TC Carburettor Overflow Pipe

[SteveW]

I'm now restoring my SU carbs. For some reason, the fuel overflow pipes have been cut very short. What are the correct lengths of these pipes please and does anyone have a picture of the original routing as there seems to be a lot of variation.

By the way, when I stripped the carbs down for inspection I found that the jet needles were different and completely none standard. One was an FJ profile (more taper than standard) and the other was a GV (aside from the first 1/4", this profile is straight sided to the end). The standard one for a TC is an ES. I know that the car was put together from storage to sell, so I guess that they just put random needles in. But if anyone can come up with a reason why someone might have wanted to run the car like that, then please let me know. As far as I can see, the jets are stock.

[bloodysalmon]

Hi Steve, good to see you are sorting your carbs. Note that the replacement pipes from the Octagon are 30" long. There may have been a specific route originally, but you may wish to consider it may not have been the best route! After all, they can expel petrol right onto the exhaust pipe, which to me seems somewhat risky. So i take the thought to try avoid it dripping anywhere near the pipe. Saying that, its not that easy to choose an alternative route and exit point other than to the front l/h of the engine mounting area! There's perhaps a safer option to try to get the end of the pipe to exit further outboard

[Steve Simmons]

The routing is down, then forward to meet the front pipe, then both continue down the front face of the engine plate where they are secured by a clip. Escaping fuel ends up on the ground in front of the engine.

The length doesn't really matter so long as it reaches below the bottom of that plate.

Edit: Tom's photo below is so much better than my description!

[Tom Wilson]

Here's how overflow pipes were done originally on TCs. This is on TC0279, one of mine.

[antijam]

Mine run similarly, discharging in the region of the front engine mount.......

I've wondered if there should be a clip attaching to some part of the engine anchoring the ends of the pipe to stop them flapping about? At the moment mine are clamped together with a cable tie.

[Tom Wilson]

Clip on the front engine mounting plate, held in place by one of the bolts attaching the plate to the block, on the carb side, lower area, holds the carb overflow pipe ends in place.
Part number CL070 at From the Frame Up. The clip offered at Moss Motors is incorrect.

[antijam]

Thanks for that Tom - one more thing I can tidy up.

[SteveW]

Thanks, that's really helpful. Those pictures have also reminded me that I need to polish the suction chamber pots.

By the way, my pistons didn't have springs with them but I've read conflicting information about whether they are needed or whether gravity to drop the pistons back to the closed position is sufficient.

[Steve Simmons]

The springs are only needed on the later aluminum pistons. If you have brass pistons, you don't need them.