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Alternator conversion

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richie

richie

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Acknowledging this topic has been covered many times before, I am more curious to know if anyone values an alternator kit (like offered by britishwiring) vs purchasing a ubiquitous GM/Delco 7127 and performing the hacksaw/spacer mods outlined on VTR. I'm aiming for a clean look and minimal trips to the store on this one and don't mind spending the extra money if it's in fact well spent!

The only somewhat unclear portion of going on my own with a 7127 is the pulley. Is the idea to purchase a model with the correct pulley, or do we need a specific pulley, is the generator pulley to be swapped (if compatible) etc?

Thank you!
 
Unless you have installed a narrow belt conversion, you will have to source and install the wide belt pulley. There is no Delco alternator that comes with a pulley for the stock belt, and the pulley from the generator won't fit without machining to fit the alternator shaft. The stock generator pulley is also larger diameter than is optimum for the alternator installation.

For a simple bolt-on, it's probably best to go with the kit. I've always done my own conversions (back then I was not aware of any kits offered), and it has always been an iterative process.

One question to ask : Does the conversion keep the original ammeter functional? Most do not, which may or may not be important to you. Some folks actually prefer the simplicity of a voltmeter, but I prefer an ammeter.
 
I did my own conversionon the 3A gutting out a non-functional regulator to hide the electrical connections.
I used a long stud with double nuts and a tube squeezed between the ears of the TR alternator mount. I first tried to hang it just using the front ear of the TR mount but it quickly vibrated itself loose. Stud mkes it easy to r&r.
Pulley is easy to find as it is common for tractor conversions. You might not need to cut that 1/2" off the alternator ear, mine didn't. Just make sure that you line up the pulleys (use flat washers) and then decide.


Richie, I think that I have a spare wide pulley. I'll PM you if I find it.
 
I got mine from ebay seller triodiode. Came with a special nut.

I've got a just-in-case spare but easier to get one from one of these sources.
 
I bought the british wiring kit, and it "bypasses" the ammeter by running power directly to the starter solenoid. Also, the kit does not eliminate the need to take off material from the alternator housing to align the pulleys. The alternator is stock and has not been modified. The kit includes the single wire alternator with correct wide belt pulley, correct bolt and spacers to mount in original engine block bracket, the heavy wire cable harness to the solenoid, several pigtails used to reconfigure the harness connections to the control box, and directions.

In the end I wanted to keep the ammeter (which I prefer to the voltmeter), along with the original wiring connections to the control box. So I purchased a control box from a lister that had been gutted and modified for this purpose, installed the alternator, replaced the connectors on the existing wiring for the alternator, and rearranged the control box connections as directed. It works great, the wiringn looks original, and the current draw on start up has always been below 30 amps so to date I have not yet found the need to install the Ammeter Shunt Modification that Randall has described in several posts. In the end, for me, it was worthwhile to get the new (not rebuilt) alternator with the correct pulley installed, and mounting hardware, even though I did not use any of the cables or wiring bits included in the kit. If you want a voltmeter, or don't mind a non functioning ammeter, the kit makes total sense....
 
For what its worth I've done both my cars. Generator to alternator. I am just too cheep to spring for the kit..some 200 bucks. You can get the alt. way cheeper. I used the pully off of the original gen. and had the electirc shop drill it out to fit the new alt. 25 bucks i think. Its very easy to do. I saw a nipon alt. or something like that at one of the car shows..very small.. maybe half the size of the regular alt. It was in a restored tr3a and it looked great... I wish I had known about this one when I did mine. The only other thing that I didn't do was to take the insides out of the regulator so you don't have to cut any wires and It looks away better. I don't have any charging issues anymore.
 
What about keeping the thinner pulley on the replacement alternator and changing the crankshaft and water pump pulleys to match and get the advantages of the thinner belt? Has anyone done this? Any idea of the cost comparison or where to get the pulleys?
 
SMGoose said:
What about keeping the thinner pulley on the replacement alternator and changing the crankshaft and water pump pulleys to match and get the advantages of the thinner belt? Has anyone done this? Any idea of the cost comparison or where to get the pulleys?
Click to expand...
That's the way I plan to go, when I get around to building a new motor. The alloy kit I bought from BFE includes a harmonic damper in the crankshaft pulley but was kind of pricey. They have (or at least had) a less expensive kit as well that was based on MG parts.
 
It looks like British Frame & Engine still lists two thin belt damper kits.
https://www.britishframeandengine.com/parts1.html

Randall, are you saying that the only one available now is the one for $420?? I bought the less expensive one from Ken several years ago when I was doing the resto. At the time, he told me that the more expensive damper was basically for racing use where the engine would be seeing rpms of 7K.
 
Moss has a kit, #837-508 and it includes the H-damper at $255. You can save a few bucks on that price if ordered from LBCC. I'll be converting to alternator and smaller belt when I get to that point in my restoration. I have a hard time accepting Moss's price on their alternator kit though, $269 for essentially an alternator and bracket??. Probably end up like Randall did and roll my own.
 
I went with the thin belt fan elimenator kit from Moss for about $250 .The belt size matched the 40a kubota alternator pulley.Seemed the best way to go for me since my car came with no useable radiator,gen,fan or control box.
Tom
 
martx-5 said:
Randall, are you saying that the only one available now is the one for $420?? I bought the less expensive one from Ken several years ago when I was doing the resto. At the time, he told me that the more expensive damper was basically for racing use where the engine would be seeing rpms of 7K.
Click to expand...
Sorry, no, I didn't mean to say that. Only that Ken isn't very good about updating the web site; and I don't know if he still carries that one or not. Most likely he does. I believe it is basically the same conversion that TriumphTune came up with, many decades ago.

PS, I also did not mean to be complaining about Ken's prices. I deliberately chose the more expensive, custom-made unit, as I do plan on extending the factory redline somewhat (tho certainly not to 7K).
 
Richie, I bought the alternator and mounting bolt from Cambridge Motorsport (https://www.cambridgemotorsport.com). It fits on the standard generator mount. I used the 45 amp alternator which is about half the weight of the generator. It is made by Nippon Denso and I think is also fitted to Kubota yard tractors. I already had a thin belt conversion which included a modified MGB crank damper so the pulley was not a problem. My car also had an electric fan which was handy as you cannot run the standard fan with the crank damper. Until I fitted the alternator, I had not noticed that my ammeter was a 50 amp VDO which obviously had been added earlier in the car's life. So no problem there either.

An alternator is one of the best mods you can make, as you can run lights, wipers, heater and radio all at once. You can also fit a smaller lighter modern battery which I am told reduces scuttle shake as well as reducing backache from installing/removing the standard battery! To paraphrase Shakespeare, "lightness is all".
 
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