This 'lipped' performance crankshaft, produced by QUATTRINI, was conceived for exclusive use with their revolutionary M-232 performance cylinder kit.
The crankshaft-webs are hand-finished to ensure an optimal gas flow and the term 'lipped' has been established as the best description of this form of crankshaft. They are specially shaped to allow the fresh-fuel mixture unrestricted passage between them, without the obstruction and disruption caused by other types of web-arrangement. This reduction in web dimensions also leads to an increase in available crankcase volume. The PX 200 motors normally quite high primary-combustion compression sinks, allowing a higher volume of fresh fuel mixture to be present for eventual combustion. This layout creates a wider usable power-band and a greater power potential.
A special recess on the crank-web is provided for the fresh-fuel being drawn into the crankcase. The crank-webs are identically weight-matched and the crankshaft is balanced to the 12 o`clock position. The con-rod is, with its length of 126mm, 16mm longer than the original PX 200 item but weighs in at only 125gr. This increase in length, combined of course with the whopping 72mm cylinder bore, enables the voluminous 232cc.
The inlet port timings of the disc-valve were determined by looking at the clutch-side web. '131° / 9° after TDC' means that the inlet is opened at 9 degrees before Top Dead Centre and remains so for 131 degrees before closing. Please consider that these values are approximate, due to their individual manufacture by hand.
MAX QUATTRINI has conceived this crankshaft and cylinder with durability as the main focus, providing as 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 : At last! A plug and play high-end cylinder with performance to match!
'Lipped' racing crankshaft / 57mm stroke / 126mm con-rod / 24-25mm oil-seal and bearing / M 12
'Lipped' racing crankshaft, 57mm stroke, 95mm diameter flywheel side web, 97.9mm diameter disc-valve web, 24mm diameter oil-seal seating, 25mm diameter bearing seating, balanced to 12 o`clock, 126mm con-rod length, thick and stable flywheel shaft stump with a M 12 thread, small-end bearing included in the delivery.
SIP-TIP : This crankshaft is designed for exclusive use with the QUATTRINI M-232 cylinder. 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. Do not forget to order new engine bearings, oil-seals and woodruff keys!