TR2/3/3A TR3 alternator conversion

[TFB]

I have been reading posts about this conversion.

I am wondering if any of the Nippondenso,Edge,kubota etc.,which all look similar if not the same,units are of the 3-wire type internal regulated.Any numbers to look for appreciated,in the 40-60 amp range.They all apperar to be 1 wire.

The GM10si is cheap enough,but looks a little big,although ebayer has the 5/8- 3/4belt pulley for 14 bucks,so this may be my final choice.
Thanks
Tom

 

[TR4nut]

I bought a 3 wire Denso type but haven't hooked it up yet - I'll try to dig up my source. But as to a 3/4" pulley, I haven't found one yet for the Nippondenso - I'm sure one could be made but if that is what you want the 10si would be easiest I think.

 

[Moseso]

I used the Denso in my 3. With the mounting adaptors I used, there was no way to stuff the Delco in. I know it's been done, but I wasn't finding the way. I went to an Auto Electric specialist/rebuilder locally, and told him what I was looking for -- the small body Denso alt. He reached up on a shelf and pulled down just that. Swapped out the flat-belt pulley for a V-belt pulley and we were done.

I didn't really <span style="font-style: italic">want</span> to spend the extra money on a small-belt conversion for my car, but I have NOT been sorry I did it. Replacement belts available at ANY auto parts store -- and rather a LOT easier to get onto the car than the big ones.

It's a 3-wire 50 amp unit -- I'm afraid I couldn't give you a part#.

 

[martx-5]

I used the Denso in my 3. With the mounting adaptors I used, there was no way to stuff the Delco in. I know it's been done, but I wasn't finding the way.

I work for a an electrical rebuilder, and could have stuffed anything I wanted in the TR3, but chose the Delco 10SI for several reasons, one of them because it is virtually bullet proof. I didn't have to make any modifications to the unit, so if I had to replace it on the road somewhere, I know it would be available at any parts store. It is a snug fit, but there is enough room to get it in there. I also opted for the narrow belt conversion.

 

[Moseso]

The crucial part of stuffing a 10SI into a TR3 is the bracket conversion. Mine, a generic tractor part, didn't work. What did you use? Pictures of the mounting bracket would be a huge help, here, to those who want that alt. I KNOW you take pictures, Art.

 

[TR4nut]

On my TR4, I just used a threaded rod/coupling and the existing lower mount. Doesn't that work for a TR3? The only real irreversible modification is grinding away on the 10SI case.

 

[TFB]

Art's GM unit does look a bit snug,and thats with no manifolds in place.
Any part numbers or applications for the Denso appreciated,or pics of your unit.
Are Nippondenso and Denso the same?
Thanks again
Tom

 

[martx-5]

Art's GM unit does look a bit snug,and thats with no manifolds in place.
Any part numbers or applications for the Denso appreciated,or pics of your unit.
Are Nippondenso and Denso the same?
Thanks again
Tom

Here's some info on the Nippondenso (or Denso...same thing) units.

Edit: BTW, here's a description of what I did to get the 10SI in there. I sent this as a PM to one of the forum members that asked about this.

"Yes, I did this conversion, narrow belt and alternator. For the alternator, I used a Delco 10SI. It can be bought in any parts store. The one you want is a 7127-12. That's an industry number, and the "-12" means that the plug in is at the 12 o'clock position, when looking at the back of the alternator with the adjusting ear straight up. Basically, GM cars from the mid-'70s to '80s had these alternators. Depending on application, they came in different clock positions.

The way I handled the brackets is that first of all, I left the original generator bracket in place, but took off the front spacer that the front ear of the generator bolts to. Since I have a machine shop at work, I was able to fabricate some pieces for the rest of the mounting. But, basically, the alternator's swing leg, the long leg at the bottom, goes right in front of the generator bracket. The belt should line up well. Now you've got to get a 3/8 bolt that is long enough to go all the way through the alternator leg, to the back of the bracket, with a spacer between the legs of the original generator bracket. Or, what I did, was make the spacer, and tap each end or the spacer to accept a 3/8 bolt. One more item I added was a spacer where the adjusting bracket bolts to the water pump housing. I added a 5/8" spacer (with longer bolt) so the bracket lined up nicely with the front of the alternator adjusting leg. Some guys have mounted the bracket to the back-side of the alternator bracket, and others have just bent the bracket to fit...whatever.

While your at the parts store, get a repair plug for the alternator. Most places have them. The plug-in has two wires on it. One is the sense wire, the other is the dash (ignition) light wire. Again, looking at the back of the alternator, the sense wire is the one on the right. That you can put a ring terminal on and hook it right up to the alternator output stud. The other wire then goes to the dash light. I believe there is a write-up on the wiring changes needed voltage regulator somewhere. I'll dig it up if you need.

Also, The alternator may require a longer belt then what is supplied with the narrow belt conversion. I had to get one 20mm longer."

I'll see if I can provide some pics after I get home today.

 

[eschneider]

I use worldwide / remy #14824. I have installed a few of them on Customers' TR-powered Morgans. It is a 3-wire setup, very compact, and about 60A.

A photo is attached at the bracket modification - I cut off the rear tab and move it forward. The bottom half of the ear is notched to allow room for the bolt head. The pedestal mounting bolt also has to be shortened.

I have installed these 2 ways:

1) replacing the main power wires in the harness, and eliminating the control box.

2) leaving the harness undisturbed, and using the control box as a junction / distribution block. I remove the guts, and replace the spade connection with screw studs. I use a strip of copper underneath to link the studs as necessary.

