SCORE Journal - The Official Publication of SCORE Off-Road Racing
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RACE READY GM’S LS V8 has become ONE OF THE MOST POPULAR POWER PLANTS IN OFF-ROAD RACING By Dan Sanchez Photos Courtesy General Motors Without a doubt, GM’s LS series engines are some of the most popular used by off-road racers and enthusiasts. While the engine first gained popularity in drag racing and the hot-rod enthusiast aftermarket, it has made its way into off-road racing due to its compact size and ability to make lots of horsepower. While there are various LS engine designs that have been produced by GM over the years, the history of the LS engine is still rooted into the traditional “small block 350 CID Chevy” that dominated drag strips and the streets for decades. “We enjoy the versatility of the LS platform architecture, just as we still enjoy the versatility of the original small block Chevy V-8,” says Curt Collins, Manager Chevrolet Performance. LS Engines In Off-Road Racing One of the reasons why the LS engine design has become popular in off-road racing classes is its reliability and the ease in which this engine design can make more power; the same attributes that made it popular in other motorsports. “The LS engine has competed successfully in drag racing, oval track, road courses, and most recently in off-road truck racing. As a company that sells more than a few Silverado trucks, we’re very happy to see vehicles like SCORE’s Trophy Truck Spec vehicles wearing the Bowtie on the grille, and sporting an LS engine under the hood.” Utilized in some buggy classes, Class 8 vehicles and Trophy Truck Spec trucks, the LS engine platform has proven itself to be reliable in competition. Many off-road engine builders have the LS engine as part of their line-up of off-road racing powerplants and offer a variety of engine packages for them. “The LS is a popular choice for spec racing because it is a compact lightweight package with tons of aftermarket support,” says Kolby Enger at Turn Key Engine Supply. “Power, durability and price make LS crate engines better than most other manufacturers crate engines.” SCORE’s Trophy Truck Spec class is one of the largest stages for showcasing the performance and reliability of the LS engine. Within this class, the engines must be stock and don’t require much modification to make them race-ready. This also gives teams the advantage of a lower cost of entry into the class and is one of the reasons why the Trophy Truck Spec class has grown in recent years. “The stock GM crate engines for Trophy Truck Spec racing are upgraded with high volume oil pumps and timing set upgrades,” says Kolby. “With these changes, a typical LS engine can easily compete in an entire season of racing with little maintenance and no internal engine work, it doesn’t get much better than that for a $7-$8K crate engine. We have dozens of teams we support in SCORE and other off-road racing sanctions around the world that utilize this engine platform.” Making More Power From Your LS V8 While everyone in spec classes is stuck using factory components, there are some ways to get more power from them. “Where everyone is using the same engine in a spec class, tuning the ECU to maximize the intake and exhaust system to the vehicle is the best way to get maximum power and durability,” says Kolby. In other classes where modifications are allowed, however, the LS engine responds very well to minor changes. “Depending on the class, and the racing environment, the most common changes are a swap to forged pistons, along with different cam profiles and valve springs to match,” says Collins. For teams that want to dramatically increase horsepower and torque levels well above OE settings, the LS engines respond with big gains after cylinder and camshaft changes. “There is a noticeable power increase when the already very good cylinder heads are opened up in the CNC process,” says Collins. “There is a domino effect, however, when you start replacing parts you’re also looking for the weak link that is inherent in nearly every design. The factory LS engine parts are strong, but the simple fact is that racing pushes the power output and range of operation way beyond the intended design use.” No one knows this more than off-road racers. The extreme conditions of racing in Baja can destroy the most “bulletproof” of engine designs. So engine builders often upgrade some of the LS engine’s components to keep them reliable and up to the task. “That’s just the nature of racing,” says Collins. “The biggest return-on-investment with these engines, however, is in the heads, cam and calibration package.” The LS Engine Of Choice For Most Racers Of the