The stock modular block was...
The stock modular block was used for this buildup. The bores were enlarged 0.030 inch more than stock.
Kuntz and Company was tapped to build the short-block. The company is probably best known for being a longtime race-engine shop out of Arkadelphia, Arkansas. This modular engine build was to let the world know Kuntz and Company isn't just a high-end race-engine shop, but also a place that does stout street engines. The stock-block's bores were enlarged by 0.030 inch, and the holes were filled with off-the-shelf Arias pistons and Eagle rods. The piston-rod combo swings off a stock-stroke steel crankshaft. Compression ratio sits at a turbo-friendly 8.5:1. The bottom end was designed to withstand the rigors of boost, no matter what the Hellion crew cooks up for this R&D car.
Topping the modular short-block are stock heads and camshafts. Urist wanted to push the factory pieces to the limit and felt the stock castings flowed enough air to support the volume of boost the turbo was capable of injecting into the engine. "Turbos are less affected by heads and/or camshaft changes when compared to a naturally aspirated or supercharged engine,"he says. "With this in mind, there are minimal gains from headwork and camshafts with this combination. I suggest saving time and money and invest it in fortifying the rest of the engine." That's not to say you won't pick up power with that work, just not enough to warrant spending another grand or two. The money saved could be better put in other areas of your S197 Mustang, such as the fuel system and drivetrain.
Just having a strong engine to survive 20 psi of boost isn't enough to go out and trounce the dyno rollers. Other pieces of the puzzle included a Modular Mustang Racing (MMR) complete fuel system, consisting of a -8 feed line with a billet Y-block, fuel filter, and billet MMR fuel rails. They deliver the fuel to eight 60-pound injectors. Nate Phillips used DiabloSport software to tune the stock computer. Backing the potent turbo engine is an ACT single disc clutch, much like the one Urist employed behind the twin-turbo '03 Cobra we covered in the Jan. '08 issue ("The Manhattan Project").
Break-in consisted of roughly 500 miles that Hellion's Dwayne James happily drove. He cruised the streets of Albuquerque, New Mexico, and resisted the temptation to mash the throttle. A quick oil change and the car was strapped to Dyno Edge's DynoJet chassis dyno. A few easy pulls were made to check the air/fuel ratio, and then the staff let it rip. A mere 17 degrees of timing were dialed in, and the Three-Valve engine sucked in Trick 101 fuel. We watched patiently as the car threw up power in the 650-rwhp range. Phillips played with the computer and made some more pulls. Power shot up to the 680 range. He then did a few tricks with the variable camshaft timing. We saw huge gains with the changes. The final results were an outstanding 731 rwhp and 666 rwtq.
The Hellion '05 Stang exhibits docile street manners and a stock idle, thanks to the stock camshafts. That story changes when the hammer is dropped. A chain is only as strong as its weakest link-having a fortified bottom end ensures this chain won't break when it drags LS-powered cars down the strip.
A steel crankshaft was selected...
A steel crankshaft was selected for its strength. The crank carries a 3.54-inch-long throw. When combined with the 3.58-inch bore, final cubic inches come out to 285.
There's a lot of stuff crammed...
There's a lot of stuff crammed into the engine package.
A Fel-Pro gasket sealed up...
A Fel-Pro gasket sealed up the bottom end.
Oiling is very important with...
Oiling is very important with big-horsepower engines, and a Melling high-volume oil pump was added to this mod motor.
Pumping the oil is only part...
Pumping the oil is only part of the story; you also need to control it. This Canton pan not only holds more oil (7 quarts), but it also has special baffles inside to keep the oil away from the crankshaft-aiding in power production.
Having a strong foundation...
Having a strong foundation is a must when you're dealing with power adders. If the bottom end can survive, then feel free to turn it up! We did-20 psi is no joke, and the Kuntz and Company short-block survived with ease.
The bottom end was complete,...
The bottom end was complete, and it was time to focus on the upper half of the powerplant. We used stock heads and camshafts. Urist feels that money is better spent on other parts rather than porting the heads and adding camshafts. He says the gains are minimal in this type of turbo application.
S197 engines feature three...
S197 engines feature three valves per cylinder: two intake and one exhaust valve. They're a huge step up from the Two-Valve heads on the '96-'04 base V-8 engines.
Fel-Pro replacement head gaskets...
Fel-Pro replacement head gaskets were used in this application. ARP 2000 head studs were also implemented in the plan to hold the heads in place during the severe combustion process.
Dwayne James lifts the big...
Dwayne James lifts the big head onto the deck of the block.
The camshafts feature variable...
The camshafts feature variable cam timing, meaning the computer will advance or retard the cam timing based on the driving situation. Nate Phillips fooled with the cam timing inside the computer program and found a solid 50hp increase. Technology is amazing.
The cam chains and knock sensors...
The cam chains and knock sensors (in the valley of the engine block) have been installed.
A cover is fastened to the...
A cover is fastened to the front side of the engine.
Act came through with a single-disc...
Act came through with a single-disc clutch to hold the extra torque and horsepower from this boosted Three-Valve powerplant. The stick-shift transmission remained stock, save for the Pro-5.0 shifter.
We went with a better set...
We went with a better set of motor mounts when dropping the engine into place. The left mount is a UPR Products piece and the right is stock.
The engine easily dropped...
The engine easily dropped into place.
Hellion's crew is well versed...
Hellion's crew is well versed with installing their turbo system. The only difference between this install and the base model is the turbo unit-we went with the 76mm unit with optional dual-ball bearings.
Once everything was buttoned...
Once everything was buttoned up, the engine was broken in and tested on the chassis dyno. It spun the rollers to an impressive 731 rwhp and 666 rwtq. The car drives like stock since the engine is essentially a factory piece with stronger components, so we could crank in 20 psi of boost.