Type Three Tuning Page -- Generator

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> Also, [the generator] ate through a set of generator brushes in a couple of hundred miles.
> 
> Currently have newish brushes in.  Red light always on now.

The tops of the brushes need sit somewhat above the top of the brush 
guides. If the end are below the ends of the guides they are too 
short to reach the commutator reliably.

Look at the side of the brush, where the pigtail comes out. There's a 
notch in the side of the brush guide to allow the pigtail to come 
out, but if the pigtail is hitting against the bottom of that notch, 
the brush can't drop down any more. That keeps it from reaching the 
commutator.

BTW, Bosch made several different versions of brushes for different 
generators. They differ in length and the angle of that little ramp 
at the top where the brush spring presses down. For beetles, where 
the generator rotates in the opposite direction (in relation to the 
brushes) that ramp faces the other direction. If you get the wrong 
set of brushes with the ramp facing the wrong way, the brushes will 
tend to hang up in the brush guides. Likewise, if you get a set of 
brushes that are too long, the spring will be pressing more sideways 
than down and this will also make them stick. You have to be careful 
to get the right brushes.

> For a while, my voltage regulator has been buzzing a bit.

The buzzing VR is also telltale, and indicates that you should 
probably replace it. I don't know if a bad VR would eat brushes 
quickly. I haven't noticed that, but noise from the VR is always an 
end-of-life sign. When the VR makes noise, the relay contacts inside 
it are welding and breaking open. This would put an intermittent 
heavy load on the generator and brushes which might cause rapid brush 
wear.

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Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
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Custom
Generator to Alternator conversion document by Toby Erkson.
Generator-to-Alternator Conversion
Revised as of 11Dec2003.  Part number included.  Current picture on my engine.
Here's a blurb from another person who used my document with a different alternator:

I want to start by saying thanks for all the info and help. I'm still pulling all the parts together to complete the switch from 6 to 12 alt. I contacted your friend Bill Jungck at PMX about the alternator and he does still have the part although he wouldn't tell me much of the specifics. Fortunatly at the same time my local parts guy hit pay dirt. It's a rebuilt Nippondenso 50 amp part #14945. It is identical to your picture and the circumfrence is a perfect fit into the fan housing. The only difference is in the electrical connections. While it does have the battery cable bolt on the side, it does not have the "pig tail" connection you spoke of. Instead there is a small recessed cup with three male terminals in it. The first one,according to the paperwork, is an ignition terminal."This terminal must have voltage from the ignition switch usually by means of a ENG fuse." The second is a terminal S." this voltage is supplied directly from the battery and will be present whether the ignition is on or off. The third terminal is labeled L. The only info I have is that it is connected to an "alt fuse" and that " the alt fuse protects the indicator warning lamp from current spikes in case the BAT wire should become disconnected from the alternator. This fuse may not have voltage present which is normal under many circumstances."


RX-7 Conversion by Pat
I know that a lot of you are in search for a good Alternator mod for the type III engine. I have found one that works well. It is a Mitsubishi 70 amp from a late model Mazda RX7.. ya I know... yukkk, not German. I cut off all of the mounting brakets, used a belt sander to round the unit to fit in the generator saddle, and then made a new mounting strap out of flat steel to hold the little devil down. The generator pulley fits the shaft...woopie... but there is no key on the shaft. No matter, the bolt snugs down on the pulley and all is wonderful; no key needed. You need to cut the spacer that comes with the Alternator to space the pulley away from the sheet metal. The stock belt fits. You may need to go to the next length up. The cover tin fits great ... A few photos ... of the 3rd engine I have installed it on.

Engine shot 1  Engine shot 2   Belt cover on  Belt cover off   Top view close up  Top view   Back side close-up

It is a 1776 FI engine. This alternator looks the same as the Late Model RX7 one that is 70amps, but is a erlier one that is 55amps. Both are installed exactly the same way. I cut off all of the brakets, used a belt sander to round off the unit, and then drimled out a few spots on the housing for an exact fit. When I get this engine in and running, I will take a shot of the wireing on the back. There is a plug that goes in the bottom back for the "GEN LIGHT" wire, a ground wire that secures to a bolt, and the hot wire from the stock generator goes on the hot stud/bolt. Take all of the wires that are red at the stock regulator, and tie them together. This is done because of the alternator has a regulator in it. It is wired up just like if you were installing a OEM alterantor on a Type I to replace the generator.

Get back to me with your questions. Thanks, Pat@volksclocks

Here's some more from Pat:
I have just done a run of a few auto wrecking yards and these are the part numbers for the types of Mitsubishi Alternators that are on the RX7 cars. Some are 50 amps, 55 amps, and 70 amps.

