Constantly refined over the years, the legendary cast-iron cylinder kits for Vespa have now a new code, after undergoing further upgrade concerning above all the main and rear transfer ports, the exhaust port and intake port, this latter considerably increased in its dimensions.

It is the one and only cylinder kit of its kind using an o-ring as sealing gasket between head and cylinder, in order to guarantee better sealing and heat dissipation.

By improving torque at low RPMs, this cylinder kit further increases performance.

The head has been heavily revised, starting from the cooling fins, which are now curved and more winding, exposing a greater surface area to the air and maximising the cooling effect. The head fins have also been inserted into the cavity between the head and the cylinder to create significant air flow, capable of further improving operating temperature. The result is pleasing to the eye for its unique and original shape thanks to the precise positioning of the fins, the design of which only stops when absolutely necessary, at the holes for inserting the fixing screws.

The very structure of the head has been revised, increasing the mass to obtain record rigidity, bringing together lightness with maximum possible cooling fin length, and making most use of space freed by the conveyor. The inside of the head is hemispherical and is worked with digitally controlled machines. The position of the spark plug is noticeably inclined, even though remaining in the centre.

The kit contains two centring bushes to guarantee perfect coupling between the head and the cylinder, only separated by an O-ring. This solution, which comes straight from the world of competition racing, guarantees maximum hold and maximum possible heat exchange, eliminating almost all kinds of seal and so removing all barriers between the head and the cylinder.

With this development Malossi technicians went beyond all expectations once again!

Cast-i-cylinder kit ø 61

Cylinder

• Material: special self-lubricating, wear-resistant, highly refined cast iron alloys, obtained by Shell Moulding gravity die-casting.
• Machining: on numerically controlled high precision machine tools.
• Recalculated and increased heat exchange surfaces.
• Exhaust and transfer ports designed and tuned for maximum thermodynamic performance.
• Dimensional and surface finish quality control performed according to Malossi’s internal specifications.
• Cylinder and piston selected for a 100% fit of 0.010-0.005 mm.
• Checking of all the seals carried out.

Piston

• Material: special aluminium alloy with high silicon content and low thermal expansion.
• Machining: on numerically controlled machine tools.
• Lightened and strengthened.
• Heat exchange surfaces increased.

Piston rings

• Piston rings in very strong modular cast iron with ground, wear-resistant, hard chrome metal-spray coating on the contact surface.

Head

• Material: special die-cast aluminium alloy.
• Geometry of heat exchange surfaces recalculated and increased.
• Machining: numerically controlled high precision machines with diamond tools.
• Surface rust prevention treatment.
• Viton Head Gasket.
• Hemispheric combustion chamber with centred squish and spark plug.

 

3117181	Ø 61 mm
Use	Urban / sport
Power range	14 / 22
Level of elaboration	easy
Carburettor recommended	Si 24/24 phbh 30
Stroke	57
Compression ratio	1:10,5
N° piston rings	2
N° ports	7
Head	Hemispheric
Spark plug	Iw f 27



 

Product reserved exclusively for competitive use in areas designated for competitions, according to regulations stipulated by the relevant sporting authority. We do not accept any liability for improper use.