I want to find out any info I can about the tube that runs under my intake manifold and between the rear exhaust manifolds of my 67 type1 beetle. I have heard others call it a balance tube but I'm unsure if that is correct.
I did ask a mechanic and he told me that it was there to warm up the intake manifold for driving in icy weather and that I wouldn't need it in Australia. Is this correct?
At the moment it is blocked with carbon and I'm having trouble getting it out. I have drilled a hole in the bend points so that I can get into the straight section of the tube but I still can't get anything in there to break it up. I'm thinking of welding up the holes and just leaving it blocked. Any suggestions?

No it's not a balance tube.
As the mechanic said it's keeping the manifold heated and it's needed in even the hottest climates.

VW would have saved a bunch of $$ leaving it off if it wasn't needed.

Warmer climates it's not needed as badly but it still makes a huge difference to running.

Its the change of state that causes the issue.
The carb turning fuel from a liquid to a vapor causes refrigeration effect, same principal as how a fridge or A/C works.

Best way to clean it out is a piece of clutch cable in a drill and if its really bad fill it up overnight with caustic soda first.

Thanks for info Joel.

I'll try the caustic soda and see if that helps to loosen it up first.

Thanks again for the help, Al.

Back when i was running a single carby i cleared the the tubes by turning it upside down, filling it with liquid drain cleaner and letting it soak over night. It still took an hour or so of drilling afterwards, but it does make a difference. Instead of clutch cable, i went to Bunnings and bought the liquid drain cleaner and some metal pipe unclogger (in the same section as the drain cleaner.) It's usually used for unblocking hair and things down sinks and toilets, and it's a thick metal cable and only a buck or two each. Put that in a drill and off you go.

That rust can chew right through into the inlet manifold and cause problems.
Cleaning out the rust can be impossible.
If it's a 1600 twinport I recommend buying a new one. There not that dear.
Earlier engines manifolds, however, can be hard to come by.

It's a single port Phil and it's connected to the inlet manifold with a lead cast so I would have to get another whole set-up.

I looked at a few for sale as second hand parts and they all had the same problem.

I haven't really checked to see if someone sells new ones but I might try the drain cleaner and caustic soda to start with to see if I can rescue the original item. Plus a trip down to Bunnings on the last day of the year sounds good to me.

Have a good New Years Celebration everyone.