Can you put a motorcycle engine in a car? This question is asked by many petrolheads, and the answer is yes, why not! Many companies offer motorcycle engine-powered cars off the shelf. Some of them are turn-key machines, while others come in an assembly kit. What’s more, you can even build your own motorcycle/car hybrid from scratch. Believe it or not, these unique vehicles can even outrun muscle cars!
However, keep in mind that not all cars and motorcycle engines are compatible.
For these conversions the most commonly used cars are the lightest models like Mazda Miatas, Mercedes Smarts, or Mini Coopers.
If you want to find out more about motorcycle-powered cars, you are in the right place.
We at PowerSportsGuide have compiled the pros and cons of motorcycle/car engine swaps, along with the best videos about these custom vehicles!
Can You Put a Motorcycle Engine in a Car?
Yes, contrary to popular belief you can put a motorcycle engine in a car. On the other hand, keep in mind that a car/motorcycle engine swap is an enormous job that requires a lot of skills, time, and money.
If you want to own one, you can choose from many different options.
For instance, you can find car kits in various stages, but you can also build a machine from scratch.
But if you are looking for something off the shelf, you can choose from many factory-built machines. (We’ll discuss these manufacturers in detail in this post.)
However, keep in mind that these machines are mainly built for racing purposes rather than everyday use.
But before we take a closer look at these unique cars, we should discuss the differences between motorcycles and car engines.
What is the Difference Between a Car Engine and a Bike Engine?
It’s safe to say that the main difference between car and motorcycle engines is that the latter is designed for moving lightweight machines. Therefore, motorcycle engines have smaller displacements, run at much higher RPMs, and produce far less torque than car engines. Also, their transmission is built into the engine and lacks a reverse gear.
Let’s get down to the nitty-gritty and talk about these factors in detail.
Motorcycle/Car Engine Swap Issue I: Engine Power
There is no question that the main con of using a motorcycle engine in a car is the lack of torque.
Although motorcycle engines are very powerful, they feature smaller cylinders to keep the overall weight of the engine low.
This means middle-weight and heavy motorcycles are typically powered with 600-1300cc engines. In contrast, the majority of cars are manufactured with much larger 1500-5000 cc engines.
Because of the smaller pistons and shorter strokes, motorcycle engines run at much higher RPMs and offer far less torque (especially at low RPMs).
These power sources do a good job in lightweight motorcycles, but don’t work well in cars. Why?
This is because cars are much heavier than motorcycles meaning that they require a great amount of torque for a reasonable performance.
That’s why motorcycle/car conversions are exclusively built based on very small cars, as they offer great acceleration even with a far less torquey engine.
For a better comparison, we’ve compiled the performance specs of some popular cars and motorcycles into one chart:
Motorcycle/Car Engine Swap Issue II: Transmission and Drivetrain
If you want to put a motorcycle engine in a car, the other issue you have to face is the transmission.
Unlike in cars, the transmission in a motorcycle is built in the engine, which means it’s hardly separable.
That’s why some of these hybrid vehicles feature the original motorcycle transmission.
It’s the cheapest and most convenient way, as bolting a car transmission onto a motorcycle engine is an enormous task.
Let’s face it, motorcycle transmissions are designed to move a much smaller mass.
This means with the original transmission you have to hammer the engine very hard to move a car
This solution may work if the vehicle is built for fun, but it’s not recommended for racing purposes. Since the gear ratios are far from ideal you can expect low performance.
On top of that, as motorcycle transmissions are not built to handle this type of load, this often leads to low reliability, durability, and high fuel consumption.
Another problem is that a motorcycle’s transmission doesn’t feature a reverse. To solve this problem, you can build an electric reverse into the vehicle.
These electric reverse kits are commonly used on trikes and heavy cruiser motorcycles like Honda Gold Wings or the flagship Harleys.
But many builders are not happy with the performance of motorcycle transmissions, and finally bolt the car’s transmission onto the motorcycle engine.
This is not at all easy, but in many cases this is the only way to go.
Besides the transmission, the oil supply can also be an issue.
Simply put, a motorcycle’s oil sumps are designed to consider the inertial forces.
This means while the bike leans into the turns, these forces help the oil reach the bottom of the pan, providing continuous oil flow for the cylinders.
But if you place a motorcycle engine into a car in a horizontal position, it may end in oil starvation and finally a seized engine.
