Simply put, the different types of motorcycle engines are as follows:
- Single-cylinder
- Parallel-twin (or inline-two)
- V-twin (long, trans)
- L-twin (or “angled” V-twin)
- V4
- V5 (racing – very rare)
- Inline (2 / 3 / 4 / 6 cylinders)
- Flat (2 / 4 / 6 cylinders)
- Rotary (Wankel)
- Electric
On the other hand, motorcycle engines can also be classified into the following categories:
- Number of strokes: 2-stroke / 4-stroke
- Cooling system: Air-cooled / Liquid-cooled
- Number of cylinders: 1,2,3,4,(5),6
- Displacement: 50cc-7000+cc
- Layouts (see above)
As you can see, there are many different types of motorcycle engines on the market.
If you want to learn about the various designs and compare their pros and cons, this post is for you. No confusing terminology, just a simple explanation of each type of engine!
What are the Different Types of Motorcycle Engines?
2-stroke/4-stroke
The two main types of motorcycle engines are the two-stroke and four-stroke power sources.
In the past, there were many more 2-stroke motorcycles on the road, but over the years 4-stroke machines have become more prevalent.
Today it’s safe to say that all street motorcycles are powered by 4-stroke engines. But surprisingly, 2-stroke motorcycles haven’t disappeared as many dirt bikes still come with 2-stroke engines.
Consequently, if you are considering buying a new street bike, you can only choose among 4-stroke machines. But don’t worry, as these engines have many advantages over the outdated 2-strokes.
4-stroke motorcycle engines are cleaner, more reliable, last longer, and require less maintenance than 2-strokes. They are also more fuel-efficient and don’t consume oil. This means that you don’t have to pour oil in the oil tank (or even mix it with the gas!) all the time, as 4-stroke engines don’t burn oil along with gas.
Because of these factors, 4-stroke motorcycle engines are easier to maintain and much more user friendly.
If you would like to learn more about the differences between 2-stroke and 4-stroke motorcycle engines, don’t miss this informative video!
Cooling Systems
Motorcycles are often classified by their cooling system. Based on this, the main types are air-cooled and liquid-cooled motorcycle engines.
Air-cooled power sources, as their name suggests, are cooled by air. As the motorcycle moves, air passes over and cools down the engine. The efficiency of this cooling system is dependent on many factors like the engine design, speed of the bike, and air temperature.
Unlike their air-cooled brothers, liquid-cooled motorcycle engines use water or oil to transfer the heat from the engine. The cooling system of these engines is very similar to the system in your car.
The liquid coolant circulates around the engine and transfers the heat to a radiator, which is mounted in front of the engine. As the radiator is exposed to wind, the passing air cools it down. The coolant flows through the radiator, its temperature drops, and then it flows back to the cylinders.
Liquid-cooled motorcycle engines typically produce more power thanks to a lower operating temperature and tighter tolerances.
Capacity and Engine Power
Finally, motorcycle engines are also categorized by their engine displacement, which is also known as a “CC” number. The main motorcycle engine categories by their displacement are as follows:
- 50cc
- 125cc
- 250cc
- 300cc
- 400cc
- 500cc
- 600cc
- 750cc
- 1000cc
- 1000+cc
In this article, we won’t go any deeper into this topic, but you can learn more about motorcycle engine displacements here.
Now, let’s move on and take a closer look at the main engine layouts!
Main Types of Layouts on Motorcycle Engines
It’s safe to say that most riders classify the different types of motorcycle engines by their design. The layout of a motorcycle engine always refers to the arrangement and number of cylinders.
How do you read motorcycle engine layouts?
Simply put, these terms always consist of two parts. The first part refers to the arrangement while the second is the number of cylinders. Two examples:
V-twin: “V”: The cylinders are arranged in a V-shape. “Twin”: the engine features two cylinders.
Inline-four: “Inline”: The cylinders are arranged side-by-side in a row. “Four”: the engine has four cylinders.