If there is more interest, I can provide dimensions of the brackets (It does vary slightly from Morgan to Morgan, and surely will be slightly different for a TR). I could also provide a wiring schematic, and specific applications for the alternator I use.

 

[eschneider]

Photo of the alternator...

 

[TFB]

Thanks for all the replies ,pics and part numbers.Great info.
The Remy 14824 seems readily available new or rebuilt,or looks like Suzuki Samurai And Sidekick 87-95 or Chevy Sprint 85-88 would be good donor vehicle.
Thanks again
Tom

 

[deadair]

I believe there is a write-up on the wiring changes needed voltage regulator somewhere. I'll dig it up if you need.

I'll see if I can provide some pics after I get home today.

After much handwringing on an alternator decision, I pulled the trigger on the Delco 10SI.

Art, if you could dig up the write-up for the voltage regulator and pictures of your mounting bracket, that would be very much appreciated.

 

[TR3driver]

There is a decision you get to make regarding the wiring of the alternator. Most of the instructions on the web tell you to connect it between the ammeter and the battery, which is easy and reliable. BUT, that means your ammeter will now always read discharge, and no longer indicate whether the battery is being charged or not.

I used an alternate approach for the conversion on my TR3A, which I felt worked very well. Basically, I created a new tie point in the alternator output lead, which is where I connected all the new high current devices (MSD, radiator fan, 100w headlights). The original brown/white and brown/blue wires were removed from the control box, and joined together along with a new wire to the new tie point.

Then I added a shunt across the back of the original ammeter, so it read roughly 60 amps full scale instead of 30 amps.

This setup worked great for nearly 20 years, was still working fine when the car got totalled. When I put an alternator on the project TR3, I'll do the same.

 

[martx-5]

I believe there is a write-up on the wiring changes needed voltage regulator somewhere. I'll dig it up if you need.

I'll see if I can provide some pics after I get home today.

After much handwringing on an alternator decision, I pulled the trigger on the Delco 10SI.

Art, if you could dig up the write-up for the voltage regulator and pictures of your mounting bracket, that would be very much appreciated.

Here's the write-up by Dan Masters from the vtr site on wiring up a Delco 10SI in a TR3.

Let me dig up the pics and see what I've got.

Here's one, but it's not so good. I think I'll have to try and take some more.

 

[Perrymip]

What exactly is a "shunt" and what is it for. In you photo it looks as though you've connected the two terminals of the ammeter with about three inches of nicely dressed wire.

And what are all those dangling, bare, and unlabeled wires at the edge of your photo doing?

 

[DNK]

Perry, I think he was in the middle of a Dan Masters upgrade kit.

 

[TR3driver]

What exactly is a "shunt" and what is it for. In you photo it looks as though you've connected the two terminals of the ammeter with about three inches of nicely dressed wire.

That is exactly what it is. The concept is that roughly half of the current flows through the length of wire, rather than through the ammeter. For my TR3A ammeter, it turned out that 3.5" of 16 AWG copper was about right.

That photo was taken while I was in the middle of dismantling the car (after it got wrecked). Unfortunately I had the panel almost out before it occurred to me to take a photo of the shunt (& ground wire for the fuel gauge), hence all the disconnected wires.

For the original install, I actually used uninsulated steel "handy wire" (aka baling wire, almost as handy as duct tape

). Not knowing what a suitable resistance was, I used a "trial and error" approach. Pulled the ammeter out of the dash (with the battery disconnected), then carefully arranged so the wires could not touch anything and reconnected the battery. Turned the headlights on and noted the ammeter reading, then added strands of wire directly across the terminals until the read was half of what it was before. Only took three strands (but I don't know what size they were). That worked fine for maybe 10-15 years, but then I was cleaning up some things and decided to replace it with the insulate wire shown above.

I've checked several TR3/A ammeters, and they all had about the same 1.2 milliohm resistance. But a friend checked his early TR6 ammeter and found that it was 2.7 milliohms; so it would need more like 8" of 16 AWG to make a 50% shunt. As I've tried to outline, it's fairly easy to try different lengths until you find the right one. (I can explain how to measure milliohms if anyone wants to know; but it's not necessary.)

PS, while Dan's harnesses are very nice, I never got around to installing mine. Not quite what I wanted, and I enjoy making the original harness work (with some tasteful additions

)

 

[eschneider]

Never got the whole shunt thing.....

The concept is that roughly half of the current flows through the length of wire, rather than through the ammeter...... Turned the headlights on and noted the ammeter reading, then added strands of wire directly across the terminals until the read was half of what it was before.

why would you want to only read half the current?

I can explain how to measure milliohms if anyone wants to know; but it's not necessary.

I'm assuming something other than an ohm-meter? I'm curious.

 

[TR3driver]

why would you want to only read half the current?

Because my alternator conversion would charge at up to 60 amps after every start; but the stock ammeter only reads to 30 amps. Also, with all the new loads I had installed (forgot to mention the high power stereo), the load could exceed 30 amps in the other direction. I don't like having gauges that hit the peg (and in fact it started sticking against the "+" peg before I added the shunt).
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]I'm assuming something other than an ohm-meter? I'm curious.
[/QUOTE]
There are ohmmeters that will read that low, but they are expensive and, more importantly, I don't own one. So instead, I ran a current through the stock ammeter and my digital ammeter; then used another digital meter to measure the voltage drop across the original ammeter. Since R = E/I, it was easy to calculate the resistance from the two measurements.

From there, I looked up the resistance per foot and chose a wire gauge that would result in a reasonable length. 16 AWG is given as 4 ohms per thousand feet, or 4 milliohms per foot. The remainder is left as an exercise for the student

 

[eschneider]

Thanks again for the benefit of your experience. This forum is better than colleje.