Because of this, a custom pan and other tweaks on the oil system is usually unavoidable.
Finally, don’t forget that the cooling system, exhaust, and drivetrain also have to be heavily modified in many cases. As you may assume, these are not easy tasks!
Factory-Built Cars with Motorcycle Engines
Vintage Cars with Motorcycle Engines
It’s a lesser-known fact that in the past many cars were powered by motorcycle engines. These tiny vehicles were often 3-wheeled cars called cyclecars or autocycles.
For instance, the 1955 BMW Isetta featured a single-cylinder motorcycle engine, which was replaced with a 600cc twin in 1957.
Motorcycle engine powered cars also appeared in the fleet of Japanese manufacturers. Surprisingly, the first Honda cars, namely the N600 and Z600, were also powered with a 600cc, air-cooled, 36.5 HP motorcycle engine.
Besides these models, many other motorcycle/car hybrids appeared in the early 20th century.
These ‘microcars’ were really competitive with regular cars thanks to their low manufacturing and maintenance costs.
On the other hand, they were extremely small and lacked seat and storage capacities. Therefore, they slowly disappeared from the market.
Today these aged vehicles are mainly owned by collectors, but some of them appear on the market or at auctions.
What’s more, builders have also discovered these lightweight cars, and drop modern motorcycle engines into them!
Factory-Built Motorcycle/Car Hybrids
If you are looking for a new motorcycle/car hybrid, the good news is that many manufacturers sell ready-to-go vehicles off the shelf.
One of the most well-known brands on the market is the British Morgan Motor Company.
The manufacturer offers lightweight 3-wheeler cars that are powered by big V-twin motorcycle engines. These 1998cc power sources crank out 68-83 HP depending on the model.
At first glance, it doesn’t seem like an outstanding performance, but don’t forget that these engines have more torque than the average motorcycle engine.
Another well-known motorcycle/car hybrid is the Campagna T-REX.
This vehicle is actually a reverse trike that features a lightweight tubular frame chassis.
The sportier T-REX RR shares the engine with the Kawasaki Ninja ZX-14R. This 1441cc, inline-4 power plant puts out no less than 208 HP.
Thanks to the lightweight chassis and the 3-wheeler configuration, the weight of this vehicle is kept under 1,000 pounds.
The other model in this family is known as T-REX 16SP, which is powered by a 1649cc, 6-cylinder, 160 HP BMW engine.
Although this car is not powered by a motorcycle engine, the Polaris Slingshot is often referred to as a car/motorcycle hybrid.
Just like the T-REX, the Slingshot also features a reverse-trike design and a 2000cc, inline-4 Polaris engine.
Motorcycle Engine-Powered Race Cars
Surprisingly, you can find many motorcycle engine powered race cars on the market. These superlight cars typically house heavily modified motorcycle engines.
One of the most well-known brands on the market is British Radical Precision Engineering.
The company manufactures high-performance power sources using a Suzuki Hayabusa engine as a base.
Radical offers several street-legal sports cars as well as special cars for closed-course racing. Some of their well-known models are the Radical SR3 and the V6 RXC.
Car Kits with Motorcycle Engines
If you like building, you should take a look at the car building kits. Kit cars are typically very small and lightweight, which is why some of them come with motorcycle engines.
Some of these kits come with all the required parts, while others are missing some key features like a drivetrain.
The latter option allows you to be creative as well as to cut costs.
Car/Motorcycle Engine Swap
If you have the skills and are looking for a side project, you have to consider building your own car/motorcycle hybrid from the ground. If you want to drive something unique or want to build the vehicle for specific purposes (like drag racing, drifting) this is often the only way to go.
Of course, you can find professional services like Z-Cars that offer “turn-key” re-imagined classic cars with motorcycle engines.
Mainly the price, as you might assume these track-focused special vehicles come with hefty price tags.
So, if you are on a budget, or just want to gain the satisfaction of building your own vehicle, you should consider building one from scratch.
Let’s see how you can do it step-by-step!
How do You Fit a Motorcycle Engine into a Car?
If you want to fit a motorcycle engine into a car, you have to deal with many technical issues, which are as follows:
- Designing new engine mount placements
- Bolting the car’s transmission onto the new engine (if you are not happy with the MC transmission)
- Building a new driveline from scratch (if you stick to the MC transmission, or consider 4WD)
- Redesigning the oil system (adding a dry sump)
- Making the cooling system more efficient
- Modifying the exhaust, and the fuel line
- Dealing with any other necessary changes (pedals, wheels, gauges, seats, painting, etc.)
