KEK

1925 Buick starter motor-generator

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Hugh -

 

Thank you for posting the distributor rebuilding information. I am going to get to that in a couple weeks after I return from an out of town trip.

 

On setting the timing the procedure says to raise the spark advance lever all the way up. On my car raising the lever will advance the timing and lowering the lever will retard the timing. I thought you fully retarded the timing on these old cars not advance the timing? That is how I time my model A by retarding the timing. However on a model A you raise the lever to retard and lower to advance. Just the opposite of the Buick...

 

Did you set your timing at the 7 degree mark?

 

Ken

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Ken, 

    Thanks for pointing that out.  The person that owned my car before me was a Model A person, and he flipped the lever arm that is over the starter geberator so that the spark lever worked in reverse (Like a model A).  I have corrected the text.  

 

Regarding setting my timing, I went between the 7 degree after mark, and the 1-6 line.   It advanced it a few degrees, and I feel I could still hand crank it when necessary.  I tried my car at the 7 degree before spot for full retard setting, but I could not tell any performance difference.  Others say they can tell a difference.  

 

Hugh

Edited by Hubert_25-25 (see edit history)

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Ken, 

    This is some timing and tune up information that you may find useful.  They did not have dwell meters and timing lights back in the day, and I have not seen any early work using vacuum gauges and compression testers either.  This is how I set my timing and I did use a vacuum gauge to improve the performance as well.  It is interesting how carburetor setting and timing will effect the vacuum.   Hugh

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Edited by Hubert_25-25 (see edit history)

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Hi Hugh -
 

I removed the distributor shaft from the body and the 3 centrifugal springs on the bottom of the plate look new. I noticed that the inside of the distributor body had been repaired with what looks like epoxy. I don’t know why it needed to be repaired but the pot metal probably was cracked or something like that. You mentioned that you have an extra steel distributor. I am interested if you are willing to sell it. Please let me know.

 

Great information on timing you posted above. That’s my next step later this week.  I plan to time my 25 the same as you did yours. That is a few degrees advanced. Before I pulled out the distributor I checked the timing and it was also set a few degrees advanced so I am going to return it to the same timing. I live in Colorado at 4500 ft and a few degrees advanced on my other cars works good.

 

My compression for 5 out of the 6 cylinders range from about 65 to 68 psi. One cylinder is at 60 psi but this engine is new and the rings have probably not seated completely yet. 

 

My manifold vacuum is around 15 to 16 in Hg. My vacuum gage indicates a healthy engine should pull about 20 in Hg at sea level. Since atmospheric pressure is about 30 in Hg at sea level and about 25 in Hg at 5000 ft I need to adjust my gage readings by about 1 in Hg per 1000 feet of elevation. At 4500 ft in elevation where I live a healthy engine should be about 15.5 in Hg (20 - 4.5). 

 

I found that adjusting my fuel mixture screw about 3/4 of the way open and my air adjusting valve flush with the end of the housing provided the best tune. This is exactly how you have yours set also. That gives me a lot of confidence I am on the right track. 

 

How important do you think it is to check the dwell? I dont see any obvious way to adjust the dwell if I need to.

 

Edited by KEK
Corrected atmospheric pressure at 5000 ft to 25 in Hg (see edit history)

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Ken, 

   Adjust your points with a feeler gauge.  If it looks good, put a dwell meter on it for reference only.  Then it is an easy check if you just want to see how the points are doing in the future.  Sounds like the motor is pretty healthy.   I will PM you regarding the distributor body.   Hugh

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Hugh - When I tighten the special bolt with the spring that holds the distributor down I can rotate the distributor 20 degrees but it hangs up and is hard to rotate in one place. If I back the bolt out 1/2 turn then the distributor rotates freely. It seems to me this bolt should be tight so it doesn’t loosen up and fall out. Do you tighten this bolt down tight or is it designed to be backed out a little?

 

PS- I meant to say that atmospheric pressure is 25 in HG at 5000 ft (not 20 in HG). The calculation is correct that you need to adjust your vacuum gage reading approximately 1 in HG per 1000 ft of elevation. I don’t know how to revise my post above so I thought I would mention this so as not confuse anyone.

 

Ken

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Ken, 

       You can revise your postings.  I do it all the time.  Lots of knowledgeable folks on this forum and I find a need to correct what I say so that it does not get etched into history.  There is an Edit and a save button for each posting.  

 

The bolt is designed to be tight.  If you remove the spring, there should be .145 distance between the end of the threads and the bottom of the outer barrel.  

- Make sure the spring is not hanging up on the bottom shoulder of the bolt and preventing the barrel from moving.  

- Once assembled, you should be able to move the barrel "up" just a little and you should hear it spring back.  If the barrel will not move up, maybe you need to remove a small amount off the top of the barrel.

