By Steve Turner
Photography courtesy of Prestige Motorsports
If you have a project car out in the garage that needs an engine, you have dreamed of dropping a mega-power engine between the shock towers. For fans of the LS platform, which is a popular swap into many platforms, a boosted version of this engine would really take that project to a new level. To that end, Holley Performance Products definitely tugged at enthusiasts’ horsepower heartstrings with its 2020 LS Engine Sweepstakes.
To create this engine, Holley turned to the custom engine builders at Prestige Motorsports in Concord, North Carolina. This outfit is known for constructing everything from robust powerplants to full automotive builds. Like those assignments, this one had a really specific target.
“The mission for this build was to put together a custom LS stroker engine utilizing all the best internal parts and show the benefits of the TorqStorm dual supercharger kits. Of course, we could not do this without the help from the great folks at Holley, which we work very closely with in development of new combinations and parts testing year-round,” Shawn Meekhof, Sales And Marketing Specialist at Prestige Motorsports, explained.
Obviously a giveaway engine prize that carries a retail value over $23,000 is something special, but this engine isn’t really that far removed from the typical builds emerging from the Prestige shop.
“…This is just another example of what we offer. Many LS enthusiasts want boost, so we basically lay out all the options from centrifugal/roots/screw blower to turbochargers and explain the pros and cons of each package. At that point just pick your boost!” Meekhof explained.
Obviously as a promotional vehicle for Holley, the engine leans generously on Holley products. From the induction to the fuel injection, the Holley gear is omnipresent, but given the company’s large footprint in the LS market, that is no surprise.
“The all-new Holley Lo-Ram Intake looks great atop this 427 LS and the Holley Terminator X Multi Point EFI works seamlessly with this combo as well. It’s a great EFI kit that we install on hundreds of engines over the past couple of years and would recommend to anyone looking for fuel injection,” Meekhof said. “When completed this engine literally looks like a piece of jewelry, but with the performance to match that anyone would be proud to put under the hood of their ride.”
Of course, constructing a complete engine robust enough to survive a twice-boosted life requires sourcing components from a wide array of aftermarket suppliers. The foundation of this monster motor is one of Dart Machinery’s LS NEXT blocks.
“Special considerations would first start with the block as this is the foundation of the entire package. Although an OE block could be used for boosted applications, it is always a good idea to look at stronger foundations to ensure all the rest of the goodies installed stay in place!” Meekhof explained. “For that reason, we chose the Dart LS Next SHP Pro. This uses larger head studs, which provides better clamp load for the head gaskets. The crankcase area is also opened providing better bay-to-bay breathing and reducing windage.”
Featuring six-bolt mains with billet caps, the block received the full machining treatment. Prestige decked, bored, align-bored, honed, clearanced, and cleaned the block before embarking on the assembly.
“It always must be precise and thorough. Clearances are very important in every aspect on every engine. On engines like this we open the clearances for the additional heat and expansion created with forced-induction applications,” Meekhof added. “This leaves a little more clearance for the rods and mains and more piston to wall along with the larger ring gap previously mentioned. We also look at the deck finish for optimal combustion sealing. Up top, attention to cylinder head seat size, design, material, and valve margin are important factors in dissipating heat from the valves, especially the exhaust valve. Speaking of valves, extreme duty or also known as Inconel valves are highly encouraged.”
Of course even an robust block is only as durable as its internals. As such Prestige filled the LX NEXT block with one of Eagle’s internally balanced crankshafts forged from a 4340 alloy and delivering a 4-inch stroke. It swings Eagle’s 4340 forged H-beam rods spinning on King bearings and pinned to a set of D.S.S. Racing’s gas-ported, 2618-alloy pistons sized for a 4.125 bore.
