Malossi 178cc cylinder Ø 63 IN CAST IRON FOR VESPA COSA - PX 125-150 CC

Description

Malossi cylinder Ø 63 IN CAST IRON FOR VESPA COSA - PX 125-150 CC INSIDE YOU WILL FIND THE CALIBRATION KIT SI 20 VES. PX CVF COD.68 4013 EMULSIFIER BE3 GETT.MINIMUM 52/140 MAX. JET 115-105 HEAT EXCHANGER ASSEMBLY Ø 63 IN CAST IRON CYLINDER The cylinder has been bored to 63 mm with a displacement of 178cc and completely revised internal fluid dynamics. The new transfer system allows for correct coupling with both connected crankcases and completely original crankcases, and features a special profile designed to optimise flow and achieve significant performance gains, even without additional work on the vehicle. TRANSFER CHANNELS The intake transfer channels have a profile designed to correctly orient the incoming flow and achieve high turbulence, thus ensuring improved combustion efficiency and optimal scavenging. These improvements increase combustion efficiency, reduce fresh charge losses at the exhaust and maintain the temperature in the chamber within the permitted levels, even on the piston crown. The rear transfer ports have been the subject of in-depth study, leading to the definition of an innovative double-angle profile (1-2) which, by exploiting the well-known Coandà effect, allows for a higher flow rate than traditional rear transfer ports, while differentiating the orientation of the jet from the single inlet opening into the combustion chamber: this has made it possible to reduce fresh charge short circuits at the exhaust and simultaneously increase the amount of fresh mixture introduced. The exhaust has also been thoroughly redesigned and features new, wider timing and a redesigned profile to ensure the correct flow of exhaust gases towards the silencer. PISTON Ø 63 The Ø 63 twin-ring piston has been calculated and optimised thanks to hours of testing in the test room. The piston has a profile designed to cope with the high temperatures developed in the chamber during operation, especially under the most demanding conditions. Allowing the piston to assume the correct cylindrical shape once the operating temperature is reached ensures a more uniform sliding surface on the cast iron cylinder. Thanks to this new profile, it has been possible to reduce the coupling clearance between the cylinder and piston to ensure better guidance in the reciprocating motion in the barrel and reduce rotation around the pin axis, thereby reducing the risk of seizure, a very dangerous and recurring phenomenon in high-performance cast iron cylinders. Even the metallic rattling, audible at idle speed and typical of this category of vehicles, has been significantly reduced. The double elastic band ensures correct piston sliding and, at the same time, a constant seal over time at the pressures developed in the chamber. HEAD The head has been completely redesigned, starting with the cooling fins, which are now curved and more sinuous, exposing a greater surface area to the air and maximising cooling. The head finning has also been inserted into the cavity between the head and the cylinder to generate a significant air flow that further mitigates the operating temperature. The result is pleasing to the eye thanks to its unique and original shape, achieved by the careful positioning of the fins, whose design is interrupted only where necessary, around the fixing holes for the stud bolts. The structure of the head itself has been thoroughly revised, increasing the mass to achieve unrivalled rigidity, combining lightness with the maximum possible length of the cooling fins and making full use of the space available from the conveyor. The inside of the head is hemispherical and machined with numerically controlled machines. The spark plug is positioned at a considerable angle, while remaining central. The kit includes two centring bushings to ensure perfect coupling between the head and cylinder, separated only by an O-ring. This solution, imported directly from the world of racing, guarantees maximum sealing and the greatest possible heat exchange, eliminating any type of gasket and therefore removing any barrier between the head and the cylinder. 3117676 Ø 63 mm Use Urban / sport Power range 14 / 22 Tuning level easy Recommended carburettorYes 24/24 phbh 30 Stroke 57 Compression ratio 1:10.5 No. of piston rings 2 No. of transfers 6 Head hemispherical Spark plug iw f 27