Intake Manifold from SERIE PRO for converting to diaphragm control and for installing 3-hole PK engines in Vespa small-frame frames.

Converting to a Reed Valve system isn’t just useful when seeking a significant performance boost. Especially when the sealing surface of the rotary slide valve inlet is damaged, installing a Reed Valve often becomes unavoidable in order to continue using the Engine. To do this, the Intake Manifold must be replaced.

When an older Smallframe model is converted to a technically interesting PK engine, problems often arise. The intake manifold required for the PK engine—with its 3-hole mounting—does not match the Smallframe chassis in terms of shape and bend radius. Until now, this problem could usually only be solved by making major modifications to the frame, such as cutting out or enlarging the existing cutout.

The special SERIE PRO intake manifolds are equipped with a 3-hole Base Plate and a matching Connecting Piece for Vespa 50-125/PV/ET3 frames. This allows the Intake Manifold to adapt perfectly to the shape of the chassis, making the conversion to a 3-hole PK engine significantly easier.

For conversion to diaphragm control, major modifications to the Crankcase are recommended. In return, the engine benefits from a control system that allows fuel-air mixture delivery independent of the Crankshaft’s intake timing. This allows the engine, so to speak, to determine for itself when it needs fuel. The Intake Manifolds for the PHBL 24/25, in particular, offer significant performance potential when paired with the right Carburettor and corresponding peripherals.

Conclusion: Saves engines with damaged rotary valve intakes while simultaneously providing significantly more tuning potential.