* 6274 - OBR 7.5hp Full Mod Zenoah 30.5cc 4 Bolt Torque Engine

OBR Motors are now CNC ported and hand finished. We've seen more power and reliability with the CNC porting because of the higher accuracy.  Also, every piston port engine is now coming with a billet crankcase.

Same specs as our normal full mods but tuned for more torque. This engine was specifically desinged for the Losi 5ive-T, MCD and other 4 wheel Drive Cars and Trucks. We have installed a CY clutch and fan cover for a direct bolt up.  The full mod 30.5cc has proven to be one of the most popular engines we build. With the higher reliability of the 4 bolt Zenoah engines we were able to achieve more power with out sacrificing reliability. We put all of the knowledge that we have picked up from years of dyno and field testing and came up with a monster. To start we completely tear down the engines and perform the following modifications:

1. Machine combustion chamber for a proper squish clearance without stacking cylinder gaskets
2. Reshape piston
3. Lighten piston
4. Relieve piston to prevent seizes 
5. Modify intake port for better flow
6. Adjust intake duration to our specs
7. Resurface all ports
8. Modify transfer ports for better flow
9. Enlarge and reshape exhaust port
10. Adjust exhaust duration to our specs
11. Remove stock crank and install 2mm stuffed crank
12. Install all new gaskets and c-clips when engine is assembled
13. Re-bevel all porting and stock bevels to prevent damage to the piston and/or cylinder