When a new engine platform arrives on the scene, everyone in the performance aftermarket is excited to get their hands on it. They want to start developing high-performance aftermarket parts and see what the new engines are capable of. When GM released the new Gen-V small block back in 2014, the story was no different.

For the past decade, plenty of high-performance parts have hit the market for this direct-injected V8, and performance shops and race teams have used the new platform to chase horsepower and track records. Back in 2019, Katech built a 427 cubic inch Gen-V LT that made a then-record setting 806 horsepower naturally aspirated. Then, the SDPC Raceshop pushed the dyno record further with its 440 cubic-inch iteration, making 835 horsepower. Gwatney Performance Innovation and Kuntz Racing Engines are no newcomers to building high-horsepower engines, and their latest Gen-V 454 LT pushes four-digit horsepower.

The team at Kuntz Racing Engines strapping the Gen-V 454-cube small-block to the dyno for its record-setting pull.

Starting From The Bottom Up

GPI started with a Kuntz-prepped and sleeved Gen-V 6.2-liter LT1 OEM block. The production cylinders can only handle about 0.020 inches over the stock 4.065-inch bore. So, to hit that big-cube displacement; they needed the max bore of 4.185 inches, which only an aftermarket sleeve could provide. Steel main caps and ARP studs clamp down a Callies Performance Magnum crankshaft with a 4.125-inch stroke.

Connecting rods come from Molnar Technologies and are their forged H-Beam design made from 4340 steel, heat treated and shot peened to increase tensile strength and fatigue life, then fitted with ARP2000 hardware. The cylinders are filled with custom-forged pistons and rings from Diamond Racing Pistons. These pistons are custom-machined with a dome to fit the CNC chamber of the cylinder heads to produce a concussion-inducing 16:1 compression ratio — no 93-octane for this 454.

Diamond Racing custom forged pistons fill the 4.185-inch bore cylinders.

The bumpstick in this bored-and-stroked Gen-V LT is a GPI custom 0.800-inch-lift hydraulic-roller camshaft ground by Cam Motion to their specifications. Your eyes did not deceive you; you read that correctly. This 1,000-plus horsepower, 9,000 rpm redline goliath is not running a solid roller camshaft and lifters, but off-the-shelf Johnson short travel tie bar hydraulic-roller lifters (P/N: ST2116LSR). The stock GM oil pump isn’t designed to spin to 9,000rpm, even if it’s on a short dyno run, so a Moroso external oil pump and vacuum pump combo was installed on the side of the block and connected via a cogged belt to the ATI balancer. At the time of testing, the vacuum pump was not hooked up, and the crankcase pressures were vented to the atmosphere.

The stock GM oil pump can’t handle the 9,000-rpm redline. However, this Moroso external oil pump and vacuum pump can without breaking a sweat.

Topping It All Off

Keeping those high cylinder pressures sealed requires the use of ARP head studs and custom Cometic MLS stainless steel head gaskets topped with a pair of Competition Induction Designs SRC casting cylinder heads. These are CID’s aftermarket castings with thicker decks and are manufactured in Ohio. A one-off CNC program pummels the intake and exhaust ports to shape, so these heads flow the volume of air this 454 needs to reach its lofty power goals.

The heads are assembled with custom 7mm-stemXceldyne titanium valves to match the CHE precision bronze valve guides and CHE iron valve seat inserts for durability. PAC 1238X dual valve springs with titanium retainers keep the valvetrain stable to the 9,000-rpm redline. A set of Jesel Sportsman steel shaft rockers actuate those super-lightweight valves.

Jesel Sportsman Steel Shaft Rockers top the CID CNC cylinder heads.

CID also made the intake manifold to match their heads and bolted on a Katech 112mm throttle body. The short runner design, paired with the large plenum lid, is aimed solely at those with high-RPM power goals and 7.0-plus liters of displacement. Our more eagle-eyed readers may have noticed that this intake can be machined for port fuel injection, but this LT isn’t using it. That’s because this 454 small block is still running the GM factory LT4 high-pressure fuel pump and direct injectors with a DSX Tuning auxiliary fuel pump system to inject E85 from the local gas station directly into the combustion chamber.

Brandon Hill’s 6th generation SS Camaro will be pushing the limits with the new 454 small block.

Drumroll Please!

With only a few days left in July, the crew at Kuntz finally made the highest horsepower pull to date on the engine dyno: 1,008 horsepower at 8,400 rpm and 678 pound-feet of torque at 7,000 rpm. All that power, and it still utilizes direct injection, hydraulic- roller cam, and E85 from the corner gas station? It almost sounds like a high-performance street engine being described instead of a record-setting custom stroker build.

On the engine Dyno at Kuntz Racing Engines, the Gen-V 454 LT pushes 1,008 horsepower at 8,400 rpm and 678 pound feet of torque at 7,000 rpm.

A few years ago, Brandon Hill’s 2017 Camaro SS Camaro was built and tuned by Ryan Stevens from Gwatney Performance Innovations and turned into a nine-second quarter-mile 6th gen that still utilized the factory block and rotating assembly, the stock 8L90e automatic transmission, the stock suspension, and the stock 2.77-geared rear differential. The next step for this big-cube LT is to go back between the fenders of Hill’s Camaro to see if this GPI/Kuntz 454 LT can push it deep into the eights. You can bet we’ll be watching.