Long anticipated and now a reality : The QUATTRINI M-232 performance cylinder, for the 'big-block' PX 200 motor is finally available! The QUATTRINI legacy of producing the mightiest Vespa motor components has reached the premier-league and its huge 232cc is a redefinition of the current state-of-the-art of Vespa tuning! Certain tuners on the German speaking scooter-scene have already announced 50 PS projects based around this potent cylinder.
Surprisingly perhaps, no extra modifications are required to enjoy this cylinders performance, in spite of the whopping nicasil lined 72mm bore. Quite literally, plug and play! The main course of the transfer ports is arranged so far up the flanks of the cylinder that no matching work is absolutely necessary, although highly recommended for a taste of this cylinders vast potential. The original motors cylinder base gasket surface area is fully sufficient, making any extra welding, machining and matching unnecessary. Another aspect of the versatility of this cylinder is its compatibility with both disc and reed-valve induction systems. The inlet port timings are governed by the clutch-side crankshaft web (disc valve) and the cylinder is centralised on the crankcase using the four cylinder holding studs in combination with precisely dimensioned stud openings on the cylinder. Due to the manufacturing tolerances allowed in the production of Vespa motors the stud spacing can vary, which will require the enlargement of one of the stud openings on the cylinder to 9mm in diameter. If this modification is necessary, full details of this job are included in the Italian instruction manual. If you wish to run this cylinder kit in combination with a reed-valve assembly a facility enabling the ideal positioning of the manifold is provide above the boost ports, opposite the exhaust outlet. The carburettor can then be mounted directly onto the cylinder. The design of the cooling fins on the cylinder head have a similar fan-shaped arrangement to that found on certain old KREIDLER mopeds. The increased fin surface area helps improve the cooling performance of the cylinder head. The optimal squish clearance for this cylinder has been measured at 1.35mm and this can best be achieved through adjustment of the cylinders base gaskets. The cylinder head nuts should be tightened, with a torque wrench, to a value of 20 Nm. 'You can't beat cubes' and this cylinders cavernous 232cc has been achieved by Max with the help of a specially developed 'lipped' QUATTRINI racing crankshaft (# 45048000). This crankshaft has been designed for exclusive use in combination with the M-232 cylinder. Although its stroke of 57mm is familiar, its length of 126mm is noticeably longer than the original and responsible (in part) for the increase in capacity. This all-new design, combined with being hand-finished, provides an extremely smooth-running, enduring motor.
MAX QUATTRINI has conceived this crankshaft and cylinder with durability as the main focus, providing an ideal basis for a powerful, road-legal, touring scooter set-up. A combination of this cylinder and its crankshaft, with an original Dellorto SI 24 carburettor (135 main jet), a SIP 'Road' exhaust, a Vespatronic ignition (26° pre-ignition) and the original 26/35 overall transmission ratio produced 22 PS @ 7500 rpm for Max and his team! The maximum torque produced was 28 Nm @ 5100rpm and the maximum revs peaked out at 8800 rpm! A welcome power boost from MAX 'Power' QUATTRINI for all fans of the PX 200 motor!
Conclusion : A plug and play high-end cylinder with performance to match! Considering the minimal cost of the required peripheral components (Dellorto SI carb, SIP-Road exhaust) unbeatable bang for your bucks!
Aluminium / 72mm bore / 6 transfer ports / 232cc
Aluminium cylinder with a nicasil -lined bore, 6 transfer ports, 2 large bridged side-ports, 2 boost-ports (opposite the exhaust-port), centred cylinder head with a semi-spherical combustion chamber and centrally located long threaded spark plug facility. Piston includes 2 piston rings. Check both the carburettor jetting and ignition timing before initial use.
The crankcases do not require immediate modification in order to run this kit, although a cylinder of this quality most definitely deserves being properly matched to the motor eventually!
SIP-TIP : This cylinder can only function when combined with the QUATTRINI crankshaft (#45048000). The minimum peripheral components include a Vespatronic electronic ignition, a fuel pump and our very own SIP-Road exhaust. To unleash more of its enormous power potential a SIP Performance 2.0 exhaust, a large reed-valved carburettor and strengthened drive-train components will put you on the right track!