Malossi cast iron thermal unit D 47 75cc

The Malossi Ø 47 thermal unit is a high-quality product designed to improve the performance of Piaggio Ape 50cc, Vespa PK, PK HP, PK XL, and Special 50cc engines.

The cylinder is made of special self-lubricating cast iron alloys, which guarantee a high degree of refinement and wear resistance. Its processing is carried out on high-precision CNC machines, ensuring a perfect shape and roughness according to Malossi standards.

In addition, the heat exchange surfaces have been recalculated and increased, while the exhaust and transfer ports have been designed to achieve maximum thermodynamic efficiency.

The coupling between the piston and the cylinder is guaranteed 100% in selections of 0.010-0.005 mm, while dimensional and hydraulic seal checks are carried out with precision.

The piston is made of a special aluminum alloy with a high silicon content and low thermal expansion, lightened and reinforced to improve performance. The heat exchange surfaces of the piston have also been increased.

The segments are made of high-strength spheroidal cast iron.

The head of the thermal unit is made of a special die-cast aluminum alloy, with recalculated and increased heat exchange surface geometry. The processing is carried out on super precise CNC machines with diamond tools, ensuring excellent quality. The head is also treated with an antioxidant coating for increased durability over time.

The compression seal is guaranteed by a Viton gasket, while the combustion chamber is hemispherical with squish and a central spark plug.

SPECIFICATIONS

• Displacement: 74.60
• Usage: Urban / Sport
• Power Range: 6/8
• Tuning Level: Easy
• Recommended Carburetor: Shb 16 - shb 19
• Stroke: 43
• Compression Ratio: 12.5:1
• No. of Rings: 2
• No. of Transfers: 6
• Head: Hemispherical
• Spark Plug: Central iw f 24
• Piston: Aluminum alloy 21%