Steve Baur
Former Editor, Modified Mustangs & Fords
August 1, 2006
Photos By: Dave Massey

Now That we're more than 10 years deep into the realm of modular motivation, we find ourselves a bit friendlier with the overhead cam design of the latest Mustang powerplants. This translates into more aggressive research and development of performance parts for these engines.

That being said, it's no surprise people have already torn apart the Three-Valve Mustang 4.6 to find more power. Yes, the factory has still left something for the aftermarket to discover, and Boca Raton, Florida's Blow-By Racing has found it in the form of CNC-ported cylinder heads and performance camshafts.

Looking to maximize the available horsepower, Blow-By proprietor Chris Jones started off with a heavy Stage 2 CNC-port job on the stock Three-Valve heads, and aggressive Stage 2 camshafts, the specs of which were not divulged.

This combination, along with a fully worked exhaust system and tuning, resulted in 382 rwhp and 346 lb-ft of torque as installed on the com-pany's LNR prototype Mustang. On race gas with a radical tune, BBR saw 409 hp and 361 lb-ft of torque.

BBR's Stage 1 cylinder head is in develop-ment, but we were able to test the Stage 1 camshafts with the Stage 2 cylinder heads. The Stage 2 heads for '05-'06 Mustang GTs retail for $1,699.95 and use the stock valvetrain. Stainless steel valves and upgraded springs are optional.

Stage 1 BBR camshafts are available as regrinds ($825.00) or in billet form ($999.99). For our test, we employed the reground Stage 1s.

As installation is available for all of their products, BBR's Jones and Dave Massey performed our head/cam swap at their shop. If you plan to take on this endeavor yourself, there are a few things you'll need, including new Ford head bolts (ARP doesn't offer 3V studs yet, though the 2V and 4V studs look like they will work), an upper gasket kit (PN 4R3Z6079AA), a lower gasket kit (PN 4R3Z6EO78AA), some assembly lube, and the phone number for your local Ford dealer in case you break the coolant sensor, like we did. It felt like it was threading in easily, when it snapped off. Removing it from the surprisingly high-mileage (65,000 on the odometer) engine might have weakened it prior to installing it on the new cylinder head, though.

This was your author's first time seeing a mod motor dismantled and put back together in person, and understanding how the whole thing goes together really took away some of the stigma associated with chain drives. They really aren't that bad-probably no worse than changing the cam on a 5-liter.

Unfortunately, time constraints did not allow us to baseline our subject vehicle, but average stock numbers for the Three-Valve Mustang are around 262-265 hp and 280 lb-ft of torque as measured at the wheels on the Dynojet. Our test subject was modified with an off-road x pipe system and Magnapack mufflers, so figure in an extra 5-10 ponies on top.

Once the engine was together, tuning commenced, and equipped with the Stage 1 cams and Stage 2 heads, the '05 put down 330 hp and 320 lb-ft of torque to the tires.

While we had planned to test BBR's Stage 2 cams as well, our portable dynamometer had to head out, but not before we tossed on a JLT cold-air intake. The big, open element delivered, raising horsepower to 351 and torque to 336. The new heads and cams are obviously moving more air than the stock induction system can deliver, and with a gain of around 70 normally-aspirated rear-wheel horsepower, your S197 Mustang GT should get up and go lots faster.

In addition to the Stage 2 cams, we were looking to test a set of long-tube headers from American Racing Headers, but we ran out of time. Be sure to check the Horse's Mouth section in the next issue where we'll update you on the Pony's progress.

Photo Gallery

View Photo Gallery
Blow-By Racing's '05-'06 {{{Mustang}}} {{{GT}}} 3v Stage 2 Cylinder-Head Flow Numbers*
Intake
LiftStockCNC
CFMCFMPorting
0.{{{100}}}77.175.3
0.{{{200}}}147.0162.0
0.{{{300}}}199.6228.3
0.400216.0273.8
0.500223.2283.6
0.{{{600}}}224.8292.9
Exhaust
LiftStockCNC
CFMCFMPorting
0.10052.746.2
0.20097.8104.3
0.300120.2135.7
0.400138.1163.2
0.500148.2177.0
0.600153.7189.6
*Manufacturer's data