Without further ado, let’s dig deeper into this topic and check out the main motorcycle engine layouts!
What is a Single-Cylinder Motorcycle?
Simply put, a single-cylinder motorcycle is powered by an engine that features only one cylinder in a horizontal, vertical, or even an inclined position. Single-cylinder motorcycle engines have the simplest design, one that results in low weight and easy maintenance.
Virtually the majority of the smallest street motorcycles (50-125cc, and many 250cc) as well as all dirt bikes are powered with these power sources.
But surprisingly, you can find single-cylinder engines in many middle-weight naked, supermoto, and dual-sport motorcycles up to 700cc (known as “big singles”). Anything above that would cause too much vibration, which is why you can’t find 1000cc single-cylinder motorcycle engines.
Pros:
- Simplest motorcycle engine design
- Fewer parts
- Cheap and easy to maintain and repair
- Inexpensive to manufacture
- Lightweight
- High torque
Cons:
- The piston has to work hard
- High vibration especially at higher displacements (difficult to balance properly)
- Limited capacity (up to 700cc)
Which single-cylinder motorcycle is the best? Many say that some of the best single-cylinder motorcycles are as follows:
- Honda Grom
- Honda CB125
- Honda CRF250L Rally
- Honda CBR300R
- Honda Rebel 300
- BMW G 310 GS
- KTM Duke 390
- Benelli Imperiale 400
- Honda CRF450L
- Kawasaki KLR650
- KTM 690 Duke
- Husqvarna 701 Svartpilen
Which is the biggest single-cylinder motorcycle?
The biggest production single-cylinder motorcycles are powered with 600-700cc engines like the KTM 690 Duke, Husqvarna 701, and the Kawasaki KLR650. But when it comes to the world’s largest single-cylinder motorcycle, this title is claimed by a custom bike called “NSU Bison 2000.” This bike was built on the base of an NSU Konsul 500 and features a 2000cc, single-cylinder engine!
The main disadvantage of stock single-cylinder motorcycle engines is their limited capacity and significantly lower power.
But in the world of motorcycles there are many performance riders who always want more, more displacement and more power.
And this is where multi-cylinder motorcycles come in handy. It makes more sense to add another cylinder to the engine rather than having to deal with the vibration issues.
So, let’s shift to multi-cylinder engines!
What is a Parallel-Twin Motorcycle Engine?
Parallel-twin motorcycle engines have two cylinders that are arranged side-by-side. In fact, these are the smallest inline engines, which is why they are often referred to as “Inline-twin” engines. Unlike V-twins, the cylinders of parallel-twin engines share the same cylinder block. These engines are typically mounted transversally within the frame, but in a few bikes the cylinders are behind each other.
(The latter engine layout was more prevalent on vintage motorcycles.)
You can usually find parallel-twin engines in smaller sportbikes and commuter motorcycles.
On the other hand, there are many middle-weight adventure bikes out there powered by parallel-twin engines like the BMF F850GS or the Triumph Thunderbird.
These engines are more well-balanced compared to their single-cylinder brothers, but sadly they still struggle with vibration.
Pros:
- Simplicity
- Compact dimensions
- Smooth power delivery
- Well-balanced (compared to single-cylinder engines)
- Cheaper to manufacture and maintain
Cons:
- Vibration
- Moderate performance
Examples:
- Kawasaki Ninja 300
- Yamaha YZF 3R
- Honda CBR500R
- Kawasaki Versys 650
- Honda NC750X
- BMW F 850 GS
- Triumph Thunderbird
- Triumph Bonneville Thruxton
- Honda CRF1000L Africa Twin
What is a Triple Motorcycle Engine?
A triple motorcycle engine, as its name implies, features three cylinders. These engines are also known as inline-three or inline-triple motorcycle engines as their cylinders are placed in one row. In most cases the engine is mounted transversely within the frame. In another words, a triple motorcycle engine is a parallel-twin power source with an additional cylinder!
