Cylinder Kit MHR Testa Rossa 100cc RC-ONE (Flanged Mount)

The most powerful thermal unit ever produced by Malossi: over 32 HP at 14,000 RPM. With its large displacement and flanged design, this kit is exclusively for liquid-cooled scooters.

Specifically designed for top-level racing, it features the latest evolution of Malossi’s iconic 7-port technology. The standout feature is the support provided to the main rear transfer ports through the use of two ports opposite the exhaust, combined with the advantage of eliminating the space taken up by the through-studs, which are now shorter and positioned externally. This allows full utilization of the additional space provided by the flanged design.

The cylinder has a close deck structure paired with a redesigned modular head.

The head is designed to enter the cylinder’s combustion chamber, safeguarding the nickel coating in case of detonation.

To install this thermal unit, modifications to the RC-ONE engine case are required:

• In the boring area, to accommodate a crankshaft with an increased stroke and a longer connecting rod (specifically, a 47mm stroke and a 100mm rod);
• the transfer ports need to be further matched.

The volumes and flows have been revolutionized, to unleash all the power this cylinder has to offer. No compromises: a carburetor between 30 and 34 mm is necessary. To ensure perfect synergy and maximize on-road performance, the 100cc kit should be paired with our crankshaft, which has been renewed with a 100 mm connecting rod.

With this cylinder, the engine benefits from creduced loads on the pistons and bearings, thereby extending its lifespan. Additionally, friction is significantly minimized, resulting in increased engine efficiency, along with a notable reduction in noise and vibrations.

The exhaust system accompanying the 100cc kit is the result of targeted engineering, designed to enhance performance and perfect the fluid dynamics of the new Malossi cylinder.

How did we achieve this? By optimizing the exhaust port angle and implementing a custommade coupling.

Moreover, to ensure an effective connection to the exhaust pipe, we have developed an ingenious flange-coupling system, which attaches to the cylinder with three cylindrical head screws and an O-ring seal at the exhaust duct. This solution, simple yet highly effective, prevents any possible leakage from the thermal unit.

Technical features

• Cooling: H2O
• Porting: 7 transfer ports
• Material: Aluminum
• Bore: 52 mm
• Stroke: 47 mm
• Displacement: 100 cc