Crankshaft SIP PERFORMANCE 24810 - 19959

High end crankshaft for Vespa fenderlight models. Highest quality for a perfect revision and a motor with maximum reliability and low vibration.

Together with the cylinder and piston, the crankshaft represents the beating heart of any internal combustion engine. It is amongst the hardest working components and the conversion of the pistons stroke to a rotary movement places the highest demands on both quality and the care taken during construction. The crankshaft should also be well balanced to reduce any unwanted vibrations and the oscillating mass kept to a minimum to support an efficient delivery of the power created by the motor. The big-end bearing rotates at the same rate as the motors RPM, receives lubrication from the petrol/two-stroke oil gas mixture and must withstand two abrupt changes in direction of the piston for each motor revolution. The crank-pin, connecting both crankshaft webs with the con rod, has to be pressed into the webs with a certain clearance to the openings in the webs. If this connection is not strong enough the crankshaft can twist and the crankshaft webs become misaligned and seize. To ensure the big end bearing receives sufficient lubrication the big end of the con rod should be provided with slots to facilitate this.

The SIP crankshafts:

This all-new range of performance crankshafts are produced for SIP in Italy and satisfy all of the above listed demands. We have concentrated our efforts to provide the highest quality combined with tried and tested technological features. Each crankshaft is balanced specifically to suit the stroke, con rod length and model of scooter for which it is intended.

The crankshafts available in this range can be split into two main types. The 'Premium' are equipped with a 'standard' high end con rod type, meaning that its surface finish remains unmodified. It is provided with lubrication slots and holes, for the big and small end bearings respectively.

The 'Performance' crankshaft models include a con rod of extremely high quality and they are made more enduring with an intensive polishing procedure that provides a more stable molecular structure. The smooth polished flanks of the con rod also help reduce turbulence. The polished con rods also have been optimised with a reduction in weight. They possess a gas-flowed profile and been modified around the big end to improve the bearings lubrication.

The crankshafts for the Vespa 150 VB1T / VGL1T / VL1-3T models:

For the engines of the very early fenderlight models we also offer crankshafts of the highest quality as original replacement. We offer both 54mm stroke, as well as the 57mm stroke version in premium quality. In addition, the 57mm stroke version is also available with the high-quality Performance connecting rod. All variants have generous cooling slots for the high-quality needle roller bearings, top and bottom.

Conclusion: The better replacement for the original crankshaft.

Our recommendation - SIP-TIP:

• When replacing the crankshaft always change the bearings and oil seals.
• Very useful are the crankshaft tools # 27338000, # 21071000 and # 18119000.

This crankshaft requires on the flywheel side the woodruff key of the Vespa GS 150, art. no.: 87071000.