VMC 177cc Crono with 57 mm stroke and 63 mm bore.

Traditionally, there are many racing cylinders for the Vespa largeframe models with the small 125cc and 150cc engine blocks. In addition to many large, well-known manufacturers, small manufacturers are also revitalising the market and selection. The VMC is a low-priced alternative in the 177cc racing cylinder market. It is made of aluminium with a coated raceway. It has 4 overflows, 3 boost ports and a three-piece exhaust.

• 3 split outlet 
• Cylinder head CNC machined
• Bolted exhaust

Like most racing cylinders in this segment, the Crono has a bore of 63mm. It is intended to use a crankshaft with 57mm stroke and a 105mm connecting rod. As delivered, the cylinder has 120° overflow time and 176° exhaust time.

The cylinder head is CNC manufactured, is sealed with an O-ring, is centred and is screwed 8-fold. The bolting of the cylinder is separate from that of the head. The stud bolts do not go through the cylinder and the head at the same time. Recommended crimp is 1.3mm (+/-0.1mm). Foot gaskets of different thicknesses for adjusting the squeezing edge are included in the delivery. The exhaust flange of the VMC cylinder is screwed to the cylinder with 4 screws, is made of steel and is sealed with an O-ring.

Conclusion: Modern cylinder with a good price-performance ratio.