5.0 Mustang & Super FordsHow To Engine
Two-Valve Mustang Buildup - Double Stuff
Getting Twice The Power From A Two-Valve With More Flow And 15 PSI
Horse Sense: Not only does Patriot Performance offer Stage II and III ported versions of the Romeo and Windsor Two-Valve heads, but bare and assembled versions of its own 185cc small-block heads for 5.0 and 351W engines are also available.
After bouncing around Gulf Coast Dyno in Sarasota, Florida, we took a moment to lament that we'd been so caught up in keeping with the S197 mania while not forgetting our Fox roots that we really hadn't done much 4.6 Two-Valve stuff lately. So we asked Ray Walker if he'd be up for playing around with a Two-Valve combo. Naturally he was, and he even had a white '01 GT sitting in the corner of the shop. Our idea was to throw the book at a Two-Valve and build a powerful, streetable combination.
It's tough to reel Ray into building something mild, as his mind instantly thinks of pegging the boost gauge. So we compromised at building an off-the-shelf combination and topping it off with a single-turbo kit. It seemed simple enough. We'd bolt it all together, make big power, and everything would be cool-and ultimately it was.
We should have put stouter springs in our ported heads to work with the boost. Of course, when you boost an engine, the increased cylinder pressure makes it harder to open the valves. Since boost rises with rpm, it only makes it harder on the valvesprings at high rpm. Hey, we all make mistakes and overlook the small stuff from time to time, but we're man enough to admit it. Besides, we still managed to more than double the Two-Valve's output. The car is super-streetable, plenty fast, and should be bulletproof since it can't rev to the moon.
Besides, as Ray put it, "400 rwhp is enough to run mid-11s with a good driver and a five-speed." Most people would be plenty happy with that kind of power, but if you're jaded like us, throw in more aggressive valvesprings and have even more fun.
A stock Two-Valve 4.6 doesn't exactly make a performance enthusiast swoon, but it does hold the potential to really build some power. Knowing we'd be pumping up the power well beyond the levels the stock short-block could handle, Gulf Coast Dyno's Ray Walker filled the stock block with 8.5:1 CP pistons, Manley rods, and a Cobra crankshaft. Besides a Terminator dual-pump fuel tank to feed what we planned to throw at it, the rest of the combo was stone-stock.
First we moved to replace the stock Two-Valve heads with a set of Stage II-ported Windsor heads from Patriot Performance (PN 1004W; $1,295). These are fully assembled CNC-ported castings that feature a five-angle valve job, stainless valves, bronze guides, 0.600-inch lift springs, and titanium retainers. They're said to flow 215 cfm and are also available bare if you want to go with your own spring/valve/retainer package. The bare versions ring up at $1,095. Prelube the cams before getting out the torque wrench.
Patriot recommended Comp Cams 262H (PN 102100; $620.23) cams for its Stage II head package. The cams spec out with a duration of 224/232 at 0.050, a 0.500-inch valve lift, and a lobe separation of 114 degrees. These are direct-replacement cams offering a smooth idle but still lets you know the car has cams. It's said to pull from 1,500 to 5,200 rpm. Ray torques the cam towers to the factory 87-lb/in specs.
Ray says the factory lifters will remain pumped up for quite a while, even if they've been sitting on the workbench or the engine hasn't run lately. He bleeds them down manually with a shop rag and a vice; then compresses and releases the lifter several times to squeeze the oil out of it. This ensures that you'll be able to pop the lifters and rockers back in without a hitch.
With the cam towers torqued into place, Ray drops the lifters back into the heads. The Patriot heads are assembled but don't include the lifters and rockers, so you'll have to swap those over from your stock heads. With the lifters in place, Ray uses this handy tool from Ford to compress the spring; then he slides the rocker in by hand. This same tool is used to remove the rockers from the stock heads.
With the heads completely assembled, Ray gives the block a quick cleanup. Since the short-block was rebuilt before our project started, it didn't need full machining again.
Ray replaces all the fasteners and gaskets with new hardware from Fel-Pro. Quality gear helps an engine stay together, and there's no better example than these resilient multilayer-steel gaskets. These gaskets seal well and stand up to a lot of abuse.
Following the typical inside-out, criss-cross pattern, Ray torques the Patriot-ported Two-Valve heads to the stout short-block. As you can see, he dropped the whole K-member out of the car to swap the heads. It might seem like a lot of extra work, but Ray says it ultimately saves time and is easier on your back.
After properly aligning the cam gears, Ray installed the chain guides, followed by one timing chain at a time. Each chain has one darker link that lines up with the dots on the cam sprocket, so it's hard to mess up. It might seem daunting, but Ray thinks the modulars are easier to work on than their pushrod predecessors. Don't forget to install the timing wheel on the crankshaft before you button up the timing cover. You don't want to pull the cover off again to reinstall it.
Knowing we'd give up our JBA mid-length headers with the turbo kit, Ray satisfied his curiosity by testing the full JBA exhaust system-mid-length headers (PN 6622SJT; $1,099.95), two-cat H-pipe (PN 6632HC; $449.95), and after-cat (PN 40-2623; $469.95)-before we went crazy with heads, cams, intakes, and turbos. With his custom DiabloSport tune, the full JBA system picked up an impressive 20.29 hp and 25.52 lb-ft of torque over the factory manifolds, factory H-pipe, and existing Magnaflow mufflers in back.
Since boost was part of the plan, we ditched the plastic factory manifold in favor of Trick Flow's Track Heat manifold (PN TFS-51811002; $799.95) with a stealthy black-powdercoat finish. The Track Heat is a direct-replacement manifold that trades the bottom end for more gusto at higher rpm. Our version uses the stock-style round throttle body, and it offers an operating range of 1,500-6,500 rpm. If you step up to the twin-blade-throttle-body-style upper, the useable range shifts from 2,000 to 7,000 rpm, so you definitely want some robust valvesprings if you're going to wind it that high.
We started making some headway as Ray wrapped up the intake swap, added ACCEL's upgraded coils, and dropped on the cam covers. We're almost ready to drop the car back on its engine.
Before doing that, however, Ray made the wise choice of adding a SPEC Stage 3 clutch and aluminum flywheel to harness the turbo Two-Valve's newfound power.
We had to go back to the office to work on some other stories, so we weren't around to see Ray strap on the Hellion turbo kit, but longtime readers have seen us cover turbo installs before-swapping headers, attaching plumbing, tapping oil pans, and so on. Ray happened to have a used T-76 turbo laying around and got the rest of the kit from Hellion. Though it kept the costs down on the project, it did prove to be a mismatch because the 76 didn't start pulling hard until 4,500 rpm. Ray says the 66mm turbo is a better choice for a street car since it brings on the boost earlier. The combo produced about 15 pounds of boost and really helped us double our baseline power numbers.
Working to get just the right tune for this combination, Ray found that the best mass air combination is a JLT housing from one of the company's popular cold-air kits, fitted with a Ford GT mass air sensor and augmented by a DiabloSport MAFia. Ray says this combination and a few hours of tuning work yielded the best driveability he's seen with cams and this level of boost. As you can see, we gave up on the bottom with free-flowing heads, cam, and intake. Of course, once the boost builds, look out.