The all-new POLINI 177cc aluminium race cylinder is the return of a tuning legend, with a fresh lightweight concept. Unlike its cast-iron predecessor the newcomer is constructed using aluminium combined with a very robust bore lining material. The more complicated manufacturing process of this type of cylinder provides this Vespa largeframe all-round performer with greater thermal stability and longevity.

Alongside their choice of aluminium POLINI also included a few other new features. The cylinder head design provides the choice between using a centrally-located spark plug or the standard offset position. A blanking screw for the spark plug thread not in use is included in the kit. The cylinder head is also equipped with eight fixing points, ensuring sufficient compression without mechanical tension.

The outlet port has also been redesigned and the exhaust manifold stub is made of steel and is screwed into place. This makes it not only much tougher and replaceable, but also much easier to modify once removed.

The 63mm diameter piston has two 1mm thick steel piston rings and the port layout, with 5 transfer ports and a single exhaust port, is traditional. This cylinder kit is conceived for use with a 57mm stroke crankshaft.

According to the engine this racing cylinder mounted on a taller primary drive is often useful.