THE V4 ENGINE –WHAT’S WITH THAT ?
The V4 engine is an interesting one for cars , lovable in its uniqueness because of the fact the pistons are essentially just 2 beside each other, V4's are shorter than inline 4's. There are obviously different angles, like every V engine, but, like every V engine, 90 degrees gives perfect primary weight distribution, reducing vibration. The shorter crankshaft also reduces torsional vibration, and it is more rigid because of its smaller length.

HISTORY OF V4 ENGINES
• In a car, the first use of the V4 layout was in Grand Prix, one of which was a Mors, which placed the engine in the back. By 1901, though, I4's took over as the lack of vibration turned out not to be a good enough incentive.
• In 1907, the biggest ever GP engine was a V4 engine at 19,891cc (20 litres!), a front transverse engine driving the front wheels, although it only lasted 4 laps before retiring.
• Lancia was the first marque to bring the V4 into the production market, in the revolutionary 1922 Lambda.
THE LANCIA
Lancia has probably had the most use of this sort of engine, having used them for over 50 years after the Lambda, until 1976.
In total, the marque has used a V4 in 7 cars, although very few of them have been their most iconic or popular model.
The angles of their engines were extraordinarily narrow, being between 10 and 20 degrees. Due to the tightness of the V, the engines were unique as they had a single rocker cover and rockers.

MOTOR BIKES
One of the first times this engine layout was put in a motorcycle was for a Matchless Silver Hawk from 1931 to 1935 and had a narrow 16 degree angle so only 1 cylinder head and all that, like the Lancia engine.
In the 80s, V4s were used for bikes, particularly by Honda who used transverse, 90 degree, water cooled engines.
Most current Moto GP bikes also use the V4 layout, like the Honda RC213V , Ducati Desmosedici , KTM RC16 , Aprilia - 90° V4 for the 2020 season.

Ducati Demosedici

KTM RC 16