1930 Model 68 Heat Pipe

[michaelod]

Hello All,

I am in need of a exhaust heat valve to carburetor heat tube for a 1930 Model 68 with the Master series engine. In the event I am unable to locate one, could someone tell me the correct outside diameter and is the pipe sleeved on the ends? From the picture I have attached it appears that the tube has a slight bend in it; is this correct? I don't know if there is any difference in this part between the Master and Standard series engines.

Thanks for your assistance,

[Mark Shaw]

Michael,

Remove the carb & heat riser to remove the upper tube intact. Take it to a good muffler shop & have them make you one with the slight bend in it. They should be able to use standard exhaust pipe and expand it to just fit.

Or, just put freeze plugs in the valve and heat riser (like most of us have done) and eliminate the unnecessary pre-heat system altogether. The old heat tube can then be re-installed just for show.

[Fred Rawling]

If I remember correctly, the O.D. of the tube is 1 1/8 inches.

I bought some seamless steel tube from the pipe and steel supply and bent it by heating it in the vice with a tourch and bending it with a piece of rod stuck inside. Then I cut it to length.

It is not as pretty as the original but it fit and it works.

The muffler shop would be easier if they have the correct size pipe.

[michaelod]

Many thanks to both Mark and Fred for their help with my questions. Once I get the car running (which should be very soon) I think I will take it over to a muffler shop here in Raleigh that has a mandrel bender. Should be a simple job for them.

[Fred Rawling]

You should disassemble the set up before you go to the muffler shop.

The reason being that the old heat pipe may be rusted in the heat riser. It may take some time to get it out without breaking the heat riser.

Most shops do not want to spend the time to remover stuck parts carefully.

The packing collar is hard to get out in one piece if it is rusted to the heat riser.

You need rope packing to go into the openings in the heat riser and manifold before the packing collar is installed.

[michaelod]

Well Fred disassembly will not be a problem as the heat control valve is severely broken and the heat tube entirely missing in my car. I suspect that the valve was frozen up at some time in the past and was destroyed when a previous owner attempted to free it up. The picture shown above is not my car and just used to illustrate the part I am missing. In any case I have purchased a new heat control valve from Bob's Automobilia and it looks to be a very well made reproduction in my opinion. The heat tube will need to be made here locally.

You mentioned a packing collar and rope packing in your previous message. I notice there is a small sleeve pressed into the end of the new heat control valve where the heat tube attaches. Is this what you are referring to?

Thanks,

Edited December 16, 2009 by michaelod
Text (see edit history)

[Fred Rawling]

Yes, that small collar is needed on both ends of the heat tube. It holds the packing in the opening on the heat riser and the exhaust manifold. There is a 1/4 20 hex head set screw that holds the collar in place. I think that I made one with my lathe from a piece of 1 inch water pipe. If one came with your heat riser, then Bob can probably sell you another one.

Fred