Piston -GRAND SPORT- Vespa GS150 / GS3 150cc (1959-) -

Grand Sport pistons are special pistons manufactured in small series, with significantly better material properties than their original counterparts.
They are manufactured in Italy and offer the advantage of a higher silicon content (18%) than conventional pistons. This makes them thermally stable and very durable.

Some special versions also have thin and extremely stable steel piston rings. These have a clear advantage over cast piston rings in terms of break and speed safety and torsional stiffness. A nice feature for cylinders whose outlet should be much larger.