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Polini Thor 202 is born from the experience acquired with Thor 200 and from the demand of the market for a powerful and lighter engine that at the same time grants more thermal stability. The solution adopted by Polini’s technicians is the liquid cooling system, technology tested for many years on the Thor 250.

Particular attention has been given to the aesthetic and aerodynamic aspects, with a modern, compact airbox design. The highly powerful cylinder guarantees maximum performance.

The Cylinder
The core of the engine is the cylinder, designed and manufactured with last-generation details. The real displacement is 205cc with 66mm bore and 60mm stroke. The cylinder has 5 transfers to give precise performance and fast output, able to offer more than 90kg of static thrust with a 130cm propeller installed.

The Muffler
2-stroke engines are in Polini’s DNA. The new expansion exhaust is light and compact, tuned to find the perfect union between expansion and gas flows for a stable, progressive power output at all rpm. It is installed with a system that assures free movement and reduced vibrations, with a spherical coupling positioned one third along the muffler that extends its life.

The Carburetor
The new Thor 202 is available with the Dell’Orto VHST 28mm carburetor. It delivers flowing performance with low consumption thanks to an efficient Venturi effect: 2.4 liters/h at 5000rpm, corresponding to 30kg of static thrust at level flight with a 130cm propeller. The design makes it less sensitive to changes in atmospheric pressure, humidity, and altitude, and it can be equipped with the Polini throttle control.

Air Box
The air filter is the result of a deep fluid-dynamic study to optimize air speed and feed the carburetor at every rpm. An S circuit stabilizes turbulence for a linear, constant output. The filter uses polyurethane foam with 30 PPI open cells, opens in half via two screws for easy servicing, and sits 45mm closer to the engine than previous versions, reducing aerodynamic resistance.

Cooling System and Water Pump
Cooling is granted by a 16-component compact radiator (300x170mm) designed to work without an expansion tank. The cap has a 1.4 bar valve to self-regulate expansion. Omitting the tank aids aerodynamics and reduces weight. Blue silicone pipes grant longer life.

Reed Valve
Direct intake into the crankcase via a reed valve designed by Polini R&D, using 6 carbon fiber reeds with calibrated elasticity to react uniformly at all rpm.

Engine Crankcase
Die-cast aluminum with high silicon content for stable, long-lasting performance at reduced weight. Optimized and reinforced where most stressed, increasing the TBO up to 300 hours.

Crankshaft
The best steels and thermic treatment with perfect centering eliminate vibrations from unbalancing. CNC-machined to tight tolerances with very high quality bearings.

Countershaft, Gear and Clutch
The front crankcase houses the centrifugal clutch, mechanical reduction, and balancing countershaft, all in oil bath. The centrifugal clutch keeps the propeller static at minimum rpm for pre-flight safety. Helicoidal gear teeth soften the overturning torque, and the balancing shaft grants maximum flying comfort.

Electronic Ignition
Thor 202 uses an inductive electronic ignition, more compact and lighter than the Thor 200 HF, reducing engine length by 16mm.

Flash Starter
Equipped with the latest Flash starter, reinforced at its critical points for a longer life, with an ergonomic handle for a safe, stable grip.

Fixing System
Polini maintains the same fixing points across all Thor engines, so one frame houses the entire range. Pilots can swap Thor engines without modifying the frame. The 202 ships assembled with all parts necessary to install it.

*Values detected at sea level, standard atmosphere. Thrust and consumption may vary with air temperature and density.