Logo

1962 Gray Marine generator to alternator conversion

shelbygt

New member
I'd like to convert my delco generator to an alternator with built in regulator. Is there an alternator that would bolt in with same generator brackets??
 
I highly doubt that you'll find an alternator that mounts in a similar fashion as an older generator would.

The Delco 10si, in the Marine version (in what they call the "1 wire"), would be a good candidate.
They are fairly inexpensive, and use an internal regulator.

They do require a bump in RPM to become self excited, but once excited they will remain excited until shut down.


Here's the typical mounting style for a Delco 10si.

02367_B.jpg





.
 
I'd like to convert my delco generator to an alternator with built in regulator. Is there an alternator that would bolt in with same generator brackets??

I probably should mention it's an AMC 327, gen 1. Wonder if there are any brackets available to convert to alternator?
 
With the old generator mounted in the OEM bracket (layout and distance from the mounting holes to center of belt shiv), a good fitter should be able to fabricate a new bracket for the alternator.
 
With the old generator mounted in the OEM bracket (layout and distance from the mounting holes to center of belt shiv), a good fitter should be able to fabricate a new bracket for the alternator.

I went ahead and bought a 1 wire marine alternator, I believe the 12si in marine form. From what I'd read on various forums you need to remove enough of the lower mounting ear of the alternator in order to bring it forward and allow the belt to line up. I removed the old generator over the weekend and put the alternator where I thought it should be to line up. Looks like I need to take off 5/8 of an inch. Looks like I'll need an 8"bolt to run all the way through both ears of the existing generator bracket. I'll cut a piece of round stock to length to make up the difference between the rear generator bracket and the back of the alternator ear. It should work..... The worst part is that the boat is 2 hrs away. Hope to finish it this weekend.
 
Last edited:
shlebygt - How did you end up solving your conversion? I am ready to do the same thing on my Gray 327. Did you need a custom support bracket or did the new 8" threaded bolt work for you?
 
shlebygt - How did you end up solving your conversion? I am ready to do the same thing on my Gray 327. Did you need a custom support bracket or did the new 8" threaded bolt work for you?



Yes. As I recall I cut a half inch or so off the front ear of alternator to bring it forward. You Basically want it forward enough to make the belt run true. I'm thinking it was an 8 inch bolt. I then cut a piece of steel tube to make up difference behind the alternator. Works great.
 
Thanks. Did you disconnect your ammeter? I've read that the 1-wire ammeters only connect to voltmeters.
I'm not aware of a 1 wire amp meter.
An Amp Meter functions on the Shunt Resistor principle, meaning that full current charge power must pass through it in a series fashion.
Series must have two points of connection.
The resistance is then measured by the shunt resistance principle, allowing the needle to indicate current flow in amperes... or what we call Amps.

The difference between using an Amp Meter and Volt Meter, will be in the engine/hull harness configuration.
The Amp Meter requires a heavy Positive circuit to it and from it, whereas a volt meter only requires Positive and Negative to it.
By going from an Amp Meter to a Volt Meter, the return portion of the old Amp Meter circuit can be eliminated.


.
 
Oops. I meant a 1-wire alternator. I am using vintage Stewart Warner gauges in my 1961 Century Sabre that cannot be swapped for modern ones (unless someone knows of a vintage SW voltmeter). Since I am replacing my generator with the Delco 1-wire alternator, which is wired directly to the battery, how would I wire a new circuit to the ammeter and back again to the alternator?
 
Oops. I meant a 1-wire alternator. I am using vintage Stewart Warner gauges in my 1961 Century Sabre that cannot be swapped for modern ones (unless someone knows of a vintage SW voltmeter). Since I am replacing my generator with the Delco 1-wire alternator,
1..... which is wired directly to the battery,
2.... how would I wire a new circuit to the ammeter and back again to the alternator?

OK... let me take a stab at this.

1.... As for the alternator charge lead, typically this lead will connect to the starter motor solenoid terminal, where it then uses the MBSS "common" cable.
When wired in this manner, the MBSS can select either battery bank as to receive alternator charge.
Conversely, the MBSS position determines which bank we crank from and which bank our House Loads are derived from.

Otherwise, the only battery bank that will recieve an alternator charge, will be the bank that has the charge lead directly connected to it.
Other than battery Pos/Neg cables themselves, I do not care for an arrangement of direct battery connections. (it causes issues)


2.... I may not be familiar with this setup.
Typically the single charge lead leaves the alternator, and would not return to it.
If the SW ammeter uses an internal shunt, then a heavy lead will leave the alternator, connect to the ammeter, and will then return to the starter motor solenoid terminal, where it is then directed to the battery bank that is currently being selected by the MBSS.


SW way back did offer an Amp Meter for heavy current whereby the Shunt Resistor was remotely located.
The shunt sensing leads (twisted pair, if I recall) then ran up to the Amp Meter, ending up using the same principle, but with the shunt remotely located.
If... key word "if".... there is a remote shunt, just make sure that the Delco 10si power lead goes through it in a series fashion.

So.... you have some homework to do:

Is this SW instrument an actual ammeter (internal shunt) with a pair of #10 or #8 red and orange leads to/from it?
Or...... is it an ammeter using the remote shunt resistor, with smaller leads to/from it?



.
 
Last edited:
This may help explain the ammeter types.

With the remote shunt resistor style ammeter (top image), small circuits run from the shunt to the ammeter and back to the shunt.
With a more standard ammeter (lower image), long and larger circuits must run to the ammeter and back to the starter motor solenoid terminal.

As you can see, the MBSS selects which battery bank is either being pulled from, or charged to.

A volt meter only requires a circuit from the existing helm keyed power... plus a negative from the same area.
 

Attachments

  • Ammeter shunt resistor.jpg
    Ammeter shunt resistor.jpg
    52.9 KB · Views: 244
Last edited:
Ricardo - you nailed it. I do have the standard ammeter, with only one battery (the boat is only 18'). Your drawing is exactly what I need. Thanks.
 
Back
Top