What is a V6 Engine (explained)


Oct 01st, 2019

What is a V6 Engine (explained)

Chances are you have heard about the V engines - be it the V6 or V8 - if you are a car enthusiast or looking to buy a car. Well, if you are out to know more about this engine type, you just caught the right train.

The Basics of the V6 Motor
Car engines have cylinders enclosing pistons which perform the pumping action. This pumping aids in the conversion of fuel to the desired energy form. The cylinders have an up & down movement on the crankshaft.

This movement action regulates the mixture of air and fuel for proper combustion. The energy generated as a result of this combustion powers the vehicle. Therefore, the number of cylinders in an engine dramatically contributes to the performance of the car.
Four-cylinder engines usually take the inline configuration. Unlike four-cylinder engines, six-cylinder engines can be arranged in shape resembling the letter "V". For this reason, as you've guessed it, they are referred to as V6 Engines.

V6 engines are not new in the automotive industry. They have been around since 1905. The Marmon Motor Company developed the V6 in 1905, but it never really took off. It was until the 1950s that the V6 engines hit the market.
In 1950, Lancia introduced the V6 engine in its Aurelia model. By the end of that decade, the V6 configuration had made a name for itself. Racecar manufacturers started adopting the engine in their autos. General Motors are credited with developing a compact V6 engine that lacked vibrations.

Design of the V6 Engines
The V6 engine consists of a crankshaft onto which the six cylinders are attached in two arrays. Each of the arrays has three cylinders, set at a right angle (90°), an acute angle (60°), or an obtuse (120°). There are other angles, but they are uncommon because they bring about vibration problems.

Since the banks have an odd number of cylinders, the V6 engine is not balanced naturally. As a result, most of them come with a balance shaft. The shaft additionally contributes to the smooth operation of the engine.

For a front-engine layout, it can be laid out in two unique ways to afford the front or rear-wheel drive. The engine is positioned perpendicular to car length for the front-wheel layout and parallel to the car length for the rear-wheel version.

Angle designs for the V6 Motor
We classify V6 engines according to the angles at which the cylinders oppose one another. As such, there are 60°, 90°, 120°, and other unconventional designs.
1. 60 degrees
The crankpins onto which the rods connect have a displacement of 60°. The main advantage of this connection is that the firing interval is even; hence, there's no primary vibration.
A 60° eliminates the need for a balance shaft as the layout can be tweaked to achieve smoothness. The smoothness, however, is not as perfect as that produced by other engine configurations such as inline-six.
The 60-degree design fits in most modern engine compartments both perpendicular and parallel to the car length. Its cube-like outline makes this possible. Essentially, it is one of the most compact designs.
It is affordable for vehicles whose power requirements can't be achieved by four cylinders.
2. 90 degrees
Although the V8 engines were popular and well-received, the market wanted a lighter bantam version. Manufacturers then opted to get rid of two cylinders from a V8 engine.
Primarily, the V8 engine has a 90° design; hence, removing two cylinders left it with six and a 90° mount.
Not only did this make the new V6 engines wide but also resulted in more vibrations. Although this approach lowered production costs, it was not effective. Nowadays, manufacturers overcome this limitation by having the split pins offset by 30° to produce even firing intervals.
Counterbalancing shafts are also used to reduce the vibrations to the crankshaft, which lower the performance of the engine.
3. 120 degree
A 120° design means that the cylinders fire at an interval of 120° (angle of the crankshaft rotation). With this design, pairs of pistons can be attached to the same crank journals.
Just like with the 90° design, a balancing shaft is required when using this design. The odd number of pistons in each bank cause imbalance to the system.
This configuration does not require split crankpins.
Although a configuration of 120° is thought to be a natural one, it still has some limitations. V6 engines making use of this layout take up so much space. As it cannot fit in most engine compartments, the 120° V6 engine is limited to racing cars.
Unlike other vehicles that have engines designed to fit the compartment, racing cars are the complete opposite. Manufacturers design these cars around the engine.

Other angles
V6 engines that use angle designs other than the 60°, 90°, and 120° are uncommon due to their association with serious vibration problems. A few manufacturers, however, have built designs with these unconventional angles.
These engines are designed to meet specific needs in the cars they will be used. They include:
80° Honda RA 168-E in the McLaren MP4/4 Formula One car
15° or 10.5° Volkswagen VR6 engine  
65° Renault V9X
75° Isuzu V6 engine found in the Isuzu Trooper

Advantages of the V6 Engine
The V6 engine has a considerable edge over other engine models. Some of the upsides of the V6 engine relative to other engines are:
Compactness. Compared to the inline 6-cylinder engine, the V6 engine requires little space to fit. What's more, its cube shape allows transverse and longitudinal layouts. Depending on the position, it is easier to achieve rear-wheel-drive and front-wheel-drive layouts.
The V6 engine offers more rigidity than the inline six-cylinder engine.
It is easier to maintain a V6 engine because it has fewer parts compared to a V8 engine.
The V6 engine is more powerful compared to 4-cylinder engines and provides faster acceleration.
Compared to the V8 engine, V6 engines are fuel-efficient and have better gas mileage.
In additional to being powerful, the V6 engine still manages to be less noisy than the 4-cylinder engines.

Disadvantages of the V6 Motor
Despite all the merits of the V6 engine, it is not without flaws.
The V6 engine is more complex than inline engines, hence, difficult to repair.
Compared to the V8 engine, the V6 has less acceleration and speed.
Application Areas of the V6 Engine
The modern V6 engines have a displacement ranging from 2.0 to 4.3L, and you can still find sizes outside this range.

Today the engines are widely used in vehicles including sport utility vehicles, compact cars, and even trucks. The engine has also featured in a motorcycle. A V6 engine powered the Laverda motorcycle that competed in the 1978 Bol d'Or race.
If you want a powerhouse with a decent gas mileage, the V6 engine is your ideal choice.