Specifications

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Engines & Accessories
28
Thunder Tiger first introduced the well-known Pro-46 in
1992, from then on the Pro-46 has been the standard
for 2-stroke aircraft engines. To be the great Pro-46’s
successor, the NEW Pro-46 inherits the incredible
and reliable performance, and has many new features,
making for better durability and easier maintenance.
• Heat-Spreading Design Enhances Cooling
• Non-Seizing Flange Mount Carburettor
• Steel Inserted, Lightweight, Composite Backplate
• New Crankcase for Improved Structural Strength
• Swept Back Needle Valve Design for Safety
• Same Side Mixture Screw and HS Needle Valve
Adjustment
• Precision Crankshaft Ball Bearings
• High Performance Streamlined Muffler
• Knife Edged 7075 Aluminium Connecting Rod
• High-Silicon CNC Machined Piston
• XC2 (Extreme Composite Coating) Cylinder
• Redline R2 Glow Plug Included
Displacement: .46 cu.in. (7.47cc)
Bore: 21.8mm (0.86“)
Stroke: 20.0mm (0.79“)
Practical R.P.M.: 2,000 - 17,000rpm
Output: 1.60 hp @ 16.000rpm
Weight: 465g (16.37oz)
£399.99
£349.99
OS has always listened to the top drivers who run their
engines. By doing so, they can respond to the changing
needs of racing and keep their designs at the very cutting
edge of technology. The B2101 is very much an engine
driven by driver feedback and technical advances alike. Just
about every component has been re-designed from the
Speed 21XZ Ver2 predecessor in order to give you the very
best engine on the market. Whether it’s the DLC coated,
gas flowed crankshaft with Tungsten balance weight or the
specially coated brass liner with high silicon piston, or even
the aerodynamic high-strength connecting rod, to OS, every
detail matters in the pursuit of excellence. The B2101 has
a revised ‘square’ bore/stroke ratio to change the torque
into a more useable area for off-road use, yet still give the
top end power you would expect.
Displacement: 3.46cc (0.211 cu.in.)
Practical RPM: 4,000 - 42,000
Power: 2.61 hp @ 34,000rpm
Bore: 16.40mm (0.646”)
Stroke: 16.40mm (0.646”)
Weight: 352g (12.42 oz)
Displacement: 2.10cc (0.128 cu.in.)
Practical RPM: 5,000 - 45,000
Power: 1.73 hp @ 35,000rpm
Stroke: 14.30mm (0.563”)
Bore: 13.67mm (0.538”)
Weight: 352g (12.42 oz)
O.S. Speed B2101
O.S. Speed T1201
£94.99
Thunder Tiger Pro-46 Aero
Part Number: L-OS1A200
Part Number: TT9143
Part Number: L-OS1A400
The OS concept of involving its top drivers in engine
development has also been extended into the B1201. Getting
the very best performance from even the smallest engines in
the range has always been an OS strength. How else could
you squeeze a massive 1.75PS from a mere 2.2ccs? The
world of 1/10th Touring car racing is a specialised one
and the engine has to perform impeccably to get over the
line first. With many technical features borrowed from the
R2101 and B2101, the T1201 is not short of technology
either. The relentless pursuit of reducing internal friction
is even more important in smaller engines, so features like
DLC coating and precision ball races are all there. Then
there’s the need to get porting and tapers correct along
with thermal expansion in order to reach those 35,000RPM
peaks as well as give crisp throttle response. The new bore/
stroke ratio has moved the torque a little lower in the rev
range for better punch out of corners.