how to repair top casting on sidebowl carburetor???
 

Hello all, got a doozy for you. I was driving my A to the gas station and back and discovered that one of the ears to my carburetor has snapped off. amazingly it ran, albeit roughly, having to goose the pedal to get it down the road. now here is the question, how do I repair it? I don't want to put a standard zenith on it as it's a late 31 with the indented firewall, and this was a lovely example of a side bowl. now the break did not affect any passageways which is good and it was a clean break, can this be soldered or brazed on? I dont have the skill to braze and I know that welding cast is risky. if I wanted to gamble epoxy is not off the table but I would rather use more tried and true methods. thanks for your time and I hope we can figure something out.

Re: how to repair top casting on sidebowl carburetor???
 

Yes find a good welder and he will be able to properly weld it for you! Been there done that! Or try and find a new top!put word out at local club or maybe contact Berts model a parts he might have one.Bert's Model A Center | Call: 303-293-FORD

Re: how to repair top casting on sidebowl carburetor???
 

a new top is hard to come by and I just can't make my self trash a rare part, I can weld most stuff, but cast is out of my leagu, i do have a welder friend who might be able to weld cast, I'll see if he can. I tried soldering and it went about as well as trying to make a soup sandwich, solder cant take the pressure of tightening the bolts

Re: How to break off the MOUNTING flange on carb casting
 

Breaking the ears off the flange is a common thing when people use a 5/16ths-18 bolt that is too long.

If bolt is too long it bottoms out on the casting after it screws through to opposite side of flange.

Then when they force the bolt to tighten the carb, the force breaks the flange off!

See yellow arrow in photo.

This is also an example of why it is a bad idea to use an impact wrench when installing any parts.

In this case you can break the flange with a six inch hand open end wrench.

Click image to make it larger

Re: How to break off the MOUNTING flange on carb casting
 

Re: how to repair top casting on sidebowl carburetor???
 

[QUOTE=Gary WA;2313030]Yes find a good welder and he will be able to properly weld it for you! Been there done that!QUOTE] x2 !!

Re: how to repair top casting on sidebowl carburetor???
 

These days there are specialty rods for welding cast iron. Search for that. V the break, clamp the ear on, and weld. If you do not feel confident doing that yourself, find a good welder, one who has welded cast iron before.

Re: how to repair top casting on sidebowl carburetor???
 

This isn't a side bowl, but same problem. It was given to me broken, so I silver brazed it. Made a jig to hold the 2 parts in the proper relationship. Would look better if it was cleaned up and painted.
FWIW, I'm not a welder, just a get-er-done hobbyist.

Re: how to repair top casting on sidebowl carburetor???
 

Hello y'all, going to be taking the top to my friend next week to have him weld it up, if y'all are wondering how the ear snapped off it wasn't due to too long bolts nor was it dropped, I broke the ear off while tightening the sidebowl filter bolt. I heard a click when it happened but thought it was a lock washer popping or something, my truck actually ran to the gas station and back on the broken ear, but it was needing to have the gas pedal goosed all the time. I was the dumdum today. I work on these cars all the time, but I dont have a torch to braze and I just have a small flux core welder for light work, it's way above my pay grade to fix this screw up haha.

Re: how to repair top casting on sidebowl carburetor???
 

Done that on my 31 side bowl, had it welded, cleaned it up with a Dermal.

Re: how to repair top casting on sidebowl carburetor???
 

A thick gasket puts bending stresses in the ears of the carburetor when the mounting bolts are tightened. Make a gasket from a brown paper bag (0.003" thick paper) and with the thin gasket use a very thin film of silicone gasket maker.

Re: how to repair top casting on sidebowl carburetor???
 

Zenith and Holley retained the more robust top flange design from the earlier carburetors while Fords (Zenith 3) design is a thinner flange with added support shown in the photo. There is a Zenith 3 piece posted on Vince’s Ford Garage….,

I have not tried this rod yet but it is used to repair cast iron.

The photo of a Zenith sidebowl carb with a nicely done braze job, and nice part alignment. More than likely done using a fixture to hold the piece in place.

Check for stress cracks in the top casting in the bowl area too. Some are very small and can be missed at first glance……

Re: how to repair top casting on sidebowl carburetor???
 

When I took a night school welding class in 1977 or so, the instructor said to use "machinable nickel rod" for cast iron.

Re: how to repair top casting on sidebowl carburetor???
 

Tim that material is for use on a mig welder?

Re: how to repair top casting on sidebowl carburetor???
 

Re: how to repair top casting on sidebowl carburetor???
 

Gas
I bought it for another adventure and did not get to complete the project. I have a couple of side bowl tops with cracks that i am interested in trying it on.

Re: how to repair top casting on sidebowl carburetor???
 

Good points on the thinner bolt area cast. Be careful to tighten even. ( B carb is the same).also hopefully the crack didn’t go down into the idle port area like mine did.

Re: how to repair top casting on sidebowl carburetor???
 

I would braze it. first wire brush clean. use proper flux you can drill too holes in an aluminum plate to hold it steady, disassemble the unit heat till the flux melts on contact this is how i judge heat when it's hot enough the brass will flow and fill. let it cool naturally
if the flat area that meets the manifold needs clean up place a good sheet of emery on a flat surface and clean till its flat. I have repaired many cast iron parts over the years, generally the repair if done well is stronger than the parent unit.