How to build a Vette-based V-12 engine, the hard way

For decades, General Motors' LS V-8 engines have been a favorite of hot rodders, since GM builds them by the minute and their pushrod construction makes them easy to tune. Now a Washington shop has gone where few other craftsmen fear to tread by messing with the basic design of the aluminum LS to build a V-12 from the parts of two Corvette-ready V-8s — with a level of ingenuity and skill that's easy to appreciate even if you think a firing order is something Army recruits learn in basic training.

Cutting up and reforming an engine block may seem like little more than superfluous labor — why not just buy a bigger engine to begin with? — but it's a daring, complex undertaking, the welder's equivalent of open-heart surgery. Adding cylinders requires re-routing oil, air, exhaust and water, deducing how the new engine will run and building the supporting parts, heads and computer controls to make it fire without immediately turning into a gas-powered ball of shrapnel. The very idea was so incredible to the old hands of the LS1 forum that several asked for a video to prove they weren't being taunted by expert Photoshop artists.

Because GM's only ever built LS engines as V-8s, going where even the General fears to tread holds a special appeal. The builders say they've got two LSV-12 engines of 8.9 liters (545 inches) running in the wild; one installed in a Chevy Suburban, the other powering a replica P-51 Mustang. Along the way, they've refined their build process; for example, they say they can now mate a crankshaft from two spares rather than having to carve one from a chunk of metal as they did for the first engines. (As for firing order: 1-5-3-6-2-4, reversed on the opposite side, or as the designers call it, "like a V-16 minus four cylinders).

With five LS V-12s in progress, the builders told LSX.TV the first to be finished is heading into a Datsun 240Z project, where it's expected to make more than 500 hp. The builders also want to experiment with strapping a massive supercharger to their beast in part to see whether their work can handle the stress; they've also set no price yet for building one for the rest of the world, but if their work holds up, there may be a new rumble in the hot rod jungle.