A5T20374    12v/50amps    built in regulator - 70s RX7
A5T30574    12v/55amps    built in regulator - early 80s RX7
A2T04474    12v/70amps    built in regulator & cooling fan - late 80s RX7

There seems to be 2 different types of these alternators. One type has a cooling fan mounted on the outside and behind the pully. This fan needs to be removed so that the pully will fit into the sheet metal housing that has the fan belt in it. You may use the stock VW pully after cuting the spacer down that comes behind the stock RX7 pully. You may also use the RX7 pully which is smaller outer Diameter which makes it spin faster. The choice is up to you. You can see this type in the pics that Toby has on his site of a modification I did recently. It was a 55 amp one. The lack of a cooling fan is made up for by the cooling air hole located in the fan housing under where the generator/alternator sits. The second type of alternator is the internal fan type. All of the 70 amp ones I have seen have been this type... and about half of the 50/55 amp ones are too. If you use this type, just use the stock RX7 pully and get a fan belt about 1 to 2 inches smaller.
Toby,
  I saw your orange squareback in the January 2001 issue of Trends. That
slick alternator conversion was the answer to my prayers!  I inquired
with VW Trends in January 2002, which was published in the July 2002 Nuts
and Bolts section (page 76). I printed out the your instructions and got
to work. 
  I was also aided by Global Remanufacturing in Warren MI. The Nipondenso
50 AMP alternator is rare here in Michigan and runs $315 for a new one.
The guys at Global showed me a 70 AMP and a 90 AMP Nippondenso unit. I
chose the 70 AMP ($100) which is just slightly larger in diameter than
the stock generator, and just fits under the deck lid!. This unit is used
in 1992 model year Honda automobiles. 
  I made two special brackets from 1/8" x 1" cold rolled steel (some MIG
welding required) that utilized the alternator's stock mounts, this
allows about 3/16" swing travel for belt adjustment. Starting with your
suggested Goodyear 15391 36" alternator belt, two more trips to Murrays
Discount Auto Parts and a very helpful, understanding salesman, I ended
up using a Goodyear 15396 39.60" belt. Your cabling scheme worked great.
The setup has been working perfectly since July 20, 2002! 
  I decided not to use the stock rubber boot that went between the
generator and the fan housing as it didn't fit well and the engine
cooling fan tends to pull a small amount of air through the alternator
which seems to aid in cooling. We had a sweltering summer here in
Southeastern Michigan with daytime temperatures in the high nineties. The
external running temperature of the unit never went above 180 degrees,
checking with a digital temperature probe.
   Thanks to your guidance, I have gobs of electrical power and no longer
have to judiciously use accessories! 
   By the way, my Type III is a 1968 Fastback that's been in the family
since it was new. I'm running a 1955cc motor with 7 to 1 compression
ratio (91 M+R/2 Octane pump fuel), Mofoco 042 heads and hydraulic lifters
and cam. I eliminated the stock oil cooler and use a remote plate style
cooler with an electric fan and a remote oil filter. I modified the left
hand cylinder tin so all the cooling air on that side goes over the
cylinders and head, I also use a set of "cool tins". Sump oil temperature
rarely goes above 160 F. Fuel delivery is the dependable stock Bosch
D-jetronic fuel injection with a custom 76mm throttle body. Other stuff-
Jacobs Bug pack ignition, headers flanged to the heater boxes with a
custom 2" catalyst-resonator-muffler set up. Transaxle: Transform, beefed
up, superdiff, stock 1,2,3,4th gears with 3.88 ring & pinion. Plenty of
power, runs cool, clean and can get 28 MPG highway/city if I don't drive
like I stole it!

Happy Motoring.
Joe Chircop

Just a quick note, I found another alternator that works but requires
more modifications to the body than the one you listed.  It is designed
to go on a Caterpillar.  That's right, a Cat.  It's a 4" dia. 55 amp
alternator that needs 2 wires, 1 for the battery and 1 for the field.
It is basically the same housing you have other than the mounting
brackets are different.  It is a Denso 101211-2770 or a Cat number
144-9954.  Usually they cost $200.00 or more but this was sitting in the
junk pile of the alternator rebuild place where I live.  He had got a
new one for the guy that brought this on it.  He gave it to me so I
could show the local suppliers that one like this does exist.  Little
did he know that another rebuild place in the next city over had one
with the opposite parts broken than this one.  Combine the two together
and for $65.00 I have a 55 amp output unit.  <click for picture>
...
Chris Jensen
Chris is using a Type 3 engine in a baja. ~Toby