Point Alignment

[BButturff]

You're saying that the Model A distributor gets hot enough to melt the plastic follower? I've been considering switching, but this could be alarming. Anyone else have this happen?

I ran Ford V-8 style points in racing engines during the '70s and early '80s. Big horsepower V-8 engines, high voltage coils, most had dual point distributors and those engines ran much hotter than any Model A. We never had ignition point problems. Fast forward to today, when most things are made out of Chinesium, and quality certainly becomes suspect. If I were to use "modern" points and condensers today I wouldn't be afraid to use the Standard Motor Products Blue Streak line. Last I heard they are USA parts assembled in Mexico.

 

[bobbader]

2speed, you may be fairly new to the Model A world or to replacement parts in general. Re-read Brent's reply to Bob Bidonde about the buying public and their affinity to buy parts based on price. There are a wide variety of manufacturers of Model A parts. Several are quite good, want to make the part correctly, and listen when they get feedback. Others are large volume manufacturers of "widgets" who produce mediocre parts that can be sold at a cheaper price. Many hobbyists shop several different vendors catalogs and websites and buy parts strictly based on price either due to the limits of their budgets or because they just believe "parts is parts", they all come from the same place, and the vendor with the higher price is just in it for more money. So, it may seem unacceptable, to you, for a distributor shaft to need modification. The actuality is low-cost sellers will almost always succeed in finding a market because most people would rather complain about poor quality than to be inconvenienced by sending a part back.

As you plunge further in this hobby, it is wise to read many threads here and digest them. The mention of the better suppliers in the industry will almost always "rise to the top".

 

[Diastole]

In response to post #19

Yes, I experienced this problem over the weekend. Drove the car in 90-degree weather for over two hours on four separate 30-minute trips. 2 miles from home, the car started to run rough. One mile later, she started backfiring like I was being chased with a Tommy-gun. Then she quit. I noticed on my TinyTach my RPM was 6,310 (normally it is 560-2100).

Swapped out the distributor to one I had preset up and timed. Points 0.020", B grind cam, wireless upper plate, two-piece shaft, condensor 237 nf. She started right up.

Inspected the plugs. All good. Yes, I run a W18 in four and W16Y in 1, 2, and 3. All at 0.035". See photo. all plugs good

On inspection of the points, they were charred, and the arm had the stigma of metal thermal failure; see the rainbows in the distal aspect of the metal arm. I measured the gap prior to disassembly, 0.006"!! The points had closed due to the block melting, and then the points charred. See photo

The extremely small gap is the reason the TinyTach perceived so many fires from the coil. The points never opened enough to prevent sparking.

Final analysis:
10 coolant badly soiled, checked head studs all 55 ft lbs. Will check compression this weekend and see if I blew out my gasket. Also, will sniff new fluid for hydrocarbons
20 Oil clean without water
3)Car runs good, good performance and pick up.
4)Only problem: a new knock i think is coming from inside the block at #4. Not sure. It is subtle. Not audible at RPMs over idle and not audible when driving.

So yes, points blocks can melt.

Diastole in the Smokies

 

[nkaminar]

Good analysis. Thanks. My modern points burnt too but it was because of a bad condensor. The point were still opening correctly.

 

[Cape Codder]

I just received some Spark Plug washer seals, and to me the outside diameter was very small! I had some like it already so when ordering I asked about them. Was assured these are correct ! So NOW I have two sets that I think are incorrect.

Has anyone noticed this part getting thinner in O.D. or is it ME ?

 

[Cape Codder]

I recently bought some Spark Plug Washer Seals. When ordering I asked if these where of thin outside diameter but assured they were the proper ones. So I bought TWO sets !

Question is have these Washer Seals gotten smaller in outside diameter and that is the NEW part or did I get took ?

 

[Diastole]

I have received many messages. Thanks for all feedback

Therefore, I will correct my above statement. My points rubbing bar did not melt. It is Delrin or Nylon. Melts will above 400 degrees F.
I measured the rubbing bar on the points that heated and charred 13/64” exactly. I measured all my backups and found the same measurement +/- 0.002”. See photo of the roasted points.

The consensus is they did not melt, but the gap decreased for some reason and the points tried to weld themselves. At disassembly, the screws were both tight. But the gap was 0.006”.

Bottom line my points failed for some reason. The electrodes charted. The arm suffered thermal degradation. The gap closed 70%.

Which occurred first; the charring and thermal deformation of the arm or the points gap adjustment closed? I do not know, now!

Diastole in the Smokies.

 

[BButturff]

I have received many messages. Thanks for all feedback

Therefore, I will correct my above statement. My points rubbing bar did not melt. It is Delrin or Nylon. Melts will above 400 degrees F.
I measured the rubbing bar on the points that heated and charred 13/64” exactly. I measured all my backups and found the same measurement +/- 0.002”. See photo of the roasted points.

The consensus is they did not melt, but the gap decreased for some reason and the points tried to weld themselves. At disassembly, the screws were both tight. But the gap was 0.006”.

Bottom line my points failed for some reason. The electrodes charted. The arm suffered thermal degradation. The gap closed 70%.

Which occurred first; the charring and thermal deformation of the arm or the points gap adjustment closed? I do not know, now!

Diastole in the Smokies.

Thanks for the correction/update. As part of your analysis, was the condenser tested for failure?

 

[bobv]

I needed to grind some off of the ignition points because it was interfering with the distributor body so I couldn't set the gap.

 

[BButturff]

I needed to grind some off of the ignition points because it was interfering with the distributor body so I couldn't set the gap.

Yes, they come with part of the pivot end of the point plate already "clipped" if bought from Nu-Rex or any of the Model A parts vendors. It's normal.

 

[katy]

The consensus is they did not melt, but the gap decreased for some reason

Check the surface of the distributor cam for smoothness, it needs to be super smooth, some replacement cams are not as smooth as they should be. Also a small amount of lubricant on the cam.