We all know the versatility of GM’s excellent LS V8. From powering some of the toughest trucks ever made to powering some of the world’s best sports cars, the LS pretty much has the lock on affordable, dependable performance. But what about double or nothing? What about Frankensteining a couple of LS V8s into something truly incredible? Back in the day, General Motors was sort of notorious for creating larger-than-life engines. So, the fact that the company made at least one 16-cylinder LS-based monster mill might not come as such a shock to folks with good memories.

The 2003 Cadillac Sixteen concept featured 16 cylinders of LS power.

The Cadillac Sixteen

It all started in the 1930s. Cadillac was The Standard Of The World, and they bolstered that fact with the launch of their coach-built Series 452. Produced for 10 years, the Series 452 mounted an overhead-valve V16 in a chassis that could be finished in over 70 different styles. See, unlike European competitors, the General had their own in-house coach builders: Fleetwood and Fisher. That made Cadillac’s ‘Sixteen’ about six times cheaper than comparable cars from the ‘Old World’ stalwarts. The result was over 4,000 sales from 1930 to 1940 despite the Great Depression’s crippling effect on the automotive industry.

Fast forward to the late 1990s and early 2000s, an era when V10s and V12s were all the rage. General Motors brass felt that reviving a premier Cadillac offering seemed like a great idea, and they decided to go big or go home. Introduced in early 2003, the Cadillac Sixteen concept was every bit as lavish as a top-of-the-line, world-beating Cadillac should be. And naturally, like its namesake, the car featured 16 cylinders of overhead-valve power.

The Cadillac Sixteen’s LS-based V16 created an impressive 1,000 horsepower and 1,000 lb./ft. of torque.

Designed by the pros at Katech, Cadillac’s LS-based V16 displaced a whopping 13.6 liters and created an impressive 1,000 horsepower and 1,000 lb./ft. of torque. Naturally aspirated and engineered to be as smooth as engines of the Brass Era, the Gen IV LS-based mill combined two valves per cylinder with GM’s latest and greatest Displacement On Demand technology that could shut down 8 or 12 cylinders at a time. While an opulent, line-topping Cadillac was planned for production, the Sixteen’s beautiful powerplant was scrapped in favor of more practical V10 and V12 designs. Eventually, the entire program was scrapped due to GM’s pending bankruptcy, but that’s certainly not where the story of LS-based 16-cylinders ends.

The Devel Sixteen hypercar concept is built around a 5,000 horsepower V16.

The Devel Sixteen

The Devel Sixteen is a long-standing hypercar project that was envisioned with a 5,000-horsepower V16 engine, which would help propel it to a 350 MPH top speed. While the Devel Sixteen still seems like a lot of vaporware, the car’s 5,000-horsepower, LS-based engine certainly is not.

According to Steve Morris of Steve Morris Engines, he wanted to create something extremely innovative but didn’t necessarily want to reinvent the wheel. After all, the client’s stated goal was to create a V16 that produced 5,000 horsepower – nothing more, nothing less. So, Steve based his build around the idea of common bore, piston, and block designs that would be easily fixable and replaceable. He knew he could get 2,500 horsepower out of an LS V8, so he ordered two Chevrolet Performance LS3s. Naturally, each of the LS3s dynoed at around 500 horsepower right out of the box.

To get the engines pulling together, Steve created a custom firing order that completely altered the sequence of engine number one. It’s important to note that, despite the totally altered firing order, engine number one still made the same horsepower on the dyno. After having one ECU built to control both engines, it was time to embark on the largest aspect of the project: creating a fresh, 16-cylinder engine block. After a massive amount of CAD engineering and roughly two years of tweaks, Steve had the foundation for his LS-based, 16-cylinder engine.

Internals were a mix of what was and what would be. A one-piece billet crank tied everything together, featuring provisions for the engine’s custom firing sequence, which lit one of the 16 cylinders every 45 degrees. The front LS3 was fitted with a custom cam. But since the back LS3 maintained a standard firing order, it was fine with a Chevrolet-supplied, factory-spec cam. Likewise, the engine’s common LS3 bore meant it could continue to run LS3-style pistons, and bearings were a combination of LS and big-block Chevy components.

Steve wanted to create custom billet LS heads that shared a common intake, common valve covers, and common cooling. However, at the time, he couldn’t find anyone capable or willing to invest in such a massive and unique project. So, he switched his plan to using multiple LS heads, much like heavy-duty diesel applications in trains and large trucks. The V16 ended up wearing four LS7-based heads that were outfitted with LS7 valves and LS7 rockers. While this wasn’t ideal from a build standpoint, it did make the engine a lot more serviceable. With the heads sorted, Steve fabricated a custom intake and installed four turbos to achieve his goal.

Sixteen Power’s 1,400 horsepower naturally-aspirated V16.

On The Water

According to their website, a company called Sixteen Power currently produces multiple LS-based V16 engines for use in high-performance marine applications. Sixteen Power combines a one-piece billet crank and a one-piece billet cam with factory-style intakes, factory-style LS and LT heads, and what appears to be a one-piece block. Horsepower ranges from 900 for the mildest naturally-aspirated build all the way up to 2,000 for a bonkers quad-turbo build. Our only question is, which one of you power-hungry gearheads is going to adapt one of these bad boys for the street?

From Cadillac’s Sixteen concept to Steve Morris’ 5,000-horsepower Devel engine, and even Sixteen Power’s marine monsters, the LS-based V16 proves that General Motors’ humble small-block can be stretched into something truly outrageous. What started as a workhorse V8 for trucks and Corvettes has become the foundation for some of the wildest powerplants ever conceived, capable of moving luxury flagships, hypercars, and even boats with insane levels of thrust. Whether it’s 1,000 horsepower of refined Cadillac elegance or 5,000 horsepower of turbocharged insanity, the LS-based V16 isn’t just a footnote in GM history; it’s proof that the LS platform has no limits but imagination.