Muscle Mustangs & Fast Fords
Modular Mustang Racing 850 Stroker Engine Build Part 2
Late Nights And Tire Smoke Lead To A Stroker Engine And 12-Second Runs In Project Silver Stealth Stang.
The big hand and little hand both pointed directly at 12 on the clock at Radical Racing. The clock didn't chime when midnight came, but those present didn't need an audible reminder of that moment in time. There were only three of us left at that point, and patience was running low, at least for this author.
Our workday started some 16 hours earlier with a running and driving Silver Stealth Stang--an ongoing MM&FF project vehicle focusing on Two-Valve budget performance mods. Our goal was a simple task of installing a stroker engine from Modular Mustang Racing (MMR). The game plan was to yank the stock engine, swap over the accessories, exchange various covers and components, and then maybe make some runs on the dyno. In our minds, in the worst-case scenario we were going to walk away after a day of work with a car that would be ready to chassis dyno test the next morning. None of us thought that it would end up taking three days to get a new stroker engine into the engine compartment of Silver Stealth Stang.
While yours truly was growing impatient, Radical's Craig Radovich and Mitch Miner would crack off a giggle every once in awhile to break the tension in the air. Not once did these guys lose their cool--this wasn't their first late night nor troublesome install, after all. Radical Racing has been in business for over 15 years and the shop used to run a highly competitive Pro 5.0 car. Radovich and his staff are seasoned pros in this game. "This isn't the first Two-Valve engine we've worked on, nor is it the first that had this much trouble fitting everything together. There are so many variations of these engines that you have to be prepared for the worst, which was definitely the case with this car," commented Radovich.
Our night had been months in the making as we embarked on an adventure to turn a high-mileage '99 Mustang GT into a respectable street/strip machine--without breaking the bank. The car belongs to our esteemed colleague, Ken Miele, who most readers know from the tech question/answer column Yo, Ken! The silver Stang was purchased from a used-car lot, and we began modifying it when the odometer read 160,000 miles.
The first order of business was a new suspension system due to the extraordinarily high mileage. A Hotchkis suspension system tamed the bucking horse on the rough New Jersey roads.
Miele is a die-hard drag racer and he gave us strict instructions to start upping the ante on the dragstrip. We started simply, with a JLT cold-air kit, TFS upper plenum, TFS 70mm throttle body, and pulleys. That brought the car into the high 13s consistently. The exhaust was opened up next, with Ford Racing shorty headers, a Bassani x-style pipe, and a Bassani exhaust. We also enhanced the car's performance by switching to a looser torque converter from Pat's Performance Converters, and Radical Racing rebuilt the rearend with parts from Downs Ford Motorsport.
To help the Silver Stealth Stang on the dragstrip, an Axle Exchange aluminum driveshaft was installed. It reduces the all-important rotating weight. All said and done, the car ran a best of 13.62--with the stock torque converter. We were unable to get to the track with the new torque converter in place. We thought that with 240 rwhp and armed with the looser P.P.C. torque converter and a set of sticky rear meats, the car was a mid-13-second hot rod.
We will never know Silver Stealth Stang's ultimate fate on the dragstrip with the stock engine--the new MMR stroker bullet is secured under the hood and ready for battle. The new Two-Valve monster was featured in the May '09 issue ("The Western Swing," p. 74), where we followed along with the engine build. It's a rather simple piece; MMR added a stroker crank to a brand-new factory iron-block.
They bolted Manley rods and pistons (built to MMR specs) onto the 3.750-inch crankshaft. Moving topside, MMR worked over a pair of bare Two-Valve heads, which were purchased new from Ford Racing and are not a junkyard set. The Two-Valve heads have new Manley stainless steel valves and flow 232 and 194 cfm at 0.500-inch lift. The Comp cams are rev-happy. The card says maximum rpm is at 5,800 rpm, but we routinely went to 6,300 rpm with ease. Valve lift is 0.550 inch on both the intake and exhaust lobes. Duration is listed as 234/238 degrees at 0.050-inch lift.
The MMR crew shipped the engine across the country from Ventura, California, to Radical Racing's shop in New Jersey. In our minds, the swap was going to be a simple one as we exchanged the parts and pieces from one engine to the other. As we mentioned earlier, things didn't go as planned. Thankfully, Radical Racing handled the hiccup with ease, but not without some bailout help from Downs Ford Motorsport's vast inventory of parts.
"If you aren't doing these swaps all the time, then it's easier to buy a complete piece. After you start buying more and more parts and pieces to complete this engine, the price adds up," commented Radovich. In hindsight, we should have bought a complete setup from MMR, but we didn't thinking we'd cut costs by reusing the stuff off our '99 engine. "It's always the little things that you don't realize. On this engine, MMR used all of the newest style Two-Valve parts. That's the right thing to do--after all, engine builders and shops don't work backwards. We happened to be working with an older Two-Valve engine.
