Polini cylinder kit Big Evolution 70

Code: 166.0110

The Polini Big Evolution cylinder kit consist of a cylinder in heat treated aluminum to make it non-deformable, the head surface is nickel-plated to prevent the triggering of detonations, CNC machined with centesimal tolerance, so as to have a perfect cylinder / head coupling increasing the durability of components. There are 5 transfer ports plus an exhaust port with crosspiece to improve the elimination of burnt gases. The piston is made of light alloy cast by gravity with a high silicon content with a cast iron segment, ground and lapped, the head is also made cast by gravity, the mechanical resistance can thus be compared to that of a head made from solid.

NB: To assemble the Big Evolution Kit, it is essential to bore the crankcase and replace the crankshaft with the new Polini complete with 85 mm connecting rod specific for each model.

Features:

• Specific for: Benelli 491RR/Racing/Sport 1997> 2T water cooled
• Bore:47,6
• Stroke: 39,2
• Displacement: 69,76
• Compression ratio: 15,6:1
• Material: Aluminum
• The kit must be mounted exclusively with Polini crankshaft COD. 210.0022