Arguably, the engine is the heart of any vehicle, the driving force that has captivated gear heads for countless generations. Passion such as this has lead to many advancements in the world of aftermarket performance. This drive to improve upon an already efficient factory design has motivated some outlandish engine builds; one of which is the most ambitious we’ve seen in quite a while.

To expand on that statement, a couple of petrolheads from Australia recently hatched an ambitious plan to construct a V12 engine using the tried and true LS architecture. Brothers Matt and Shane Corish not only plan to swap one of these V12 monsters into a vehicle. The Frankenstein LS engine-producing duo also plans to manufacture these insane engines on a production scale.

We can only imagine what this beast will sound like once it’s placed between the frame rails of a deserving vehicle.

In this YouTube video by FullBoost, we’re exposed to what kind of potential this engine can brings to the table. After securely fastening it to the engine dyno at Dandy Engines in Carrum Downs Victoria, Australia — this amalgamation of LS wizardry pumps out a stout 717 horsepower at 6,300rpm and 627 lb-ft of torque at 5,600rpm on a conservative tune.

“This prototype engine is effectively a stock headed LS1 with four more cylinders and a mild cam,” Matt Corish explained. “As such, it features a very low dynamic compression ratio. We couldn’t be happier with the 717 horsepower it produced, and with the addition of an upgraded intake manifold and an exhaust system, we expect even greater numbers.”

This set of EZ-EFI throttle bodies really sets off the top end of this custom LS!

This outstanding build was accomplished by grafting a set of aluminum LS1 engines together and cutting the back cylinder bore of one block, and the front of another. After some additional welding and the introduction of a stock-stroke custom billet crankshaft (and the required rods and pistons), a 519 ci short-block was born. Combining these additional cubes equates to a ridiculous 8.55-liter engine! How impressive is that?

“We know this kind of build has been done before, but we didn’t have a shred of insight on how it was accomplished,” Corish shared with us. “It took us four or five assembly attempts to get everything right. Once you move past the fact that it’s a V12, this engine is essentially two straight 6-cylinders strapped together. The one with a right bank has a reverse firing order, and the other with a standard firing order.”

The extraordinarily long camshaft had to be custom made by Clive Cams and features a split duration of 228/238 with a 0.589-inch lift. A welded together set of unported 241 heads (outfitted with heavy duty valve springs respectively) allows this 519 ci monster to breathe at wide-open throttle. The build required a custom set of copper cylinder-head gaskets to be attached to the deck, while other notable modifications included a modified carburetor intake manifold, a set of FAST EZ-EFI throttle bodies, Haltech Elite 2500 ECU, and a modified set of LS1 exhaust manifolds.

“For this proof of concept prototype, we ensured that cuts were made in the heads and the block didn’t line up and interfere with the structural integrity of the engine,” Corish proclaimed. “Speaking of structural integrity, our calculations have determined that our block design is capable of supporting up to 1,000 hp.”

Here is the custom designed billet (bottom) crank laying next to a standard LS crank (Top). This one-off piece features a 3.622-inch stroke.

Plans have already been set in motion to get this revolutionary LS engine on the streets of the United States. Legendary U.S. car-builder Rod Saboury is currently working on a top-secret project car that will feature this outlandish engine. While Quality Custom Rides is gearing up to unveil a V12 LS-powered Camaro at this year’s SEMA show in Las Vegas, Nevada.

It wasn’t as simple as combining two cracked LS blocks together, as seen by the immense amount of welding that was required to make this dream a reality.

The brothers are already looking towards the future with their ambitious and lucrative engine design. Talks of individual intake throttle bodies, custom exhaust headers, aftermarket cylinder heads, and higher lift cams are currently on the drawing board. The concept of this engine is to fulfill the needs of the hot rod and streetcar community by being totally different.

If you’re clamoring to get your hands on one of these marvels of the crate-engine world, V12LS.com is expected to start filling orders at the SEMA show at the end of the year. Just in time to fulfill your New Years resolution of making more horsepower!