Malossi MHR TEAM aluminum thermal unit D 50 77cc dismountable head Derbi D50B

The Malossi MHR TEAM Ø 50 thermal unit is a high-quality and high-performance product, ideal for riders who want to participate in national and European competitions. This new thermal unit is the natural evolution of the Malossi MHR line and has contributed to the victories of official teams in cross and speed trophies.

The cylinder is made of a special alloy of aluminum with a high percentage of silicon and titanium, which guarantees high resistance to high temperatures. Thanks to a special heat treatment, the material maintains its mechanical and dimensional characteristics constant up to temperatures of 250°C. The chip removal processes are carried out with very tight dimensional and shape tolerances, guaranteeing a high-quality finish. The internal surface of the cylinder is coated with silicon carbides on a nickel matrix, which gives the material high hardness and remarkable wear resistance.

The piston is made of a special alloy with a high percentage of silicon, which guarantees resistance to heat and resistance to temperature variations. The external tin coating reduces friction. The structure of the piston is reinforced to withstand the stresses of a competition thermal unit, but at the same time, it is lightweight to reduce inertia forces.

The ring is made of spheroidal cast iron with high mechanical resistance, with a hard chrome anti-wear coating.

The removable Malossi head has been specifically designed to ensure the disposal of heat generated by a high-power engine intended for competition. It consists of a head made of a special aluminum alloy directly attached to the cylinder barrel, which is cooled by the coolant on its entire outer surface. This ensures a high heat exchange surface. Furthermore, being detached from the outer walls, the head can follow the cylinder's expansions. The combustion chamber is made with millimeter precision thanks to the use of numerical control machines. The removable head system is completed with a cover that ensures the sealing of the coolant. The geometry and squish of the combustion chamber have been specifically designed for use in the Scooter Speed Trophy and Scooter Cross Trophy.