Distributor Breaker Plate Melting

[DBentley]

I have my families Ford 8n, restored, 1949. I put a new distributor on it years ago since the original had a cracked and rewelded ear. I've had problems with the timing. It was converted to 12v before I picked it up. The new distributor uses a breaker plate with points permanently attached.

I can't get the points to last more that a couple of hours. The latest pictures are attached. The plate doesn't move but the phenalic piece with the contact melts and the spring pushes the contact off center. This is at least my third set of breaker plates, this one bought from Atlantic Quality parts, made in the USA, 9N12150, their part number 1100-5007.

 

[Bruce(VA)]

Best find an old plate and replace the bushings and insulator.

Check w/ Derek at nnalert's in Shelby NC and see if he can help you.
75 Tips

 

[Jim L WA]

Forgive me if this is a stupid question, but you are lubing the distributor cam aren't you?

 

[DBentley]

I asked the local auto parts store for cam lube, which they didn't have but sold me something that "would work". Don't remember what was in the tube. But even if this was the source of the problem, how is it the only melting is where the contact rivet is located?

Thanks

 

[HCooke]

I would buy an old distributor on ebay and use it. You might have to buy more than one. New distributor, starter motors, governors, etc are
problematic to say the least. Anything else I would say about them would get me bounced off the forum.

 

[Btzj02]

"how is it the only melting is where the contact rivet is located?"
Is it possible you have a leak to ground through/close to that rivet? A high resistant ground leak may not be big but it would create heat!
JB

 

[DBentley]

I'll take another look. This is the third breaker plate assembly I've replaced. The previous one looked the same, the contacts were misaligned significantly. I didn't check for the melting on that one like I have here.

 

[Mad Farmer]

(quoted from post at 12:21:41 09/22/20) I have my families Ford 8n, restored, 1949. I put a new distributor on it years ago since the original had a cracked and rewelded ear. I've had problems with the timing. It was converted to 12v before I picked it up. The new distributor uses a breaker plate with points permanently attached.

I can't get the points to last more that a couple of hours. The latest pictures are attached. The plate doesn't move but the phenalic piece with the contact melts and the spring pushes the contact off center. This is at least my third set of breaker plates, this one bought from Atlantic Quality parts, made in the USA, 9N12150, their part number 1100-5007.

Not sure what you mean by points permanently attached to breaker plate? You mean you need to replace the whole plate, not just the points? That is ridiculous!

The points should not melt like that. It's a cheap non-phenolic plastic not made for the application. Phenolics are thermoset plastics that don't melt. The cheap plastic is melting from the current going through the points. What sort of resistor/coil is in the system?

 

[DBentley]

Perhaps it is ridiculous, but yes the points are permanently attached to the breaker plate. Found that out on the first replacement after installing the new distributor some years ago. Could not use a replacement point set. Had to buy a complete breaker plate assembly

I replaced the Resistor Assembly Part Number A8NN12250A after the last failure. Clearly the rivet in the plastic or whatever you want to call it, is getting hot enough to melt the plastic and the spring puts enough load on the contact to move it forward in the soft material and off center from the other contact. That's when the tractor starts running rough at higher throttle settings.

 

[DBentley]

I'll take Bruce's suggestion and call Derek tomorrow

 

[Wild child]

That breaker plate from Atlantic has been a problem for years. The
points are not permanently attached,they put the points on the center
pin put it in the plate and expand it. You have to destroy the points to
get them off, the new points you have to make the hole bigger to fit,
yep a real pain, best to find a orignal.

 

[DBentley]

Never thought about drilling out the hole and putting the original design points back on it. I destroyed the first breaker plate assembly thinking I could get the points off it. The last two were assemblies.

 

[lha]

Try Jegs for Mallory point lube. A small tube I bought years ago still has plenty for years to come.

 

[HarryVanderpool]

Is it just me or does it seem that the majority of ignition problems reported on YT are 12 volt conversions???

 

[JMOR]

(quoted from post at 23:35:34 09/22/20) Is it just me or does it seem that the majority of ignition problems reported on YT are 12 volt conversions???

s was said, definitely NOT phenolic! Not a lube problem, either. Probably crappy plastic points material combined with more than 4 amperes steady on current. Use test ammeter & measure it & add resistance as needed.

 

[Tim PloughNman Daley RIP]

Nope, not just you, it is a fact, especially the front mount distributor, the 2nd most misunderstood system on Ford Tractors. The 1st? The 6V/POS GRN System. Guys don't know, don't understand, don't read the manuals and reference the schematics there-in, and when they encounter a non-starting situation, think they must convert to 12V because it is the 6V system fault. Shadetree mechanics are notorious for switching out to 12V and 99.98% of them are wired incorrectly. These are facts -you can look them up, or simply read the daily posts on the boards. The Front Mount Distributer is tuned up and tested off the tractor on your bench -you can't do it when it is on -and before it is remounted on tractor. The engine cam has a female offset slot on the face. The distributor cam weights has a male offset tang and the two must mate up exactly the same. If the unit gets mounted/forced down 180 degrees off, the second power is applied it will try to orientate itself and bust the aluminum base rendering it useless junk. Now, there is nothing wrong with a 12V system, but either way, 6V or 12V, if not done correctly will result in non-starting issues.