“…It is important to use forged parts in the bottom end. The rod bolts should be at a minimum ARP 2000s or better. When it comes to the pistons, we always encourage the use of heavy wall pins and a 2618 forging to handle the elevated cylinder pressures and temps. The pistons used are also gas ported to provide ultimate cylinder sealing and attention to ring end gap as they are larger for boosted applications. Head gaskets are also important,” Meekhof said. “We draw the line at 1,000 horsepower for using layered steel versions. Anything above that, we O-ring or hoop the block and heads using copper gaskets for the ultimate in keeping the boost in! When it comes to the heads, we also encourage using castings that incorporate thicker deck surfaces to keep the head more stable along with studs over bolts to clamp it all in place.”
Besides the hearty fasteners and gaskets, Prestige rounded out the long-block with a custom-camshaft grind, a Melling oil pump, a Johnson Hy-Lift hydraulic-roller lifter set, an Enginetech valve lifter guide, and GM LS1/LS2/LS6 rocker arms with a Brian Tooley Racing trunnion kit. Mr. Gasket gaskets keep the long-block sealed, including the union between the Dart block and Prestige’s own 11-degree Cathedral Port heads.
“There are a huge variety of heads on the market these days and most will perform very well under any boosted application. We chose this specific set of cathedral heads primarily because this package is primarily intended for street use,” Meekhof elaborated. “They will perform well down low where it counts on the street, but also make great peak power. They feature an 11-degree valve angle, a large deck surface, and a moderate-sized runner measuring in at 255 cc.”
Topped by a Holley Lo-Ram manifold kit fed by a Holley 95mm throttle body and fed by Fuel Injector Clinic injectors fed by Edelbrock rails, this engine is built primarily from off-the-shelf hardware, which shows the robustness of the platform and its aftermarket support.
“That is the glory with LS builds. They feature great technology right from the factory. Stronger blocks than earlier small-block designs right from GM, cross-bolted mains and laid over valve angles are great attributes to see come right from the factory,” Meekhof said. “Like anything, as we push the power farther up the ladder, we look to increase the robustness by using stronger blocks with additional cylinder head bolt locations for six-bolt design heads, as well as larger head and main fasteners. Overall, everything you see here is readily available to the masses.”
With the goal of supporting big, boosted power in mind for this build, Holley and Prestige turned to TorqStorm for a pair of its self-contained superchargers to boost the engine into four-digit territory.
“TorqStorm has been a longtime partner at the Holley Events,” Chris Beardsley of TorqStorm added. “After a few supercharged engine projects through Prestige. We were asked to boost up their next big giveaway engine project.”
Featuring self-contained oiling, hybrid bearings, and billet impellers, these blowers are good for 700 horsepower individually, but the company’s Twin Charger Kits push that potential output over 1,200 horsepower, so you can see why the giveaway engine received this treatment.
“It’s cool looking! What more can we say? Our goal for this was to achieve 1,000 horsepower and have all the creature comforts. We also wanted it to retrofit into about anything considering it was a giveaway piece so we really hope to not limit the winner from actually being able to fit it in his or her project,” Meekhof enthused. “This is where TorqStorm shines. They have done an excellent job in packaging two blowers and still managed to fit all the accessories including air conditioning and power steering!”
Keeping things streetable meant not going full-race with some of the components. Sure there could be even more performance on tap, but building this engine to fit a broad array of potential projects made a lot more sense for a giveaway engine.
“With any boost and consideration for street manners it does not require the aggressive camshafts and valvetrain needed for naturally aspirated combinations making anywhere over 600 horsepower,” Meekhof explained. “Of course, we can build it with a more aggressive camshaft and attitude but that just wasn’t the goal here. It runs a hydraulic-roller, moderately tame camshaft with plenty of power on tap. The Holley Terminator X will take care of all the tuning required with ease.”
Naturally the fuel injection system was a key part of reining in a powerful engine’s driveability. The Terminator X will also allow adapting it to just about any project the engine lands in. Offering plug and play control for the LS platform, this EFI system supports boost, onboard diagnostics, datalogging, and more. With it installed, Prestige dialed in the new engine on the dyno.
