24 replies to this topic

[soopercooper]

thanks all, will start to accumilate the bits needed

[Dan]

Also, if you want it all to look original there is a company who makes Lucas A127 type 70 amp alternators, re-built to resemble a Lucas dynamo. Proper old dynamo, black casing and everything, but well converted and with enough cooling. People put them on MGs and Triumphs and stuff, I'll try to see if I can find out who they are. I think this type would use the original dynamo brackets too.

[dklawson]

Dan, that would be PERFECT. I hope you do find the information. I have a big Motorola alternator on mine. I made a copy of the original ignition coil bracket to fit around the alternator to disguise the conversion... but there's just so much you can do to conceal a diameter and length change.

On a similar thought, I wonder if it would be possible to fit a small Japanese alternator inside an old generator housing and add an additional cooling fan. It sounds like an interesting project for the spring!

[Dan]

Here's one,

Race mettle

but that one's really expensive and none too powerful. There is another who might be called Classic and Vintage Dynamos, but I can't track down a website for them at the moment. I wouldn't be surprised if they didn't have a site as I think it's a small company that trades from home.

[dklawson]

Thanks Dan. I've bookmarked the site. I figure that to be a 40 Amp conversion based on their numbers. Better yes, but I've converted to halogen lamps. I'd feel better with something providing over 50 Amps. I love the idea or having that purely original look again though.

[Dan]

I think they call that a 40 as it is based on the 40 amp dynamo, and it actually supplies something around 60 to 70 amps as an alternator. But that is rather second hand information and could be wrong. There's nothing useful on the website though from a technical aspect which is dead annoying (I hate when people do that) so I suppose the only way to get good intel is to speak to them directly.

[dklawson]

I would be happy with 60-70 Amps but their web page said that their conversion delivered an 80% increase in output. Presumably they mean 80% more than the 22 Amps the C40 generator has. When I do the math I come up with an output a little over 39 Amps. That's not bad, but I'd like a little more. I was also scared when I didn't see any prices posted on the web site. The shipping cost alone for such a heavy item would probably be prohibitive for me.

[Lotusman33]

DK I converted my 71 - 1275GT as per KC. Gutting a control box and soldering the relevant wires. Looks far better than chopping the loom.

Siggy


Parts needed:
bracket 12G1053
pulley 12G1054
fan C37222A
belt GCB10825
1. Disconnect battery
2. Remove regulator box from car, carefully marking all connections.
3. Remove dynamo, etc.
4. Fit alternator, new bracket, and new belt.
5. Dismantle regulator (use junk regulator if you have one). Remove coils and contacts. Remove connections to blade terminals.
6. Solder links between terminals A, A1, and D, connecting all three.
7. Solder a link between terminals F and E.
8. Reconnect loom to correct terminals-EXCEPT-connect ignition warning light (brown/yellow) to terminal E.
9. Connect alternator to loom: Large wire to large terminal (output), and small wire to small terminal (sensing).
10. Reconnect battery

Help?
Great thread but come against a problem....
I have just done this modification, my yellow/brown wire used to be connected to terminal D but if I move it to E what happens to the black wire already connected there? Should I put both together?

[dklawson]

WOW!  Great use of the search utility!  I am impressed !

 

Now to your question.  Note that in the conversion you have copied above, you GUT the old control box, removing all the old coils and wires.  You are left with a bunch of LARGE and small spade lugs attached to the bakelite housing.  You connect all the large terminals to one another by soldering on heavy copper jumper wires (on the bottom side).  You do the same with smaller wire to connect the small terminals to each other.  

 

Once you have the modified control box installed in the car you connect all the wires as noted above (all the large wires on the large terminals and all the small wires on the small terminals).  EXCEPT, you do NOT connect the old black earth wire.  Tape it off and place it to the side.  It no longer connects to the control box.

 

Repeat:  Do NOT use the old black wire.  The black wire is an earth connection and ALL the wires on your modified control box are "hot".  If you connect the black wire to anything you are providing a direct short to earth and this will let white smoke out of something.

 

Again, great use of the search utility!  Well done!

[Lotusman33]

Hi Doug
Thanks for the reply, it worked perfectly today when I tried it out, not been out the garage for a while as had a hernia operation hence slow reply.
I enjoy searching out old posts as the answers are always on here someplace!

Dave :)