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Man O War Superstar Stroker Build Unleashes 1,043 Hp On The Engine Dyno-On Pump Gas!
A Grand Ol' Time
Last summer, we embarked on a mission to build a gigantic Windsor engine that would perform admirably on pump gas and still be worthy of competing at a True Street Challenge. Pump-gas performance has grown in popularity over the past few years, as enthusiasts strive to do more with less. Some say the mark of a true street car is the ability to pull up to any pump and fill up, something you can't do when your engine relies on 116 octane. But when tuning a serious supercharged engine, 93- or 91-octane gasoline adds a degree of difficulty that, theoretically, should keep power levels low. We bucked that trend by unleashing 1,043 hp with the Superstar Stroker.
Cracking the grand 1,000hp mark was quite an accomplishment for our project, and to be truthful, it was a bit of a surprise. We knew big power was to be had with this engine. After all, it's big, has a healthy induction system, and features a supercharger. Adding more pleasure and good feelings is that we think 1,100 hp is attainable by simply taking the engine to a higher engine rpm. But we're getting a little ahead of ourselves.
Our adventure into the pump-gas genre began last year over dinner with some friends when we were brainstorming combinations. I brought up the notion of building a 302 stroker engine, which I thought would be a cool project, but my friends thought it was too clich. They prodded me to go big or go home-they even pushed me to add a supercharger. Peer pressure is tough to defend against, so I adapted my original plans and ordered a set of large-bore pistons along with a long-stroke crankshaft. Big-block inches in a small-block package were the order of the day.
For the build, we enlisted the talents of Rich Groh Racing. Proprietor Rich Groh handled the details like cam profile, machining, flow testing, assembly, and dyno testing. The engine was built in the span of three issues (Nov. '06, Dec. '06, and Jan. '07), after which it sat for a few months before we had time to get it on the dyno. We apologize for the delay on the engine dyno test, but we finally got off our butts and finished what we started.
Ninety-nine percent of the parts used in this engine are off-the-shelf components that can be easily duplicated. It's scary how simple and easy it is to build a similar combination. Let's look at what it took to get such stump-pulling, extraordinary numbers from a big-inch Windsor.
The block is the foundation for any engine, and we selected a World Products Man O' War 9.5-inch Windsor block. We opened up the bores to 4.155 inches, a size that's easily attainable as the block can be safely bored to 4.200 inches. Today's aftermarket engine blocks are capable of such large bore sizes and remain streetworthy. Older blocks were limited because the water jackets would need to be filled to add strength behind the thin walls. World engineered this block to handle that size bore without intruding on the precious water jackets that keep the engine cool. Large-size engines such as this will become more popular as more people realize the blocks are capable of handling big bores and long-stroke crankshafts.
Our 4.155-inch bore was complemented with a 4.100-inch stroke crankshaft. The crankshaft size is becoming more common, which makes it easier for people to step up to large cubic inches. It brought our final engine size to 445 ci-we determined the cubic inches using the V-8 formula: bore x bore x stroke x 6.2832.
The crankshaft is made of steel and is up to the task of holding a lot of horsepower. The steel rods are a lengthy 6.200 inches and are H-beam style. The pistons naturally are forged and offer a stout ring package promoting durability and longevity. The pins are also heavy-duty, designed to take a beating in a supercharged engine like this one.
The bottom of the Man O' War block is covered with a Canton Racing Products oil pan and windage tray. A quality pan keeps the oil under control to limit windage and improve oiling and horsepower. Every nut and bolt was sourced from ARP, including the head studs and the Meziere electric water pump flows enough volume to keep our supercharged engine cool on the street.
The upper half of the engine consists of TFS Street Heat heads, an Edelbrock Super Victor EFI manifold, a Comp Cams hydraulic roller camshaft and valvetrain, and a Wilson Manifold's intake elbow and 90mm throttle body. The camshaft was designed by Groh to be mild sounding and easy on valvetrain parts. That mission was accomplished, as the engine purred like a kitten on the dyno. One would hardly think such a mild-sounding engine could make over 1,000 hp.
The camshaft profile has 0.570/0.575-inch intake and exhaust-lift values with a duration of 242/248 degrees at 0.050-inch lift. Two values that have a tremendous impact on the camshaft's street appeal are the lobe separation and lobe profiles. Lobe separation is 115 degrees, and Groh says that's perfect for a street engine. He used a lobe profile that he refers to as "quick" and that keeps the idle even and smooth. The part number for the lobe is unknown as Groh preferred to keep that information tightly guarded.
We chose the Street Heat heads because they work well despite having been originally designed in the early '90s. TFS has made some updates to them over the years, but the same basic design has remained. We opted to get regular, off-the-shelf CNC-ported heads (225 cc) right out of the TFS catalog. The flow bench showed these heads flowed 330 cfm through the intake port and 251 cfm through the exhaust port at a valve lift of 0.750 inch. We're using a camshaft in the 0.570-inch range, and our flow chart showed these babies were pushing 317 cfm and 238 cfm at 0.600-inch lift.
