Malossi MHR crankshaft 15 pin 97 connecting rod 51 stroke 19 rotary valve

The Malossi crankshaft is a delicate and important component for the Vespa engine. It manages the movements of the connecting rod and piston and regulates the intake through the phasing of the semi-shoulder.

The Malossi crankshafts for Vespa are made of high-quality hardened steel used in aeronautics and vacuum cast, a material highly resistant to scratches. The connecting rod has a shape designed to minimize weight and ensure all the necessary rigidity. The threading of the transmission side shaft of the crankshafts has been improved to increase strength, while the position of the key has been revised to not affect the threading and contribute to the strength. The crankshafts are supplied with special, more resistant nuts.

There are different lengths of connecting rods available for small frame Vespas on which the full shoulder crankshaft will be installed. The crankshaft dedicated to engines with rotary valve intake has a standard stroke and connecting rod length. The intake phase has been obtained inside the semi-shoulder, ensuring extremely effective fluid dynamics. For proper balancing, Malossi has included tungsten inserts in the crankshaft used as counterweights to increase stability.