Malossi Manifold D 22 straight pitch 65 for PHBL 21/22 carburetors

The Malossi Ø 22 straight rubber intake manifold with a 65mm center distance is designed for PHBL 21 - 22 carburetors. This intake manifold serves as an access corridor for the air-fuel mixture into the engine through the reed valve. The overall performance of the engine depends on various partial efficiencies, including volumetric, thermodynamic, and mechanical efficiencies.

The volumetric efficiency represents the ratio between the amount of mixture entering the combustion chamber and the engine displacement. One of the main influences on volumetric efficiency is the friction encountered by the fluid along the path from the air intake to the combustion chamber. The intake manifold plays a fundamental role in minimizing this loss by avoiding abrupt changes in section and sharp edges along the mixture's path.

In addition, the intake manifold acts as a reservoir for the fresh charge, allowing the mixture to accumulate and compress against the reeds when the reed valve closes. Each manifold has a specific range of engine speeds at which it offers maximum efficiency.

The intake manifold also serves the purpose of connecting the carburetor to the engine crankcase or cylinder and can dampen vibrations transmitted from the crankcase to the carburetor to prevent fuel and air emulsion in the carburetor float bowl.

With its extensive experience in engine fuel systems, Malossi has developed a new line of rubber and aluminum alloy manifolds for the next generation of scooters. These manifolds have been tested and developed by Malossi's experience department both on the road and on the track.

Malossi rubber manifolds feature a composite structure, with an aluminum insert embedded in a plastic material resistant to oils and fuels. This ensures a rigid attachment base to the crankcase and good elasticity of the manifold body.