The greatest engine swaps are either answers to questions that nobody asked (why doesn't that van have a V12 in it?), or the result of chassis X and engine Y intersecting in shop Z where mechanics have more than a little time on their hands. Whatever fever dream might inspire some of the world's most unusual, intriguing, awe-inspiring, or just plain absurd engine swaps, we're happy that a thriving community of performance-obsessed automotive oddballs is out there, willing to make fantasy into reality with a healthy dose of wrenching.
Let's take a look at 10 of the best - and a few of the craziest - engine swaps ever undertaken.
Flyin’ Miata LS-V8 Mazda Miata
The Mazda Miata has long been revered for its exceptional handing and lightweight platform, but you won't ever catch anyone lauding its plentiful horsepower. First-generation cars peaked at 130 ponies, and even the all-new 2016 Mazda MX-5 Miata can only count on 155 horsepower from its 2.0-litre four-cylinder mill.
Enter Flyin' Miata, a Colorado-based aftermarket shop that offers not just a full range of parts specifically designed to shoehorn an LS-series V8 under the hood of the Mazda roadster, but which also provides a turn-key LS-Miata building service. With horsepower limited only by your budget, these Corvette-sourced, tire-smoking Miatas can hit 60-mph in under four seconds – all without substantially affecting the balance of the Mazda chassis.
Jaguar XJ220 Ford Transit Van - secret test vehicle
Let's say you're a well-known British automaker looking to build your first supercar, and you want to take your work-in-progress to the track without tipping your hand. It only makes sense to disguise your near-550 horsepower drivetrain with the shell of a full-size transport van, doesn't it?
If you were Jaguar, and it was 1989, this all sounded eminently reasonable - so much so, in fact, that you convinced middle management to rubber-stamp the purchase of a new Ford Transit van and then stuff a twin-turbo V6 engine under the hood, along with the rest of what would eventually become the XJ220's drivetrain. The end result is a plumber's van that hits 60 mph in about five seconds, and which is still trotted out at the Goodwood Festival of Speed from time to time to remind us that even exotics can have the humblest of beginnings.
Chevrolet Caprice with BMW V12
Sometimes corporate engine swaps have less glamorous roots. When General Motors was interested in developing its own drive-by-wire systems in the late ‘80s and early ‘90s, it looked around the industry to get a feel for how other companies were approaching this relatively new technology. After being rebuffed by BMW in an attempt to purchase a complete 7 Series drivetrain for 'research purposes’, GM was forced to buy an entire 750i and extract the 5.0-litre V12 from the German sedan itself, eventually giving it a new home in a 1989 Chevrolet Caprice.
The throttle-by-wire setup was put to the test in the Chevy box, eventually making its debut several years later on the C5 Corvette. Sadly, the V12 Caprice was scrapped before it could be preserved in the company's 'heritage collection.'
1962 Volkswagen T1 'Race Taxi' Bus With Porsche 993 Twin-Turbo Engine
What's scarier than driving an original 1962 Volkswagen T1 bus in modern traffic? Being a passenger inside the same VW, only this time it's motivated by a twin-turbo Porsche 993 engine, and you're on the track at Spa! Built over the course of four years by a very dedicated Porsche fan, this 'Race Taxi' is a labour of love that has been painstakingly constructed so as to decimate all comers on a road course. Sticking an air-cooled motor in the rear of a VW Bus is always going to be a challenge, but when that same engine pushes out 520 horsepower you know it's far from plug-and-play. Even more impressive: the Race Taxi lives up to its name with four Recaro seats bolted to its flat floor, allowing owner Fred Bernhard to whiten the hair of his passengers a trio at a time.
'Rolling Coal' 1931 Ford Model A Cummins Turbodiesel
It's rare to see a Model A at a drag strip unless it's a full-on drag car, but it's even less common to find one running down the quarter mile while blowing black smoke. We don't know much about Larry Strawn's '31 Model A other than the fact that it looks like it's sitting on a modern truck chassis and that it's running a 12-valve Cummins turbodiesel engine. Oh, and it makes just under 700 horsepower and eclipses the 1320 feet in 11.3 seconds. What else is there, really?
