With the 133 Evolution Polini Motori presents a completely new development. The cylinder is made of aluminium with Nikasil coating. With 57 mm bore and 51 mm stroke, 133 cc displacement is available. The timing is 124° overflow to 179° exhaust. The layout is determined by six overflows. This is a completely new design with fat volume. The exhaust shape is also new. The exhaust is 38mm wide, which is 68% chord measurement. The stud spacing (M8) is 56 mm and there is plenty of meat for further tuning. The piston comes with two 1.5mm thin piston rings. It is coated to ease the break-in period. The head is made of cast aluminum with a high silicon content. In addition, it has additional cooling fins on the underside. This allows the heat to be dissipated much better, both from the cylinder itself and from the head. The compression was also slightly adjusted and the head is sealed with a copper gasket.
DE | €
