Mr. October...

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Inside the LSX from GMPP

The 454-cubic-inch small-block V-8 in Jackson ’s Camaro is based on GMPP’s new LSX Bowtie Block cylinder block and other engine components. The cast iron LSX block was designed for the creation of high-horsepower, large-displacement engines based on GM’s Gen IV small-block engine architecture. The iron block enables engine builders to use traditional displacement-enlarging techniques to create large-displacement small-block engines of 500 cubic inches or more. The LSX block is also designed with a thick deck and strategic cast-in strengthening features that support high-horsepower supercharged and nitrous-oxide combinations.

Jackson helped build the engine with famed NHRA racer Warren Johnson, who was instrumental in the development of the LSX block. For the Camaro, a simple but effective combination employing a single four-barrel carburetor and carefully matched cylinder head and valvetrain components was employed.

The cylinder heads are prototype LSX heads, which are derived from the LS7 7.0L engine found in the Corvette Z06. They feature six head bolts rather than five, for increased cylinder head sealing – an attribute that builders of supercharged engines will appreciate. Bridging the LSX heads is a new GM Performance Parts four-barrel intake manifold designed to match the rectangular ports of the LS7 head. The manifold is already available from GMPP, allowing customers to run a carburetor on LS7 crate engines. Atop the manifold is a Holley 850-cfm carburetor.

An ignition driver is all that’s required to change from stock-type EFI to carburetion, and Jackson ’s engine uses a custom MSD Ignition driver that is designed for GM’s Gen III and Gen IV V-8 engines. With the ignition driver connected to the distributorless ignition system, the ignition timing is automatically set at start-up.

The bottom end of the engine uses a Lunati rotating assembly with forged parts and Mahle pistons that combine with the LSX heads to deliver a pump-gas-friendly 11:1 compression ratio. A custom-grind camshaft was sourced and Comp Cams supplied the remainder of the valvetrain components.

At Warren Johnson’s dynamometer facility, the LSX engine produced 641 horsepower and 611 lb.-ft. of torque. More than the peak numbers, however, is the engine’s Kansas-flat power band. The engine makes 520 lb.-ft. of torque at only 3,000 rpm, with torque rising steadily throughout the rev range.

“The engine makes a mountain of torque at just about any rpm,” said Johnson. “The best part is this isn’t an exotic combination. It was put together with off-the-shelf parts that either are available now or will be shortly through GM Performance Parts.”



In other words, it’s a combination that is easily reproduced as the family of LSX parts and engines grows.

To complement the power packed into its 454 cubic inches, the LSX in Jackson ’s Camaro was dressed with powder-coated accessories and custom rocker covers. The engine retains a classic look at first glance, but a second look reveals the individual coil packs and other features that identify it as a 21 st-century small-block. Stainless Works fabricated a custom exhaust system, including ceramic-coated headers.

sounds like gmpp has some nice parts in store for the lsx crowd.