Stepped up Prop Flange Bushing

[JPerkins]

PC-103 has the callout for what you need in it. Look under crankshaft and related parts.

https://www.lycoming.com/sites/defau...g%20PC-103.pdf

[Pacerfgoe]

Check out Lycoming Service Instruction 1098P that should get you the info you need

https://www.lycoming.com/sites/defau...20Location.pdf

[Steve Pierce]

Went to swap props last night to the Borer prop and realized my O-320/150 narrow deck has a hollow crank with 2 recessed propeller flange bushings and 4 raised bushings which use 7/16" bolts instead of the 6 raised 3/8" bushings it should have.

Called my local aircraft engine parts store and they said they couldn't help me without a part number for the bushing since there are so many options.

So my question for you all is how do I identify the correct part number to use 3/8" bolts with my O-320?

I merged your thread with another on the subject with some useful information. The document from Lycoming will help you with the part numbers. What prop did you have installed previously?

[Broncoformudv]

I merged your thread with another on the subject with some useful information. The document from Lycoming will help you with the part numbers. What prop did you have installed previously?

Steve we bought the plane a little over a month ago. It has a Sensenich 74DM 55 pitch on it. Went to put the Borer 8241 on there and found the bolt diameter issue, also it looks like it has the incorrect flywheel as well. It currently has no stepped bushing, just two recessed bushings directly across from each other and four normal length bushings but all of them are 7/16'' bolt holes.

My IA said it has a hollow crank for constant speed prop and thats why the bushings are different.

Looks like Service Instruction 1098P has all the info I need in it to decipher the correct bushings I need to get. Thank you Pacerfgoe!

[Steve Pierce]

Did they drill the prop out to accept the 7/16" bolts?

[Broncoformudv]

Did they drill the prop out to accept the 7/16" bolts?

They must have Steve.

[Broncoformudv]

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[Broncoformudv]

Is there another source for these bushings than Lycoming? $111 each for the 5 and $47 from for the wide one from aircraftspruce seems ridiculous to say the least.

[Steve Pierce]

You need a complete set for a fixed pitch? I probably have a set.

[Broncoformudv]

You need a complete set for a fixed pitch? I probably have a set.

Yes I do Steve for 3/8” bolts. Looks like the 3/8” bolt bushings and the 7/16” bolt bushings are all the same diameter. Once you go up to 1/2” bolts they get larger.

Doesn't look like the correct flywheel either. Always fun cleaning up the surprises you find.