Swapping out a generator for an alternator

[cathead]

For what it's worth, I like to labor on Labor Day on general principles.
The generator on the D6 had failed some time ago and needed a
repair or better yet a replacement. The bearings were bad and the
key way was worn badly so opted for a new 50 amp 24 volt alternator.
The mount for the generator was a lot wider than the alternator so
had to do a bit of machining to make the alternator fit the space.
It was a struggle to remove the rod pressed into the cast iron housing
but with the use of a come along and a pipe wrench, it finally gave way.
I bored a half inch hole all the way through the rod and cut it off to
fit the alternator. I also did a skim cut on the rod so that it would be easier
to install on the CAT. Now I can run a long bolt through the rod and fasten
the alternator. The next thing will be wiring the alternator up as I don't know
if I need a regulator or if the alternator has one inside it.

The pulley was sloppy loose on the generator so I had to machine a press fit sleeve with a key way. It
seems fine now so expect it will not be problematic. Tomorrow I can install the alternator and take a look at
what will be needed to wire up the alternator.

It will be nice to use the CAT without charging the battery with a generator and battery charger every time
I want to use it.

 

[AGCB97]

A 'one wire alternator' only uses a fairly big wire to battery. Hope that's what you got!
Aaron

 

[AGCB97]

Like this but there are cheaper ones.

https://www.amazon.com/REPLACEMENT-ALTERNATOR-TRACTORS-1-WIRE-DOUBLE/dp/B07K8TKDC8/ref=asc_df_B07K8TKDC8?tag=bingshoppinga-20&linkCode=df0&hvadid=80401852210514&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4584001420365260&psc=1

 

[Toolmaker51]

Pulley swap may not achieve sufficient RPM to charge effectively. You'll want to "gear" it, diameter-wise, suitably.

 

[cathead]

Pulley swap may not achieve sufficient RPM to charge effectively. You'll want to "gear" it, diameter-wise, suitably.

The pulley ratio on the CAT looks to be at least two to one, maybe even three to one. That means
that running the CAT at 1800 RPM working speed would drive the alternator somewhere between
3600 and 5400 rpm. The other consideration is that alternators are able to charge at
lower speed than a generator. Also the pulley has a deep well configuration so I wanted to use it so it would
line up with the engine pulley and still be able to use the mount for the generator. This alternator is
specifically made to fit this CAT using the original pulley. I have heard it said that there is more
than one way to do anything which I believe to be generally true. I could have saved a few bucks
using a 24 volt automotive alternator possibly and then have to deal with the inevitable mounting
problem and the fact that the pulley would not fit the huge existing fan belt. So for me it was pretty
much a no- brainer to do it the way I did it.

 

[Superburban]

You will be fine, may not get the full 50 amps, but be darn close. Will do better then it did with the generator.Most alts do about 90% of rated cap at 3000 Alt rpm. The idle might be an issue, as most do not start until 1000 alt RPM. But often you can bump the throttle a tad, then let it back to idle, and they will work. Just need to get the RPMs up to get them started, then they will keep working when you drop back to idle.

 

[pontiac428]

Most alts need a 2:1 drive ratio. 6" is probably the most common crank pulley diameter out there. You may need to loop a resistor into your voltage regulator or install a "lamp" in your instrument panel. Sometimes regulators need to see a 3600 alt RPM blip to start charging, that's a one-time thing on startup. You can change any aspect of an alternator by swapping its components, so it's not the end of the world if it's off a pulley size or voltage regulator spec. That is where US Quick Start is your friend on the internet.

 

[cathead]

Most alts need a 2:1 drive ratio. 6" is probably the most common crank pulley diameter out there. You may need to loop a resistor into your voltage regulator or install a "lamp" in your instrument panel. Sometimes regulators need to see a 3600 alt RPM blip to start charging, that's a one-time thing on startup. You can change any aspect of an alternator by swapping its components, so it's not the end of the world if it's off a pulley size or voltage regulator spec. That is where US Quick Start is your friend on the internet.

Thanks John for the post. That prompted me to do a bit of research on the internet about the lamp or resistor. I saw several ways
to do this and took some notes so today I will get into the wiring part. The CAT has an ammeter so that would suffice to connect
the alternator output to that, maybe add the light too if convenient. The alternator has a built in regulator so don't expect it will
be too challenging. The hardest part will be to run the wires in some sort of protective piping. The old wires ran in some plastic
coated conduit so hope to be able to use some of those wires for the install. None of the wires look to be able to handle 50
amperes though so may have to improvise for the alternator output wire.

 

[Superburban]

What model is the alternator? At first I was thinking it is a Leece neville, but second look, I am not sure. I have a bunch of litature from my alternator working days. Might have what you nee for wiring. In general, it is only the older delcos that need the light/ resistor, others it was for alerting the operator, and was more optional.

 

[cathead]

What model is the alternator? At first I was thinking it is a Leece neville, but second look, I am not sure. I have a bunch of litature from my alternator working days. Might have what you nee for wiring. In general, it is only the older delcos that need the light/ resistor, others it was for alerting the operator, and was more optional.

The alternator came from Romaine Electric. The markings on the alternator are unfamiliar to me as it is labeled D+, B-, and R and the big
lug which of course is the output. I'm going to use the ammeter so don't care too much about the light part. I don't have a model number
at this location. Thanks for helping.

Edit: I got a little information from Romaine Electric. D+ is the exciter, B- is ground, and R is for an electronic tachometer.
Apparently I need to connect a lamp from the exciter to the Battery plus side or possibly a resistor instead of a lamp.
I'm thinking of using a 100 ohm 10 watt resistor for excitation.