- I am wondering if someone drove the screw in so far that the shoulder is rounded and the screw is sitting lower than it should be.

 

By the way, if anyone has an extra one of these hold down bolts with the barrel , I could use a  better one.   This came off a spare rusty Starter Gen.  I could give you this old one too if you needed it for an exchange.   It still works, it just won't win any beauty contests.      Hugh

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Hugh - I see my problem. My screw doesn’t have the barrel. I will take a photo of mine tomorrow when I go out to the shop.

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Hugh - Here is a pic of my special screw that holds down the distributor. Apparently it does not have a barrel like yours. If I put the washer below the spring then I can tighten the screw all the way down and the distributor rotates freely. Problem solved!

 

I have a question about your stop light. Mine is mounted on the rear by the spare tire. See photo. I cant find a brake switch. Does your car have a brake switch somewhere that closes the circuit to illuminate the brake light or is this just a running light.

 

Ken

 

 

 

 

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The brake light is only a running light in 1925.  I will send you my turn signal and brake light stuff when I get back to my computer.  

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Hugh -

 

That’s what I thought- just a running light. Look forward to seeing what you did.

 

Do you know if there is a way to align the pinion gear on the starter with the sliding starter gear? I don’t know why my sliding starter gear teeth were damaged and if I can’t figure out why the same thing will happen with my new gear. All the bushings seem tight. I need to do a few more tests but it seems like the starter gear and pinion gear may be binding a little bit when it first engages. So the only thing I can think of is try and align the gears but it doesn’t.t look like there is a way..

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Ken, 

     Someone put the wrong gear on my starter generator and I could not get mine to mesh.  Start with verifying this gear.   OD  and teeth.   The Master has 1 less tooth and it fits the same size shaft.  There really is no adjustment.    Also here are the two links to the brake light installation and the turn signal addition.      Hugh

 

https://forums.aaca.org/topic/337485-brake-light-installation-mid-20s-buick/?tab=comments#comment-1968834

 

https://forums.aaca.org/topic/337486-turn-signal-addition/?tab=comments#comment-1969695

 

 

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Edited by Hubert_25-25 (see edit history)

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Hi Hugh -

 

Thanks for the tail light installation instructions. I have a Model A brake switch that I think I can make work like you did yours. I appreciate your help.

 

I didn’t think there was anyway to align the motor generator but I thought I would ask you just in case. The pinion gear that was installed on my 283 motor generator was the smaller 13 tooth when the sliding gear assembly broke.  I also have a larger 12 tooth master pinion gear that I was able to compare against. When I found a replacement sliding starter gear assembly I also got another 13 tooth pinion gear for the 283. It looks the same as the other one I have. I will check next week to see if the gear matches the dimensions in your drawing but I am fairly confident it is the correct pinion gear.

 

I just can’t figure out why the larger starter gear on the sliding assembly was damaged. I checked all the bushings on the bell housing and starter and they all appear fairly tight.  Although I don’t know what the tolerance should be. Not a lot of movement. Some clearance as you would expect but not a whole lot.

 

The pinion gear on the starter looks good with little sign of wear as does the smaller flywheel gear on the sliding gear assembly. The only gear damage is to the larger starter gear on the sliding assembly.  The damage to this gear is at the front where it engages with the pinion gear. I attached a photo so you can see where the damage is. The height of the gear is not changed. The damage is on the front edge of the gear and looks like a “C” shape. This is the location  where it first engages with the pinion gear and the damaged area is the same cross-sectional shape as the pinion teeth. So it looks like it is was not properly engaging at the beginning of the process but after the gear is engaged approximately 1/4 ithen all works good.

 

I replaced the damage sliding assembly with my replacement. I turned on the ignition and the starter was ‘motoring’ properly but when I depressed the starter pedal the assembly engaged but did not turn over the motor. I immediately released the pedal. I then put the damaged sliding assembly back on and the motor turned over. So why would an undamaged assmbly not work but the damaged assembly work.... I was thinking that the clutch may have something to do with it even though both assemblies had been disassembled and the clutches cleaned and lightly greased. So I replaced the clutch in the undamaged assembly with the clutch in the damaged assembly.  Tried to start the car but it still would not turn over the engine over with the undamaged gear. I don’t know what else to do. Any ideas?

