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H1 SU vacuum advance frustration.

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apbos

apbos

Jedi Knight
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I have two sets of H1 SU carbs and neither set has the small vacuum advance pipe fitting to connect the copper pipe from the vacuum advance. Anyone have any advice where I can get one or what I can use in its place?
Thanks
Paul
PS I am using a Downton intake manifold so I want to stay with the period H1SU carbs







image.jpg
 
apbos said:
I have two sets of H1 SU carbs and neither set has the small vacuum advance pipe fitting to connect the copper pipe from the vacuum advance. Anyone have any advice where I can get one or what I can use in its place?
Thanks
Paul
PS I am using a Downton intake manifold so I want to stay with the period H1SU carbs







View attachment 29377
Click to expand...

The fitting would have been on the hard line. I have a Morris Minor here at the moment that is set up that way. I'm not sure what the thread is (probably BSP), but you might see if you can find a close size in a good plumbing shop. You can probably get a BSP die and recut the threads or just make yourself a fitting from hex brass bar stock.

Not even the obscure sources I have seem to have this early style vacuum pipe with the male fitting.

https://en.wikipedia.org/wiki/British_Standard_Pipe#Pipe_thread_sizes
 
That is what I was afraid of Gerard. I have the original copper vacuum line with the spark-arrestor, but no end fitting. I will look to see what I can find at the hardware store. My reading tells me that this is the best location for the pipe so moving it does not seem to be an option.
Paul
 
Paul
I just checked on a couple of my H1's and a 1/4-28 bolt fits in there very nicely.
You could easily make a 1/4-28 bolt into a fitting and secure it with a common 1/4-28 nut
BillM
 
Bill
Thanks! I just got in from the hardware store (OSH) and using their guides a 1/4 - 28 seems a little small. I will go to the old hardware store tomorrow and use one off the self vs those in a little bag and give it a try. Looks like great minds think alike :smile:. I was also thinking about drilling out a grease zerk to use and then using a rubber connection.
Paul
 
Check the thread on a grease zerk, I believe they are all pipe thread. Drilling through a bolt and turning it down on a drill press with a file would be easy to do.

Kurt
 
Bill was correct! The ends were rounded some in the carbs once I was physically able to run a bolt through a 1/4-28 worked like a charm! Drilled the center and this is what I got.
10061308634_e2dc902ba4_c.jpg I will braze or solder the pipe when I know I have the correct length.
Thanks everyone!
Paul
 
Necessity.........
 
Well done, we do what we have to so they stay on the road.
 
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