Polini, too, ventures into the cylinder classes above 70cc. With the BigEvolution 52mm, Polini introduces two cylinders, either with 84cc (which means with original 39.2mm stroke) or with 94cc (which requires a 44mm long-stroke crankshaft). The bore here is 52mm, i.e. 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 Evo4 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 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. For those of you who are thinking about using this cylinder in racing: so far there are no racing classes that allow this cylinder to be used. The Top Class ends with 90cc max. while the Maxiscooter Class starts with 100cc, so you will have to wait for next year.