The biggest advantage of this design is that it’s narrower than a four-cylinder engine but runs smoother than a V-twin engine. On the other hand, they can’t eliminate the vibration as well as inline-four engines.
Thanks to their compact size, you can find inline-triple engines in many middle-weight sportbikes and naked bikes.
It’s also good to know that Triumph offers an entire fleet of three-cylinder bikes. What’s more, the biggest inline-triple motorcycle engine is 2294cc and can be found in the Triumph Rocket III.
Pros:
- Compact size in the class
- High performance
- Great torque (low and middle RPMs)
- Lower vibration (compared to single and twin engines)
- Great exhaust sound
Cons:
- Not completely vibration-free
- Lack of high-end power
You can find some of the best triple motorcycle engines in these machines:
- Triumph Street Triple
- Triumph Daytona 675R
- Yamaha XSR900
- Yamaha FZ-09
- MV Agusta Brutale 800
- Yamaha MT-09 Tracer
- Triumph Rocket III
Inline-Four Motorcycle Engines
Inline-four motorcycle engines have a single-cylinder block and feature four parallel cylinders. These engines are typically mounted transversely within the frame of the bike. Due to their design, inline-four engines are significantly wider than their two and three-cylinder brothers. The main advantage of this layout is an outstanding performance and smooth power delivery.
This is the why you can find these power sources in almost all Japanese sport and naked bikes, as well as the majority of racing motorcycles.
The most well-known motorcycles with inline-four engines are 600-1300cc sportbikes, which offer higher HP rates and top speeds!
Pros:
- Outstanding performance
- Fast-revving
- Smooth power delivery
- Well-balanced
- No vibration
Cons:
- Large overall dimensions
- High weight
- High fuel consumption
- Lack of torque
- High manufacturing and maintenance costs
Examples:
- Suzuki GSR750
- Kawasaki Z800
- Honda CB650F
- Honda CBR600RR
- Kawasaki Ninja ZX-10R
- Honda CBR1000RR
- Suzuki GSX-R1000R
Inline-Six Engines
Inline-six motorcycle engines feature similar designs as smaller inlines, but instead of three or four, they have six cylinders. All these cylinders sit in one row and the engine is mounted transversely, which results in a fairly wide design.
Because of its excessive dimensions and weight, inline-six is a very rarely used motorcycle engine layout.
In the past, this type of engine appeared in some iconic models like the Kawasaki Z1300 or CBX1000. They were very heavy machines, but their design and exhaust sound were amazing!
Today you can still find inline-six engines, but only in a couple of new bikes like the BMW K1600.
Pros:
- High performance
- Fast-revving
- Smooth power delivery
- Well-balanced
- No vibration
Cons:
- Complicated design, lot of parts
- Huge overall dimensions
- High weight
- High fuel consumption
- High manufacturing and maintenance costs
Examples:
- BMW K1600
- HONDA CBX1000
- Kawasaki Z1300
- Benelli Sei 750
- Benelli Sei 900
What is a V-Twin Motorcycle Engine?
As their name implies, V-twin motorcycle engines feature two cylinders that are at an angle to each other. In other words, the two cylinders form a “V” shape. The most common types of V-twins are known as “V-twin trans” and “V-twin long” and angled or “L-twin” engines, terms that describe how the engine is positioned within the frame.
It’s safe to say that V-twin engines are the most common motorcycle power sources in the US. You can find these engines in many cruisers like Harley-Davidson or Indian motorcycles.
These offer great low-end power and a unique exhaust sound!
The most common V-twin engine design is known and “V-twin trans,” which means the cylinders are parallel with the bike’s frame. This results in more compact dimensions overall as this engine fits nicely into the bike’s frame.
In contrast, “V-twin long” engines are mounted in a longitudinal position as you can see on the Moto Guzzi models. Keep in mind that this is a very rare type of motorcycle engine on the market.
