Only 3 Production Cars Have Ever Used This Engine Configuration

In the first half of the 20th century, the automotive world employed an anything-goes policy when it came to engine design. The budding automotive industry took a stab at every configuration imaginable, until things finally settled down, and we were left with the configurations we know and love today.

One unique engine configuration that was tried out by a few manufacturers was the radial engine. Those who know their aviation facts will recall the radial engine's extensive use in prop-driven aircraft. However, a few automakers thought the radial engine would be equally at-home in a car. As you can imagine, the idea didn't catch on, but not before we got to see a few interesting attempts.

These Production Car Hopefuls Tried To Use A Radial Engine

Three Quick Facts About The Radial Engine In Cars

• First attempted in 1925 by the Julian car company
• Germany had their own plans for a radial production car beginning in 1931
• Chrysler dabbled in radial engine tech, but no official concept ever debuted

The radial engine's use in automobiles began in 1922, when a wealthy man named Julian Brown went about designing a car. However, this wasn't the first car he'd designed, as he'd already had a couple of other tried-and-failed attempts in the 1910s. He even tried to engineer an electric boat, which is a scary thought. This time around, he was determined to set his car apart from others in order to gain popularity. His way of going about this was to use a radial engine, something that hadn't been done yet.

The radial used for the job was a six-cylinder, air-cooled iteration using its cooling fan to act as the engine's flywheel. Reportedly, the motor was capable of producing 60 horsepower with a 4:8.1 compression ratio. Its 60-horse rating was high for the times and instilled confidence that Julian Brown would have his popular automobile. However, due to the extreme cost to develop, around $60,000 in 1925, the project was scrapped as there was no hope of ever turning a profit at a price normal people could afford. The Model T was already dominating the world, and getting cheaper by the year.

Only one example was ever produced, but it still runs to this day, following a complete restoration in 1966.

Porsche's Attempt At Radial Power

Just six years later, in 1931, Porsche began designing a radial-powered car called the Type 12. It's a strange-looking thing, as it embodies the art-deco, aerodynamic look that was popular in the early 1930s. The Type 12 utilized a five-cylinder radial engine designed by German machine tool and vehicle company Zundapp. The Type 12 was Porsche's attempt to build a car for the people, and was supplied with a radial engine due to ease-of-production, as Zundapp already had the motor developed.

The Type 12 never made it into production and only two sedans and one drophead coup were produced as prototypes. All three prototypes were destroyed in World War II as the result of Allied bombings in Stuttgart. However, Volkswagen ended up using many of the components found on the Porsche Type 12, such as its drivetrain, for the humble Beetle. Currently, a replica Porsche Type 12 is housed in the Museum Industrielkultur in Nuremberg.

As we now know, Porsche eventually settled on the boxer engine, which has remained a staple of the 911 since the beginning.

Britain And The US Tried It, Too

The last documented attempt at a radial-powered passenger car occurred just after World War II by a British company called Fedden. The model was to be called the Fedden Car, or the F-Car for short. Its styling was meant to resemble the then-revolutionary curves of the Jowett Javelin and the Volkswagen Type 1. Powering the F-Car was a three-cylinder radial engine measuring just 1.1 liters.

The F-Car utilized a unibody construction, with only three sections joined together with four bolts, making proposed production relatively easy. However, the F-Car would never see production, and only one prototype was produced. As of the 1960s, its whereabouts are unknown.

Chrysler also tried their hand at a radial-engine car in 1936, but its attempt, coined the A-106, never made it into the metal-bodies prototype phase, and only a wood and a clay mock-up were created. It was supposed to feature a 1.1-liter radial engine that produced 30 horsepower.

The Radial Also Made It Into Motor Racing

Well, almost made it into motor racing. There are two documented cases of a radial engine being tried in racing cars, the first of which occurred in 1935 and was called the Monaco Trossi Grand Prix Racer. Augusto Camillo Pietro Monaco, an established race car builder from Brazil, was struck with the idea of building a radial-engine Grand Prix car. He joined forces with engineer Giulio Aymini to develop the new car, and was granted the use of Italian automaker Fiat's facilities to test it.

The 16-cylinder radial engine chosen for the job was mounted on the front of the race car, which proved problematic for weight distribution, with a 75 percent front / 25 percent rear measurement. The radial engine, which produced 250 horsepower, was also prone to extreme overheating. It would get so hot, its spark plugs would become destroyed, rendering the engine unusable if debris from the broken spark plugs gets into the combustion chamber. Ultimately, the project was abandoned.

The other well-documented case of a racing car utilizing a radial engine is the 1939 Guidobaldi Prototype Racer, built by Francois Guidobaldi. The prototype featured an eight-cylinder radial engine reportedly producing up to 200 horsepower with the help of a Bugatti-bred supercharger, although official power ratings were never found, nor would the engine's exact displacement figure. The Guidobaldi Prototype Racer also featured a novel suspension setup consisting of an accordion-like structure supported by springs and rubber stoppers.

Like the Monaco Trossi Grand Prix Racer, the Guidobaldi Prototype Racer never saw a single race. It wasn't even completed until the mid-1950s, as Francois Guidobaldi built the entire car by hand alongside his other projects. Reportedly, he took the finished product on an extensive test drive and the prototype handled terribly due to its strange suspension setup, which caused the car to roll in all directions at seemingly random times.

Why The Radial Engine Failed To Catch On

When it comes to motorsport, the radial engine proved to be extremely inefficient, especially in the case of the Monaco Trossi Grand Prix Racer. Because of the radial's usual air-cooled nature, it needs to be mounted where the air is, or where a massive fan is located. In an airplane, this isn't a problem, as the air moving over and through the engine sufficiently cools it in most cases. A car doesn't travel at airplane speeds, for the most part, meaning it can get too hot.

Another issue with the radial is something called the pendulum effect. The pendulum effect, in essence, describes a side-to-side swinging effect, and it's seen mostly in towing. However, this is caused by the radial's method of operation. A radial engine's crankshaft is constantly spinning in one direction, as its cylinders are positioned in a circle. Because of this, a jumping or swinging effect can be caused by the weight of the crankshaft. As you can imagine, this is an extremely unwelcome effect on an automobile. In short, the radial engine is best left to the airplanes, and we'll keep our four-bangers and V8s in cars.