Cylinder Mallossi Alu. 80 CC one ring H20 for Engine Derbi euro 3 (D50BO)

CYLINDER KIT MHR modular head
The new MHR MODULAR-HEAD CYLINDER KITS are the natural evolution of the MHR MALOSSI line. The result of the research of its engineers, they have been a decisive factor in the victories of the official national and European teams in the cross and speed trophies. Malossi is happy to be able to guarantee that all riders taking part in the coming season National and European Trophies will have a product offering excellent quality and performance.

CYLINDER
- Material: special aluminium alloy with high percentage of silicon and titanium that guarantees exceptional strain strength even at high temperatures.
- Heat treatment: special quenching and stabilising treatment that gives the material increased toughness and strength, guaranteeing that mechanical and size specifications will remain unaltered for temperatures of up to 250 °C.
- Chip-forming machining: carried out on NC machining centres with extremely-limited size and shape tolerance (roundness, perpendicularity).
- Inner surface coating: effected using silicon carbide on a nickel matrix with heat treatment that guarantees extreme hardness (around 600 HV0, 1/5) and excellent resistance to wear.
- Internal machining of cylinder: using special machines that allow a degree of finish on the cylinder barrel walls whose roughness corresponds with the angles set at the design stage (grinding process using special stone).
- Port and exhaust diagrams: designed and manufactured especially for racing. The definition of the port and exhaust diagrams has requested considerable effort on the part of our engineers both on engine test stands and the circuits on which the trophy is held.

PISTON
- Material: special aluminium alloy with a very high percentage of silicon and titanium that guarantees both excellent heat resistance and strain strength upon temperature variation.
- External coating: graphite coating that guarantees a very low friction coefficient.
- Structure: reinforced in order to offer resistance to the stress suffered by cylinder units used for top-level competition, but at the same time light enough to reduce inertial force. 

PISTON RING
Ring in very strong modular cast iron with ground, wear-resistant, hard chrome metal-spray coating on the contact surface.

HEAD
The new Malossi modular head has been specially created to guarantee elimination of the notable amount of heat that develops in an engine with a very high specific horsepower designed for racing. 
It consists of a head in special hardened and tempered aluminium alloy with high silicon content that is fixed directly to the cylinder barrel. It is lapped over its entire outer surface by the coolant thus guaranteeing a very large heat-exchange surface. In addition, being unattached to the internal walls it is free to follow the expansion of the cylinder.
The combustion chamber is entirely manufactured using numerical control machines in order to ensure shape and size tolerances to within just one hundredth of a millimetre.
The modular head system is completed by a cover that closes off the upper part of the cylinder, thus guaranteeing that the coolant is fully sealed. 
The geometry and cross-section of the combustion chamber for this cylinder unit have been specially designed for use in the Scooter Speed Trophy and Scooter Cross Trophy.