Trueing up pulley on modified crank mount fan

B

bill41ford

Member
Just installed a modified crank mount fan pulley on my 8ba in my 41 coupe. Got suggestions on this forum that got me to this point concerning the mods to get this done. Everything is lined up with pulleys but when I ran the engine the pulley (that was removed and turned around and rewelded) does not run completely true. I tried to get it straight on shaft before I welded it but evidently it wasn't exactly correct. I am getting a slight wobble from the pulley. nothing radical, belt tracks ok, but not totally smooth as I would like it. Not quite sure if I need to take it off and reweld or some other way without getting that carried away. Don't have lathe or balancing machine. Any ideas?
 
Bill, Would it be possible remove the pulley, grind out the bad weld and reweld it so it runs true? If so, just tack weld it, try it out and then remove and finish weld it.
 
I should have tacked it and tried it to begin with, but when I put the pulley on it seemed really straight - I guess what your saying is what has to be done, thanks.
 
Sorry. Wrong thread. 8^0
 

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Sometimes you can apply a small bead of weld to pull a piece in a certain direction.
Identify the long side. Apply a bead and it will shrink it back.
Just one tool in the toolbox and might or might not be suitable in this case.
 
I should have checked trueness before final welding - It is possible I got carried away with my welding and warped it - Going to take it apart and start over - the only good thing I did was buy a second pulley assy. in case I have issues taking the pulley off, the original spot welds were relatively easy to drill out compared to what I have with my rewelding. Thanks for suggestion.
 
You can get it to run true, just by heating it in the right spot/s. Find someone in your area that can do it, then get it balanced. You then don't have to worry about it trying to shake itself apart.
 
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Hi Bill, When I did mine the same thing happend . I took it off a sat it in my press with a deep socket that slid over the rear sleve and lightly pressed it true. it didn't take much pressure at all and came out perfect, Tim
 
After further review and removing the fan and pulley, the pulley is slightly skewed on the hub, but I also now have found that there is runout on the crank. I never noticed that before and I didn't indicate it yet but with the engine running I lay my finger on the front of the shaft and I can feel that it is not running completely true. I don't think that is correct. I will try that on the pulley, thanks, Tim. Any ideas about the crank movement?
 
It shouldn't have much at all, .002" or less. However, I'd bet that .005" wouldn't be noticeable, and even as much as .010" might be "ok" on a low rpm stock application. The only way the snout has runout is a bend or the mains were ground without the crank being properly dialed in on the grinder.
 
checked snout runout about 1/4" in from end and get about .0020. This engine was just built about a year ago with no road miles. I know the builder went "over" the crank. I trust that he thought it was ok or he would have told me. He treated me very good and informed me about things that he didn't have to. Now will try to true up pulley. Thanks for info.
 
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