RR12L5.....
This engine is excellent, 710 or mtx3 with NSR 3 or 5 ports have problem keeping up with this engine. I have been keeping up with 1/8th drivers ( i also race 1/8th, and these drivers like myself normally are in the A final ) at my club with this engine. The acceleration is awesome (you have to set the clutch and gearing right first).