many LS engines produced by GM over the years, the most popular used in off-road racing is the LS3. This engine was originally produced in 2008 and measures 6.2-liters. In stock configuration, the LS3 produces 430 horsepower and it is widely used in Trophy Truck Spec, but engine builders can easily modify the LS3 to almost double the power, thanks to a wide variety of aftermarket power components. “There is more aftermarket support for the LS engines now than there has ever been,” says Kolby. “They are dominating spec racing and unlimited buggy classes due to weight, size and power potential. The stock crate engines can be extremely reliable with the few upgrades that are allowed in the spec classes. Built LS engines, however, have proven to be a very reliable platform for the unlimited classes making 800+ horsepower.” While the LS3 remains the most cost effective and most widely used of this engine series in racing, engine builders like Kolby foresee that there may eventually be a shortage of these power plants, as they are also just as popular in other forms of motorsports and by enthusiasts for their own vehicles. “The current LS3 crate engines are the last phase of LS production motors from GM,” says Kolby. “When the supply from GM dries up I think the Gen-5 LT1 motors will be the next go-to engine for Spec racing.” In the meantime, off-road racers enjoy the benefits of relatively low cost, highly reliable LE engine platform that continues to power vehicles like SCORE Trophy Truck Spec racers across the finish line. SOURCES Chevrolet Performance www.GMPerformanceMotor.com Turnkey Engine Supply www.turnkeyenginesupply.com Reference Guide To THE LS ENGINE FAMILY There are a variety of LS V8 engines that GM produced over the years for a variety of Chevrolet, Pontiac, Cadillac, and Corvette vehicles that they were initially used in. Here’s a brief description of the various LS engines that were produced throughout the years. LS1/LS6 (5.7L / 346 cu in) – Produced between the 1997 and 2004 model years in the United States and stretching into 2005 in other markets. The high-output LS6 was introduced in 2001 in the Corvette Z06 and was manufactured through 2005. LS2/L76/L77 (6.0L / 364 cu in) – In 2005 the LS2 and the Gen IV design changes debuted,with L76 and L77 versions following. This engine is one of the most adaptable in the LS family,as LS1, LS6, LS3 and L92/L94 cylinder heads work well on it. LS3/L99 (6.2L / 376 cu in) – Introduced on the 2008 Corvette, the LS3 debuted with larger bores to increase displacement. The L99 version was equipped with GM’s cylinder deactivation system as standard equipment on Camaro SS models with an automatic transmission. LS4 (5.3L / 327 cu. in.) – The most unique application of the LS engine in a car, the LS4 was a 5.3L version used in the front-wheel- drive Chevrolet Impala SS and Pontiac Grand Prix GXP. It has an aluminum block and unique, low-profile features, including a “flattened” water pump, to accommodate the transverse mounting position. LS7 (7.0L / 427) – The largest LS engine offered in a production vehicle. Unlike LS1/LS6, LS2 and LS3 engines, it uses a Siamese-bore cylinder block design for its big, 4.125-inch bores. Competition-proven heads and lightweight components, such as titanium rods and intake valves, make the LS7 a street-tuned racing engine. LS9 (6.2L / 376 cu in) – The supercharged engine from the C6 Corvette ZR1, it was rated at 638 horsepower and used a strengthened 6.2L block, stronger heads, and an Eaton TVS supercharger. LSA (6.2L / 376 cu in) – Another supercharged LS, this one was used in the Cadillac CTS-V and Camaro ZL1. Although similar to the LS9 in design, it is built with several differences, including hypereutectic pistons vs. the LS9’s forged pistons and a smaller supercharger. Gen III & amp; Gen IV truck engines – Although performance car engines typically carried “LS” designations, truck versions were generally labeled Vortec and were offered in 4.8L, 5.3L, 6.0L and 6.2L displacements. The 4.8L was made exclusively with an iron block and the 6.2L was made only with an aluminum block. The 5.3L and 6.0L versions were manufactured with iron and aluminum blocks. LT1 Gen V (6.2L / 376 cu in)- Introduced on the seventh-generation Corvette Stingray, the 6.2L LT1 V-8 is the next chapter of the Chevy small block engine. It is architecturally similar to the LS family, but with a unique block casting, cylinder head design, oiling system – including standard oil-jet piston cooling – and more. It also combines advanced technologies including direct injection, Active Fuel Management (cylinder deactivation) and continuously variable valve timing to support an advanced combustion system.