Length of thermostatic choke control tube

Does the length of the thermostatic choke control tube from carburetor through the exhaust manifold really matter? Will a longer tube significantly adversely affect function? ((Carter WA 1 carb)

I'm sure heat transfers faster through shorter tube, but it is easy to bend a longer tube, hard to bend a short one to replace the original. I would also like the tube to extend below the manifold.

I don't fully understand how the tube works: does air flow through the tube, or is its function solely dependent on heat transfer in a static column of air? If the former, tube length might be irrelevant, if the latter , maybe length will matter.

Thanks

This may help:

http://www.thecarburetorshop.com/Automaticchokes.htm

Jon.

cant see a slightly longer tube would be an issue

The ones I have seen, the manufacturer did not make much effort to make the tube shorter. They did put insulation on them. I would go with the longer tube within reason and put an insulated sleeve on it.

Thanks to all. Carbking's link should be required reading for guys like me. It also points out my problem: tube rust-through at the exhaust manifold, and that should have been anticipated when I rebuilt the engine. Live and learn. Now the rust-through is really an exhaust manifold leak, so there is another project re-do.

Rusty OToole and ted sweet let me justify my longer tube also.

See if you can find a picture of your engine when new and make the tube the same.

I'd love to find one! The tube just isn't visible in most images. I have a rough idea of what it should look like, but it remains difficult to bend a tube to that contour