Fuel pipe diameter

[Steve Bryant]

Thank you guys. This seems to confirm that the OD of the pipe would be 1/4 " diameter.

Will send off my order to my favorite cherished  supplier.

Cheers,
Stephen

[Nick Turley]

Yes it is

[Steve Bryant]

What radius is the vibration loop  for the fuel line ?
Thanks,
Stephen

[Greig Smith]

Steve it kind of needs to be small enough to fit into the available space and big enough do at least a full circle with the line. 

The one in our '30 Triumph Super 7 is vertical but the Super 7 has a much higher scuttle, so the top of the loop is actually below the level of the on-off tap & has never caused any hassles. For the A7 it should be a sideways coil, so whatever size will fit into the space you have.

To bend the copper pipe nice & easily you need to anneal it to make it soft. Using a small propane torch just work up & down the length of the pipe until it's red hot glowing. The colours will begin to dance in the pipe just before this stage, then quench it quickly in cold water. Blow clean & dry with compressed air. Stopper one end, I used a rubber bung, fill with dry builders sand & tamp it in until the pipe is full. Stopper the other end.

Bend it over a suitable size 'former' in the vice - round pipe, a tin of peas or whatever will return the diameter you want it to take. Then  do all your bends to the carb fittings etc etc while it's still soft from the annealing process. Empty the sand & blow the pipe clean again, wash it out with water & then dry with compressed air. Trim to size with a proper rotary pipe cutter, then fit your ferrules and nuts / glands etc.

Lastly give it a once over with some fine steel wool to remove any residue from the heating earlier. Bending the pipe will work harden the copper again & the vibration from the motor will complete the work-hardening process.

Sorry for the excess detail, but following the above make the process really easy. I've done some rather tight curls in copper pipe and the sand stops any risk of kinking. Here's the double oil jet conversion curl as well as the condensing loop on the top of the Green Job's radiator which was a double loop with a bend to one side straight out the top of the cap - that did take me 2 goes to get right. Was wrapped around a length galvanised water pipe in the vice - Looks the part.

Beloved peddling the Green job at the Simola Hillclimb, her first ever event in a vintage car.


Aye
Greig

[Steve Bryant]

Thank you  Greig for your detailed reply. I will have to see how much room I have to work with when the body and engine bulkhead have been erected.  I definitely want it to be as compact as possible as you may guess but that remains to be seen once I get the that point.

Love the pic by the way. How'd she do?
Cheers,
Stephen

[Robert Foreman]

Hello Steve, 
 here is a couple of pictures of an original petrol pipe of my unrestored RN saloon. Note that it is quite crudely done. If you look at the period pictures in Wyatt's book you will see similar ones.
  The copper pipe is supplied in the annealed state therefore does not require annealing. You can gently straighten tube from a coil by passing it through a drilled hole in a piece of wood and straighten accordingly. The tube does not need to be filled to be able to bend it.
   Hope this is of help.     

[Steve Bryant]

Thank you Robert for these pics and information. Most appreciated. 
All the peripheral items for this car of mine were missing so it has  been a long hard slog getting information to fill the gaps in what things looked like and were missing. There are no other cars here I can look at so books and internet have been the mainstay for getting info.

Thank you again for this.
Stephen