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MG MGB Technical - Generator to Alternator conversion

I have almost completed a ground up restoration on a 1966 roadster. I have switched to negative ground and installed the pertronics ignition. At this point I want to remove the generator and install an alternator with internal regulator. I need any information concerning which one, bracket modification, wiring conections etc. Thanks
ARB Bell

I recently did the same conversion and I used the info from this site:

http://www.mgcars.org.uk/MG_Elec-tech/pwr_conversion.html

I kept the regulator in place as it looks better IMHO.

Easy to do but take your time. Good luck
Mike MaGee

Mike:
That URL just takes me to the MG Cars home page. Is it correct?

Andrew:
You can easily convert to a 40-something-amp Lucas alternator from a later MGB:
http://www.mgbmga.com/tech/mgb6.htm
http://www.middlebank.co.uk/NegEarth.htm

...or a 50-something-amp Bosch from a Ford Fiesta:
http://hometown.aol.com/idbritcars/boschAlt.html

...or with more difficulty, to a 70-something-amp AC-Delco from a Chevrolet:
http://www.mgbexperience.com/service/delco.html

Having first done the Lucas conversion on my '67 MGB GT, then the AC-Delco, I would strongly recommend the Lucas or Bosch conversion over the latter. The bracketry for the AC-Delco is quite challenging on an early MGB, but it is much cheaper and replacement alternators will be readily available long after our MGBs have all rusted away. Should you decide to go AC-Delco route, I have lots more information on this conversion.

~Jerry
Jerry Causey

Welll, I copied the URL from the page and I guess it won't automatically bring you there and brings you to the home page. Oh well.

I did the Bosch conversion and it was pretty easy. I did tap and put a helicoil on the alt so I wouldn't have to use a nut for the adjustment arm. It makes tightening the alt down mucho easier. All other cars I own have that feature. Just a little mod that makes life easier.
Mike MaGee

Try this URL to get to Rick Astley's Electrical Site http://www.mgb.bc.ca/electrical ~ well worth bookmarking and if you check out the Charging area, you will find info on converting from an early MGB generator to an alternator. Good luck!
Bob Muenchausen

Andrew, I was planning to do the same 8 years ago. But then I got the same advice I'm passing on now: Why in the first place do you want to replace the generator with a - non stock - alternator? I'm still happy I followed that advice. I restored my '66 B in '95, converted to neg. ground - which IS a useful upgrade, installed new bushes in the generator. Haven't looked at the generator ever since. Maybe I don't make the mileage (mine 5000 k/year) you are planning, but even then, why replace something which works OK?
Bert Otten

Andrew, several years ago I was also planning on changing my MGA over to an alternator, when a fellow MG enthusiast asked me why. If you don't need the extra amperage that the alternator puts out, the generaters were IMO, more reliable.

When's the last time you were out with a group of MG's and a generator went out? How about an alternator?
DLD Densmore

An alternator will charge at idle whereas a generator probably will not. There was a spate of Lucas alternator diode stacks failing in the 70s, but since then I would say they are *at least* as reliable and there is a lot less mechanical things to wear out on the alt than the generator and control box. Given that there were close to three times as many alternator equipped cars as generator equipped it would be easy to gain a perception that alternators are less reliable. My only generator-equipped car failed with worn brushes in the first week of my ownership having covered only 35k miles from new, since then I have only had one alternator failure and that was the aforementioned diode stack in the 70s, even though I have covered over 60k miles in at least two of them. Having said all that, If I had a car old enough to have been equipped with a generator originally I wouldn't change it.
Paul Hunt

Thanks for everyones input seems like quite a bit of good information. Now heres an interesting poll. How many owners still with generators (pre 1968) versus converted
over to Alternators? I pretty well decided to rebuild my generator and leave orginal.
ARB Bell

I've kept the generator (and positive ground) on my 66B. Just like it that way.
Kim de B

67 MGB still has generator and positive ground with positive ground AM radio. (still works)
Jim
Jim Lema

There is nothing wrong with using generators unless you spend a lot of time sitting idling, as Paul points out. In the days when batteries were not nearly as good as they are today, alternators were a real asset to keeping the charging system up to snuff. Today, it is perhaps not so necessary. Someone like Dan Masters or Paul could probably give you better insights into this question, but this is how I have thought about this question before converting my MGA to an alternator.
Bob Muenchausen

I vote for leaving the generator too! I have 66B with a negative ground conversion and have had NO trouble with the generator in years. Also brushes and bushes for the generator are cheap.
Russ
Russ Williams

ARB Bell, Here is something to consider. I found out recently that British Car Conversions sells a 50 amp 6 lb. alternator with installation kit that will fit a late model MGB without disturbing your present wiring. I would imagine it would work on any MGB. It uses a one wire hook up that goes to the + battery and that's it. They have models that use two wires that also don't require disturbing any of your original wiring for a less. It's described under "pictures" on their website. It says for Mini, midget, etc., but the guy I talked to said it would definitely fit the MGB but hasn't had the opportunity to add it to the description. Look at Killerbv6.com
Kevin

Still have a generator in my '65 B. I'm about to rebuild it because of a rattle in the bushings. This will be only the second rebuild in tens of thousands of miles over the 15 years I've owned it. I've considered converting as well but have never come up with a good enough reason to. My headlights are plenty bright.
Steve Simmons

Generators, like alternators, fail too. A friend's generator packed it up when the bearings froze. I do a lot of idling living as I do in NYC and the electric fan can suck up a lot of juice.

Do as you please - it's your car.
Mike MaGee

"In the days when batteries were not nearly as good as they are today"

Ah, but you have got to stick with the twin 6v as well ...
Paul Hunt

ARB,
I converted my '66 from generator to a Geo Metro alternator this year. It is tiny and produces 56 amps. I made my mount from two pieces of 1/2" bar stock welded side to side with the ends drilled and tapped. The two pieces fit in the existing generator mounts on the engine and between the mounting ears on the alternator. A local alternator shop supplied a grooved pulley to replace the serpentine stock piece for $5.00. I paid $7.00 for the alternator at the U-Pull It. It works great and it really freed up a lot of room under the Webers on my cross flow.
David
David

David,
email me about your Geo Metro conversion, or do us a website about it. I am always curious, even if there is no good reason to be (you may have noticed that by now!).
Bob Muenchausen

This thread was discussed between 27/11/2003 and 30/11/2003

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