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Gen > Alt conversion Question

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64rocksprite

64rocksprite

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Hello all,
I've researched the forum like a mad-man..lots of references to alt upgrades and conversion. I see lots of folks have used the Mitsu generator, or other (Fiesta, subaru, Delco)

I know I need an internally regulated alternator for the conversion, but when shopping for a alt, how can you tell? The Delco ones are specified as such, but I agree with some folks that think the unit is rather large for the engine bay.
I found a new alternator for a 280Z on CL..has the right mount configuration (with some spacers I'm sure..but the question on the internally regulated.
Can someone shed some light on this?

Thanks!
Devin
 
Devin,

Look out when trying other brands of alternator, as the direction of rotation is an issue. Look at the vanes on the front pulley and ask yourself if it will turn in the correct direction when mounted in a spridget. Other than that, volts is volts.

I've got Mitsu alts on a 1960's A14 Datsun engine in a Morris Traveler, a 1275 in a Sprite and in an Austin A35. Well worth any trouble.

Glen Byrns
 
Why do you necessarily need an atternator with a built-in regulator? On my Mini's I put lots of Datsun alts on with external regulators and they worked fine (and were cheaper!). I have stuck with a generator for my Sprite since it is a "toy" car and not my daily transportation and it works well for that.
Bill
 
The perfect alternator conversion, re: direction of rotation, size, internal regulator etc. is the one out of a Nissan/Datsun B210 pick-up truck (80s vintage)! See below... (pardon appearances as it was sitting for a while when this was taken!) I had to put the Sprite pulley and cooling fins on (see red arrow where I had to bend the fins - since redone by cutting rather than bending!) Red arrow on left shows later-model Spridget alternator bracket - originally we welded one up!
 

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Bill,
I had read a post that said "Any modern internal regulated alternator will work." Which, as Glen pointed out, may not be the case depending on rotation (Thanks Glen...hadn't thought of that aspect).
I am guessing that an internal regulator was suggested for simplicity..(?) Are your 'external' regulators mounted on the alt itself or a separate unit?

So both Mike and Bill have Nismo alts... Mike - what was the clearance issue that you had to modify the fins? the bracket or h2o pump ear..or ?

So if I find a Nissan, Mitsu alt..I should be off and running. For $25 this 280Z new alt might be the ticket!

Thanks all
Devin
 
Belt alignment as I recall meant putting the pully up closer to the body of the alternator which made the cooling fins rub a bit, It's been years since I did it though ( at the same time I switched to Neg. ground and I have NEVER had charging or electrical problems with it!). PS: it's also a single-wire hook-up to the switch which simplifies things a bit,ie 1 wire to cchargecthe battery and 1 to the electrics!
 
Nearly all engines turn the same direction, with only few exceptions. Also some cars like the Jag V12 put the alternator in front of the belt, or have the drive belt mounted on the back of the engine. These will turn backwards, but are easily recognised by the fan.

An internal regulator adds both simplicity and a cleaner engine compartment. I have never seen an external regulator mounted on the alternator. Usually with a foot or so of wiring connecting them.

Rather than bend the fins, I would probably have cut down the mounting ear so that the alternator sat further back. Plus a "little" alignment problem isn't too bad. More is bad.

For me, the biggest differences are that some alternators use the "one ear" system, like the Delco and some Mirelli and Ducelear. Some use the "two ears" system like the original sprite unit or Bosch. Definately use a two ear, from personal experience. The Delco on my Land Rover is a bear to remove. The one ear system uses a very long bolt. (I since replaced it with a Bosch)

Sorryfor rambling
 
The reasons I went with 1-wire alternators in all three of my LBCs is everyday driveability. All are used around town in traffic and thats where generators are at a disadvantage. No matter where I am in this country, if my alternator goes out, NAPA has a proper replacement. The Lucas voltage regulators are known for screwing up and overcharging batteries. Hence the rarity of an uneaten battery shelf. As mentioned above, the simplified wiring is nice and neat. You can pick a version that will make enough power for whatever outrageous accessories you've added to you LBC. (Giant amp, stereo, woofers, Megasquirt, halogen headlights, emergency TIG welder outputs, all the above..)
The only reason I can think of for using an original LUCAS generator is for showing an original car to its best advantage. Who cares how much power it does or doesn't make when you just drive it onto a trailer and maintain the battery with a trickle charger?

Glen
 
Ford Festiva, most Mazdas, (Mitsubitchi alternators) and some Hondas all have omnidirectional alts. They don't care what direction they spin. And most of them do not have fins anymore. I pick up junk yard alts for about $25, of the dozen or so I snagged, only one was dead.
Most of the modern cars will need the serpentine belt pulley replaced with a V belt pulley. And there is that alignment problem, I just grind about 1/8" off the water pump ear and the belt runs true.
Make sure the alt you pick has 2 mounting ears similar to the Lucas alt and generator, the ears should be 180* across or you will have mounting problems.
I think my Sprite with the festiva alt even uses the stock fan belt.
 
I have a hard time understanding why there should be a direction-of-rotation issue at all. Either way, an alternator just generates the same AC output, which is rectified to DC by the diodes. Obviously, if there is a fan, that would have to be right for the direction of rotation, but I can't think of anything else. Is there a mechanical issue, apart from the electrical one? Or, am I missing something obvious? (Wouldn't be the first time.)

I'm interested in this, because I would like to replace my generator with an alternator. I like the engine compartment looking basically original, but now that I've installed an ammeter, I'm seeing that the generator doesn't come close to meeting the electrical load below about 2000 RPM. Indeed, there are plenty of alternators out there that could work, but the real issue, it seems to me, is fit and belt alignment.

Also, for some reason, it seems that lots of replacement alternators don't come with a pulley or fan, and those seem hard or expensive to buy. Guess I gotta get used to visiting junkyards...!
 
As far as I know, the rotation of a generator is determined by an angular offset of the field and armature centers. The alternator doesn't have such an offset due to the constant magnetic field on the rotating stator. The only difference would be the fan.

But I could be wrong. ;-)
 
Sarastro said:
Guess I gotta get used to visiting junkyards...!
Click to expand...

/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif You really should!! I find that a once-a-month or two visit to a junkyard is great therapy /bcforum/images/%%GRAEMLIN_URL%%/grin.gif , even when I don't find anything I need!!! /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif
 
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