"You can't get mad--these little things happen in this hobby. The important part is not to rush because you want to install the engine with the proper components," was Radovich's comment to our frustration. Don't overlook the small steps in the excitement of firing up your new engine.
Our first problem started with valve covers. Miele's stocker has the Windsor 13-bolt valve covers and the new bullet needed the Romeo 11-bolt covers. Radovich and Miner then began to swap over the little parts and pieces. The crank-trigger was the next bump in the road. The thick steel crank-trigger interfered with the crank sprockets. A quick raid on the Radovich parts bin netted us a thin steel trigger that slid on. Radovich leveled with us: "You have to be careful and check the small stuff like the crank-trigger clearance. We've seen a couple of different thickness triggers. It could get ugly if you install the wrong one." Radical provided us with a new front cover and the appropriately sized bolts, too.
Downs Ford Motorsport came through with intake gaskets, front cover gaskets, valve-cover gaskets, and new oil-pump bolts that fit the pick-up tube. The reason for all the new components is that we counted four different variations of the Mustang Two-Valve modular engine, with possibly more out there and many service updates. Radovich also added a new intake manifold. The stock plastic piece was updated with an aluminum water crossover. Ford changed to an intake with the aluminum crossover for better durability over its service life.
It took Radovich nearly a day to go through the engines and identify the parts and pieces needed. One day later, the parts were delivered from Downs Ford Motorsport, and the MMR engine was fully dressed and dropped into its new home. At this time, we kept the shorty headers and stock manifold in place despite the restrictive nature of each component. We also kept the factory 19-pound fuel injectors against the advice of MMR's Mark Lutton, who suggested 30-pound units for this combination. The car was strapped to the DynoJet chassis dyno at Radical Racing, but only after Miele drove it around the block a few times to make sure everything checked out okay.
Silver Stealth Stang screamed on the chassis dyno, and its initial output was 279 rwhp with low timing. Radovich dialed in the air/fuel ratio and tried various timing settings. He started at 22 degrees and went as high as 27 degrees. "The car produced the best power with 24 degrees. Going higher or lower resulted in a loss of horsepower. It was a minimal loss, but still a loss," stated Radovich. He also noted that the stock injectors were providing enough fuel, but if we were to add an intake and full-length headers, then a larger injector would be required. The 19-pounders were nearing their capacity in the upper rpm range. As for power, the car registered a best of 285 rwhp and 294.31 rwtq--impressive for a Two-Valve engine that doesn't benefit from forced induction.
As with all of Silver Stealth Stang's horsepower mods, dragstrip testing was required to finish off the article. Englishtown awakened from its winter slumber, and the track management applied a healthy dose of traction compound for our private track rental. The looser torque converter and extra power under the hood forced us to add some sticky tires out back. The Nitto 555 tires barely worked on the street just leaving from idle. We bolted on a pair of Mickey Thompson 26x12.50-inch ET Street DOT slicks. The tires are mounted on 17-inch wheels and tire pressure was set at 12 psi. The temperature at race time was a spring-like 63 degrees. Miele performed a smoky burnout for the cameras and brought Silver Stealth Stang to the starting line. The green light popped and Miele left cleanly, covering the first 60 feet in only 1.81 seconds. On the top end, the silver Stang streaked to the finish line with a 12.85 at 106 mph. Launch rpm was 2,000 rpm and Miele simply matted the throttle at the green. "The transmission shifted early on the 2-3 upshift," was his comment immediately following the run. He backed up the 12.85 with a 12.87 and a 12.90, all at 106 mph. Miele continued: "I think the car could have gone in the high 12.70s if the 2-3 shift was a few hundred rpm higher." Amidst the excitement over the 12-second runs, Miele forgot to drive over the scales. The car is hefty thanks to the spare tire in the trunk, large front brakes, and heavy 18-inch front wheels.
From the outset, Lutton told us the engine was capable of making similar power to the '03-'04 Cobra Terminator. Armed with that information, those cars regularly put down 340 rwhp on the Radical Racing dyno in bone-stock trim. Why didn't Silver Stealth Stang achieve that mark? The answer lies in the slushbox Ford nicknamed the 4R70W. Using the popular 15-percent conversion from stick to auto, our calculator showed a Terminator engine should make 289 rwhp if backed by an auto. The engine barely has 150 miles on the odometer, so we think once it's broken in, the power will rise about another 5-10 rwhp, bringing it inline with our estimate. Editor Smitty told us that he has personally compared the auto and stick transmission in a back-to-back test with an old project car. He saw a loss of 50-60 rwhp, which backs up our guesstimate.
The final tally after several long days and a trip to Englishtown netted us near 300 rwhp and solid 12-second runs. There is certainly more power lurking under the hood, and in the coming months, we plan on adding bolt-on parts such as a larger intake manifold, a MAF sensor, a throttle body, 30-pound injectors, and whatever else we can in order to get more out of Silver Stealth Stang. Our work on the modular family's red-headed stepchild isn't done yet. Stay tuned.