Alternator Conversion

[Breiber]

Ok folks if you aren't sick of this subject yet here we go again. My decision is made. I ordered the alternator. I will source what parts I can and fabricate the rest. Stay tuned.

[Rednaxs60]

Brian - you are probably going to have to set the fan out about an inch. A fellow who did this mod has used bolt unions to get the extra distance required. Here are a couple of pics showing a bolt union:

Threaded on both ends.

Cheers

[Breiber]

That's not a bad idea Ernest. I was thinking more along the lines of cutting a small piece of 12 mm ID pipe and using it as a collar. All good ideas. It's just a spacer so when I get to that point it will be whatever is simplest and looks good. I think I found some metric studs that will work to shim the rad out.

Hopefully the alternator will arrive this week so I can start on that on Monday.

Meanwhile this compressor is a pain. I disconnected it all and removed it to paint the fairing. I wanted to dry the dessicant. The stubs on the end of the lines broke so Im trying to make new copper air lines

[Rednaxs60]

How goes the battle?

[Breiber]

Alternator arrived yesterday. I hope to start in the next day or two. It looks like it's going to be a pretty easy fit though.

Brian

[Rednaxs60]

Great! What are you doing for a crank pulley and what size?

[Breiber]

Ernest,
I shoukd have a better idea tomorrow. The alternator pulley is 2.5" and it's a vee. I might change it out for a smaller serpentine. I'd like to keep the crank pulley to 4" or less.

It depends on what I can find locally.

Brian

[Breiber]

How did your stator work out?

[Rednaxs60]

Have the stator on the bench ready to go back in, but I have taken a trip to Ontario to visit family. Will be back next week.

You probably also know that I am doing a clutch rebuild as well. While I was waiting for the stator and clutch friction plates, I rebuilt the clutch MC and slave, rebuilt the fuel shut off valve (leaked when I turned it to off), and replaced the clutch lines with SS teflon lines from Coast Industrial.

I took the clutch stack out and noticed that the all the steel discs had been overheated to varying degrees with one having been scored around the circumference. I have these on order and will pick them up when I get back.

I am also going to do the "bin the damper" mod where you replace the damper with two steel discs, one at the pressure plate, and one in the stack where the damper was.

Have feelers out to friends and family to make the crank pulley for the alt mod. Will get the bike back together with the new stator, but do intend to do the alt mod in the future when I have all the parts available.

Cheers

[Breiber]

A little progress today. I could do so much more if I could only get more than an hour or two of uninterupted work done but such is life.

I ordered and received a 35 amp GM mini one wire alternator from DB electric. I assume that it is the same size as the one that everyone uses out of the Geo. Either way it looks great and hopefully works as well as it looks. I am a little concerned that I went on the light side and should have gotten the 55 amp version but either way it will still produce more than the stock stator. It came with a industrial style v pulley. I have swapped it out for a 2" 3 rib flat pulley and a matching 2" crank pulley. I also have a 2.5" crank pulley I could use that is a 2.5" I got all 3 pulleys from my local alternator repair shop for $30. A lot of people are hung up on the 2-1 ratio so that the bike will charge at an idle. I believe that Don Pigott is on to something with the one to one ratio. Alternators don't like to spin past 10,000 rpm. It is hard on the internal bearings and who knows what else, bigger pulleys put more unbalanced weight on a crank that was not designed for it, bigger pulleys require more rad/fan modifications. I am going to start with one to one and it is easy to upsize the pulley later.

I have taken a different approach then everyone else. I was able to hang one ear of my alternator off the horn mount. I will have to add a bead of weld and a gusset to the other side to make sure it doesn't move but that won't be hard. I picked up a chromed alternator adjustment bracket for $20 from Lordco (could have paid less for a rusty one at a junk yard) and cut it to fit my application). I had a 29.5" belt on and it barely clears the side cover so I have a 29" coming in tomorrow which will allow me to move the alternator in a bit more. I will drill the timing belt covers tomorrow as well and hopefully spin the alternator early next week. Once I am comfortable with the alignment I will beef up the brackets and I should be ready to hit the road.


