3 brush to 2 brush generator conversion

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countershaft

3 brush to 2 brush generator conversion

#1

Post by countershaft » Thu Apr 21, 2005 8:30 pm

Anybody done a conversion on Gen. to switch from 3 brush to a 2 brush to boost output.At one time had article on how to do it used same case cant remember what allyou had to change. Id forget my ole ladies on the back of putt if she didnt keep hitting me side the head yellin some crap bout slowin down!
thanks countershaft



Cotten
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Re: 3 brush to 2 brush generator conversion

#2

Post by Cotten » Fri Apr 22, 2005 1:11 am

The conversion does not so much change output as it allows a regulator instead of a primitive relay, thus enabling the machine to operate at modern highway speeds and still maintain the battery.

The best reprint of vintage instructions is in KickStart M/C Parts' catalog (616-245-8991). Although the catalog is devoted to earlier models, there is much that applies to rigid Pans, and the effort deserves patronage.

The conversion just involves removing the third brush and wiring the two fields in series, and then using the -47 Delco regulator (I prefer Argentinian replacements to USA Accell crap) instead of the relay. Obviously a regulator mount is the most tedious aspect.

Rammy
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Re: 3 brush to 2 brush generator conversion

#3

Post by Rammy » Mon Apr 25, 2005 5:11 pm

I did this conversion to my Glide, It works well , no more games with over or under charge. nothing to buy except regulator. ;)

King
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Re: 3 brush to 2 brush generator conversion

#4

Post by King » Mon Apr 25, 2005 6:18 pm

Hi Cotten and Rammy

My 32E is acting strange and i think it's time for the 2 brush conversion. Any info on suppliers of the regulator like the Argentinian model?
Thanks

King

Cotten
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Re: 3 brush to 2 brush generator conversion

#5

Post by Cotten » Tue Apr 26, 2005 2:42 am

The Argentinian Bosches are not the same regulator as the -47 Delco unit.

I found the cheap repops to be the same as expensive ACCELs, except ACCEL's occasionally are dead right out of the box.

kell
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Re: 3 brush to 2 brush generator conversion

#6

Post by kell » Wed Apr 27, 2005 12:57 am

Once you change to a 2 brush setup it works the same as a generator from a 1960's car, and you could probably use a cheap replacement regulator from, say, a 1967 Dodge Dart.
Not all car generators were wired the same. On some, the regulator went between the field and ground, same as on a Harley. I'm pretty sure Chrysler used that setup. On the other hand, you woud not be able to use a Ford regulator because they had a system where the regulator goes between B+ and the field.

I didn't actually use a Dodge regulator on my pan's 12 volt conversion, I used a regulator from a Delco 10 SI alternator (a GM type), so I can't speak from experience that the 1960's Chrysler system also works, but from what I've read on the net it is the same as the GM. The Delco alternator I used is just inconvenient to wire because it is an internal regulator and doesn't have labeled terminals, plus it requires an extra diode.

Cotten
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Re: 3 brush to 2 brush generator conversion

#7

Post by Cotten » Wed Apr 27, 2005 2:20 am

Beware of auto regulators, as they put out amperage for a much larger battery.

As I posted, there is nothing wrong with the cheapo Delco repop replacements. (Only the expensive ones have a bad rep! I think Accell buys seconds and returns and repackages them, like CCI and so many mailorder houses.)

108
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Re: 3 brush to 2 brush generator conversion

#8

Post by 108 » Wed Apr 27, 2005 4:57 am

Cotton, On a post above you refered to the 3-brush generator as not charging at highway speeds and some other post mentioned their gen light comeing on at high speed . why would this most likely happen ? I've also wondered- If the 3-brush system was so trouble prone, why did HD use it for -what- 40 years? :-/

Cotten
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Re: 3 brush to 2 brush generator conversion

#9

Post by Cotten » Wed Apr 27, 2005 1:04 pm

108!

The 3-brush is very simple and primitive, which is good in some ways,...but when roads were no longer simple and primitive, machines began operating for extended periods at highspeeds. The unregulated system works great if you are constantly reduceing speed to avoid a cow or a pothole, but it discharges at highway speeds by design, lest it boil the battery.

It seems incredible today that a vehicle would be designed for "low performance", but machines were expected to service offroad as well as on ... well into the 1950's. Another classic example of this archaic engineering approach is the Knucklehead itself, which demands occasional rapid de-accelleration, or it will flood the heads with oil after 15 to 30 miles at highway speeds (thus, the notion that Knucks are notorious leakers resulted from ignorant modern riders!)

An extended stretch of un-interrupted 60mph+ highway was comparatively rare before the Eisenhower administration. We must not forget that we are truly riding pieces of history.

Countershaft

Re: 3 brush to 2 brush generator conversion

#10

Post by Countershaft » Wed Apr 27, 2005 10:16 pm

Great job on this site everyone!!!!!! Does my heart good to know there are alot more people riding Pans than I thought used to seeing trailer queens around here
Thanks for the article Panhead just what i was looking for! Ride safe Ride Hard

Countershaft

108
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Re: 3 brush to 2 brush generator conversion

#11

Post by 108 » Thu Apr 28, 2005 4:46 am

Cotton , thanks for the reply on thr 3-brush high speed discharge. I'm not shure I understand since mine seems to show about 3-4 amps. at 65mph( lights on all the time of course) but I'll read all I can about it and study for awhile untill I do. Also , I thought the hard decell at times durring a high speed ride was recomennded so the high vacuum would suck oil down the valve guides lest they get too dry. Or was that just on Pans?

Cotten
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Re: 3 brush to 2 brush generator conversion

#12

Post by Cotten » Thu Apr 28, 2005 12:15 pm

I'm not too bright about e-lek-trisity, so I shall have to look for my genny literature at the shop, although I'm pretty sure it is discussed in Palmer's.

The Pan was the first HD OHV where you could plant the throttle and forget it.
You really do not want much oil in your guides. That's why they invented seals!

108
Posts: 179
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Bikes: 1948 FL 74in Panhead Chopper , 1958 Zundapp Citation 500
Location: Indianapolis

Re: 3 brush to 2 brush generator conversion

#13

Post by 108 » Fri Apr 29, 2005 2:43 am

Cotton, you're correct about oil in the valve guides of coarse . I should have thought a little longer before that post. the quote I was remembering was in an old Pan manual reprint and under "high speed tips" it said ...." snap the throttle shut at times when at high speed to draw axtra oil into the cylinders to help lubrication and cooling"

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