How Do Manifolds Work?

It goes without saying that generators and engines are complex machines with numerous interconnecting components. The manifold is a key element within an engine, and many cite them as being the lungs of the machine.

Ensuring that all components, including the manifolds, are in full working order is an essential part of generator servicing and maintenance. Here, we unravel some of the mysteries hidden within an engine and take a look at what manifolds are and how they work.


What are Intake Manifolds?

Intake or inlet manifolds feed into an engine to facilitate the flow of air to ensure that the combustion cycle takes place properly.

How Do They Work?

These manifolds are usually made from a series of four connecting tubes known as runners. These runners take air from the main component of the manifold, known as the plenum, and distribute it into each cylinder within the engine. Without the right amount of oxygen, an engine could not run properly, and combustion could not take place.

Manifolds work in conjunction with the air intake, throttle body and fuel delivery system to make sure that the appropriate amount of air and fuel is being burned in the engine.

After air travels to the intake and throttle body, the plenum distributes it equally between the runners. Low pressure is created in the cylinders when the intake stroke moves the piston – this means that the highly pressurised air in the runners is sucked into the cylinders. This process will happen continuously, supplying air to the right places, until the engine is switched off.

How Do Manifolds Work?

How Manifolds Can Influence Engine Performance

The size and number of runners will affect how an engine performs. Larger car engines designed for increased performance will have more cylinders for the manifolds to feed into. More expansive plenums and runners will allow for better, more efficient airflow.

With a smaller single-cylinder generator engine, the intake manifold will only need to supply one cylinder. Thus, it will be smaller and less specialised.

Manifold Splits and Leaks

As with any other component within a complex piece of machinery, manifolds are not immune to experiencing problems.

It is fairly uncommon, but occasionally an intake manifold can split and develop a leak. If this happens, you may be able to hear an unusual hissing noise coming from the engine.

When a split occurs, it can mean excess air is sucked in through the crack because of the lower pressure inside the manifold. This means too much air is directed towards the cylinders, decreasing the amount of fuel in the cylinders and making combustion less efficient.

Smaller cracks and leaks can usually be repaired, but it can sometimes be better to replace the manifolds altogether.

If your generator’s engine has been running less efficiently, it could be down to a fault with the manifolds, though this can be a rare problem.

If you have noticed a drop in performance from your generators or if there is an obvious maintenance issue, why not contact our experienced team here at Edge Technology to see how we could help?