Need some info on Hemi choke heat tube in the right exhaust manifold

[AR67GTX]

I went through the 66 Hemi carbs last winter and had everything working good including the choke system. A couple months ago I had a hanging fast idle and the choke plate was dragging from something in the choke housing. I could cycle it some and free it up but it has continued to be sticky. I took it apart today and there was some residue inside that I would guess is from exhaust and probably means the tube inside the exhaust manifold is leaking from rust through. I cleaned it up and reinstalled and it’s back to good as new - but probably for not long.

If anyone has a right Hemi manifold sitting on their bench where they can get to it, could you measure the inside diameter of that tube - drill bit diameter would be close enough? I’m thinking of getting some copper tube that will slide inside it with some red RTV or exhaust joint seal and maybe cut down on the leaks/residue until some day when I have the manifold off and can do a little more permanent repair.

If anyone can get that inner tube size I would appreciate it.

 

[dan juhasz]

I had the same issue, the degradation of the interior of that chamber keep making the piston bind. I installed a carter electric choke, direct fit on the housing and kissed that issue goodbye.

 

[AR67GTX]

If I can’t solve this with a sleeve that may be my approach.

thanks

 

[RJRENTON]

I went through the 66 Hemi carbs last winter and had everything working good including the choke system. A couple months ago I had a hanging fast idle and the choke plate was dragging from something in the choke housing. I could cycle it some and free it up but it has continued to be sticky. I took it apart today and there was some residue inside that I would guess is from exhaust and probably means the tube inside the exhaust manifold is leaking from rust through. I cleaned it up and reinstalled and it’s back to good as new - but probably for not long.

If anyone has a right Hemi manifold sitting on their bench where they can get to it, could you measure the inside diameter of that tube - drill bit diameter would be close enough? I’m thinking of getting some copper tube that will slide inside it with some red RTV or exhaust joint seal and maybe cut down on the leaks/residue until some day when I have the manifold off and can do a little more permanent repair.

If anyone can get that inner tube size I would appreciate it.

Imo....do yourself a favor and DO NOT use RTV red, labeled for hi temp. But bear in mind that the exhaust gas at the failed tube location, is in the neighborhood of 1000° F. IF, you decide to replace the tube, consider a stainless steel alloy TUBING, not pipe. Fastenall or McMaster Carr is a source sold by the ft. Consider using SS 304, SS 316 or SS 309, ......But the easy fix as suggested by Dan Juhasz #2 above....
BOB RENTON

 

[AR67GTX]

I think I have some Walker exhaust system sealer that the manufacturer of my Cobra replica suggested using on header slip joints. It seems to hold up for sealing yet comes apart with a little effort. This is just a temp fix until sometime when I have the manifold off and can do a proper replacement. Do you know the existing tube inner dia? Possibly I can measure it unscrewing the lower connection.

 

[Fran Blacker]

Years ago think someone made stainless steel ones. Don't remember who made them.

 

[AR67GTX]

Bump - anyone have a right side manifold sitting around they can gage the inside diameter of the choke tube?

 

[AR67GTX]

Once more - bump

 

[Fran Blacker]

1966-74 A B E-Body Hemi Choke Tube

 

[AR67GTX]

Damn, never figured there might be a reproduction of that. I’ll get one and measure the inside for a temp fix and hold on to it for the permanent fix later.

thanks Fran

 

[AR67GTX]

Change of events. I pulled the line to the carb loose and seeing that it fits inside a larger piece of tube as a socket, measured the OD of the choke line which was 1/4”. I took a 1/4 bit and hanging on to it tightly slid it into the manifold and it fine fine and precision like so it looks like the ID of the tube in the manifold is just a hair larger than 1/4“ and the OD must be like 5/16“ or 11/32”. I stuck small diameter piece of straight tube down next until it bottomed and it went in over 8”.

So I had an old line with the 1/4” OD to the carb and I cut a straight piece of it out at 7“ long and slid it down inside until it bottomed. Then I stuck the line to the carb back in and it seated about 1-1/4“ to 1-1/2“ deep and secured it back into the choke housing. It might still pull a little soot in past the old, apparently rusted tube from engine vacuum, but if so, I suspect it will seal up pretty quick.

Only time will tell if it’s a long lasting fix.

 

[lyndondb]

I had the same issue, the degradation of the interior of that chamber keep making the piston bind. I installed a carter electric choke, direct fit on the housing and kissed that issue goodbye.

What do you do with the open tube from the exhaust?