This weeks technical article, although titled Chevrolet’s LS engine should really be simply called GM’s LS as it has gone into many of the old General Motors brands. The LS was the successor to the LT and its main difference is that the LS block is made from aluminium rather than cast iron and it has a smaller bore but longer stroke to provide the same capacity. The LS is also known as the Generation 3 and Generation 4 V8. It is an overhead valve engine rather than Ford’s comparable Modular V8, which is an overhead cam engine.
In 1997, the LS1 was launched as a 5.7 litre V8 that was rated at 350 horses in the US although Holden in Australia took it and extended the power to 382. Callaway also had a play with it and stretched it further to 400 horses. Holden Special Vehicles used the Callaway C4B version in its GTS model.
The motor was first fitted to the base Corvette C5, after a year it then went into the Camaro Z28 and the Pontiac Firebird. Then in 1999 it left the US to be fitted to Holden models in Australia, only to head back to the US in the Holden built Pontiac GTO. The 2006 Elfin Streamliner built in Australia also used it.
To confuse the enthusiasts, GM developed a high-powered version of the Gen 3 LS1 and called it the LS6. The LS6 was used in the Corvette Z06 and the Cadillac CTS V-Series. The power output was similar to Holden’s version of the LS1 although the block was redesigned with new components.
The LS2 was the start of the Generation 4 motors. It was an extension to the LS1/LS6 motor but now incorporated provisions for newer technology. For example, the LS2 had the ability to support variable valve timing, the disconnecting of cylinders (front/rear or each bank) and could be extended to larger displacements and power outputs. The 2005 model Corvette and SSR models plus the Pontiac GTO and Cadillac CTS had the LS2 fitted as standard. It also went into the SAAB 9-7X and the HSV models from Australia including the rebadged Vauxhall Monaro VXR. The LS2 shared heads and other components with the LS6 but with a better delivery of torque through the rev range.
The LS2 spawned three other units: the L76 used primarily by Holden as a 6 litre for their cars and Chevrolet and GMC on their SUVs. This motor was an LS2 loaded with many of the active fuel management functions. The L98 was essentially the same motor without all the extra fuel management kit and was used solely by Holden and went into the Chevrolet Lumina/Caprice SS models for the Middle Eastern market – basically rebadged Holdens. The final motor was the L77 which allowed the motor to use flex fuels – ie petrol, ethanol or a mix.
The LS2 was also the basis for a NASCAR motor. Alongside the LS2 is the LS3 which is an LS2 bored out further to 6.2 litres and this engine became the base motor for the Corvette with HSV adopting it for all its models. It can also be seen in the 2010 Camaro. The LS4 is a 5.3 litre block designed for use in transverse designs like the Chevrolet Impala and Monte Carlo models plus the Pontiac Grand Prix. The crankshaft is shorter and all of the ancillaries are driven by one longer belt. It delivered about 300 horsepower in base tune.
General Motors have also built the LS7 – a 7 litre, 500 hp motor. This has a longer stroke than the LS2 on which it is based. It can be found in the Corvette Z06 from 2006 and was also fitted to the W427 by HSV. These versions are hand built and can be bought as a crate engine if you want to drop it into another shell! The LS7.R is the racing version found in the Le Mans class winning Corvettes.
GM have also added a Roots Supercharger to the LS3 and called it the LS9 with 640 hp. It can be found in the Corvette ZR1. Finally the L99 version is based on the LS3 with the Active Fuel Management system added. There were many other minor versions of the LS motor that were used for specific power and torque outputs for US only SUVs from the whole GM family. The original design has proven to be a fabulously reliable and competitive motor with plenty of room for tuning and management.
I’m surprised that more low volume manufacturers haven’t used the LS engines – they are very reliable and hugely powerful if needed. Clearly Callaway and HSV did a great job in making high performance versions and it would be good to see them slotted into other cars. If the AMG Mercedes V12, BMW V10 or Rover V8 engines can get into low volume cars, why couldn’t the LS be put into similar cars? Perhaps it is now too late with public servants eager to kill off the internal combustion engine.