bent prop flange

[dblj006]

If you have a bent prop flange on a Lycoming what are your options?
Of course replace your crankshaft. I have also been told that some can be straighted out as long as the runout does not exceed a certain limit.
But I heard another solution today. I was told that there are some shops that will replace the flange, only in a non-aircraft application(for airboat use only). Has anybody else heard of this? And if so can help with some info as who does?

Thanks

 

[grant]

dblj006,

Get a big crescent wrench, a cheater pipe, a dial indicater and get busy. It is possible, not easy but possible to straighten out a bent flange this way.

grant

 

[Davie GSO480]

Larkins machine shop in Perrine florida, has straightened several,,,,,,he says, big wrench, dial indicator as mentioned,,,,and a hammer,,,got to ding the crank while pulling,,,,,
Richard Larkin,,if ya want a phone # pm me

 

[dblj006]

Grant, Davie,
Good info, thanks. At least my options are improving somewhat.

I appreciate the help. I might have found somebody that can help here in

Sarasota. If not I'll get with you on that #.

 

[OVER BUDGET]

dblj Have you tried Roehrs machine shop they have been helpful to me in the past. There on orange Ave.

 

[rick]

I bought an angle valve 170 several years back that had a replaced prop flange. I didn't know it at the time, but later figured out that an O-320 didnt take 1/2" bolts to hold the prop on like mine...it was an O-360 flange.

I ran it for several years thinking it might be okay...then one day it wasn't. The prop flange broke, sending the $1600 composite thru the cage and left me & my buddies diving to find the hub on a cold day south of HWY 50 on the St. Johns.

It's just my opinion, but I'll never run another crank like that.

Rick

 

[dblj006]

OVER BUDGET,
I'm gonna call Roehrs on Monday. I need some other stuff I'm hoping they can help me with too.

Rick, the welding of a flange doesn't seem to be an option anymore.
I have been told that it has to be done with the crankshaft out of the engine.
If it has to be that far then I'll just send the motor out and have the crank replaced and cam and followers too. I'm gonna try this other method first.

Rick that must scared the heck outta you, I know it would've me.


OB, Rick, thanks.

 

[Davie GSO480]

The 0-290 (125hp stock, has a thin flange, you Can use the 0-320 (150HP) CRANK,,,,lots more metal....

 

[Olf Art]

One comment if I can ..... I know you might be tempted to heat one, or hit it with a hammer if it's only a little bit off. Please don't.

The forces on a prop flange can be measured in tons when it's spinning up. No room for anything but 100% right.

olf

 

[dblj006]

No heating. Only cold bending. With a BIG cheater pipe. And if it can't go back to within .018 runout on the dial indicator, its going to get another crank. But its worth the try. We'll see.

 

[Des Moines Boater]

When they mentioned hitting it with a hammer while bending it, I think they were refering to a technique called shot-peening the metal. It is used in aircraft manufacturing to help anneal the metal or stress relieve it by altering the mechanical properties of the metal. The hammer was probably a ball peen hammer.

 

[Olf Art]

I know, Des ...... but it matters too where you do the peening.

O.