11-A Distributor Thread Size

Ramjet47

Ramjet47

Member
I have a stripped thread on a distributor I am overhauling. What is the thread size of the vacuum connection?
 
NO expert BUT being a brass fitting/tube wouldn't it be a "NPT" or a National Pipe Thread because "Machine" threads do not "seal" so you couldn't seal the "vacuum" with a machine thread!!! MY "guess" would be a 1/8th NPT or 1/8 National Tapered Pipe Thread!!! AS I said....MY GUESS
 
Rock, no, mate, I just went and checked, it is the fitting for a 3/16 tube, which is 3/8-24 UNF.

A 3/8-24 tap screws in nicely but a 1/8 NPT barely starts and goes tight straight away.

It was late when I posted last night, but was able to do a physical check today.

The nut has a tapered end which bites into the pipe.

Mart.
 
If you've stripped it, you could go 1/8 NPT and use an adaptor to get back to 3/16 tube.
 
Here is the fitting it takes I think.3/8 24 as Mart said
 

Attachments

  • 3:8 24 fitting.jpg
    3:8 24 fitting.jpg
    32.3 KB · Views: 11
rockfla said:
NO expert BUT being a brass fitting/tube wouldn't it be a "NPT" or a National Pipe Thread because "Machine" threads do not "seal" so you couldn't seal the "vacuum" with a machine thread!!! MY "guess" would be a 1/8th NPT or 1/8 National Tapered Pipe Thread!!! AS I said....MY GUESS
Click to expand...

The sealing required at this fitting would not be accomplished at/or by the 3/8-24 threads.
 
Mart said:
If you've stripped it, you could go 1/8 NPT and use an adaptor to get back to 3/16 tube.
Click to expand...

Mart, wouldn't any adapter require a provision to seal the original 3/16 fitting. I think it is going to require some measure to repair the existing threads or switching to some other method to seal the 3/16 tube with the adapter. Unless there is an adapter that provides the seat required for the original fitting.
 
Ya, I would really think hard about any attempt to tap it out to a different size, could really open up a can of worms.
 
Ford used a lot of unusual thread sizes and pitches. At our shop we aways save any "left over" nuts and bolts. We have several coffee cans of them, and have been glad we did.
 
Thank you to all who replied. I have now re cut the thread back to 3/8”x24 UNF, not perfect but with thread sealant it will be OK. Best regards Roger.
 
You must log in or register to reply here.
Back
Top