Minibusa
Like the Miata, the original Mini's small size made it a ripe target for engine swap fanatics looking to improve on its modest horsepower. Perhaps the most extreme Mini ever realized is the Minibusa, which doesn't just install a new motor but also completely alters the drivetrain layout of the iconic hatchback. Built by England's Z Cars, the Minibusa converts the Cooper to a rear-engine, rear-wheel-drive setup, sticking a Hayabusa motorcycle engine in the passenger compartment just behind the front seats. Available in kit form, with a full subframe replacement provided alongside the necessary structural enforcements to keep the Minibusa driveable, the Suzuki motor's 173 horsepower is a huge step up over the base Mini, and its small 1.3-litre size (and sequential transmission) help to keep the car light on its feet. Just remember to put in your earplugs before hitting the ignition switch.
Ford Festiva SHOgun
Continuing the small-car / powerful-engine / altered-drive-wheels trend is the SHOgun, a perversion of the unlamented Ford Festiva subcompact hatchback that arguably combined the best and worst of the Blue Oval's early ‘90s efforts. Making a Festiva fun to drive isn't that hard, it seems: all you have to do is replace the original four-cylinder with the Yamaha-tuned V6 from the Taurus SHO, and then install it in the back seat (just like the Minibusa) where it can unleash its 220 horsepower on the rear wheels instead of the fronts. Oh, and give it a widebody so that everyone knows you're about to destroy them at a stoplight. Only seven were built back in the day, so if you can find one and talk the owner out of it, you too can own a piece of automotive history.
Saab 9-3 Wagon with Dodge Viper V10
What do you do if you own a Saab 9-3 wagon and want to get a little – okay, a lot – more performance out of it? How about dumping a Dodge Viper crate engine between the front fenders? Oh yeah, you'll also have to do an insane amount of fabrication to make the 8.0-litre V10 fit, and of course cut up the entire chassis to accommodate the T56 six-speed manual transmission along with the rear-wheel-drive conversion that goes hand-in-hand with the swap, but if you live in Sweden where everyone is simply tuning the turbos on the original four-cylinder motors that came with these Saabs, that's the price you pay to be different.
BMW E30 M3 with M5 V10
Want to be 'different' like Mr. Saab-Viper and drive a 10-cylinder Euro-sleeper, but feel the need to spend a whole lot more money in the process? Maybe a BMW E30 M3 with an M5-sourced V10 is more your style. With 2.5x the number of cylinders it started out with, and about 150x the complexity, this car has been for sale on and off over the course of the past few years as the owner undoubtedly tries to recoup the insane cost of the build. Much of the car has been reinforced to handle the 10-cylinder's extra output (including an E92 3-Series suspension setup), which is considerable given the fact that the unit was stroked and built by Dinan to 5.7-litres (the original M5 motor was good for 500 horses). A six-speed manual gearbox keeps things interesting for the 'FrankenM3,' which weighs only 75 kilos more than a stock S14-equipped example.
LS-V8 Mazda RX7
Our list of the greatest engine swaps is book-ended by a pair of classic Mazda must-dos. It's not so much that the third-generation FD RX-7's twin-turbo rotary engine isn't robust enough to be fun, it's just that, well, apex seals have a way of ruining the party unless maintenance has been kept up to an extraordinary level. This is why so many of these gorgeous early-‘90s RX-7 coupes have been given the LS-series V8 treatment. Not only does the lightweight, aluminum-block Chevy engine fit the Mazda like a glove, but it gives the car a huge leg up when it comes to reliability. Sure, it costs almost as much to do the swap as it would to simply purchase a C5 Corvette, but if you couldn't tell by now, logic has no place in the world of engine transplants.
