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Generator Options
Posted: Mon Nov 20, 2017 10:55 am
by joefarmer
Pulled the generator off the 1964 Monza this past weekend. I've got a bad armature and the insulation on the field coils is shot to pieces. I have two options: rebuild from California Corvair ($210) or buying the parts from Clarks and rebuilding myself ($160). Which should I do and why?
Not really interested in doing an alternator swap. An alternator in an EM looks strange to me....
Re: Generator Options
Posted: Mon Nov 20, 2017 11:19 am
by Jerry Whitt
Many local auto parts stores may have a generator available. Local prices vary greatly !
Your statement about a bad armature might be in error. Usually polishing the edges where the brushes slide will help. Then using a cutter of some kind
to clear the spaces between the segments will work pretty good.
The paper insulation on the field coils usually looks really bad, but by trimming it away is all that is necessary. You can test the coils with an ohm meter to make sure there are no broken segments and check to make sure they are not grounded to the case.
Re: Generator Options
Posted: Mon Nov 20, 2017 1:37 pm
by 66vairguy
You might get lucky with a DIY rebuild, BUT -- after all these years it's best to find a good auto electric shop to test and rebuild the generator. They can test the armature and field coils with equipment just not available to the average person.
If you don't have a good electrical shop in the area, then the next best thing is a rebuild from a auto parts chain - at least you can exchange it if it doesn't work well.
Years ago I rebuilt several starters with a tool borrowed from a club member - a "growler" that can test the armature for shorts. Sadly he passed and the family sent all his stuff to the DUMP!!!
Re: Generator Options
Posted: Mon Nov 20, 2017 9:02 pm
by bmwtodd1
I have a couple around. I have the growler and am experienced with generators. If you want I will look and see if one is good, and you can have it, just pay shipping. My email is
brittsandbeemers@cableone.net.
Re: Generator Options
Posted: Mon Nov 20, 2017 9:35 pm
by dave t
I took an old generator to an old non-chain auto parts store. The guy's there know their stuff. They got me a generator for a 57 Chevy. I took it home and swapped the end plate to the corvair one. Worked great.
Don't forget to polarize the generator every time the battery is disconnected. The shop manual shows you how.
Sent from my SM-G930V using
Corvair Forum mobile app
Re: Generator Options
Posted: Tue Nov 21, 2017 5:44 am
by bbodie52
Here is some additional info on polarizing a generator system...
Re: Generator Options
Posted: Tue Nov 21, 2017 6:52 am
by joefarmer
Fellas - Thanks so much for the help. A few comments:
1. Thanks Jerry. So, the armature is bad not because of wiring, but because the threads are pulled off of the pulley end. Went in to replace the bearing and ended up pulling all the threads off of the stud trying to get the pulley nut off.... bad luck I guess.... or inexperience haha
2. I've cleaned and checked the field coils per the shop manual and I think I'll go with it. Also, I don't even want to try and get those side screws out. They look like they have become one with the gen casing.
3. bmwtodd1 - you're what makes this forum great. Just when I think I'm going to have to drop a lot of cash on a simple fix, this forum comes to the rescue! I will be emailing you shortly. Thanks so much!!!
4. bbodie52 - Thanks again for your help on this. You seem to have a wealth of knowledge on this subject. Will tie a string around my finger to remind me to polarize when the gen goes back into service.
New plan is to get an armature, clean up everything around the field coils, put in a rebuild kit from clarks (bearing, brushes, etc), polarize, and driver-ize this Vair!!
Thanks to everyone!!!
Re: Generator Options
Posted: Tue Nov 21, 2017 10:24 am
by 66vairguy
You stripped the armature threads --- If I recall correctly - Corvair generators had reverse threads (clockwise to remove nut). Turning the nut CCW to remove it would strip the threads as that would be tightening it on a Corvair. Corvair generators AND alternators turn opposite to all other GM cars and yes the cooling fans on them are different.
BTW - the Corvair alternators used standard threads for the fan/pulley nut - and yes they do come loose if they are not tightened adequately. A fellow in our club had that happen.
Re: Generator Options
Posted: Tue Nov 21, 2017 4:12 pm
by Frank DuVal
You
need a shop manual. See page 8-11 of the 61 manual for taking the generator apart. It highlights the left handed thread.
Now, if the generator happened to be repaired back in the 70s 80s, and the armature was bad, then the shaft might have a right hand thread nut. This is because there were so many more used right hand thread armatures sitting around generator repair shops in those days. Or, someone swapped in a 57 Chevy unit, like mentioned above. So, either way, always try
BOTH ways on a Corvair generator nut to be sure!