Prop flange bushings for Borer Prop

[TVATIVAK71]

Converting our O-320-B2B with a MT constant speed to a fixed pitch Borer 8243. The MT took 7/16” bushings and I’m trying to sort out through some manuals what the right part number would be for the flange that accepts the 3/8” bolts that came with the Borer. Right now I’m looking at part numbers 72066(index bushing), 72067 and or 18921(index), 18922 was gonna measure the thickness of the Prop flange and research the lengths of the bushings. Are the part numbers in the Lycoming manual referencing the B2B for 3/8” bolts?

Next question is when the MT was removed only 4 bushings extended past the face of the flywheel, I was under the impression all six bushings had to extend past the flywheel for the prop to stock on. Which is normal? (maybe I should take a better look under the prop I just removed to see if it would only take four longer bushings). Anyway it’s late just thought I would see if anyone knew here before I start digging more into it.

[Steve Pierce]

You need this information in Lycoming service instruction 1098Q.

https://www.google.com/url?sa=t&sour...FAmLsu-dK61z7f

[TVATIVAK71]

Thanks! I’m thinking that letter/instructions are the way to go.

[Steve Pierce]

Gone both way using the Service Instruction.

[Fortysix12]

I sent you a private message.

Jeff