The Polini Thor 202 engine was born from the experience gained with the Thor 200 engines and from the request for a more powerful and lighter engine which at the same time guaranteed greater thermal stability. The solution adopted by Polini technicians to achieve all this was to use liquid cooling, a technology tested on the award-winning Thor 250.
Polini Thor 202: 33 horsepower in just 16.8 kg of weight. The torque curve optimized at each rotation speed guarantees power and low consumption. The balancing countershaft and powerful liquid cooling system ensure greater flight comfort and reliability.
Particular attention was paid to the aesthetic and aerodynamic aspect, designing and creating an airbox with a modern design and small dimensions. The high-performance thermal unit always guarantees maximum performance.
The heart of the engine is the thermal unit specially designed and created with the latest generation features. The actual displacement stands at 205 cubic centimeters with a bore of 66mm and a stroke of 60mm. The cylinder is equipped with 5 inlet ports to ensure precise performance and fast delivery capable of offering over 90 kg of static thrust with a 130 cm propeller.
2T engines are in Polini’s DNA. Thanks to the experience gained by the company over years of studies and designs, it was possible to create a new exhaust system.
It is characterized by a totally new expansion concept, which makes it more compact and lighter. Thanks to extensive testing work, it was possible to find the perfect combination between expansion and gas flows: the result is a muffler that ensures stable and progressive delivery at all speeds, with fixing to the engine guaranteed by the suspension system that ensures freedom of movement by dampening all vibrations.
A further improvement is given by the revisiting of the joint, positioned one third of the muffler itself, and composed of a spherical joint which allows complete freedom of movement, further guaranteeing the durability of the exhaust.
The new Polini THOR 202 is equipped with an Orto carburettor.
The 28 MM Dell’Orto VHST carburetor allowed the carburetion setting to be perfected, guaranteeing smooth performance.
The main features are the very low consumption due to a very effective Venturi system: consumption is 2.4 liters per hour at 5000 RPM, which corresponds to approximately 30 kg of static thrust, average level flight value with a 130 propeller cm (data collected on standard settings at sea level and which can be improved in a competition setting).
The particular design makes it much less sensitive to environmental changes in atmospheric pressure, humidity and air pressure, ensuring greater stability to variations in latitude/longitude and altitude and reducing any setting interventions to a minimum. This carburettor can also be equipped with the Polini starter control to be able to operate the air starter even from a harness.
Thanks to all these advantages, combined with various setting possibilities, the Orto carburettor will be able to perfectly satisfy the needs of all pilots, thanks to the very high precision, fluidity and power delivery, combined with very low fuel consumption .
The new air filter is the result of an in-depth fluid-dynamic study which aims to optimize the speed of the air inside it to guarantee the ideal pressure to feed the carburettor at every rotation speed. Reproducing an S-shaped circuit that stabilizes turbulences, the new filter allows linear, smooth and constant delivery. Completely openable and inspectable, inside there is a support frame for the new 30 PPI (pores per inch) open cell polyurethane foam filter mat: this support frame is designed to have a fixing capable of preventing over time to the mat from moving or collapsing on itself. Furthermore, the filter box can be opened in two halves with just two screws, making it easier to replace during routine maintenance.
The new filter boasts a modern design and is more compact than previous versions: this means that it is located 45 mm closer to the engine: this decreases aerodynamic drag during flight.
Cooling system and water pump
Cooling is guaranteed by a compact 16-element radiator measuring just 300 x 170 mm and has been designed so as not to require an expansion tank.
The cap is equipped with a 1.4 bar valve which allows the system to self-regulate the expansion of the liquid inside without weighing on the other components. The exclusion of the vessel and its components contributes to aerodynamics and a reduction in overall weight.
With a view to greater attention to design, pre-shaped blue silicone hoses were chosen which, in addition to making the engine colorful and attractive, guarantee greater durability of the hoses over time.
Reed valve pack
The engine is equipped with a reed valve with direct inlet into the engine crankcase. The reed valve pack, expressly designed by the Polini R&D department, is designed to maximize performance. This result is achieved thanks to the use of 6 carbon fiber blades with calibrated elasticity to react uniformly at all rotation speeds
The Thor 202 crankcases are made of die-cast aluminum with a high silicon content: thanks to this alloy and to the production process controlled during all phases (starting from the foundry, passing through painting and then arriving at the mechanical processing on sophisticated CNC machines), stable and long-lasting mechanical performance combined with low weight is achieved.
The design of the crankcases has been optimized to be essential and reinforced at the points of greatest stress, extending to a good 300 hours of TBO.
The choice of the best steels and heat treatments, combined with perfect centering, eliminates parasitic vibrations due to unbalances which over time could lead to premature wear or failure.
Thanks to the aid of numerical control machines and latest generation measuring instruments, the dimensions are maintained within pre-established tolerances with maximum perfection. The whole thing is completed by high-quality bearings positioned on the connecting rod and in the engine crankcase.
Countershaft, reduction gear and clutch
In the front half crankcase there is the housing of the centrifugal clutch system, the mechanical reduction and the balancing countershaft, all in an oil bath.
The centrifugal clutch allows the propeller to remain immobile when the engine is at idle and to maximize safety for the pilot in the pre-flight phases.
The reduction is mechanical with helical teeth: this system reverses the direction of rotation of the propeller with respect to the rotation of the drive shaft, clearly dampening the overturning torque.
The balancing shaft dampens the vibration resulting from the unbalance generated by the oscillation of the piston which, passing from the bottom dead center to the top dead center, shifts its mass with each rotational cycle of the engine, thus guaranteeing maximum flight comfort.
Polini THOR 202 is equipped with an inductive electronic ignition: more compact and lighter than the version present in the Thor 200 HF, it allows the overall overhang of the engine to be reduced by 16 mm, making the engine more compact.
The Thor 202 is equipped with the most updated version of the renowned flash starter, a system that guarantees immediate and simplified starting of the engine.
In the latest version the critical points have been reinforced and the centering improved, improving operation and guaranteeing a longer life. Furthermore, an ergonomic handle allows for a safer and more stable grip during the lighting phase.
Polini Motori has decided to maintain the same fixing system on the entire range of Thor paramotors. A choice that benefits both manufacturers and drivers.
Manufacturers can produce a chassis that can accommodate the entire range, significantly reducing both production costs and lead times.
Riders can change Thor models without having to replace or modify the chassis.
Like the entire Thor range, the new 202 is also sold complete with all its parts, fully assembled and ready to be installed on the frame with extreme simplicity.
- 928.000.090 – Dell’Orto carburettor – Euro 2,560 + VAT
|2 stroke single cylinder
|Bore per stroke
|54 x 54
|67 Kg with Ø 130 cm propeller
|In aluminum with Gilnisil coating
|Two chromed bands 1 mm
|Reed valve in the crankcase
|Walbro WG8 / Polini tray Ø24
|Electronics with possible battery charger
|Battery charger preparation
|Output power 40W at 5500 rpm
|With 5K Ω resistor
|E5 or LL 100 AV GAS petrol – 2.5% with 100% synthetic oil
|2.9 Lh. at 30 kg of static thrust
|Helical teeth in oil bath, reduction ratio 3.43
|Oil bath centrifuge
|Expansion with aluminum silencer
* The values reported were measured at sea level in standard atmosphere. The thrust and consumption values may vary depending on the air temperature and the density level.
** E5 defines the type of petrol that can be used. E5= 95 octane green petrol with maximum 5% ethanol. This symbol is shown on all petrol pumps in Europe.