Does anyone have any great advice on how to align the belt with the pulleys other than "eyeball"

Cheers,
Brian

[Rednaxs60]

A straight edge of 5/8"X5/8" aluminum angle should give you a decent straight edge to line up the pulleys using the crank pulley as the guide.

[Rednaxs60]

I forgot to mention that this looks like a great install, very ingenious. When you fit the rad, remember to leave room to remove the belt without moving the rad, been mentioned on a few other installs. Good on the pulley change - v-belts need more room to remove. Look forward to the end result.

[Breiber]

Thanks Ernest,

I'll give that a try.

[Breiber]

Well that was wishful thinking. I mounted the pulley and covers today. There's no way I can drive the alternator from the horn bracket. I guess I'm grinding out that fairing mount. Not what I wanted to do but I guess that's what has to happen. I underestimated how far out those steps on the cases protruded.

[Rednaxs60]

What did you use as a spacer?

[Breiber]

That pulley has a small offset so I didn't need much. I used a nut and a washer for a spacer. Not fancy but it works. I could maybe narrow the spacing up a bit but I'm going to leave it for now. The rad only has to tilt out 1/2" as is.

I'm running a 2.5" on the crank and 2" on the alternator. Unfortunately 1 is a 4 rib and the other is a 3. It's all they had. I have 2 - 2" 3 ribs but I need the offset and besides the ratio is better.

[Rednaxs60]

Brian - thanks - have seen pics on other threads where there has been a 4 rib pulley on the crank and three rib pulley on the alt. It has worked fine. The serpentine belts allow for this mismatch.

Cheers

[Breiber]

Yes, the belt won't care. It will run on the 3 ribs it is aligned with. It's just a housekeeping thing for me. I wish I could have matched them up. At the end of the day nobody will see any of this so as long as it works I guess that is the main thing.

[Breiber]

Well, I took a little break from the bike to focus on some other projects but I finally got back to it a couple of days ago. I ended up pretty much copying the poorboy installation. I still think I was on the right track but I'm just not set up at home to fabricate some of the things I would have liked. I picked up some angle iron and in no time had things installed as per the poorboy system. The alternator is working well and is showing about 14 volts at 2000 rpm. It is only a 35 amp alternator so I'm not sure how well that will work out. I'm happy with my install and my efforts have given me a better understanding of my bike. I have only spent about $200 on my alternator install but I have wasted countless hours. My advice to most would be just buck up and buy the poorboy system. You could be done in a weekend easily.

Now to complete my restoration and get riding.

Happy Riding Everyone,

Brian

[Rednaxs60]

Good install Brian - always a challenge as every bike is different. I notice on my '85 LTD there is a small coolant hose that I will have to address, may have to relocate. The right timing belt cover inboard bolt is directly behind the pulley so the install of the pulley and covers has to be sequenced as well.

Look forward to seeing it in person.

Bike looking good.

Cheers

[Wolf Rider]

I hate to be accused of reserecting a long dead thread, but Brian and Ernest, you guys have done such a great job on this all around.
I am contemplating doing the same procedure on both my 1986 GL1200A's.
I'm not in a hurry at this point since the stators are still operating nicely. I am considering increasing the electrical load, however.
I thought it was a very good point made on pulley sizing and alternating rpm and possible unintended forces on the main crank bearings with a larger pully. its something I'm debating in my mind.
Another thought I had was with a one wire alternator (internal regulator), you would have 35A-55A going through a battery definitely not intended for that kind of current. What happens if for some reason the battery goes almost dead and you manage to get it started? Is she going to melt down, burn, or blow? China Syndrom?
I have also wondered about a notched belt configuration. V-belts are crude and take up a lot of room and reqire a method of tensioning. Serpentine belts are designed with utilising an idler pully.
Chain drive would be excellent except for if and when it fails it could cause a lot of damage. Notched belting would be the best of both.
Another thought I had was a dual charging system. Since my stator isen't pooched yet, install the alternator to power only the high draw accessories with a second battery. The 2nd alternating system would be truly islanded(independent). I would want to rig up DPDT switching as a method of allowing one system to take over the load of the other in case of failure of one.
Welcome any all critiques to my ideas.

