1971 Superbee 440 broken valve cover mounting hole

[jefferwin]

This one has me a bit worried.  The lower corner threaded hole for the valve cover is broken.  The small outer corner of the head casting broke off so there is no way to re thread or put a helicoil in.  Very small break, doesn't affect anything else but leaks a bit as I am unable to put a bolt in.  Using cork gasket, put some silicon in the hole and tightened the nearest bolts a little to see if it will seal.

Any way to fix this other than replacing the head?

[John_Kunkel]

A good welder could build up the corner with rod (Muggy Weld 77) so that a hole could be drilled and tapped for a bolt/stud.

[timmycharger]

What John said is the best solution in my opinion.     If you don't have access to this type of repair I was able to get away with a different method for several years.

I did the same thing about 20 years ago with the 440 on my Charger.  I ended up getting a tube of magnum steel, they make many different brands of the same stuff but its a 2 part putty that you knead until you get something like clay that hardens to a very hard substance. 

I built up the corner with this stuff then carefully screwed in a small stud while it was still pliable and when dried I was left with a surface that I filed flat. I then used a cork gasket with RTV.   That ridiculous repair held for a few years until I replaced the heads. 

Not a permanent repair but it worked for me for several years.   

Good luck!

[jefferwin]

Thanks for these ideas. Right now the high-temp silicon in the bolt hole and tightening the other bolts a tad seems to be working. There isn't any real pressure under the covers so maybe this will hold. If not I will try the magnum steel and helicoil idea. 

Th4se things are wonderful when they aren't leaking, smoking or catching fire.....

[c00nhunterjoe]

The original heads were only 4 bolt. Clean the rail extremely well, use a good rtv and dont go past snug until it sets.

[ACUDANUT]

The original heads were only 4 bolt. Clean the rail extremely well, use a good rtv and dont go past snug until it sets.

Bolting the heads on and the 6 bolts to hold the valve cover on are two different stories. Wait is it 5 

[c00nhunterjoe]

The original heads were only 4 bolt. Clean the rail extremely well, use a good rtv and dont go past snug until it sets.

Bolting the heads on and the 6 bolts to hold the valve cover on are two different stories. Wait is it 5 

Ok, let me rephrase it for you. The early mopar big block heads were 4 bolt valve covers.

[b5blue]

I see listings for bolt/stud/nut sets (Hoovers Auto) where studs are used in the 4 lower corners. You could glue the stud/broken corner in place and snug down the nut.

[John_Kunkel]

Ok, let me rephrase it for you. The early mopar big block heads were 4 bolt valve covers.

And they leaked at the lower corners. That's why they added the two additional fasteners in the corners.

[ACUDANUT]

 Sorry never seen this. My 63 426 has 5 or 6 bolts each (valve cover).  

[b5blue]

https://picclick.com/Big-Block-Mopar-Max-Wedge-4-Bolt-Valve-124535743658.html   

[John_Kunkel]

Sorry never seen this. My 63 426 has 5 or 6 bolts each (valve cover).  

The 6-bolt valve cover was introduced in mid-year '63.