Japanese manufacturers’ huge expansion since the late 1960s is partly responsible for the rise of the inline-four motorcycle engine.
The Honda CB750’s release in 1969 met the demand for excellent performance, dependability, and reduced vibrations at an affordable price. And for this reason, transverse straight four-cylinder engines are used in sports bikes, tourers, and broader capacity machines.
What are Inline Four Motorcycle Engines?
Inline four motorcycle engines are a type of engine configuration commonly used in motorcycles. As the name suggests, these type of engines consist of four cylinders arranged in a line or straight configuration. Each cylinder has a piston that moves up and down, and the combustion process occurs within each cylinder to generate power.
Inline Four motorcycle engines are well-known for their smoothness, power, and versatility, making them popular among enthusiasts who value performance and a thrilling riding experience.
Inline Four Engine: Pros
- Smoothly delivered electricity in large numbers.
- The design’s affordability and simplicity.
- Simple upkeep.
- Good reliability and minimal vibrations.
Inline Four Engine: Cons
- Low-down torque suffers from high-end power.
- Possibly very large and broad.
- Some instances, especially those at lower speeds, have drawn criticism.
Inline Four Motorcycle Engines: History, Power, Maintenance
Along with the Kawasaki Z1, which had a higher capacity, the BMW K100 came after the Honda CB750. More touring and long-distance driving, where the lack of vibration and smooth power delivery has become a huge plus, was made possible by ten years of big BMW production. Additionally, it is one of the few longitudinal four-cylinder motorcycles.
It was the perfect engine for Japanese sports bikes since it produced horsepower at high revs. The inline-four was the preferred powertrain for everything from the 1986 Suzuki GSX-R1100 and the 1992 Honda CBR900RR Fireblade to the Yamaha R1. And that includes the 998cc inline four Kawasaki Ninja H2, the quickest production motorcycle currently on the market.
An inline-four is extremely comfortable to ride, even with its enormous power and high speeds. Modern sports cars feel uncomplicated until you reach the potential driving ban speed at which they potentially exceed the UK national speed limit.
The inline four-engine architecture has several advantages, including easy production and maintenance. They can be readily removed and serviced from the top of the engine, reducing maintenance time and expense. Additionally, they provide space for fuel systems, electronics, and airboxes and clear ways to connect exhaust pipes.
A BMW Boxer or Moto Guzzi V-Twin engine adds width, although not as much as an inline four-cylinder engine. And as technology advanced, engines shrank.
It’s imperative to note that several businesses, like Honda, have tried increasing the number of cylinders. The Goldwing and its derivatives were the most widely used six-cylinder motorcycles, although their MotoGP V5 concept never served as the model for a production motorcycle. Anything more substantial (such as a V8 or V10) has only been available as limited-edition rarities because they are too tall and bulky for most bikes.
Why Aren’t Inline Four Engines Used By All Bikes?
Cruisers are sold on personality and low-down torque, which a V-Twin arrangement makes more readily available. Secondary imbalance vibration may need to be reduced by the mounting method’s damping effect. Small-capacity motorbikes (often 250cc and smaller) tend to have single- and twin-cylinder designs that are more affordable and have lower revs, primarily due to cost. This is also true of cruisers.
Drawbacks Of Inline-Four Motorcycle
The inline-four motorcycle engine has very few drawbacks. They have been criticized as being a bit bland to ride, but that depends on the approach used by particular manufacturers. A Yamaha XJ600 will feel very different from an MV Agusta F4.
The 2009 Yamaha YZF-R1 employed a cross-plane crankshaft with a big-bang firing to achieve power delivery similar to that of normally more expensive V4 engines, a major innovation.
The time between cylinder firings also improved traction, although more and more of this task is now done with sophisticated electronics. The R1 utilizes a Slide Control System instead, which receives data from a six-axis gyro.
In comparison, the 1998 R1 advertised 150 horsepower measured at the crank. The 2017 model can produce 200 horsepower when equipped with the Circuit ECU designed exclusively for racing. It is also capable of 190 horsepower when equipped with conventional road ECUs. The top speed has increased from 168 mph to 182 mph as a result of this.