The LS2 small-block GM engine has only been out for a couple years, and it's already captured the imagination of the automotive world. As standard equipment in the GTO or base C6 Corvette, it provides for one thrilling ride with 400 horsepower and 400 lb-ft of torque on tap at the crack of a throttle. Also available from GM Performance Parts as a crate engine, the LS2 ships with 364 cubic inches (4-inch bore with a 3.62-inch stroke), 10.9:1 compression, and the same heads and cam that came in the LS6 engine from the Corvette ZO6. It is a rev-happy engine that responds to the simplest of modifications as we showed you in our last issue. Our quest to further study the LS2 led us to the aftermarket stroker kit combinations for this engine. And, once again we found ourselves standing at the gates outside Livernois Motorsports (Dearborn Heights, Mich.) looking for assistance.
This time around, Livernois Motorsports was more than happy to share with us their LS2-specific stroker kit, which takes your 364-inch performance engine and turns it into a 404-inch monster! As you would expect from a high-performance application like this, Livernois uses only the finest components and materials when they designed their LS2 stroker kit.
"The LS2 is a great engine," Dan Millen, owner of Livernois Motorsports tells us. "GM has delivered us with an awesome starting point with the LS2. We've put a lot of R&D time into looking at what gives our customers a good return on their investment. Once you've done the cam and heads, the next area to turn to for more power is with more cubic inches. The heads, when they are CNC-ported by us, are of such a good design they can easily supply the extra 40 inches that we get with our stroker kit. You also get premium parts with our LS2 stroker. We can sell them to the customer as a kit they can install, or we'll build them a custom motor and put it into their Corvette or whatever they want."
What You GetLivernois Motorsports sell their LS2 stroker kit as a complete package of parts ready to assemble. The heart of the stroker kit is the crankshaft. Livernois utilizes a custom forged steel 4340 crankshaft with a 4-inch stroke. These cranks are tough! And, Millen tells us they will easily handle 1,000 horses. The pistons are Mahle forged units with a 4.010-inch bore. There are two dish sizes available: 12 cc for naturally aspirated applications (10.5:1) and 32 cc for forced induction applications (9.0:1). Obviously, the larger dish drops compression ratio to decrease detonation with a blower or turbo. The kits comes with rings: Mahle plasma moly top rings on top, cast iron reverse twist second, and standard or low tension oil rings. And, the rods are Manley 4340 H-beam units with a 7/16-inch ARP 2000 rod bolt. For the LS2 stroker kit, you get a 6.125-inch rod. Livernois also provides you with coated surfaces on the main, rod, and camshaft bearings. When installed in a .010-inch over LS2 block, you get an honest 404-cubic-inch LS2.
Mike Schropp, one of Livernois Motorsports' engine designers tells us, "This kit is intended for somebody who wants the highest quality parts and materials available without having to go to the extreme of billet parts and pricing, and the kit will work for all but the most extreme applications where custom parts are needed."
And, while this story is about a stroker LS2, we thought we would also key you in on the Livernois non-stroker LS2 kit that is coming out. This will be a stock-stroke LS2 kit offering higher quality parts than what the factory offered. It will feature an Eagle or Livernois custom forged steel crank with all the other high-quality parts that come in the 404-inch stroker kit. Admittedly, Livernois is not expecting to sell the standard size kit in the same volume of orders that they see with the stroker kit, but it is there for enthusiasts looking for stronger engine parts with factory stock dimensions.
The AssemblyAt Livernois Motorsports, we had the opportunity to shadow John Lohone while he put together an LS2 stroker kit for one of their customers. Lohone is one of the head engine builders at Livernois Motorsports, and he comes to that position after a long and storied history in the high performance world, which included a 15-year position with Roush Racing. So, to be able to have access to such a talented engine builder was truly a treat. With all of the machine work and preparation done right on the property of Livernois' expansive engine building facility, John was able to quickly put the new, 404-inch LS2 short-block together. Check out our photographic log of the work that was performed for a blow-by-blow. Throughout the exercise, we were impressed with John's skills and the quality of the parts he was putting together. Forged bottom-end components that squeeze out an extra 40 cubes is good stuff!
DynoWhile at Livernois shooting this story, we were able to catch a 404-inch LS2 in action on the chassis dyno as a C6 Vette had been upgraded with the stroker motor, CNC-ported LS2 heads, and one of Livernois' Stage 2 cams. The car kicked out an impressive 490 rwhp! And, remember this is in a car that weighs a little over 3,200 pounds with driver. What also struck us was how much torque it picked up with the 404-inch LS2 stroker kit.
"Our LS2 stroker is worth about 40 more horsepower to the tire," Millen explains. "But, the real deal ... what you really feel when the car is going down the road is the 50 lb-ft of torque that you get with the stroker. That's 50 lb-ft that you can't get on a naturally aspirated car any other way."
ConclusionWe agree with Dan. Once you've sorted out your cylinder head and camshaft combination, the next area to look for power in an LS2 is more cubic inches. Not only does it provide you with a 40-horse boost, but also the torque that Dan praises so much is the real eye opener. Our sources at the GM factory tell us that the trend of larger cubic inch engines from the GM LS family will continue. So, if the OEM is doing it, why can't you?