641 6 volt coil question

[Sean in PA]

The one in my boat is 1.5 ohms. Being out in the elements in the boat, it needs to be replaced about once every 10 to 15 years. First the epoxy covering the hole in the back of the ceramic gets brittle and starts crumbling away. Then, once the metal of the resistor coil is exposed to the salt air, it corrodes and breaks in about a month.

 

[ole fred]

The one in my boat is 1.5 ohms. Being out in the elements in the boat, it needs to be replaced about once every 10 to 15 years. First the epoxy covering the hole in the back of the ceramic gets brittle and starts crumbling away. Then, once the metal of the resistor coil is exposed to the salt air, it corrodes and breaks in about a month.

Gotta love those 455's. I have one out of a 69 98LS. We bought it from a friend with about 60k on it and drove it to a little over a hundred thousand miles and the timing chain jumped and I said, heck, it's got a hundred thousand, it's ready for an overhaul. I pulled it out looked at the bearings and they were like new. I think I put a set of rings and bearings in it but didn't do the heads. Put back to together and ran it a while and it digested a couple of lifters and cam lobes. I didn't have sense enough to put them back in the same holes. I went to the junk yard a half mile up the road and took one out of a 73?? and put it in matching the lifters to the cam this time. We drove the wheels off that car and when my youngest son wanted to get it running again and paint it up like the high school mascot, I said "go for it". Bottom line, that engine had 240000 miles on it and still didn't use any oil. The TH350 behind it was never rebuilt but had the fluid changed several times. When he quit driving it after graduation, the transmission was so worn out that when you stopped it would loose oil pressure and go into neutral until you revved it up a little.
I still have that engine sitting out there in a semi trailer. It's been there since 1991 and I'll bet I could get it running without much trouble. Maybe not though. Hmmmm
FWIW, I think that crank had 3.25 main bearings. It certainly was a hefty one though.
Another thought - I just junked 5 855 Cummins cranks a couple of weeks ago. They weighed 346 pounds each. Hood-a-thunk-it.

 

[MeanGene1]

How many ohms is it? I'm not trying to start an argument, I want to know. YT says .8 ohms. That doesn't seem like enough.

Couldn't tell you right now- I did this a few years ago and did my research then to get the right one, and then just saved the box label with the part number in case I needed another. Of course there is one person in this thread that would be able to conjure up a reason why that wouldn't work lol

 

[soaked]

Hi ole fred, if you get a 1.8 - 2.0 ohm resistor, it should run fine. You will still have a positive ground coil running in a negative ground system.
Here is a post where JMOR( RIP) gave info on that topic---

J

Post in thread 'Tale of two,Positive Grnd'

Aug 24, 2023

(quoted from post at 15:26:23 08/24/23) I've searched posts with many contributors such as JMOR and souNdguy and others and I'm looking for additional verification pertaining to the NAA 6V Pos ground.

Owned for 30 Yrs a Fergy TO30 6V Pos Grnd, and coil terms have a + and - . The + goes to the Distributor. Runs great always has.

Also a 53 NAA Jubilee 6V Pos ground and the Coil that came with it and reinstalled had [b:9e18d603b3]Bat[/b:9e18d603b3], and [b:9e18d603b3]Dist[/b:9e18d603b3] stamped on it. Coil only fits one way with dimple located to hole in bracket. Terminals are on...

• JMOR

Converted this 52 8n to 12 volts back in 2010, put a pertronix 1244A electronic ignition and this pertronix 40511 12 volt coil. It starts instantly, with no choke and runs perfect. Use it to mow my 2 acre back yard. Dont want to fool with points or condensores.( fits the phrase better than condenser )

 

[Keith Williams]

