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Offline BillT

distributor voltage
« on: March 13, 2019, 09:59:45 AM »
Am I understanding this correctly? Do all Willys jeep cj2a and cj3a distributors operate from a 6 volt input? My understanding is that the 12 volt systems use a resistor to drop the voltage from 12 volt to 6 volt. Correct? What I am getting around to is the condenser voltage. There has been some discussion on faulty/ poorly made condensers and other brands have been suggested and I am interested in getting one. But the ones I have looked at don't tell me if they are for a 6 volt system.

Thanks
'52 CJ3A, early M38A1, '70 Commando
25' travel trailer, Lance 855S truck camper
Love to camp

Online 1955CJ-5

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Re: distributor voltage
« Reply #1 on: March 13, 2019, 08:58:00 PM »
Here is what I have learned about this from other threads and through learning about the Model A Ford which is also 6 volt, but 12 volt conversions are popular.

6 volt systems use a coil with about 1.5 ohms across the primary winding, that's the winding with the two exposed connections/terminals.

12 volt systems use a coil with about 3.0 ohms resistance. Or you can use a resistor together with the 1.5 ohm coil

So...

With Ohm's law, both systems deliver 4 amps to the distributor.

12v/3=4 for a 12 volt system

6v/1.5=4 for a 6 volt system.

So to me that means the capacitors and points are the same in terms of voltage and amperage between the two systems.....

There are variations also, so this sure isn't a hard and fast rule!

I hope this helps a little:)

« Last Edit: March 13, 2019, 09:00:00 PM by 1955CJ-5 »
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Offline BillT

Re: distributor voltage
« Reply #2 on: March 13, 2019, 09:46:17 PM »
Thanks for the explanation 1955cj-5. I remember one of my earlier jeeps used an external resistor, some called it a Ford resistor. Anyway appreciate the reply.
'52 CJ3A, early M38A1, '70 Commando
25' travel trailer, Lance 855S truck camper
Love to camp

Offline stony

Re: distributor voltage
« Reply #3 on: March 16, 2019, 01:11:56 AM »
To expand on what CJ-5 says.  The �Ford� resistor was probably used with a old school Ford type starter remote relay that was used when converting to 12V and using a push button or key switch to start.  That relay would bypass the resistor when the starter was turning.  Normally when running and charging you have about 14v, with 3 ohm = 4.7 amps.  When the starter is turning the high current draw causes the battery voltage to drop to about 10V (especially since these carbureted engines need to crank a bit when cold) with 3 ohms the current drops to 3.3 amps resulting in a weak spark, but with the resister bypassed you only have 1.5 Ohms and a current of 6.7 amps and a nice hot spark to get her going. As soon as the relay opens when the engine starts the resistor is no longer bypassed.  The capacitor is used to absorb the voltage spike that is fed back to the distributor when the points open and the spark is generated.  This prevents arcing between the points, which cause them to burn and pit.
Terry
1949 CJ3A 11159 body 11225 engine 11140
On preservation vs. restoration:Roscoe Lee Brown "the Cowboys" when he met the whores on the trail:"Well, I have the inclination, but not the time.

Offline BillT

Re: distributor voltage
« Reply #4 on: March 16, 2019, 08:19:29 AM »
I appreciate, and I'm sure others do also, your detailed explanation Terry. All to often explanations get lost in generalities.

So correct me if I'm wrong, please. When in the starting mode, the difference in 6vdc and 12vdc systems is, when in the cranking mode the 12volt starter is receiving 12 volts while the 6volt starter is receiving 6volts, once the engine cranks the 12 volt systems resistor is back in the distributor circuit and reducing the voltage to the coil to aprox. 6volts. The 6volt systems use no resistor.
'52 CJ3A, early M38A1, '70 Commando
25' travel trailer, Lance 855S truck camper
Love to camp

Offline stony

Re: distributor voltage
« Reply #5 on: March 16, 2019, 01:20:45 PM »
That is correct, however you can�t use a relay on a CJ3A because the starter is run by pressing a switch directly on the starter.  You can use a relay on a 2A by using the floor starter switch to activate the relay.
Terry
1949 CJ3A 11159 body 11225 engine 11140
On preservation vs. restoration:Roscoe Lee Brown "the Cowboys" when he met the whores on the trail:"Well, I have the inclination, but not the time.

Offline BillT

Re: distributor voltage
« Reply #6 on: March 16, 2019, 02:00:43 PM »
Don�t �cha luv the foot starter. Nothing like being stopped on a hill and holding the foot brake, giving it gas ,and pushing the foot starter all at the same time. A quick starting engine is a plus as well as an operational emergency brake.

Thanks for the info stony.
'52 CJ3A, early M38A1, '70 Commando
25' travel trailer, Lance 855S truck camper
Love to camp

Offline mtnman37879

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Re: distributor voltage
« Reply #7 on: March 17, 2019, 04:46:59 PM »
If you are stopped on a hill you don't need the foot starter. Put her in gear, roll and pop the clutch.
People think I go out of my way to * them off.
Trust me, It's not out of my way at all.

Offline stony

Re: distributor voltage
« Reply #8 on: March 17, 2019, 05:57:26 PM »
Could get exciting if you are going UP [ch128563]
Terry
1949 CJ3A 11159 body 11225 engine 11140
On preservation vs. restoration:Roscoe Lee Brown "the Cowboys" when he met the whores on the trail:"Well, I have the inclination, but not the time.

Offline BillT

Re: distributor voltage
« Reply #9 on: March 17, 2019, 08:09:51 PM »
Ha ha ...... that what I meant to say stony. Anyway this one is my first foot starter since the sixties, seems like things don�t move as fast as I remember them.
'52 CJ3A, early M38A1, '70 Commando
25' travel trailer, Lance 855S truck camper
Love to camp

Offline mtnman37879

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Re: distributor voltage
« Reply #10 on: March 17, 2019, 10:09:51 PM »
Quote
Could get exciting if you are going UP [ch128563]
I've done it many times in reverse!
People think I go out of my way to * them off.
Trust me, It's not out of my way at all.