SU carb overflow question

[dlgis]

I’ve noticed my SU carbs don’t have the correct overflow pipes that feed fuel to below. The rear carb has one that appears ok, the middle seems to have a crimp in it that would prevent fuel flowing through and the front has been cut off and crimped about an inch from the float lid. And I only have (overflow) holes in the top of the rear and centre float lids, not the front. One thing that may explain the difference is that the rear has a AUD112R tag, the centre a AUD112F, and the front has no tag. Maybe a twin carb set up converted to 3?
So I’m assuming I need to buy the correct overflow pipes but should I also be changing the front float lid for one with a hole


Centre:

Front:

Rear:

[tinworm]

The hole is blind so it matters not. You can make new tubes out of brake pipe - solder them on to the banjo connector.

Barrie

[JerryL770]

Well, IMHO the front lid cannot provide overflow if there is no path for the excess fuel to flow. Not sure what is meant by "no hole".

Use 3/16" cunifer brake pipe soldered into the banjo but don't use too much solder else you may block the pipe. Make sure you can blow through it. I found out the hard way what happens if the overflow is blocked. What happens is fuel flows out of the carb air intake!

[dlgis]

Thanks I’ll make up the overflow pipes using brake pipes

[E703SU]

Originality questions for a '70 S2 with SU carbs:
- What were the original overflow lines made of (copper, maybe cad plated)?
- Is there a definitive original pattern to the tube bends (pictures available somewhere)?
- And is there a definitive original routing of the tubes (pictures available somewhere)?
I imagine there were no material differences among the 3.8s and 4.2s on the above.
Thx

[Heuer]

The three copper SU overflow pipes are gathered together in a line of three and supported by the bracket on the filter housing:



The Service Manual shows the routing:

[E703SU]

Thanks, David.

[Geoff Allam]

You may find this description useful. Credit goes to the original poster. His name is on the screenshot.