Video: Harrop-blown L8T on the dyno

The gurus at Mast Motorsports strap a Harrop TVS2650 supercharger to a built L8T


It is no secret that Ford has struck gold with their 7.3-litre pushrod V8 dubbed Godzilla. Built primarily for use in F250 trucks, the Godzilla is also proving popular as a boost-ready crate motor for the aftermarket.

GM has a similar offering, although it doesn’t have quite as many cubes or such a catchy name. Nevertheless, the 6.6-litre L8T is going to be an important part of GM’s armoury in the aftermarket.

The iron block L8T makes 401hp at 5200rpm and 464lb-ft at 4000rpm in stock form. Like the rest of the Gen V or LT family, the L8T runs direct injection.

Compression ratio is 10.8:1, down a touch on the L8T’s smaller cousins. Othe key specs include aluminium heads, forged crank, forged powdered-metal rods and hypereutectic pistons.

The aftermarket is already on the case, as the crew from Harrop found out when they visited Mast Motorsports in Nacogdoches, Texas.

Mast are currently testing one of their L8T crate motors with1046hp a Harrop port fuel injection-optioned TVS2650 blower strapped on top.

“That engine itself has had a rod, piston and cam upgrade with valve springs and ported heads; one of Mast’s basic stock-displacement packages,” says Harrop’s Heath Moore.

With a 102mm throttle body and running on E85 fuel, the blown L8T made 1046hp and 958ft/lb on the engine dyno.

As GM winds back production of LS-based motors, expect to see more of the L8T and other Gen V-based millls making their way downunder.