Since your fountain of misinformation is overflowing once again we will correct it . Absolutely no Ford 3 cyl tractors built from 1965 through late 1974 used an ignition bypass wire EVER ! Those particular tractors used Ford part number coils 1) FAC12029A and 2) D2AF12029A these are both external resistor type coils and used the resistance wire in the wiring harness . HOWEVER in late 1974 Ford redesigned their coils the new revision D5TE12029A coil still used the resistance wire in the harness and they added the bypass wire to the system to correct a starter draw problem weakening the spark during cranking . Again Ford NEVER installed a 6 volt coil on a CAR , TRUCK or TRACTOR with a 12 volt system EVER . Again I will say prove your lies with Ford part numbers and Ford literature proving they did that . I have never asked for example of something Ford NEVER built because I know they NEVER built one that way . You can keep insisting what you want but you have not proven anything with Ford part numbers showing that they actually did it which of course they did not . Your Google search means absolutely nothing because it details no FORD information just broad based nothing . This debate started when you claimed you could use the original 8BA12029 Coil which is a 6 volt ONLY coil on his 12 volt conversion if you want to call it that on his 641 . That’s what ole Fred was asking about go back and read his post . Then Soaked chimed in and also said it will work when it will not . You keep changing the subject trying to muddy the waters with your B.S. because you can’t prove anything through Ford .

Tony, I just drove the 41 miles to my farm to look at my 1974 Ford 2000. Serial Number C434356 Model B10230 Unit 4H14B. Took pictures of the 2 wires coming in to feed the coil. One from the Switch ( a fat resistance wire) and one from the solenoid.

Do you need me to show them to YA?
I hope you had a GREAT day!
Keith Williams

 

[ole fred]

Hi ole fred, if you get a 1.8 - 2.0 ohm resistor, it should run fine. You will still have a positive ground coil running in a negative ground system.
Here is a post where JMOR( RIP) gave info on that topic---

J

Post in thread 'Tale of two,Positive Grnd'

Aug 24, 2023

(quoted from post at 15:26:23 08/24/23) I've searched posts with many contributors such as JMOR and souNdguy and others and I'm looking for additional verification pertaining to the NAA 6V Pos ground.

Owned for 30 Yrs a Fergy TO30 6V Pos Grnd, and coil terms have a + and - . The + goes to the Distributor. Runs great always has.

Also a 53 NAA Jubilee 6V Pos ground and the Coil that came with it and reinstalled had [b:9e18d603b3]Bat[/b:9e18d603b3], and [b:9e18d603b3]Dist[/b:9e18d603b3] stamped on it. Coil only fits one way with dimple located to hole in bracket. Terminals are on...

• JMOR

Converted this 52 8n to 12 volts back in 2010, put a pertronix 1244A electronic ignition and this pertronix 40511 12 volt coil. It starts instantly, with no choke and runs perfect. Use it to mow my 2 acre back yard. Dont want to fool with points or condensores.( fits the phrase better than condenser )
View attachment 159639

If I understand it correctly, all I have to do is reverse the low tension wires. I've already done that and it starts and runs fine

 

[Hobo,NC]

8BA-12029 ICR7, 1.14-1.26 ohms
FAC-12029A IC10, 1.42-1.58 ohms use ICR10 are 11 resister
D2AF-12029A IC17?, 1.25-1.36? ohms use ICR13
D5TE-12029A IC21, 1.36-1.48 ohms use ICR25 or 26

 

[Hobo,NC]

 

[Tony Jacobs]

Tony, I just drove the 41 miles to my farm to look at my 1974 Ford 2000. Serial Number C434356 Model B10230 Unit 4H14B. Took pictures of the 2 wires coming in to feed the coil. One from the Switch ( a fat resistance wire) and one from the solenoid.

Do you need me to show them to YA?
I hope you had a GREAT day!
Keith Williams

I guess you missed the post where Ford said their approximate date was Oct 1974 at serial C438900 . So their own information was off a little a little at least it wasn’t ten years off .

