FAQ – LS7 Specifications

April 8, 2015

The engine that may have really kicked off the success of the LS engine, the LS7 is one of the most powerful small block engines ever built. Based on the C5R Corvette engine platform, the LS7 was developed by GM to produce big block power in the small block form factor. Simply put it’s still one of the most powerful small block engine that GM has ever manufactured.

First found in the 2006 Corvette Z06, the LS7 is built on the same LS1 GEN III architecture and sports red top engine covers from the factory. While it shares the same base as it’s smaller cousin in the LS1, the LS7 uses a bigger 4.125″bore with pressed-in dry cylinder liners and a siamesed cylinder bore.

If you are in the market for a performance engine to swap into your chassis, you could do a whole lot worse than the LS7. This is what our LS7 Specifications Guide is for, to help you identify and decide what engine is perfect for you.

Displacing 7.0 liters and belting out 505 horsepower and 475 ft. lbs of torque, the LS7 doesn’t stop there in differences from it and the earlier GEN III engines. Custom CNC ported aluminum cylinder heads and a forged crank with a 101.6mm stroke help maximize power, while the titanium connecting rods and lightweight valvetrain components allow the LS7 to rev to 7000 rpm.

Other differences would also include the unique LS7 dry sump oiling system. The OEM oil sump system is what drove the C5R to victory, and what makes the Corvette Z06 so special. Maintaining oil pressure under the highest and most demanding of race conditions, the dry sump oiling system keeps your LS7 running. Tested to cornering loads upwards of 1G, the LS7 utilizes a special oil pan and windage tray for scavenging purposes.

Eliminating the need for a gear driven oil pump also allows you to prime the engine before starting it dry. This goes a long way in preventing piston shrinkage and premature engine bearing failure, as your engine is properly lubed and primed before starting.

While it’s a technology commonplace in race vehicles, or purpose built race cars, the Corvette Z06 is one of just a few production vehicles with this kind of oil pump system.

Differences vs the LS2 engine

There’s quite a few differences between the LS7 Specifications and it’s smaller cousin the LS2. Lightweight titanium rods top the list of modifications and upgrades that allow the LS7 to stand alone. These titanium rods are over 30 percent lighter than the LS2 counterparts, and allow the LS7 to rev higher and faster with less strain and rotational mass.

The LS7 is also deck plate honed and features forged steel main bearing caps, offering more strength and superior rigidity properties. The larger bore is further reinforced by the pressed in cylinder sleeves, while the six bolt CNC machined main caps keep your LS7 together. It’s remarkably powerful, lightweight and compact for the level of performance right out of the box.

Reluctor Wheel Differences

The LS3 Specifications also feature the newer reluctor wheel design with 58X teeth, a change from the GEN III GM engines of the past. The newer reluctor wheel promises for more accurate and immediate translation of exact crankshaft positioning. This allows the engine control module to adjust ignition timing with greater precision, which optimizes performance and economy. For more information on GM reluctor wheels, check our Reluctor Wheels and You Guide.

But GM didn’t stop there, electing to upgrade the camshaft position sensor to a 4x cam gear pickup. The equally spaced sprocket with four seperate slots help the GEN IV PCM dictate and read the camshaft and crankshaft position sensor more accurately and quickly. The dual 58X/4X measurement ensures extremely accurate timing for the life of the engine. Moreover, it provides an effective back-up system in the event one sensor fails.

The LS7 Specifications rival the numbers found in many production engines:

505 horsepower @ 6200 rpm
475 lb.-ft. of torque @ 4800 rpm
7000-rpm redline
Unique engine block with larger 104.8-mm (4.125-inch) bores and pressed-in cylinder liners
Forged steel crankshaft with 101.6-mm (4-inch) stroke
Titanium connecting rods
Cast aluminum flat-top pistons
Racing-derived CNC-ported aluminum cylinder heads with titanium intake valves and sodium-filled exhaust valves
Dry-sump oiling system
11.0:1 compression ratio
Camshaft with 15-mm (.591-inch) lift
Hydroformed exhaust headers with unique “quad flow” collector flanges.