Regarding angles between the cylinders, most V-twin motorcycle engines are at a 45 or 90-degree angle. For instance, the majority of Harley-Davidson models use a 45-degree angle while Ducati motorcycles come with a 90-degree “angled” V-twin engine.
These angled V-twins are a special type of V-twin motorcycle engine, which is also known as the L-twin layout.
L-twin motorcycle engines are basically regular V-twins that feature one nearly vertical and one nearly horizontal cylinder. Because of this layout, the cylinders form an “L” instead of a “V” shape.
Pros:
- Narrow design (long layout)
- Unique exhaust sound
- Low center of gravity
- Great torque
Cons:
- Vibration
- Cooling issues on the rear cylinder (long layout)
- Delivers much less power than inline engines
Which V-twin motorcycle is the best? It’s hard to tell, but some of the best V-twin motorcycles are as follows:
- Harley Davidson (all model)
- Honda Shadow
- KTM 1290 Superduke
- Suzuki SV650
- Aprilia Dorsoduro 750
- Ducati Scrambler 800
Who makes V-twin motorcycles? Although V-twin motorcycles are made by many major motorcycle manufacturers, some of them use this layout almost exclusively, like:
- Harley-Davidson
- Indian
- Moto Guzzi
- Ducati
Which is the largest V-twin engine for motorcycles?
The largest V-twin motorcycle engine ever made is a 6728cc, 45-degree V-twin power plant. The bike itself is a custom cruiser designed and built by Clemens F. Leonhard and his team. Just like its engine, the dimensions of the bike are also impressive as it weighs 1,433 pounds and is more than 11 feet long.
What is a V4 Motorcycle Engine?
A V4 motorcycle engine is virtually a fusion of two V-twin engines, meaning that it features four cylinders in a V position. Just like inline-four power plants, V4 engines deliver plenty of power. The main con of this design is the high cost of manufacturing and heavier weight.
Because of this, the V4 is a very rare motorcycle engine type. There are only a few street-legal bikes powered by this engine like the Aprilia RSV4 and the legendary Ducati Panigale V4.
However, you can also find V4 bikes in Honda’s fleet.
Pros:
- Compact size
- Amazing exhaust sound
- High performance
- Low vibration
Cons:
- Complex design
- Expensive to manufacture
- Heavy weight
- High running and maintenance costs
Examples:
- Ducati Panigale V4
- Aprilia RSV4 RF
- Honda VFR800X Crossrunner
- Honda VFR1200F
Flat-Twin Motorcycle Engines
Boxer motorcycle engines are also known as “flat” engines because of their design. Simply put, boxer engines feature two, four, or six horizontally-positioned cylinders.
Flat–twin motorcycle engines feature two horizontal cylinders that are located on the two sides of the crankshaft.
There are many advantages of boxer motorcycle engines, from a low center of gravity to an efficient air-cooling. Although you can find these engines in some BMW street bikes, this is not a widely used motorcycle engine design.
Pros:
- Great power and torque
- Good balancing
- Low center of gravity
- Efficient air-cooling
Cons:
- Complex design
- Expensive to manufacture
- Expensive to maintain and repair
- Limits the lean angle
Examples:
- BMW R 1200 GS
- BMW R 1200 RT
- BMW R NineT
Flat-four and Flat-six Engines
Just like flat-twin, flat-four, and flat-six motorcycle engines are also boxer engines, but feature four or six cylinders depending on the model. It’s safe to say that these engines offer by far the smoothest operation and power delivery.
You can only find these engines in a couple of motorcycle models, typically in the biggest touring bikes.
The first flat-four motorcycle engine hit the market in 1975 when Honda released the first Gold Wing with a 1000cc boxer engine. But over the years the displacement of these models has significantly increased as the newest flagship Gold Wings are already powered by a 1833cc, flat-six engine.
Pros:
- Smooth operation and power delivery
- Great power and torque
- Good balancing
- Low center of gravity
Cons:
- Complex design
- Expensive to manufacture
- Expensive to maintain and repair
- Heavy
Rotary / Wankel
A Wankel engine is also a very rare type of motorcycle engine, however it has appeared in some models during the year. Instead of regular pistons, Wankel motorcycle engines feature a rotor that creates a turning motion.
