When a V-twin motorcycle engines is mentioned, you think of something red, Italian, and with Ducati inscribed on the side. You might have thought about a Moto Guzzi or an Aprilia. Despite the popularity of other manufacturers’ V-twin engines with two cylinders, Italian motorcycle companies and the V-twin are special. The exception is Harley-Davidson.
What is a V-Twin Engine?
A V-Twin engine also refers to a “V2” engine. The number represents how many cylinders are in the engine; the V-Twin has two cylinders with pistons. This engine’s interesting feature is its “V”-shaped cylinder arrangement, which gives it its name.
Although they can also be found in more compact cars or commercial machinery, V-Twin engines are most frequently found on motorcycles. Most configurations maintain a 90-degree angle between the two cylinders that make up the “V” because this angle offers maximum stability and primary balance when combined with the appropriate counterweight. However, these engines may occasionally be called “L-Twins” rather than “V-Twins” due to the 90-degree angle between the arms. Crankpins are used in V-Twin engines with acute angles (less than 90 degrees).
V-Twin Engine: Pros
- Superior over a single or parallel twin engine in terms of power.
- More personality in power application.
- The engine’s striking appearance, especially for cruisers.
- The three major producers of V-twin motorcycles provide an iconic heritage.
V-Twin Engine: Cons
- More complex and costly to maintain.
- Smaller cylinders produce more vibration.
- Longitudinal V-twin engines are prone to sideways movement during rapid and deceleration.
Design, Complexity, And Cooling
A V-shaped engine is longer and more sophisticated than one with parallel twin engine. Nevertheless, V-twins have been present since the early 1900s for a comparable amount of time. Three of the brands mentioned above cover the available V-twin (and L-twin) motorcycle engine range. The two basic variations are the V configuration’s cylinder angle and crankshaft orientation.
Most motorcycle engines have a transverse layout, starting with the crankshaft. This implies, like on Harley-Davidsons and Ducatis, that the crankshaft is mounted perpendicular to the frame. The engine becomes smaller as a result, although the back cylinder often receives less airflow.
While Moto Guzzis with air cooling use longitudinal crankshafts. As a result, motorcycle cylinder heads rise on each side. Without something to counteract the crank’s influence, you can notice that the bike jerks to one side when you accelerate quickly. It also jerks to one side when you brake hard. Degrees are another significant distinction.
1. 45 Degrees
As early as 1907, William Harley and the Davidson brothers advertised a 45-degree V-twin engine with double the power of their original single-cylinder motorcycles. However, sales of V-twins increased after a more compact, more effective model was introduced in 1911, and they have dominated manufacturing ever since.
The cylinders fire irregularly due to the initial trade-off between a large capacity, high torque engine in a relatively small package. However, it has since evolved into a Harley hallmark with the recognizable “potato-potato” sound rather than being a nuisance.
There is a lot of vibration from the engine due to the angle of the cylinders and uneven firing. However, Harley-Davidson has found ways to lessen this vibration using counterbalancing or rubber mounting systems.
No matter the manufacturer—Harley-Davidson, Indian, Victory, Honda (such as the VT1100 Shadow), or Suzuki (like the VX800), most cruisers share a similar cylinder angle.
With the V-twin engines powering several models, including the Shadow, Transalp, Deauville, and Africa Twin, Honda increased the angle to 52 degrees. With the Vulcan line, Kawasaki joined them. However, the 45-degree transverse V-twin always leans towards cruising versions, with the Brough Superior SS100 and Vincent Rapides serving as prominent classic exceptions. The Yamaha Virago, with a 75-degree angle V-twin, is the cruiser that travels the furthest.
2. The Ducati L-Twin 90-Degree
Harley used the drawbacks of a V-twin engine as a selling feature, whereas Ducati adopted a different strategy. The L-twin name refers to the wide angle between the cylinders of the 90-degree engine Fabio Taglioni created in 1970. The Ducati 750 GT production bikes and 500cc versions were the first Italian company products to enter Grand Prix racing.
Trellis frames and V-twin engines became a Ducati bikes trademark, appearing on production motorcycles like the 888, 916, and 998, as well as their ultimate high-performance 1299 Panigale. This tradition is ending as the company transitioned to a V4 adapted from its Desmosedici MotoGP machines.
Why did the company continue using the broad-angle V-twin for so long? The engine is longer but narrower because it is positioned transversely. Additionally, the design necessitates water or oil cooling for the rear cylinder on larger Ducatis. But it also provides the ideal balance between prominence. Power delivery and handling are smooth.
That explains why V-twins designed for sports typically have cylinders at a 90-degree angle. SV and V-Strom motorcycles from Suzuki are examples, along with the Honda VTR1000 Firestorm and SP1 World Superbike Racer.
Famous sports bikes like the Aprilia RSV Mille (60 degrees), Suzuki RGV250 (70 degrees on the VJ23 model), Buell 1125R (72 degrees), and KTM 1190 RC8 (75 degrees) closed the cylinder gap.
3. The 90-Degree Longitudinal V-Twin From Moto Guzzi
Nearly a decade before Ducati, in the 1960s, Moto Guzzi created its Italian V-twin. To win an Italian government competition for an improved police bike, designer Cesare Carcano chose a strong air-cooled V-twin after learning about the issues with a tremendously complicated V8 500cc Grand Prix motorcycle that frequently failed to finish.
The capacity and output of that original engine design have increased throughout time, including the current range of the V7, V9, California, and MGX-21. The V-twin now has 1,380cc and 96bhp, more than double the power and nearly twice as much as their first V-twin.
The Moto Guzzi V-twin leaves sufficient engine space for transmission and shaft drive in the frame. Torque reaction during rapid acceleration and deceleration is a drawback. It’s still part of riding a Moto Guzzi. However, the effect is usually mitigated by manufacturer upgrades like rotating flywheels and alternators.
However, Moto Guzzi, Europe’s oldest motorcycle manufacturer still in operation, has tried to position its engine’s distinctiveness as a selling factor, much like Harley Davidson.
