XTR RACING have introduced the new AR3 TUNED nitro engine. AR3 engine is based on the last European Champion engine but incorporates numerous improvements and refinements with focus on maximum bottom and top-end power. The 3-port engine includes a ceramic bearing and diamond-coated crankshaft. The crankshaft is individually balanced with a tungsten weight and filled with silicone. The sleeve and piston set were specially selected and matched. The engine features 10-rib engine head.