
|.100 ||64||52 |
|.200 ||116 ||98 |
|.300 ||162 ||135 |
|.400 ||192 ||162 |
|.500 ||213 ||182 |
|.550 ||217 ||189 |
|.600 ||218 ||193 |