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Tip on repairing a warped carb air horn??


John_Mc

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Guys below is a picture of the air horn to my original '61 Lincoln Carter ABD carburetor.  This car is new to me but when pulling the carb for rebuilding, this is what I found.

 

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These are pretty rare so I DO NOT want to replace if even I could find one.  Anyone know a person or process that I could use to get this cast piece back square again?   Thanks to all who respond.  My phone is 847-997-9944

 

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Posted Today, 04:59 PM

This kickdown switch was in the oven at 500 F for a while then I drove a previously prepared wedge Gently between the block and switch,  I had an old carburetor that I put a propane torch to and found that it melted above 500F, using a "temple stick" something welders use to check welding temperatures.

  Your situation appears a bit more involved, maybe with some long machine screws a flat surface and some heat it might work.

Good luck,

Jay

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IT DEPENDS ON THE POT METAL!!!!!

 

We have straightened hundreds of carburetor castings MADE AFTER WW-II by using heat, pressure, and PATIENCE!!!!!

 

The method we have used very successfully:

 

(1) Cut a piece of 1/4 inch steel to fit against the warped surface.

(2) Drill holes in the steel to line up with the mounting holes in the item being straightened.

(3) Mount the casting to the steel piece with just enough tension so it does not move.

(4) MEASURE THE AMOUNT OF WARPAGE!

(5) Measure the warpage again, just to be certain!

(6) using the screws, C-clamps, whatever, clamp out 0.003 inch of the warpage

(7) Place casting, plate, clamps, the whole thing in an ELECTRIC oven, and heat to 400 degrees F.

(8) Turn off the oven, and allow the item to cool in the oven until at room temperature - don't hurry the process.

(9) Remove from the oven (if you used clamps, they will probably fall off).

(10)  Repeat steps 4 through 9 as many times as necessary.

 

I have straightened castings with more than 0.100 inch successfully using this method, sometimes heating 25~40 times.

 

The mix of pot metal began changing significantly in the 1930's. I have had zero success on pre-1935 castings, and limited success on 1936 up to 1942 castings.

 

DON'T EVEN THINK OF TRYING THIS ON PRE-1935 POT METAL, SOME OF IT WILL ACTUALLY EXPLODE LIKE A HAND GRENADE!

 

By the way, that ABD you have is an excellent carb, for a two-barrel; but that is a large engine for a two-barrel.

 

And even though the method has worked for me for maybe 30 years, try it on a junk piece of pot metal to prove it to yourself. Over the years, we have experimented on lots of junk to learn things. Some of what we learned wasn't what we wanted to learn (see the second paragraph above!); but we did learn. Knowledge gained through experience is normally useful!

 

Jon.

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I straightened the bowed pot metal carburetor float cover for my 1933 Chevrolet years ago by heating it with a blow torch and gently tapping it into shape with a small hammer on the flat area at the back of my vice.  Don't get it to hot or it may melt.  

 

I like the oven idea also.

 

Took several steps​ to get it totally straight, do not try to get it straight with one heating.

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