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Here’s the Basis for Building a 1,000-Horsepower LS Engine

HOT ROD logo HOT ROD 7/21/2018 Barry Kluczyk

With all the 1,000+ horsepower ratings permeating the pages of magazines and websites, it's easy to get complacent about achieving those lofty numbers. After all, they're seemingly so common that anyone with a salvage yard 5.3L, a couple of Chinese turbos, and some cleverly routed tubing is just a few degrees of timing away from the four-digit dyno club.


It ain't that easy. It's true that the airflow capability of the LS engine family enables output in street engines that wasn't even dreamt of for old-school small-block racing-engine builders, but getting there takes careful planning and prep work. We're talking about the bottom end of the engine, as well as the clamping capability for the cylinder heads, because when the boost level heads toward 20 psi and beyond, containing that cylinder pressure and ensuring the high-rpm durability of the rotating parts ensures repeatability of that stellar dyno result.

It was for those reasons that Australian performance specialists Harrop Engineering turned stateside and to experienced LS builder Brian Thomson to helm the assembly of an engine topped with their latest 2.65-liter supercharger. Like the LT5 engine in the new Corvette ZR1, the supercharger uses the latest and larger Eaton TVS rotors to pump out more boost. Improved adiabatic efficiency, as well as reduced drive power requirements, helps expand the power capabilities from the compressor's new rotors. On a 427-cubic-inch foundation and pushing about 15 psi of boost, that should make for about 1,000 horses or so on E85.

"There may be a lot of 1,000-horsepower engines out there, but getting there takes as much attention to detail in the assembly as it does in the amount of boost you can cram into it," said Thomson. "You have to be very diligent about measuring all the clearances throughout the engine, because at the levels of cylinder pressure and temperature that come with 1,000 or more horsepower, there is no room for error or 'close enough'."

1000-Horsepower-LS-Engine-Build-Part-1-002.jpg© Hot Rod Network Staff 1000-Horsepower-LS-Engine-Build-Part-1-002.jpg

An all-forged rotating assembly goes without saying in a build like this and we've outlined the details in the accompanying photos. When it comes to the block, however, Thomson decided on Concept Performance's LSR aluminum block. We outlined the block's attributes in an earlier issue of Chevy High Performance, but this represents the first build for Thomson with the block, as well as our first engine-build story featuring it. Like Chevrolet Performance's iron LSX block, it offers six bolts per cylinder head clamping, but in an aluminum casting that weighs only 113 pounds.

One thing the LSR block doesn't offer, however, is provisions for oil-jet piston cooling, giving us the opportunity to try out another new product: Get'M Garage's Piston Cooling System, which allows the main webbing of the block to be tapped for oil jets.

"At the power level we're talking about, the cylinder temperatures are extreme and the oil helps keep the pistons from literally melting," said Thomson. "It's a must in a supercharged LS engine."

Additionally, Thomson spends hours deburring the cylinder block, smoothing out and knocking down casting edges and other stress risers to eliminate potential sources of cracks.

In part 2 of the story, we'll finish off the engine with a set of Chevrolet Performance LSX aluminum cylinder heads and the intercooled Harrop supercharger system then push it into the dyno room to see just how easily and reliably 1,000+ horsepower is achievable on a well-prepped foundation. CHP

Additional Sources

Brian Thomson Engines


Concept Performance


Get'M Garage



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