ässä on todella mielenkiintoinen uutuuskone polttiskrossiin;

Arrow Racing on tehnyt moottorin osia jo aiemmin mm. O.S.:lle sekä isompiin autoihin ja moottoripyöriin (mm. Moto GP sarjan -pyöriin). Nyt he ovat keskittyneet tekemään oman .21 -koneen polttiskrossiin eivätkä ole lähteneet lanseeraamaan koko sarjaa halppiskoneista huippukoneisiin. Siis saatavilla on tällä hetkellä 3-porttinen huippukone sekä varaosat näihin koneisiin. Heillä on suunnittelupöydällä seuraavaksi 5-porttinen kone, joten se tulee markkinoille myöhemmin tänä vuonna.

Specs:
‧Displacement:3.46 cc
‧Bore:16.6 mm
‧Stroke:16.0 mm
‧Ports :3 1
‧Practical range:3,000-48,000 rpm
‧Power Output:2.9 hp @ 36,000 rpm
‧Crankshaft: 14mm
‧Slidevalve carb:8mm & 9mm carb restrictors
‧Glowplug:Turbo
‧Weight:365 gr

In order to produce an engine with plenty of torque at all three different places- the low, mid and high ranges, a fully balanced crankshaft with larger openings, ported piston, forged con rod, and specially treated sleeves are not enough. Ultra-low friction treatment in all moving components is the only solution. The Arrow Racing GTR .21 is made to achieve solid and punchy linear power while maintaining low fuel consumption. One of its key success is its piston. Grain-size refinement of the alloy and high-grade silicon content all play a major part in creating a piston that when contact with the sleeve produces ultra-low friction. Hence, low wear and extension to its lifespan are two qualities of the GTR .21.The other one is its piston sleeve. The sleeve itself is specially treated with Advanced Hard Chrome Technology for its superior wear resistance and friction reduction. All these advancements make the GTR .21 engine more powerful with plenty of torque, reliable and ultimately last longer.

The crankshaft used in the GTR is constructed from excellent hardened steel, avoids the problems of friction and wearing. The material of this piston alloy with high silicon and grain size refining content, this piston material is to reduce friction and to expand the lifespan. The cylinder used in the GTR is constructed from advanced Hard Chrome technology for superior wear resistance and friction reduction. Which make the engine more reliable and longevity.