Polini has projected a new power unit for Minarelli and Piaggio engines exclusively dedicated to the on track races since it features an up-rated 52mm bore. It wants to satisfy many demands coming from riders and lovers who are willing to own a tuned-up engine able to give high performance during every driving conditions TECHNICAL FEATURES Light alloy die-cast cylinder “Closed Deck” system for internal flow of the coolant. 52mm bore – 44mm stroke – Connecting rod: 85mm – Displacement: 94cc Barrel with Nickel-silicon coating 5 transfer ports plus an exhaust port with booster design. The exhaust port optimises the gases scavenging. Distribution diagram is really performing The light alloy gravity cast piston with high silicon content has a chrome-plated "S10" cast iron segment. The light alloy gravity cast head features a combustion chamber with specific squish designed to eliminate any detonation problems. Solid crankshaft A REALLY SPECIAL CYLINDER KIT Before assembling the cylinder it’ s necessary to bore the cases both in the crankshaft and in the cylinder housing. It can be fitted together with the exhaust system specific for this cylinder and a crankshaft, 44mm stroke. Compatible with: - Aprilia: Area 51_S, Rally 50 LC_S, SR 50 Min.LC_S - Malaguti: F12 LC_S, F15 Firefox_S - Mbk: Mach G 50 LC_S, Nitro 50_S - Yamaha: AEROX 50_S