INTAKE MANIFOLDS

The intake manifold turns out to be the access corridor for the air-fuel mixture into the engine through the gate formed by the reed valve.

The total efficiency of an engine is calculated as the product of several partial efficiencies, which are:
- volumetric efficiency
- thermodynamic efficiency
- mechanical efficiency

Volumetric efficiency indicates the ratio between the amount by volume of mixture that can be fed into the combustion chamber and the displacement of the engine.

One of the main factors affecting volumetric efficiency is the frictional loss that the incoming fluid (air-fuel mixture) encounters from the air filter to the combustion chamber, so one of the components that significantly influences this loss is the intake manifold, since all the incoming mixture must pass through it with as little loss as possible , which is why abrupt increases in cross-sectional area and sharp edges along the path of the mixture must be avoided at all costs.
Another function of the intake manifold is to act as a storage lung for the fresh charge , since the column of mixture traveling at a certain speed takes a certain amount of time to stop when the reed valve closes and thus mixture comes to accumulate in the manifold, compressing against the reeds. Therefore, each manifold has its own well-defined rpm range within which it expresses maximum efficiency (tuned manifold).
In addition, the manifold performs the task of supporting the carburetor by connecting it to the crankcase or cylinder , so it also has, when required, the task of dampening the vibrations that are transmitted from the crankcase to the carburetor, preventing the phenomenon of emulsion of gasoline and air in the carburetor bowl.
Therefore this seemingly simple component requires considerable study in order to take full advantage of all its qualities, a result that Malossi technicians have perfectly hit.
Malossi, strengthened by its decades of experience in engine fuel systems, has created a new line of rubber and aluminum alloy manifolds for new generation scooters, tested and developed by the Malossi experience department, both on the road and on race circuits.
In particular, the Malossi rubber manifolds have a composite structure in that they are constructed starting from an aluminum insert that is encased in a special plastic material that is impervious to oils and gasoline, thus guaranteeing considerable rigidity of the base of attachment to the crankcase and good elasticity of the manifold body.