What the — ? A commutator question

[hull 433]

My commutator was acting up, so I took it apart and found the fiber washers had split.

In the process I noticed a notch in the brass spacer nuts. Not in the Ford parts list for the year of my car so I’m wondering what they’re for and whether they’re Ford parts at all — or just repurposed from something else during an ancient shop repair.

[TRDxB2]

A picture of your commutator would help. There were many styles and I'm just using one as example. Is it like yours?
In comparing to the timer on the left, your timer would need a nut or equivalent to hold the threaded piece in place when the thumb nut was loosened or tightened . So is the mystery piece threaded?

[hull 433]

Hey Frank,

Here’s the mystery commutator in situ, with a well worn stock example on the right for comparison. Both came with the car. The contact points on both have a smaller surface area than your example.

[TRDxB2]

My initial reaction from the photo is that the disk may have been added to raise the wire contacts away from the timer housing because of the amount of solder on the connectors. Wonder what brand that timer is.

[Mike Silbert]

I am not an expert on the early cast timer but my gut is telling me it is one of the many replacement ones made over the years.
The Encyclopedia has some good pictures of the Oil Funnel 1912 cast style and I assume it is built like that one but without the funnel
Look at how the insulators, nuts, and other hardware is done for the terminals.
If it were mine I would make new insulators to replace them and add new brass nuts to replace what I assume is their attempt to be a nut.
It might need a quick trim on the inside but does not appear to have much wear.
Mike

[hull 433]

Here is the accessory timer case on the left, compared to a stock (but well worn) Ford timer on the right. The missing parts were on another table when I took the picture.

The accessory timer seems to use wood for its insulation, and all four of the wood grommets have split. I won’t say it’s a cheap construction for failing after 110 years, but the Ford insulators in comparison are in excellent shape. If it were not for the heavy grooved wear I’d be using it.

The car came to a sudden halt while driving, allowing me to coast to the curb. Attempts to restart it did nothing save one threat of a kickback. Normally she stars and runs nicely, so I’m thinking the split insulators led to a short. Has anyone experience with this?

[Mike Silbert]

Stan,

If a timer terminal (or wire) shorts it will cause that coil to continuously fire the spark plug.
This will effectively kill that cylinder and possibly fire back through the carburetor due to sparking when the intake valve is open.
The clue is listening to the sound the coil box makes.
While cranking it normally will have spots that coils fire and spots where coils do not. Also each coil sounds slightly different so that may be noticed also.
But the key is noticing that the coil box sounds different from normal when it happens.

Coming to a sudden halt when driving is interesting.
To shut off a running engine it normally takes killing more than one cylinder.
At shows I start removing coils until there is only one left and the engine still runs, just a bit rough.
I would expect an insulation failure would produce a rough running car and not a sudden shut off, so this might not be the bottom of the issue.
I have seen timer and wiring shorts before but never on more than one cylinder at a time.
I have seen a bunch of random insulators crack but I cant recall if any of them were ever on a timer.
When I find cracked insulators I just make new ones to fit.

My opinion is: The timer needs to be fixed, but that might not the end of your troubles.
I hope you prove me wrong and it runs great soon so you can go back to enjoying it.

Mike

[speedytinc]

Mike has a point.
Your engine kill doesn't sound like a timer issue.
Sounds like a power in put issue. Faulty switch, band fuzz interfering with the mag contact, etc.

[Mark Nunn]

I had that happen to me. It was my ignition switch.

[love2T's]

I had that happen to me. It was my ignition switch.

Yeh, especially with the cheap repop switches for '26/27 cars. Just had that happen to me two days ago. Switched to battery and ran fine. Sadly this was with my original switch, but the repop was worse so it sits on the shelf for "emergency replacement".

[hull 433]

Mike,

That’s interesting, and good to know the commutator is probably not the issue. I’ll fit in new insulators, recheck the timing and move on to the ignition switch now. Thanks for the comparison images, they help show it definitely is an accessory commutator, albeit an ancient one.

The coil box and ignition switch were previously restored over sixty years ago from original parts. Plywood lining though, probably a good time to renew that in the process (no rainy day drives, so water wasn’t an issue in this case).

I guess the big question now is what can go wrong with an ignition switch, are there specific components that can get loose or misaligned to cause a short? If so, how have people repaired them?

[Steve Jelf]

I've never used a roller timer, but I understand how it's supposed to work. Two things stand out in the pictures posted so far.

1

IMG_4273.jpeg (81.02 KiB) Viewed 71 times

In the timer on the right the contacts protrude from the insulation. Is the protrusion enough to cause roller bounce?

2 So far the roller hasn't been mentioned or shown. What is its condition?

3 What symptoms suggested a timer problem?

[hull 433]

Hi Steve,

The timer on the right in the previous photo is heavily worn, giving the optical effect of the contact points being raised. In reality the “raised” part is just the edge of a roller-sized groove in both contacts and insulating ring. I’ve never used it since I got the car, assuming it was too worn to be functional.

Here’s a photo of the roller. In good shape as far as I can see, and normally the car readily starts on mag with one or two quarter pulls.

The issue is that the engine suddenly running in the midst of a drive. Fortunately it was a residential neighborhood and I was able to coast as much as a Ford can to the curb. I could not restart it or get any response except a slight kickback.

Huh, just thinking of something- it’s cut out three times before, but these seemed minor nuisances and a quarter pull always restarted it with no trouble. Now they look like signs of the current issue, supporting Mike and John’s thoughts.

[Jerry VanOoteghem]

Have you tried running/starting it on battery?