Cylinder Kit LC Polini Big Evolution 84cc Piaggio

Polini is also venturing into the cylinder categories above 70cc. With the BigEvolution 52mm, Polini is introducing two cylinders, either 84cc (i.e., with a stock stroke of 39.3mm) or 94cc (which requires a 44mm long-stroke crankshaft). The bore here is 52mm, 2mm larger than Malossi's BigBore cylinders, which is practically the maximum you can go before having problems with the cylinder studs. The external shape is the same as that used for the new Evo IV cylinders. In terms of performance, the 84cc version should be on par with the 70cc cylinder, with significantly more torque. If you want more and aren't afraid of crankcase rework, we recommend the 94cc version in conjunction with a 44mm long stroke crankshaft with an 85mm connecting rod, which will deliver performance in the upper 20hp region.

Polini also ventures into the cylinder classes above 70cc. With the BigEvolution 52mm, Polini introduces two cylinders, either with 84cc (which means with original 39.3mm stroke) or with 94cc (which requires a 44mm long-stroke crankshaft). The bore here is 52mm, ie 2mm more than Malossi's BigBore cylinders, which is basically as far as you can go before you get into trouble with the cylinder studs. The outside shape is the same as the one used for the new Evo IV cylinders. Performancewise, the 84cc version should be on one level with the 70cc cylinder, with noticeably more torque, though. If you want more and don't mind re-working the crankcase, we recommend the 94cc version in conjunction with a 44mm long-stroke crankshaft with 85mm connecting rod, which will yield performance in the upper 20hp region.