Budget 12v Conversion

[Larryb2020]

Im giving my son an 8n so he can draw firewood out at his new house this winter. I would like to convert it to 12 volts this weekend. I had a couple questions.

Will GM Delco Alternators work spinning in either direction?

I had a boat once that was diesel and it had a oil pressure activated switch which would power up the #1 Exciter Feild Tap on the alternator once the engine was running and disconnect power once the engine was shut off. Does anyone out there know the NAPA part number for this switch?
I liked the simplicity of this arrangement.

If I don"t use a oil pressure activated switch then I guess I need to use some sort of diode between the ignition switch to prevent battery draw down. Does anyone have a napa part number for this diode? Also is polarity marked on it?

Lastly I have a box of misc ignition coils. I would like to use a 12v with internal resistor so I can just run the ignition wire directly to the coil without an external resistor. Is there any way I can use my ohm meter to test these old coils to determine which ones are 6v and 12 v and internally resisted? Thanks in advance for everyone"s help.

 

[Larryb2020]

I forgot to mention it is a side mount distrubutor model so the coil is seperate.

 

[Dell (WA)]

Larry........you ask a lotta intelligent questions showing you are trying to understand.

Surprizingly enuff ALL gasoline engines turn clock-wize when looking at the front. (twin engine diesel boats have counter rotating diesel engines so you can go in a straight line, or back into the dock) So it doesn't matter which side of the engine you mount yer Delco 10SI, it will also turn the correct direction. And even iff'n you did mount yer Delco BASSACKWARDS, the 3-phase diode trio would automagicly straighten the DC volts for NEGATIVE ground.

And even more astounding, yer starter motor will also turn the correct direction whether 6V-positive ground ...or... 12V negative ground. Delco 10SI's DEMAND NEGATIVE GROUND. Its their internal solid state guttz.

The reason for the "diode" ...or... idiot-lite is to be able to turn yer engine OFF. The ignition switch ON terminal also supplies volts to the ignition coil ...but... the Delco "EXCITE" terminal back-feeds enuff volts to keep yer sparkies running without the idiot lite or diode to calm them down.

Bottomline, you do NOT NEED enny oil pressure isolation switch to keep yer new 12V battery (size 22) from discharging. The INTERNAL DIODES of the alternator will NOT allow that to happen.

We recommend the NAPA IC14SB roundcan ignition coil ($15, cheap) for the 5-nipple sidemount 12V conversions. It does NOT NEED an external resistor; EVER!!! It also has hotter sparkies (ie...more KILOVOLTS) than most roundcan 6V sparkie coils.

Iff'n yer bound and determined to use crapped out sparkie coils (they're on that shelf for a reason) real 12V coils will ohm about 3-4 ohms. But here's the deal, just 'cuz they OHM good, don't mean they are good. You can NOT test a sparkie coil with an ohmmeter to see iff'n it outputs at least 20,000V of sparkies. ........Dell, a 12V advocate for the right reasons who knows 8-ways to convert to 12V and they all work, the first time.

 

[Jon Hagen]

Yes, the Delco alternators will work spinning in either direction. The cooling fan is specific to either CW or CCW rotation, but in reality, unless your electrical load is very heavy, a wrong way rotation fan will work well enough.

I have a Delco alternator with a CW fan spinning CCW on my Oliver 1950T for 30 years now with no failures, because the electrical needs are not so great and it cools well enough.

If you have digital ohm meter, measure the resistance between the primary posts of your ignition coil.
The coil designed to work on 12V with an external resistor, or on 6V will measure close to 1.5 ohm. A coil with a 12V primary winding designed to run on 12V without an external resistor will read close to 3 ohms across the primary terminals.

 

[Hobo,NC]

NAPA OP6624 for the switch,,, I seldom use it and never on a N... Get your coil right and drop in a fresh 12V bat I use a group 35 myself... it will run for weeks off the bat alone before it needs a recharge... Then you can line up all the correct parts to do the job correct... I did not catch front are side mount :?:

 

[KL-VA]

If you really want to simplify the 12 volt conversion, get a 1-wire alternator. The current ones excite at low enough RPM that you no longer have to rev the engine to get them going. Only 1-wire to hook up is simpler and more reliable.

Oddly enough many of the rebuilt Delco alternators are now using a regulator that will work as a 1-wire if you just "forget" to hook up the 2 small wires. I don't know of any way to tell other than to hook it up as a 1-wire and see if it works.

If it works, great, if it doesn't, at least you haven't fried anything by mis-wiring the alternator connections (yet).

 

[Larryb2020]

Thank you guys so much for your sagely advice. I think I will get the napa IC14SB coil rather than try to sort out the old coils I have.
The boat I have does have counter rotating diesels so that was why I had in my head the CCW rotation question.
Lastly If I understand correctly the mere presence of the load of the idiot light in the feed between the IGN switch and the Number 1 (exciter feild tap) on the Alternator will provide enough of a resistance to stop backflow of current into the primary ignition circuit without the use of an external diode. This preventor of current backflow allows the engine to stop when the Ignition switch is turned off. Thats pretty neat as the light also provides a reminder that the Ignition is on.
Thank you guys so much for your knowledge.

 

[Jim WI]

I've heard that pre-2000 Honda engines spin CCW as viewed from the front of the engine ("front" = the end with the pulleys).

 

[tractorfix]

Honda motors turn backward cause they're on the "wrong" side of the car.