[Breiber]

The alternator I ordered from amazon came with a v pulley. I swapped it out for a 3 rib and was very happy with the way it ran. Ernest and I don't agree on this topic but I strongly believe that you shouldn't go too big on the crank pulley. I guess your sizing will depend on intended loads. I found the whole process very simple. My only issue was I don't have a welder. I fabricated my own brackets and I had to make several trips to a buddies to fab up brackets. If I did it again I would consider ordering the poor boy kit. If I were you I'd just disconnect the stator and go alternator only.

Good luck

[Wolf Rider]

Thanks for replting so quickly Brian.
I was just looking at alternators over the internet for the project.
My biggest hangup about this project is how us Canadians are getting raped by the exchange rate with the Yankee greenback and the rediculous shipping fees demanded by some venders.
I have not found a Canadian source for the Poor Boy kit and US$200 is in my opinion insane considering you still have to get the alternator.
What is the voltage of your setup at idle? Is it still charging?

[Wolf Rider]

I have not been able to get in touch with Don Piggot either. Did he pass away? Retire?

[Rednaxs60]

The alt mod is an excellent way to keep these old girls going. Thanks for the support for Brian and I. There are a lot of other fellows who have done great installs as well and I have taken several ideas from them.

As to the size of the crank pulley, the one I have was readily available, cost $10.00, and does the job. I actually do agree with Brian on the size of the crank pulley that it should be a little smaller, but you use what you can get. The crank pulley I have came off a '99 Hoda Prelude power steering pump, is 4" diameter and woks well - I think a 3" pulley would b just as good. The drawback is that if I have to take off the timing belt covers I have to remove the crank pulley - a 3" pulley may alleviate this. Check out Wes's thread as well at viewtopic.php?f=11&t=36303. He did a mod (with pictures) that moved the securing bolt for the right timing belt cover to the right clearing his 4" pulley - not a lot more work.

I agree with Brian that if you do the install, use the alternato as a primary source of power for your bike. A 40-50 amp alt will give you al the power that you need. Use a three or single wire alt, internally regulated - your choice, both are good. You can go with an externally regulate al as well, but will hav to install a regulator. I've toyed with this idea because there are some good there stage regulates out ther that would be good to trial. The Balmar marine ARS-4 regulator. Used these on a boat I had in the 1000 islands and it worked well.

I got my alt from a local shop that took an older model and rebuilt it. Out the door for $125.00. new model was just over $200.00.

I put the dimensions of my brackets on a different thread. Will post here for information. I will be duplicating my '85 LTD install on an LTD that I have at my bother's place in Ontario, then drive it back. I like the reliability and the ease of maintenance/work if needs be. As I too do not have a welder, I had to do a bit of to and fro from the local weld shop as well.

I would recommend using a serpentine belt. If you are concerned with the stress on the crankshaft, you can leave the serpentine belt snug but not too tight and it will work well.

If you are going to leave the stator hooked up as a backup, just make sure the RR is completely disconnected from the charging circuit. The two red/white wires from the RR are joined to the red wire from the starter solenoid to the ignition switch in the wire harness. Will post a schematic by Virgilmobile that depicts this. I also know this because I stripped out all the OEM stator and RR wiring when I did my conversion.

Picking up a used, rebuilt alt and doing the brackets yourself will keep the costs down. Other than the alt expense, the bolt for the crank pulley was about $15.00 because of the threads. The rest of the crank pulley parts came from Princess Auto. I think I came in at under $200.00 for the install.

It's a good project. Take your time and it'll turn out well.

Cheers