The most well-known Wankel motorcycles were the Suzuki RE5. Unlike many concept or small-series models, the ER5 reached real mass-production.
Some other examples of production/concept Wankel motorcycles:
- Yamaha RZ201
- Hercules/DKW W-2000
- Norton Interpol II
- Norton Commander
- Norton Classic
- Norton F1
- Van Veen OCR1000
Electric
Many people say that electric engines represent the future of the motorcycle industry, and with good reason. Electric cars have exploded in popularity, and motorcycle manufacturers don’t want to be left behind. That’s why we can see more and more electric motorcycle models being revealed each year.
When it comes to performance, many electric bikes promise the same engine power as performance bikes with regular engines.
Surprisingly, you can already find electric motorcycles in Harley-Davidson’s fleet!
Related Questions About Motorcycle Engines
Which motorcycle engine is the smallest?
The smallest motorcycle engines are the 40-50cc, single-cylinder power sources. You can find these engines primarily in pocket bikes, but 50cc engines can also be found in a few bigger bikes as well.
Which motorcycle engine is the smoothest?
The smoothest motorcycle engines are the large flat-six boxer engines.
What is an inline engine in a bike?
The inline engine in a bike features 2-6 cylinders that sit in one row. These engines are mounted transversally within the frame of the bike.
Are single-cylinder motorcycles good?
Yes, single-cylinder motorcycles are really good as they feature the simplest engine design. This results in a lower purchase price and maintenance costs. What’s more, these bikes are very lightweight as well.
What is the difference between I4 and V4?
The abbreviation I4 refers to inline-four engines, which have four cylinders placed in one row. In contrast, a V4 engine also features four cylinders, but they are positioned in a V-shape. This means that you can find two cylinders on each side of the engine.
Why are there V-twin motorcycles?
V-twin engines fit perfectly in motorcycles as they have the narrowest profile. What’s more, many riders appreciate the gentle torque and unique exhaust sound that V-twin motorcycles provide. This is why V-twins are still the most popular type of motorcycle engine in the United States!
Is a V-twin better than a parallel-twin?
It’s hard to tell which is better, V-twin or parallel-twin motorcycle engines as there are many pros and cons on each side. V-twins have a great sound and narrow profile but it’s easier to package a parallel-twin.
What’s better a V-twin or an inline-four?
When it comes to the V-twin vs. inline-four debate, this is not an apples-to-apples comparison. If you are a performance-minded rider, you should take a look at inline-four engines as they offer the highest RPMs and performance. On the other hand, V-twin engines have greater torque thanks to their larger cylinders, but they also cause some vibration.
Conclusion
As a takeaway we’ve compiled the main types of motorcycle engines under one roof:
- Single-cylinder
- Parallel-twin (or inline-two)
- V-twin (long, trans)
- L-twin
- V4
- Inline (2 / 3 / 4 / 6 cylinders)
- Flat (2 / 4 / 6 cylinders)
- Rotary (Wankel)
- Electric
Although there are many different types of motorcycle engines on the market, it’s safe to say that the majority of production bikes are powered by single-cylinder, V-twin, or inline engines that feature 2,3, or 4 cylinders depending on the make and model.
Lightweight motorcycles come with single-cylinder and parallel-twin engines. In contrast, the majority of middleweight bikes are powered by inline-three, inline-four, and V-twin engines.
Regarding heavy motorcycles, most of them are manufactured with inline-four or large-displacement V-twin engines.
You can find the biggest and most durable motorcycle engines in large cruisers like the Honda Gold Wing. These flat-six boxer engines have a capacity of 1833cc and feature 6 cylinders.
References:
https://www.bikedekho.com/news/different-types-of-motorcycle-engines
https://www.slothdesign.com/technology/23-types-of-motorcycle-engines
