Because you know airplane engines in cars are cool.
There has always been a link between airplanes and cars. BMW was originally a manufacturer of aero engines, particularly for the military in both World War I and II. Fiat also built planes for both World Wars while Mitsubishi made the Japanese Zero fighter planes in World War II. Rolls-Royce also built engines for fighter planes in World War II and still builds them for civil aviation today. Saab loved to link its fighter jets to its cars in advertising despite the cars not having much to do with the aerospace and defense company, and Honda has its own private jet in production. Even Ford dipped a toe in the water with a transport aircraft, a few of which are in service today.
Car racing existed since the invention of the car but really came to prominence after World War I as people started to purpose build them for racing, then even more so after World War II as leaps in technology came along with a fresh wave of people with mechanical skills and a taste for excitement. It was between the two world wars where we find the first examples of a car and aeronautical engine being mashed together. That's where we'll start, and you'll see a pattern in the first cars on the list of being made for breaking speed records before we get into the more modern and crazy uses of airplane and helicopter engines.
The beast of Turin is a 1907-08 Fiat chassis fitted with an insanely big 28.4-liter six-cylinder engine that makes 300 horsepower. For a little perspective, at the beginning of the 20th-century automotive engines peaked at around 3,000 rpm and 100 mph was fast. There were hopes The Beast of Turin could challenge the land speed record at the time of 125.95 mph but, ultimately, it topped out at 90 mph.
The Beast of Turin is an exciting car, but it's not the fire breathing monster we met on Top Gear in its 18th Season. Brutus uses the frame built in 1908 by American LaFrance, an American company known mainly for its fire engines, and a 46-liter aircraft V12 built by BMW in 1924. It generates a serious amount of noise, vibration, and 500 horsepower at just 1500 rpm while consuming a liter of fuel per kilometer.
Sunbeam was a UK based car company that in 1927 built the first car to break the 200 mph barrier. Also known as "The Slug," it's output was actually closer to 900 horsepower generated by two Sunbeam Matabele 22.4-litre aircraft engines.
The CN7 changed the game by using a Bristol-Siddeley Proteus turboshaft gas turbine engine. This was the first mass-produced gas turbine engine and generated over 4,000 horsepower in the one-off car Donald Campbell used to take the land speed record at 403.10 mph. Campbell was disappointed due to adverse conditions not allowing him to go faster, but died in a jet hydroplane crash before he could try again.
Thrust SSC is powered by two Rolls-Royce Spey turbofan engines with afterburners and currently holds the land speed record after being piloted by Royal Air Force fighter pilot Wing Commander Andy Green at 763 mph. It was also the first land vehicle to break the sound barrier. The numbers for this machine are staggering, and it's basically an airplane without lift but with four wheels. It has 102,000 horsepower, weighs over 10 tons, burned 4.8 gallons of fuel per second on the record run. In normal car terms, ThrustSCC has a fuel economy of 0.05 miles per gallon. For some perspective on just how fast that speed is, 763 mph is 341 meters per second and the record hasn't been unbeaten since it was set in 1997. Although that could change soon.
Aero engines haven't only been used to go fast in land speed record cars. In 1968, the Lotus 56 competed in the Indy 500 being propelled by a modified Pratt & Whitney ST6 gas turbine aircraft engine. Indy banned turbine cars so Lotus took the car to the Formula 1 circuit and although it never won a race, its design had a profound effect on F1 car design.
America has given us some airplane engine driven speed demons but took the creativity up a notch with the infamous Tucker 48. The Tucker story is amazing, and its early demise has left us with only 47 examples in existence. What interests us here though is that because Tucker ran out of time developing its own innovative engine, the 48 was built using a modified flat-6 Franklin 6 Series aircraft and helicopter engine that was mounted at the back of the car.
Colorado Auto Parts built this insane 1939 Plymouth pickup truck using a 12.4-liter 7-cylinder air-cooled radial engine from a Cessna 195 airplane. Gary Corns had bought the truck but left it sitting for 30 years until he and his father had time and an idea what to do with it. That idea came in the form of an old seaplane Corns senior found in a yard for discarded airplanes and they went to work building something insane and oh-so-beautifully badass.
In the 1950s, when he was 16 years old, Cliff Hix saw a car with an airplane engine and it stuck with him. He designed and built the suspension and built the frame himself, then installed the V12 engine from a P-38 Lightning fighter plane. It pushes out an astonishing 1,840 horsepower at 3,000 rpm. The engines were capable of pushing the P-38 over 400 mph in the air and Hix's car weighs just 3,200 lbs so we can imagine just how terrifying it is to drive.
The Rover SD1 is generally considered to be the last "proper" Rover before the British company trundled into darkness. It was an executive sedan that came packed with the long-running Rover V8 engine, but Charley Broomfield managed to squeeze a 27-liter Rolls-Royce tank engine under the hood. The Rolls-Royce Meteor is a tank engine, later built by Rover, based on the Merlin aero-engine. Broomfield uses a transmission from a bus and geared up the engine to make the torque useable and on the dyno it develops just 650 horsepower, but also 1,500 lb-ft of torque at just 2,500 rpm at the wheels.
The 24 Hours of Lemons is an American race series that celebrates the creativity of racing on the cheap. This MR2 retained its rear-mid engine configuration but swapped out the 4-cylinder for a Kinner R-55 motor pulled out of a 1940s Ryan PT-22 Recruit training aircraft. The 8.8-liter radial aircraft makes just 160 horsepower, which less than the original MR2 lump but a lot more fun to watch. The 24 Hours of Lemons has produced some crazy cars, but Crushed Red pepper is definitely a contender for being the greatest so far.
Radial engines are great, but what if you want to set fire to the impatient idiot in the car behind you at the traffic light? Californian Ron Patrick solved this problem by installing a jet-modified gas turbine engine from a Sea King helicopter into his Beetle. At 1,350 horsepower, it's probably the fastest New Beetle on the road, and it's on the road because Patrick has kept the original VW engine installed to keep it legal.