SPECS: Point Gap = .015" / Plug Gap = .027" / Firing Order = 1, 2, 4, 3 CCW


FRONT MOUNT TIMING PROCEDURE:

FIRING ORDER, 1,2,4,3 CCW:

FORD FRONT MOUNT DISTRIBUTOR – WHAT HAPPENS WHEN INSTALLED 180° OFF:

ECHLIN used to be one of the few reliable brands but no longer are unless they fixed the problem recently. A year ago I spent a week with my late friend, Farmer Dan Howe, and we went thru a dozen or so front mounts to rebuild, time, and set correctly. What we discovered was that all the *ECHLIN sets were junk –points were off location and couldn’t be gapped right. Lot numbers on the boxes were all over the place and purchased from different suppliers so we don’t know how long they had been like that. What we concluded was there are only three reliable point brands made today. They are: Standard Ignition (Blue Streak); CNH (Case-New Holland); and TISCO. The latter uses the plastic rubbing block but proved reliable, and the other two use the OEM type phenolic rubbing block. ECHLIN also has the phenolic block and that was one reason why they were a good choice.

Part numbers:

1. POINTS:
Standard Ignition (Blue Streak) – FD-6769X
CNH – 87744524
TISCO – ATK6FF
ECHLIN CS-35 (*see note)

2. CAP:
ECHLIN - #FA350 or STANDARD IGNITION - #FD-126

3. CONDENSER:
ECHLIN - #FA-200 or STANDARD IGNITION - #FD-71

4. ROTOR:
ECHLIN - #FA-300 or STANDARD INGNITION - #FD-104, TISCO KIT Includes rotor.

5. GASKET KIT:
SPAREX #S.60308

6. 6V COIL:
IC670

7. BALLAST RESISTOR:
# ICR40

8. SPARK PLUG WIRES –COPPER CORE – nnalert’s

9. SPARK PLUGS:
AUTO-LITE 437 (216) or CHAMPION H12 (512)

10. CAM LUBE:
STANDARD IGNITION - #SL-2
ECHLIN: ML-1






Tim Daley(MI)

 

[Richard G.]

My 52 8N which was my Dad's first tractor that I converted to 12 volt MANY years ago.
Been in the family since new.
I am on my second set of points on the 12 volt conversion.
I have Echlin points that seem to last forever.
The old gal never fails to start winter or summer.
Richard

 

[Mad Farmer]

(quoted from post at 06:17:17 09/23/20) My 52 8N which was my Dad's first tractor that I converted to 12 volt MANY years ago.
Been in the family since new.
I am on my second set of points on the 12 volt conversion.
I have Echlin points that seem to last forever.
The old gal never fails to start winter or summer.
Richard

I have a 1940 9N I bought many years ago (30), it had been recently tuned by an old timer at a Ford dealership. Still original 6V + ground.

I didn't have to go into the distributor until recently. The points would have been seviceable with a bit of filing. The points had the Ford logo on them. Tells you something about parts quality then and now. I saved the points, cap (Ford logo) and rotor. With a clean up they can be spares.

Main reason my 9N was running bad, turned out to be the coil. I got an Echlin from NAPA

I went to the Atlantic website, seems they sell points, breaker plates with points, and complete distributors. No mention of unserviceable points on the breaker plate nor distributor. They did say all parts were compatible with OEM Ford .

 

[zuhnc]

12 volt conversion done on a 1951 8N. Also converted to electronic ignition and resistance wires. No issues at all with points burning/melting, or starting in winter or summer. Those points are melting because, as has been said, incorrect material and possibly high current. Another consideration is that the peen/rivet holding all those components together is loose, causing high resistance and heat. zuhnc

 

[DBentley]

I checked the resistance of the coil and had it rechecked by other more expensive V-O meters.

The coil has a resistance of 1.4 ohms from the top screw to the pig tail. It has an open circuit from the top screw to the leaf tab.

That would suggest nearly 10 amps through the distributor contacts when the ballast resistor is cold and nearly 5 amps continuously when hot. I can understand the melting of the breaker plastic at the contact pin.

 

[JMOR]

(quoted from post at 12:01:44 09/24/20) I checked the resistance of the coil and had it rechecked by other more expensive V-O meters.

The coil has a resistance of 1.4 ohms from the top screw to the pig tail. It has an open circuit from the top screw to the leaf tab.

That would suggest nearly 10 amps through the distributor contacts when the ballast resistor is cold and nearly 5 amps continuously when hot. I can understand the melting of the breaker plastic at the contact pin.

mps are on high side. 12250 std ballast ranges from 0.4 cold to 1.7 Ohms hot, yielding 6.9A to 4.1A.

 

[grizz02]

yup, my 47 2n all original fires as fast as my 2010 chev