A good part of Z06's mystique and mind-boggling performance comes from its new, 427-cubic inch, 505 horsepower, LS7 engine, the most powerful, production V8 engine ever installed in an American road car. LS7 gets its RPO number from a 465-hp, 454 cuin. crate engine GM sold in the '70s and early-'80s so it's only fitting that GM's Performance Parts program offer a "crate" version of the new LS7 and, here at Tom Henry Racing (THR), we've got LS7 Crate Engines (PN 17802397), sittin' on the dock, ready to rock.

The new LS7 Crate Engine from THR and GM Performance Parts could have a multitude of applications limited only by a Chevrolet enthusiast's imagination. This new crate motor is the ultimate choice for retrofit in a street rod, muscle car or for replacement of the LS1 or LS6 in a C5 Corvette or '98-'02 Camaro. It'd, also, make a great high-end upgrade in a Silverado, Tahoe or Suburban. What about the ultimate Cadillac Escalade powered by an LS7 modified with a set of headers and a Stainless Works exhaust? THR has the engine and everything else for such a conversion.

The LS7 has its roots in motorsports--the four-time, 24-Hours-of-LeMans winning C5.R and C6.R Corvettes, to be exact. Its aluminum block is derived from the C5R Racing Block (PN 12480030, also available at THR) used by those road racing Vettes. LS7 is, also, related to the Generation 3 and 4 Small-Block V8 engine families used in the Corvette, Camaro and Chevy full-sized trucks, however, it differs from those production engines in certain areas.

First, it has pressed-in cylinder liners, rather than the cast-in-place liners of other Gen 3/4s. Those pressed-in liners have 104.8-mm bores rather than the 101.6-mm or smaller, bores of others. Its cylinder heads, also, have racing pedigree through a reduced, 12° valve angle rather than the 15° of other Gen 3/4 engines. The valve angle reduction improves airflow through the heads' intake ports. The intake manifold is, also, a unique part developed through the Corvette Racing program. LS7 has a dry-sump oiling system inspired by the dry-sumps used in racing and developed for the Z06's high lateral acceleration ability.

For a production engine, the LS7 has some amazing features which, until just recently, were seen mostly in racing engines, such as: 6-bolt, forged-steel, main bearing caps; titanium connecting rods; pistons with hard-anodized ring lands; tapered piston pins; titanium intake valves, CNC-ported cylinder heads and offset 1.8:1 intake rocker arms. Other, more common, yet still racy items are a forged-steel, four-inch stroke crankshaft, sodium-filled exhaust valves and an 11:1 compression ratio.

Because the LS7 Crate Engine shares the production Z06's oiling system, it comes configured for a dry sump. Crate Engine installers must supply oil hoses and an oil tank. They can purchase the production Z06 hoses and tank here at Tom Henry Racing or use aftermarket AN hoses and fittings and an aftermarket oil tank.

While the full process is still under development, it is possible that a crate LS7 can be converted to a wet sump configuration by replacing its front cover, oil pump and oil pan with the same parts from an LS2, six-liter engine used in 2005-up Corvettes, SSRs and Pontiac GTOs. These parts can be ordered from THR. When converting to wet sump, the LS7's windage tray may have to be discarded if it proves incompatible with an LS2 oil pump pick-up and pan. Also, LS7's crankshaft is an inch longer so, when converting to the LS2 front cover, there will be challenges in getting a wet-sump LS7's accessory drive configured properly. The GM Performance Parts program continues to develop the LS7 Crate Engine and as new information on the wet-sump conversion issue becomes available, we'll post it here.

The LS7 is manufactured at General Motors Powertrain Division's Wixom, Michigan, "Hand Build Center" along with the Z06 LS7s and the LC3, 472-hp, supercharged, 4.6L "Northstar" dual-overhead-camshaft V8 used in the Cadillac XLR-V.

GM rates the Corvette-spec. LS7 at 505-hp@6300-rpm and 470-lbs/ft torque at 4800-rpm. Not only does the stock LS7 make 1.18 hp/cuin. at a mere 485 pounds, it makes 1.04 horsepower per pound. Not bad for a Small-Block V8, we'd say.

That 505-hp rating comes using the SAE J1349 standard which is a "net" rating system for which the engine is tested in production trim. Obviously, in a retrofit application--for example, installation in a killer '69 Camaro--the LS7 Crate Engine is going to be used with an air intake system less restrictive than what's on a Corvette, perhaps a different camshaft with more overlap and less lobe separation, headers, no catalytic converters, a low restriction exhaust system and a computer program designed for best performance rather than a compromise of performance, fuel economy and exhaust emissions. We'll bet the LS7 Crate Engine set-up that way might make 560-hp@6500 rpm.

Wow!!