Though standard Cleveland-style...
Though standard Cleveland-style stud-mount rockers will fit the XTC-R heads, Bowen recommended T&D Machine’s shafts rockers for reliable valvetrain stability during regular high-rpm use.
Because these heads are designed...
Because these heads are designed to accept stock Cleveland rockers, adding on the shaft rockers requires cutting the mounts and rewelding them to accommodate the differing valve angles. The ⅜-inch–tapered COMP Cams pushrods are 8.850 and 8.950 inches long.
The 2.25-/1.68-inch valves...
The 2.25-/1.68-inch valves retain the traditional Cleveland cant and stagger, with the intake valve shifted 3 degrees away from the cylinder wall to promote better flow. Intake flow maxes out at 401 cfm at .800-inch lift, and 260 cfm at .800 on the exhaust. The combustion chamber is an extremely efficient 72cc Cleveland/C3 hybrid design that yields 11.6:1 static compression with our Ross pistons.
Like their NASCAR inspiration,...
Like their NASCAR inspiration, the XTC-R heads have raised exhaust and intake ports to smooth out the sharp curves that plague original Cleveland heads; the intake is raised .500 inch, and the exhaust .700 inch. The 2.185x1.68-inch intake port requires a specific gasket from FPR, but the 1.8x1.57-inch exhaust port uses standard 4V Cleveland exhaust gaskets.
This is a close-up look at...
This is a close-up look at the awesome port work inside the Edelbrock intake by FPS. These were actually discontinued and FPS bought up the remaining supply; however, FPS is planning to bring it back into production soon.
Ever seen a NASCAR intake...
Ever seen a NASCAR intake retrofitted to port EFI? Topping off our Clevor is an XFI fuel injection system from FAST with their 4150-style throttle body that flows 1,375 cfm with 65 lb/hr injectors on FAST rails.
You can’t quite see the back...
You can’t quite see the back of the valve, but the C3-style Edelbrock intake does provide a fairly straight shot into the cylinder with only a mild radius. The XTC heads are versatile, though; the CHI intake as well as other older variants through Ford Racing/SVO will fit as well.
For dyno testing we’re using...
For dyno testing we’re using a Meziere electric water pump to ensure we’ve got plenty of cooling while tuning. This is their popular polished 35-gph model.
Macy’s a tuner who’s highly...
Macy’s a tuner who’s highly in demand, and now we know why; our XFI’s air/fuel/timing landscape was mint almost immediately, requiring only very slight changes.
Speaking of tuning, Brian...
Speaking of tuning, Brian Macy of Horsepower Connection is the man who would extract every last bit of power. He’s an expert in FAST XFI systems and when not flying around the country taking care of customers, he even teaches XFI classes at EFI University.
Eric Weinrich of DYNO-Motive...
Eric Weinrich of DYNO-Motive strapped the Clevor to his DTS dyno and handled the plumbing of the Aviaid dry-sump system for testing. We’ll show you how to do it in the car in a later story.
Our MSD Pro-Billet distributor...
Our MSD Pro-Billet distributor needs a little altering to become a cam sync for our XFI; seven of the eight teeth on the reluctor wheel are broken off, by your means of choice. We’ll also remove the advance weights and springs from the top of the distributor and lock it out so that timing responds only to the XFI, not mechanical engine rpm.
To install the new cam sync...
To install the new cam sync distributor, Macy rolled the engine over to 50 degrees BTDC degrees and aligned the crank trigger pickup with the center of a magnet on the crank trigger wheel. The distributor is dropped in pointing toward the No. 1 spark plug, then the engine is rolled over and set at the lowest timing at wide-open throttle under max load—28 degrees for this one. All timing advance will now be handled by Macy and the FAST XFI.
NASCAR forbids water/meth...
NASCAR forbids water/meth injection setups like Snow Performance’s Stage 3 MPG Max Boost Cooler, which is a shame because as we proved in the Aug. ’11 issue that chemical intercooling can build big power. Mileage isn’t a goal this time, but the MPG Max system’s ability to reference injector timing (as well as boost) simultaneously and alter the injection of Snow’s Boost Juice accordingly is what we want for dialing in an optimum power curve.
In the end, the clevor was...
In the end, the clevor was happy with 28 degrees of total timing and 12.5:1 air/fuel ratio on the FAST XFI wideband O2 sensor. The EGT temps ended up close to 1,350 degrees and didn't vary much from start to finish.
By the Numbers
Block: Dart 9.5 deck Race Series aluminum Windsor
Pistons: Ross Racing
Rings: Akerly and Childs
Bearings: Clevite 77 from Summit Racing
Balancer: ATI Super Damper
Timing Set: COMP Cams
Oil pan: Aviaid dry-sump
Oil pump: Aviaid two-stage dry-sump, Petersen pulley
Cylinder heads: Ford Performance Solutions XTC-R 351
Rocker arms: T&D Machine shaft rockers, modified by Ford Performance Solutions
Intake: Edelbrock 2863 C3 NASCAR, ported and EFI’d by Ford Performance Solutions
Gaskets: Fel-Pro throughout, Fel-Pro PermaTorque MLS head gaskets
Bolts/studs: ARP throughout, ARP stainless bolt kit from Summit Racing
Cam: COMP Cams solid roller
Lifters: COMP Cams solid roller
Pushrods: COMP Cams
Distributor: MSD Pro-Billet
Plug wires: MSD Super Conductor
Valve covers: Ford Performance Solutions polished aluminum
|On the Dyno
438ci Ford Small-Block