When it comes to sportbikes, the good old inline-four cylinder engine has become the gold-standard when it comes to performance-oriented engines. These day, however, V4 powerplants have become a lot more powerful, and have managed to eke out more performance across the rev range. Furthermore, V4 engines have gone on to power to most successful racing motorcycles in today’s modern era.
Today, let’s dive a little deeper to the inner workings of our beloved motorcycles. What exactly makes the inline-four engine such a timeless design? Meanwhile, why is the V4 engine becoming so popular among European manufacturers? Is the inline-four engine’s reign of glory coming to an end? Read on to find out.
The good old inline-four engine has been around for more than half a century. Some bikes that are responsible for propelling this engine layout into stardom include the venerable Honda CB750 Four, a bike that is considered by many as the very first super bike. The inline-four cylinder engine is characterized by its four cylinders which are situated in line, or parallel. Available in either 180-degree (flat-plane) or 270-degree (crossplane) crankshaft layouts, this engine has become a staple in the world of racing.
As for its characteristics, inline-four engines are known for producing most of their power and torque high up in the rev range. It isn’t uncommon for performance-oriented inline-four engines to be capable of revving all the way up to 14,000 RPM. This is the case with bikes like the Kawasaki Ninja ZX-6R. As for sound, they produce the iconic howl that has become synonymous with racing—similar to the sound racing bikes of the 90s and early 2000s produced. These days, however, the inline-four engine is beginning to show its age in the performance game, with V4-powered motorcycles from Europe cranking out a lot more performance, as is evidenced by their success in the world of racing.
This brings us to the V4 engine. Now, this layout has been in production for several decades as well, but has only recently hit the mainstream when manufacturers like Ducati and Aprilia began using them on their mainstream street bikes. This came in parallel with Ducati’s huge success in MotoGP and WorldSBK, making use of its new V4 engine. Proving that it had the edge against the older, inline-four powered bikes, the V4 began making its way into production motorcycles, with the most popular of which being the Ducati Panigale V4.
As the name suggest, a V4 engine has four cylinders with two cylinder banks—two cylinders in each bank. Think of it as two V-twin engines strapped together side-by-side. Now, if you’re familiar with the power delivery of a V-twin, then you’d know that it has a healthy spread of power from low in the rev range, but has the tendency to taper off at the upper reaches of the tachometer. The V4 engine gets the same healthy spread of power and torque, but manages to spin faster, thereby producing more power at a wider range of revs. Because of this, it’s not surprising that most manufacturers in the MotoGP—Honda, KTM, and Ducati, are all using V4 engines for their race bikes.
Which is better?
If you were to look at things from a strictly competitive standpoint, it’s pretty clear that the V4 engine has its benefits when compared to the inline-four engine. It generally produces more power across a wider range of revs, and is a lot narrower, making for a slimmer, more nimble motorcycle. That being said, V4 engines are expensive to produce, difficult to maintain, and can get very hot, especially since the rear cylinders are positioned right below the rider’s butt.
Perhaps this is why the good old inline-four continues to live on. It’s simply a tried and tested package that’s compact, relatively affordable to produce, and easy to maintain. It can’t be denied, however, that the inline-four’s glory days in the world of racing are well and truly behind it.