After the great success of the Piaggio crankcases, Malossi completes the work: from today the aluminum thermal units Ø 47 BIG D.E.P.S. are available again!

The only cylinders on the market for HELLO / SI with split exhaust and symmetrical transfer ports !!!!

The drain connection is screwed on and offers two great advantages:

Extreme resistance and possibility of replacement in case of breakage
Possibility of increasing the exhaust outlet, further increasing performance
These results were made possible by the decompressor valve supplied in the kit which is smaller than the original Piaggio one.

The head has a central hemispherical combustion chamber.

Malossi BIG D.E.P.S. represent the ultimate balance between performance and component life! I BIG D.E.P.S. have been designed and manufactured with the precise aim of obtaining thermal units capable of guaranteeing high reliability together with the improvement of internal thermo and fluid dynamics systems.

Thanks to the experience acquired in the preparation of racing engines, Malossi technicians have brought the thermodynamics of the aluminum thermal units to the highest levels and taken care of the internal fluid dynamics of the thermal unit (see the transfer, exhaust and combustion chamber ducts ), obtaining a high turbulence in the combustion chamber which has made it possible to significantly reduce specific consumption and drastically reduce polluting emissions from the exhaust.

Technical features

Split exhaust
Symmetrical transfers
Head with central hemispherical combustion chamber
Reduced size decompressor valve
Distribution: 6 ports
Cylinders obtained by gravity casting in specific steel shells.
Material: primary alloy of aluminum with a high content of tempered and stabilized silicon.
Machining on high precision numerically controlled machine tools.
Barrel with silicon carbide coating in a galvanic nickel matrix and crossed smoothing with diamond passages with very tight tolerances.
Recalculated heat exchange surfaces.
Exhaust and transfer ports designed and tuned for maximum thermodynamic performance.
High mechanical resistance spheroidal cast iron segments with hardened wear-resistant chrome plated and lapped on the contact surface.
Dimensional checks of shape and roughness.
Piston cylinder coupling: selections of 0.010-0.005mm.
100% control of hydraulic seals.
2 muffler fittings; oversized Ø 27 - standard Ø 22.