What Are Intake Manifolds?

All vehicle engines have intake manifolds, engine parts that accept incoming air/fuel mixture gases and transport them into the engine cylinders, where they are ignited and burned, a process which creates engine power.

Intake Manifolds Funnel Air/Fuel Mixture into Engine

Intake manifolds, which are large, elongated steel or aluminum engine pieces that have hollowed-out ports, or passageways, within them, bridge the gap between an engine's fuel induction system (carburetor and fuel injection) and its main combustion chambers. Intake manifolds consist of hollow channels, or ports, through which air/fuel gases flow through en route to an engine's cylinders.

Intake Manifolds Enhance Air/Fuel Gas Heating

As a carburetor or fuel injection system prepares a vehicle's air/fuel mixture, the air/fuel mixture flows into the vehicle intake manifold, which becomes heated as the vehicle engine warms up. The heated intake manifold heats up the air/fuel mixture and helps to prepare it for combustion within the engine.

Intake Manifolds Compress Air/Fuel Mixture

As a vehicle's air/fuel mixture flows through an intake manifold, the mixture gets compressed as it flows through the narrow intake manifold ports, a process which speeds up its flow and velocity, which in turn makes the air/fuel mixture more combustible as it heads into the engine cylinders.

Intake Manifolds House Fuel Induction System

A vehicle's intake manifold is the base to which it's fuel induction system--carburetor or fuel injection system--rests. The intake manifold provides a solid, flat base to which a vehicle's fuel induction system attaches. The intake manifold ports align with the exiting fuel ports of the fuel-induction system.

Intake Manifolds Affect Engine Horsepower

The size and shape of a vehicle's intake manifold plays a pivotal role in engine performance. Standard, factory-installed intake manifolds tend to be shorter with smaller intake ports, a design that limits air/fuel mixture intake amounts and speed, which limits engine power. High-performance intake manifolds are longer with bigger intake ports, a design that enhances air/fuel mixture flow and results in greater engine horsepower.