 

Thanks- Ken

 

 

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Ken,    

   Wondering if perhaps you have a Master sliding gear.  We need to make sure on the teeth count and the diameter.   Also wondering if you can assemble the sliding gear one way clutch in the wrong direction.  I would keep the battery disconnected from the starter generator until you get the mesh issue worked out, otherwise you may grind off more teeth.  Remove the starter pedal assembly so that you can work the starter slide by hand.  It should line up easily and you should be able to engage it easily by hand.  Here is a photo of my sliding gear.   It could also be that someone used the Master pinion gear and messed up the sliding gear and now you have to fix everything.   Hugh

  

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Edited by Hubert_25-25 (see edit history)

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Ken,   This is note number 2.  Do you have the 2 cones that hold the starter generator?  Are they concentric and not some oddball something that someone put in there.  The photo with the bolts has them in the right places.  Is the ground between the SG unit and the block clean.   Hugh

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Ken,   Note #3.  Think about the theory behind all this in slow motion.  The starter generator is motoring or turning slowly.  The pedal goes down slightly - I assume (but don't know)  that the flywheel is engaged first, or the pinion engages first - maybe simultaneously.   That is when the light ticking is heard.  A little more distance on the slider and all the gears should be engaged.  Then it is straight sliding until you get good teeth contact.  During this slide, the generator brushes should be lifted.   At the end of the slide, the brushes should make contact for the starter.  With the battery disconnected, and the SG cover off,  and the starter pedal return spring unit removed, you should be able to watch all this happen.   Hugh

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Hugh - 

 

The gear count on the pinion is correct. 13 teeth and the diameter is smaller than the larger 12 tooth Master pinion gear. I am pretty confident that I have the correct pinion for the Standard. Good point that perhaps the Master pinion was originally used and damaged the starting sliding gear. Although when you match up the damaged sliding gear the shape fits the standard teeth. The troubling thing is the 13 tooth pinion gear turns the engine with the damaged starter gear but not with the undamaged starter gear. Both starter gears are the same other than the damaged area.

 

The concentric cones that hold the starter look correct. I can double check these next week. It seems that you can only put these cones  in one way and they should self-align. I’ll make sure they are installed correctly. Easy to check.

 

With the battery disconnected the gears meshed easily and smoothly. I did have to align the starter gear by hand first since the pinion gear was not motoring with the battery disconnected. That is the other thing that is so baffling. The replacement gears mesh just as smooth as the damaged gear. When I was testing the slide it work smoothly in both directions. However, one thing I didn’t mention was one time when I tried to start it with the undamaged gear the positive cable where it attaches to the starter begin to smoke. I turned off the ignition and was able to quickly remove the positive cable from the battery since i didn’t have it tight on the post. I don’t think it damaged anything. I put the damaged gear back on and all seemed to work okay. I really won’t know if anything was damaged until I try it a few more times. I think what happened was the undamaged gear did not slide back all the way so the pedal must have acted as if it was depressed just a tiny bit.  I just don’t know what happened or why the pedal didn’t return all the way. The only thing I can think of is the undamaged gear was binding in the pinion gear. The other possibility is the safety wire I put on the hold down bolt for the fork that moves the sliding gear assembly. I wrapped the safety wire around the fork shaft and then through the hole in the top of the bolt. Perhaps the wire was in just the right spot to prevent the fork from sliding back all the way. I am just guessing. I really don’t know if this is what caused it to stick. I think i will remove the safety wire and just put some thread lock on the bolt. Did you safety wire this bolt? Hope my starter armature isn’t damaged 😃

 

I am going to have my friend slowly press the starter peddle down with the battery disconnected and make sure the process is proceeding as you describe above.

 

I did find the negative ground cable a little loose. I cleaned all the battery cables and put a charger on the battery. So maybe after it is charged up and the cables are cleaned it will turn over.  I’ll give it another try next week.

 

Ken

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I wonder if someone

- installed incorrect starter generator brushes or

- bent the SG brush holders where they are engaging or disengaging at the wrong time.

What is the condition of the 2 insulators.  - The one that the pointer goes into that drops the Starter brushes, and the one on the little fork that lifts the generator brushes.  

The order would be to fix and adjust all the mechanical parts, then investigate the timing of when the electrical operation occurs - When do the generator brushes lift, and when do the starter brushes engage.  

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Hugh.

 

I finally got it working! Gears sound good without any loud noise when they engage.The armature shows no sign of damage. It pulls about 300 amps when the brushes drop on the starter which seems reasonable. I pulled the sliding gear and regreased the clutch but I don't think that was my problem. The ground cable was loose so there probably was not enough amps to spin the starter. Works fine after charging the battery and tightening the ground cable. Now I need to adjust the 3rd brush and tweak the timing a little and should be good.

 

Thanks for all your help and insight.

Ken

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Ken,   Really glad that you have the gear clash under control and in such short order.     Hugh

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Ken, 

     I needed to make the barrel that fits under the spring that holds the distributor down.  Mine came out of a rusty parts car.  No one sees it either - but I know it's there.  I needed one for my engine and one for my spare SG unit.  It did not take me much longer to make 3.  I silver soldered a 1/2" tall piece of 1/2" steel tubing to a #10 flat washer.  ID and OD matched surprisingly to the original.  I am dropping yours in the mail.    Hugh 

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Thanks Hugh that’s awesome.

Ken

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