Worn Manifold Carburetor Stud Bolts on a '42 Buick - Suggestions

[JimH56]

I own a 1942 Buick Century with a Carter 553S carburetor. In rebuilding the carburetor, I discovered that the stud bolts that hold the carb to the manifold have deteriorated. I am applying penetrating oil and may apply some heat to try to remove them and put in new ones. Has anyone experienced this, and if so, do you have any suggestions on methods to get these studs out of the manifold. I doubt they have ever been removed.

[raydurr]

I usually use a 4lb hammer to firmly strike each stud several times. I would then use vise grips to gently remove. Dont apply too much force. If it moves, go both directions several times. Use lots of penetrating oil.

[carbking]

I use heat and cold BEFORE the penetrating oil.

 

Heat the bolt slowly until it turns cherry red. Allow to cool by itself, do not quench.

 

Once at normal temperature, make a patch of tape with a hole that will slide over the stud, and press the tape on the intake.

 

Acquire a bottle of spray freon (I think that is what is used) from an electronics supply house. This is the stuff they use to test capacitors.

 

Spray the bolt with the freon, and immediately spray with penetrating oil.

 

Let it set for however long you normally let the stuff set.

 

Ray - no offense, I prefer to "double-nut" the thread, rather than using Vise-Grips.

 

Jon

 

 

[Bloo]

37 minutes ago, carbking said:

 

Acquire a bottle of spray freon (I think that is what is used) from an electronics supply house. This is the stuff they use to test capacitors.

As far as I know, that stuff is banned, however you can get a can of "canned air" for dusting out computer keyboards, etc, and if you use it with the can upside down, liquid refrigerant will come out and it does the same thing as that old electronic freon "freeze mist" did.

[drhach]

I had a stud on my 42 that wouldn't budge, and I was worried that I would snap it off. I heated it with a propane torch and melted some beeswax into the threads. It budged. I did this a few more times, each time just moving it incrementally. I got it out. I don't know why this works, but I swear by it. The Acetone and ATF trick wouldn't even touch it. But this did the trick. I highly recommend it. 

Edited August 16, 2023 by drhach (see edit history)

[nat]

.....On the other hand.  Don't fix it if it ain't broke.  The threads are fine where the nuts have been and the compromised studs are still ten times stronger than  what's needed to hold the carb in place.  

     

Edited August 16, 2023 by nat
. (see edit history)

[JimH56]

Thank you everyone. After applying penetrating oil and tapping the bolt with a hammer a number of times, I’m pleased to report that I was able to get the stud out with a Cornwell bolt extractor.

 

The stud did need to be replaced because the carb had apparently been built up with more than one gasket to avoid the deteriorated threads.

 

Now, we will see how my carb rebuild works. I have a 533S carb and the rebuild kit came with a fuel accelerator pump that was 7/64 longer than the original and had a spring that was longer than the one inch spring. Dakota Carbs made me 4 of the correct size and I used the existing spring. Fingers crossed that she works well!

[nat]

12 hours ago, JimH56 said:

the carb had apparently been built up with more than one gasket to avoid the deteriorated threads.

     Might that be the 1/2"ish thick heat insulator?  Why would the studs be that length if that thickness isn't correct?

[JimH56]

Possible, but it was not thick as a phenolic or other heat insulator, although one did have a metal core.

[Skidplate]

If you can, and you have enough thread on the stud to support it, screw two nuts (one on top of the other) and tighten them really tight against each other. Get them to where their sides match up and you can get a socket over both nuts. I.e., they won't move from where they are on the stud because you have the socket over both nuts. Then don't heat the stud, heat the manifold all around the stud. Metal will expand outward away from the stud. If you heat all around, it will expand all around. Then use an impact CCW to gently break the stud from the manifold. If it starts to move but you're not comfortable with taking it all the way out, you can impact it back in then out then in again until it moves freely. This is when your oil will also help. NOTE: if you DON'T have enough thread for the two nuts to bight, you can us a die to reduce the thread size by one on the stud. Take your time and think through what you're doing. It should impact right out. Good luck.

[nat]

13 hours ago, JimH56 said:

Possible, but it was not thick as a phenolic or other heat insulator, although one did have a metal core.

     My 39' 248 has the same three stud mounting with a 1/2" +-  insulator under it.  The studs stick out about 1 1/2" and with lockwashers about two threads come through the nuts.