 

[Tony Jacobs]

View attachment 159650

Hello Hobo , I have that same Napa parts book also . That’s not the difference and that is only a very slight understanding of the two different coil themselves . Do you have an Oscilloscope ? If you do then you should know what the 1) Primary current ramp is 2) Primary flyback spike , 3) Peak secondary voltage , 4) Spark burn duration , which of course is only milliseconds long , 5) Internal inductance . If you know what those readings are you will have the answer . As I said this has nothing to do with modern day coils or anything but a true 6 volt that was manufactured as a 6 volt coil such as the Original 8NA12029 coil built by Ford , and a true 12 volt coil that was manufactured as a 12 volt only coil by Ford back in this time frame also . Now if you test both of these coils on the EXACT same engine where Everything is Exactly the same at 100 degrees F. Typical summer weather and at minus 20 degrees F. Typical winter weather which are not any where near extreme weather . Tell me what the differences are between the two coils when being used in a real world environment . If you saw both of those coils in half you will see what their original construction ( core size , amount of windings , diameter of windings , what it used to keep the coil from overheating , etc etc) was back in the 50’s and the 60’s which all changed in the late 80’s . This particular debate has been debated on this particular website in every tractor forum since 1995 and it always comes out the same way and there has been some knowledgeable Electrical Engineers that discussed why with pages and pages of electrical theory way beyond what is needed to know to read an oscilloscope in the automotive field . None of those Engineers even thought of the simple real world testing that any mechanic with the proper tools can do . I have seen multiple answers to this question here and not even posted by me . If you don’t know what the questions are how can you find the answers .

 

[Hacke]

Tony,

Let us say that you have a 6 V system with a 6 V ignition coil, that have a primary winding resistance of 1.5 Ω.
You convert to a 12 V system, keep the ignition coil and add a 1.5 Ω resistor in series with the primary winding.
That is the only thing you change in the ignition system.
Same amount of current (4 A) goes through the primary winding in both cases.
There is a 6 V drop across the primary winding in both cases.

What differs in the ignition coil's function/performance?

.

 

[Sean in PA]

Tony, I just drove the 41 miles to my farm to look at my 1974 Ford 2000. Serial Number C434356 Model B10230 Unit 4H14B. Took pictures of the 2 wires coming in to feed the coil. One from the Switch ( a fat resistance wire) and one from the solenoid.

Do you need me to show them to YA?
I hope you had a GREAT day!
Keith Williams

Keith, thanks for that confirmation. I know that my '73 4000 had a bypass wire, but I was beginning to question my memory. I finally got rid of it several months back so I couldn't verify in person.

 

[Hobo,NC]

Hello Hobo , I have that same Napa parts book also . That’s not the difference and that is only a very slight understanding of the two different coil themselves . Do you have an Oscilloscope ? If you do then you should know what the 1) Primary current ramp is 2) Primary flyback spike , 3) Peak secondary voltage , 4) Spark burn duration , which of course is only milliseconds long , 5) Internal inductance . If you know what those readings are you will have the answer . As I said this has nothing to do with modern day coils or anything but a true 6 volt that was manufactured as a 6 volt coil such as the Original 8NA12029 coil built by Ford , and a true 12 volt coil that was manufactured as a 12 volt only coil by Ford back in this time frame also . Now if you test both of these coils on the EXACT same engine where Everything is Exactly the same at 100 degrees F. Typical summer weather and at minus 20 degrees F. Typical winter weather which are not any where near extreme weather . Tell me what the differences are between the two coils when being used in a real world environment . If you saw both of those coils in half you will see what their original construction ( core size , amount of windings , diameter of windings , what it used to keep the coil from overheating , etc etc) was back in the 50’s and the 60’s which all changed in the late 80’s . This particular debate has been debated on this particular website in every tractor forum since 1995 and it always comes out the same way and there has been some knowledgeable Electrical Engineers that discussed why with pages and pages of electrical theory way beyond what is needed to know to read an oscilloscope in the automotive field . None of those Engineers even thought of the simple real world testing that any mechanic with the proper tools can do . I have seen multiple answers to this question here and not even posted by me . If you don’t know what the questions are how can you find the answers .

At this time I am doing everything I can to get out of my shop alive this is not a priority. If I ever run out of thinks to do I may knock the dust off of my scopes until then I am only interested in paying jobs : ).