THOR 202

Polini Thor 202 whose tuning was optimized to assure more thermal stability, is now available with two carburetor variants, Dell’Orto and Tryton.

Polini Thor 202 has 33hp, weights 16,8kg only presents now a new muffler with new geometries for the advance timing and it is also available with the Tryton carburetor.

These novelties improve the performance stability, reduce the sensitivity to fuels with low octanes and to weather and altitude changes.

The cylinder
The core of the engine is the cylinder that has been 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 130cm propeller installed.
The muffler
2 stroke engines are in Polini’s DNA. Thanks to experience acquired by the factory during years of studies and researches, it has been possible to manufacture a brand new exhaust system.

The new expansion is light and with compact size. Thanks to the hard work on the tests, it has been possible to find the perfect union between expansion and gas flows: the result is a muffler that assures a stable and progressive power output at all the rpm. It is installed to the engine with a granted system that assures free movements and reduced vibrations.

Another improvement comes from the connection that it’s positioned to one third of the muffler itself and it is made of a spherical coupling that allows free movements and extends the life of the muffler.

Tryton carburetor

The Tryton carburetor reduces the sensitivity to weather and altitude variations, thus ensuring more engine stability at atmospheric pressure and it offers excellent performance event during hard environmental conditions. The smooth power output, thanks to an uniform and constant fuel flow, assures optimal combustion with consequently the optimization of the consumption. In addition, the carburetor sealing makes the carriage easier, preventing fuel leakage even with the engine tilted.

The consumption is of 2,5liters/h at 5000rpm that corresponds to 30kg of static thrust, average value at flat flight with a 130cm propeller (evidence on the standard setting at sea level and  improvable during competitions).

Dell’orto carburetor

VHST 28mm Dell’Orto carburetor has allowed to refine the carburetion setting, granting flowing performance.

The main features are: low consumption thanks to the efficient Venturi effect. The consumption is of 2,4 liters/h at 5000rpm, which corresponds to 30kg of static trust, average value at flat flight with a 130cm propeller (evidence on the standard setting at sea level and improvable during competitions).

This carburetor can be equipped with the Polini choke control to be able to activate the choke even when wearing a harness.

Thanks to these advantages and different settings options, Dell’orto carburetor will satisfy the needs of all the pilots thanks to its high precision, fluidity and power output, together with very low fuel consumption.

Air box

The new air filter is the result of a deep fluid dynamic study that has the aim to optimize the air speed inside it to grant the perfect pressure to feed the carburetor at every rpm. By reproducing a S circuit that stabilizes the turbulences, the new filter lets a linear, sweet and constant output. It is possible to open and check it; inside there is a supporting  frame for its filtering carpet made of polyurethane foam with open cells of 30 PPI (holes per inch): this supporting frame has been designed to have a fixing able to prevent the carpet from moving or collapsing on it. Furthermore the filter cage can be opened in a half through two screws to be easier to replace it during standard servicing.

The new filter has a modern design and it is more compact compared to the previous versions: thus it is 45mm closer to the engine, reducing the aerodynamic resistance when flying.
Cooling system and water pump

The cooling is granted by a 16-component compact radiator with reduced size of 300x170mm and it has been designed to avoid using the expansion tank.
The cap is provided with a 1,4 bar valve to let the system self-regulate the expansion of the liquid inside it without weighting on other parts. Tank and its parts omission contributes to aerodynamic and to the reduction of the whole weight.
With a great attention to the look, the pipes chosen are made of blue silicon that, besides having and attractive color, they grant longer life.

Reed valve

The engine is equipped with reed valve with direct intake in the engine crankcase. The reed valve, designed by Polini R&D department, has been conceived to optimize the performance. This result can be achieved thanks to the use of 6 carbon fiber reeds with calibrated elasticity to react uniformly at all RPM.

Engine crankcase

Thor 202 crankcases are die cast in aluminum with high silicon content: thanks to this alloy and to the production process during all the phases (starting from the foundry, passing through the painting, to the mechanical working on sophisticated CNC machines), it is possible to achieve stable and long lasting mechanical performance matched to a reduced weight.
The design of the crankcase has been optimized to be complete and reinforced where more stressed, increasing the TBO up to 300 hours.

Crankshaft

The choose of the best steels and thermic treatment together with a perfect centering, eliminates vibrations due to unbalancing that during the time should drive to premature worn or structural failure.
Thanks to the CNC machines and to the use of measuring tools of last generation, the dimensions stay inside pre-arranged tolerances. Moreover the bearings are of very high quality and are placed on the coil and crankcase.

Countershaft, gear and clutch

In the front crankcase there is the housing of the centrifugal clutch system, the mechanical reduction and the balancing countershaft, all in oil bath.
The centrifugal clutch allows the propeller to be static when the engine is to minimum rpm and maximizes the safety for the pilot in the pre-flight stages.

The mechanical gear has helicoidal teeth: this system inverts the revolution way of the propeller respect to the crankshaft, softening the overturning torque.
The balancing shaft reduces the vibrations coming from the unbalancing generated by the piston swinging that, passing through the BDC and TDC, moves the mass at every single rotation circle of the engine, thus granting the maximum flying comfort.

Electronic ignition

Thor 202 is equipped with an inductive electronic ignition: more compact and light compared to the model installed on Thor 200 HF  it lets the reduction of the engine distance of 16mm, making the engine more compact.

Flash starter

Thor 202 is equipped with the latest version of the well known Flash starter, system that grants an easy engine starter.
The critical points of the last version of the flash starter have been reinforced, improved the centering to extend its life. An ergonomic handle lets a safer and stable grip during the starting.

Fixing system

Polini Motori has decided to maintain the same fixing points on all Thor engines. A choice for the manufacturers and pilots benefit.
Manufacturers may produce a frame that can house the entire range of Thor engines, thus reducing significantly production costs and timing.

Pilots can replace  the Thor engine without replacing or modifying the frame.
Thor 202 is sold together with all the parts necessary to install it, already assembled and ready to be assembled on the frame very easily.

928.000.090 –Thor 202 with Dell’Orto carburetor – Euro 2.560 + VAT
928.000.094 –Thor 202 with Tryton carburetor – Euro 2.660 + VAT

THOR 202

THOR 202 WITH TRYTON CARB.