Plan to take a weekend to remove the heads from your Two-Valve mod motor and replace them
The vulnerable Two-Valve modular engine seems to be getting lost in the mix these days. We've been hitting the Three-Valve and Four-Valve modular markets pretty hard lately, so we thought we'd slide a Two-Valve mod motor Mustang into the garage for a little fun. The Dec. '07 issue of MM&FF featured a tech story on the Trick Flow Two-Valve intake manifold, and it was the perfect chance for us to take that car one step further.
We bolted the manifold on Keith Johnson's '00 Mustang GT, which was pumped up with a ProCharger P1SC blower (12 psi of boost). Other modifications to the GT included Anderson Ford Motorsport F-42 camshafts; a BBK 70mm throttle body; and Ford Racing Performance Parts shorty headers, x pipe system, and after-cat exhaust. The fuel system has been upgraded, and Mike Dezotell of Dez Racing performed a custom computer tune in this car. Holding the power is the job of a Tremec TKO transmission and Centerforce DFX clutch.
This combo with a stock manifold produced 441 rwhp and 413 rwtq. After adding the Trick Flow manifold, output results were 454 rwhp and 415 rwtq. We reestablished the baseline for this story, and Johnson's GT made 453--close enough to the 454 result we got three months prior. Torque was recorded at the same 415 rwtq.
The test results were great, and the intake picked up some power over stock. However, we thought it was better suited for something with a bit more airflow going through the engine. Sure, the test vehicle had a blower and cam-shafts, but the untouched stock heads were hurting the potential of the manifold. Others have tested the intake with different results, but our conclusion (and Dezotell's as well) was that it would work better in a package that has ported heads, cams, and a supercharger.
After kicking around the idea of adding heads to this car, we bit the bullet and called Ron Robart at Fox Lake Power Products. He said he had a set of castings sitting in his shop that were ready to roll and recommended Fox Lake's Stage 2 CNC port job and upgraded valvetrain. We prodded Robart for more information about what the company does to the Two-Valve castings. "We CNC-port the heads and assemble them with high quality parts," he told us. "We push quality, not quantity. The valves and hardware are from Manley. All ports and chambers are equal on the heads. Flow increases to about 225 cfm at 0.550 inch lift." The larger intake port would certainly take advantage of the larger ports in the intake manifold.
Pricing for Stage 2, including all of the bells and whistles that come along with it, is $1,795--you provide the cores. If you don't have a pair of heads to send in, then there is a $300 additional charge. Adding Fox Lake-ported cylinder heads will increase horsepower, a fact that has been proven time and time again over the years. It's money well spent. We could have made over 500 hp with this combination if the car had a fortified bottom end.
Dez Racing's Brian Machie begins the disassembly of the upper half of the engine. The blow
Shown here is the Trick Flow manifold, minus the upper plenum. A set of 42-pound injectors
The balancer was removed since the front engine cover must come off in order to swap the h
The easy stuff was disassembled, and it was time to dig in by removing the valve covers, f
The front cover was removed to expose the chains.
These orange plastic pieces are guides that keep slack out of the chain.