Thermal Group Ø 63 aluminum
Use Sport
Power Range 18 / 25
Processing level easy
Recommended carburetor Phbh/Vhst 28
Stroke 57
Compression ratio 1:10.8
No. segments 2
N° decanting 7
Hemispherical head
Spark plug iw 27

Caution:
it is absolutely essential to use fuel taps with increased flow rate.

The completely new thermal unit is born and designed in every part to achieve maximum results in terms of performance and durability. Every aspect of the system has been studied to maximize mechanical strength, fluid dynamics and improve combustion: the result is a top-of-the-line kit in terms of construction quality and technological advancement.

Technical features

Cylinder
Made completely from scratch from high-strength aluminum alloy and nickel-chrome coated barrel. Consisting of a constant-thickness central core around the barrel and transfers, it ensures constant heat exchange, thus a controlled chamber gas inlet temperature and optimal exhaust heat exchange.It has aerodynamically profiled cooling fins around the core designed to be penetrated with the best possible efficiency by cooling air. The biggest innovation is the completely revised and updated transfer case, introducing the CVF according to the latest upgrades gained from racing experience. The transfers have now been increased to 7, a distinctive feature of Malossi kits, thanks to which it has been possible to achieve the best fluid-dynamic performance.
The connection to the muffler is allowed by a flange-connector assembly attached to the cylinder by means of 4 cap screws and an Oring seal to the exhaust port inserted to prevent any leakage from the thermal unit. With this extremely simple system in assembly, it is possible to accommodate all types of mufflers on the market with a Ø 37 port with maximum resistance, avoiding any problem of unscrewing or rotation due to vehicle vibration.
On the other hand, the connection with the head is now made by means of high-precision centering on the support planes obtained with numerically controlled machines. A set of multi-thickness base gaskets is provided to allow the user to adjust the compression by adapting it to a wide variety of uses.

Piston
Cast with an innovative material, consisting of a steel core coated with an alloy of aluminum and silicon, which confers extreme lightness as well as excellent corrosion resistance, even at high temperatures and reflection of heat derived from combustion, the heat flow is then directed toward the dissipation surfaces favoring the cooling of the combustion chamber and maintaining it within the optimal temperature range. On the inside of the shell it has ribs immersed in the casting with which the proper strengthening in the most mechanically stressed areas has been achieved while allowing maximum piston lightening. On the other hand, the windows in the back and the diametrical recesses ensure the maximum possible inflow of fresh charge to the cylinder racks.

Head
Another revolution in 2-stroke engine design philosophy: the cooling fins have been sized to optimize heat flow from the chamber to the outside but are now also profiled according to modern simulations to allow the maximum possible penetration of air from the cooling system, which now laps the head with an efficiency increase of more than 10 percent over a conventional straight fin system.
The characteristic hemispherical-profile combustion chamber is machined to tenth-of-a-millimeter tolerances and develops highly turbulent combustion, with pressure peaks calculated at the most suitable engine speeds for maximum performance in terms of torque and power.The very high temperatures that are reached in this particular boundary area between the head and cylinder that are often the source of hot spots and detonations are regulated thanks to an aerospace-style solution: a vacuum chamber duct made with two bulkheads and a series of inlet and outlet baffles. Which convey, thanks also to a precise surface profile, a part of the cooling air forcing it not only to lap the surfaces but also to expand decreasing, thanks to a precise physical principle the pressure and therefore the temperature of the walls bordering the combustion chamber.