Here’s a great video on how to put a motorcycle engine into a car:
As you can see, a motorcycle/car engine swap is far more complex than it seems at first glance.
So, before you jump into such a big project, make sure you have the required skills, tools, and other resources.
To make the process easier, try to carry over as many parts of the bike as possible. It’s recommended that you keep the motorcycle’s original fuel system (including the tank and fuel pump) as well as the complete exhaust system.
Besides the technical issues, don’t forget that car engines have to meet different standards than motorcycle engines. That’s why many of these car-motorcycle conversions are solely used on closed courses.
Consequently, if you want to drive your vehicle on the street, don’t forget to check the local laws to stay legal. Best practice is to contact local registration authorities for further advice.
If you’re comfortable building and you’ve decided to assemble your own car at any cost, here are the most important things to look out for.
The Base Car
As we’ve discussed, if you want to power a car with a motorcycle engine, the biggest concern is always the weight of the vehicle.
That’s why the most commonly used vehicles for these projects are the lightest cars on the market. Some of the most popular models are the Mini Cooper, Mercedes Smart, Mazda Miata, Opel Corsa, Fiat 500, and Peugeot 205/206.
These tiny cars weigh only 1,000-2,000 pounds without engines, which makes them an excellent base.
Besides these vehicles, vintage ‘microcars’ like Honda N600s or BMW Isetta are also commonly used for a car/motorcycle engine swap.
With the right engine and transmission, these crazy vehicles can beat many powerful cars on the drag strip!
Let’s talk about the power sources.
As a rule of thumb, for a motorcycle/car engine swap you need the biggest engine available.
More displacement result in more torque, which can move the vehicle much easier.
The most popular motorcycle engine used in cars is arguably the 1300cc, inline-4, Suzuki Hayabusa engine.
Regarding other models, any big-bore motorcycle engine can do the job, but the most commonly used models feature a displacement of 1000-1300cc.
Besides the Hayabusa, some of the best motorcycle engines for cars are as follows:
- Kawasaki ZX-12
- Kawasaki ZX-14
- Yamaha R1
- Suzuki GSX-R 1000
- Kawasaki ZX9
- Yamaha FJ 1200
It’s safe to say that the most popular engine layout is the inline-4. Although V-Twin and boxer engines offer more torque, they typically crank out much less power.
That’s why they are less commonly used by builders.
If you are looking for more power, you can boost the engine with a turbocharger or other endless aftermarket modifications.
Since there have been many motorcycle engine-powered cars built over the years, you can find many great ideas online.
Conclusion – Can a Motorcycle Engine Power a car?
Can a motorcycle engine power a car? Yes, contrary to popular belief motorcycle engine powered cars have been around for decades!
The first of these tiny vehicles were designed for everyday use. They were economical to manufacture and maintain, which is why these cars were popular in the years after the World War II.
In contrast, today’s motorcycle/car hybrids are typically used for racing or pleasure driving. Most of them are strictly used on closed courses.
If you want to own one of these amazing cars, you can choose from a number of options, such as:
- Investing in a stock vehicle (Morgan, T-REX, Radical)
- Purchasing a turn-key upgraded vintage microcar (e. g. from Z-Cars)
- Assembling a car kit with a motorcycle engine
- Build your own car/motorcycle hybrid from scratch
Each option has its advantages and disadvantages!
If you want to build a vehicle from the ground, stick to the lightest cars available like a Mini Cooper, Mercedes Smart, or a vintage microcar.
Motorcycle engines are not designed to propel heavy weights, so you don’t want to use anything heavier!
Regarding engines, make sure to get the biggest and most powerful motorcycle engine available.
The most favorite bike for a motorcycle/car engine swap is arguably the Suzuki Hayabusa, but you can’t go wrong with any high-performance 1000-1300cc, inline-4 engine.
As the final word, make sure you check local laws and regulations if you want to drive your vehicle on the street. Keep in mind that even if you can drop a motorcycle engine into a car, this doesn’t automatically mean that it will be street legal.
This is our short compilation of the best motorcycle engine powered cars. We hope you find it useful!