Membrane intake manifold for Vespa Smallframe from POLINI and MALOSSI.
Converting to reed valve control can make sense, and not only if you are looking for a significant increase in performance. Especially if the sealing surface of the rotary valve intake is damaged, the installation of a Reed Valve is often unavoidable in order to continue riding the Engine. To do this, the Intake Manifold must be replaced.
We therefore have a large selection of diaphragm intake manifolds suitable for DELL'ORTO SHB and PHB carburettors in our range. POLINI offers these for SHB 16.16 to PHBL 24, with 2- or 3-hole mounting and plug-in connection depending on the model. POLINI also offers diaphragm intake manifolds with a flexible rubber connection to suit the PHBL 24 and its own 24 Carburettor.
MALOSSI also offers high-quality diaphragm intake manifolds with rubber connection, suitable for the PHBL 24/25. These have a slightly larger effective cross-section and are also suitable as a base for larger carburettors thanks to the rubber connection. In addition to the Reed Valve Block, the MALOSSI kits also contain all the small parts required for installation.
Although major modifications to the Casing are recommended for the conversion to diaphragm control, you are rewarded with the advantages of a system that supplies the Engine with mixture independently of the intake timing of the Crankshaft. This allows the Engine to determine for itself when it needs fuel and when it does not. The Intake Manifolds for the PHBL 24/25 in particular promise a significant increase in performance in conjunction with the appropriate Carburettor and peripherals.
Conclusion: Saves the Engine in the event of a damaged rotary valve inlet and also gives it a boost.