“It was too easy. With the great advancements in technology and the speed of the electronics these days, it is far less hassle to dial in fuel injection that ever before. The self-learning feature is great once you establish what the engine wants and what air/fuel ratio to target,” Meekhof said. “That, along with proper timing, and we have a great recipe to make huge power very easily. What we like about the quality EFI systems such as Holley is that we are able to communicate via the laptop. This a great feature and allows us to provide remote tuning and services after the sale as needed.”
As a result the big, boosted LS cranked out a whopping 1,135 horsepower on race gas, and a more than sufficient 750 horsepower when detuned and set up for a more conservative 5,500-rpm rev limiter. With that kind of output on tap, this engine should make for a welcome addition to just about any project.
“As mentioned before it is tame, streetable, and reliable with all the amenities. That said it would serve very well in a ’55 Chevy hot rod cruiser to a 240Z transplant for a drift racer,” Meekhof mused. “This is yet another reason for the cylinder head choice. With Holley’s new Lo-Ram manifold we could keep overall height down to fit under almost any hood. All that required was a cathedral design head as the LS3 and LS7 platforms were not available yet.”
Holley bestowed this boosted beauty on its new owner on June 25, 2020, and whomever was lucky enough to receive it will be able to have a lot of fun with it.
“When you pop the hood on your ride and showoff this twin TorqStorm-supercharged 427 LS, people’s mouths are going to drop,” Meekhof said. “This is really a once-in-a-lifetime prize that we are sure anyone would be blown away to have the chance to win. It almost blows our minds that we can be involved in giving away such a custom piece. When the winner gets the engine installed, we will be right there to help tune the EFI remotely to get everything running at tip-top shape.”
Twice As Nice
Highlighting this build are the two superchargers bolted to it. They allow achieving a high level of performance that is sure to delight the winner. The company behind this twin-centrifugal configuration is TorqStorm Superchargers. A newer name on the power-adder scene, the company is making a big push into the muscle car market.
“More power per dollar with a lifetimes worth of use (is what separates these blowers from other superchargers),” Chris Beardsley, of TorqStorm, said. “That has been our multi-sided focus. Refining our machining and manufacturing processes. We have been able to lead the supercharger market in horsepower per dollar. While being made in the USA with a lifetime warranty on our products. Very substantial details that continue to give our customers a great supercharging experience.”
When it comes to the LS platform, the company has fully engineered its kits to work on the platform and allow for retaining all the creature comforts.
“Belt-driven accessories have always been important to us. Having four-digit power capability with power steering and air conditioning. Realizing not everyone owns or wants a race car; we design and build our system around these accessories. Using the most common LS mounting locations for accessories,” Beardsley said. “We have a multi-level bracket system for these engines. The belts are routed to drive the accessories and utilizing automatic belt tensioners. We have made a system that is compact, powerful and keeps you cool in the summer. From the pictures you can see that we leave the front intake valley wide open for a wide range of intake options. Easily the best engineered and complete kit on the market for the LS engine.”
The company offers both single and twin-supercharger setups depending on your performance desires. For a special engine like the Holley giveaway piece, going with two superchargers was the obvious choice for big power.
“Given the power output this base engine could support. We wanted to give the winner more power potential, Beardsley said. “The single supercharger, while making good power, does not give us the airflow needed to crest the four-digit mark. With two superchargers you can slow both compressors down, use less energy off the crankshaft, lower the outlet air temperatures, and flow substantially more air.”
That substantial airflow definitely resulted in ample power from the Holley giveaway engine. Fully tuned up on race gas it easily cranks out more than four digits, and it can be tamed for more streetable duty via the Holley Terminator X EFI.
“Running twin superchargers can net you 2,400-plus cfm to work with,” Beardsley added. “With that kind of air potential on the right engine build, pushing the 1,500 horsepower mark is possible.”
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