1946 B31/33 engine build

[Farmer Jon]

Can a B33 cylinder and head be fitted to a B31 bottom end?  Is the flywheel heavier in a B33?  Are the valves different size.

[Gadorey]

Should fit without any problems. The bottom end is the same. There are a few slight differences in later years, but if your B33 parts are the same year as the B31 bottom, it all goes together.

[Farmer Jon]

Thanks just starting project...  Excited to begin

[idie]

It will work but the flywheels on the B31 are a bit lighter. This might give you a bit of vibration as the balance factor will be different.  It should help the acceleration a bit though.

[Pete Gill]

Hi Jon

Check out the Draganfly website as it has a lot of diagrams and part numbers so you can cross check when a part is universal to all models etc.
Pete.

[idie]

B31 flywheel and shaft 65-1125.  B33 flywheel and shaft 65-1235.

B31 flywheel and shaft 65-1123.   B33 flywheel and shaft 65-1233.
These are the part numbers for gear side and drive sides