The Super Victor intake is a carburetor-style intake manifold, and Edelbrock offers it in a variety of ways. Ours came with fuel-injector bungs and 11/42-inch fuel rails. We used FAST 83-pound fuel injectors-they were nearing their limits during our dyno testing. If we step up the blower size, then we'll have to upgrade to FAST's 95- or 160-pound rated injectors. Wilson Manifolds supplied us with a cast-aluminum elbow so we could mount their 90mm throttle body easily to this engine. An MSD distributor was modified for EFI use, and we also utilized a crank trigger system from said ignition manufacturer.
Vortech Superchargers came through with a V20 YSi-Trim supercharger that we thought at first was a bit small for this engine. The company's Media and Race Relations Manager, Ricky Best, assured us the YSi-Trim was up to the task, and from the start of the project, he thought the unit would help the engine produce 900 or more horsepower. It is the company's Renegade kit that includes brackets, idlers, and strut brace, and Best upgraded us to a 10-rib blower-belt combination. Despite the large 445ci displacement and high-flow heads, the engine saw 20 psi of boost. If we took the engine to redline, we are sure the dyno would have read 1,100 hp. If that's not enough, Best recommended the XX-Trim blower. "The larger supercharger should, conserva-tively, pick up the power to around 1,250," he says.
Groh doesn't have an in-house dyno, so he loaded up our bullet and headed to Opel Automotive Engineering in Streamwood, Illinois. The facility features a SuperFlow engine dyno. Groh brought along 93-octane pump fuel from a Valero station located around the corner from Opel-it's about the most non-trick fuel you can find. Feeding the gasoline to our engine was a MagnaFuel EFI pump and 11/42-inch feed lines and 31/48-inch return lines. The fuel regulator was a Weldon unit out of Groh's NMRA EFI-Renegade race car. Standard 10W-30 oil was used for both the break-in period and subsequent dyno pulls. NGK 11 spark plugs and Moroso Blue Max spark plug wires delivered the electric charge to the cylinders.
The break-in period consisted of some idling and a steady pull at 2,000 rpm. Once the engine checked out OK, Groh and Opel Automotive Engineering owner, Ted Papuga, made a few easy pulls to 4,000 rpm. Groh checked the valve lash to make sure the valvetrain was in proper working order. He also glanced at the tune he put in the Big Stuff 3 engine-management system. A little fine-tuning of the fuel curve and timing events was needed. With the said adjustments, the engine was fired up and the crew took it to 5,000 rpm where horsepower shot up to 833. Groh noticed the boost gauge was fluttering a bit and checked the blower belt. Sure enough, it needed to be cranked down some more as the belt stretched.
A tightened blower belt brought a smooth boost curve, and the result was 850 hp and 893 lb-ft of torque at 5,000 rpm. The fuel pressure held steady at 43.5 psi at idle and was advanced at a 1:1 ratio of boost to fuel pressure when at WOT. Groh stepped up the engine rpm and made a full run to 6,000 rpm. The power results were an outstanding 1,043 hp and a stellar 913 lb-ft of torque. Boost peaked at 20 psi at 6,000 rpm. Groh tried to bring the engine higher on back-up pulls, but the ignition system had a miss in it at the higher rpm, so he called it quits. The engine repeated the 1,043 peak number within a few horsepower on the back-up runs.
If the engine could be brought up to the proposed 6,500-rpm limit, we estimate output to be 1,100 or better. "We were picking up about 20 hp per 100 rpm when we had to kill the pull. Based on that, we would have easily run more than 1,100 hp," Groh says. Timing was set at a modest 17 degrees, well within the safe limits of the 93-octane fuel.
We found it interesting that torque kept climbing, and we still hadn't reached a peak number at 6,000 rpm. The long curve is no doubt attributed to the long-stroke crankshaft, which creates a lot of torque. The upward-moving boost pressure also helped the ever-increasing torque figure. This type of torque will have your eyeballs planted in the back of your head when your Mustang is flying down the quarter-mile. The car will feel as if it will continue to pull hard no matter how long you stay in the throttle.
Attaining such ludicrous numbers is signifi-cant because it was only in the early '90s that a small-block Ford engine eclipsed the 1,000hp barrier. Legendary Pro 5.0 racer Gene Deputy had fastened a pair of turbochargers to his 5.0L engine and let it rip with nearly 30 psi of boost. It was a full-on racing engine with custom parts. The final dyno numbers were 998 hp-the kind of results that had people believing Deputy sold his soul to the devil. People were dumbfounded that a small-block Ford engine was on the brink of 1,000 hp. Fifteen years later, we laugh at that notion as our 445ci street engine achieved those power levels with off-the-shelf parts and a 93-octane pump fuel. This hobby has come a long way.