Polini has fully updated the famous cylinder kit for the neat Smallframe Vespas. The RACING Version comes with a newly designed head.
The cylinder is made of lamellar graphitic cast iron self lubricated and wear resistant. It assures better mechanical resistance. It reduces the engine working temperature and avoids possible loss of power.
The bore is 57mm, what equals to 130 cc with the standard stroke and 138 cc with the 54 mm stroked crankshafts. The cylinder layout is set by six 6 transfers.
The piston is gravity cast in light alloy with high silicon content.
THe new head design comes with two fins that better dissipates the heat both in the top and in the bottom. It improves the cooling and the compression ratio. It has a new copper gasket that eliminates the gasses escaping between the head and cylinder but allows the heat to transfer easier.
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