Broken rocker stand

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1994redram

1994redram

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I bought a set of magnum R/T heads and took a bit of a gamble on them. A couple of the holes for the rocker studs have been drilled and heli coiled. That didn't seem like too much of a problem. But one of them is broke completely. The remaining hole in the head is about an inch and half deep,and threaded. Is it possible to have the part welded back on and run longer studs? Or is it possible to swap to shaft mounted rockers, which seems like a downgrade. Or did I waste my money?

I'm just about finished up with my slant 6 to stock 5.9 magnum swap and I'll be happy with the power for awhile. But heads and a cam are in the plans.
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So the separated piece is not even threaded? I think the rule of thumb in thread engagement is 1 1/2 times the diameter of the fastener. Mild build? For mild to medium build I would get a bolt that you can use to hold the broken piece in place and epoxy it. Then run it. If you are going to put any sort of money in it I would get a different head. It will always be a question though and right now you don't have a bunch invested in the head. Better than this! There is about $900 in port work in this one.

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Had an intrepid, broke the rocker shaft and took the end tower with it. New rocker shaft and i drilled down the threads until i hit water jacket,pressure tester as the indicator. Tapped it, locktite and new rocker shaft. Ran for 100,000 plus km’s and never leaked a drop. Body fell apart before engine.
 
I filled the area around the heat cross over with belzona super metal. Bolted down a shaft to hold the pedestal in place. I will dill and tap it all the way through the roof of the cross over which is 3/8" thick. Tap it one size bigger and run a thick wall rocker shaft. Use the head as a spare.

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Well that's the thing about gambling, some you win some you lose. If it was shaft rockers I'd say maybe. Pedestal I wouldn't but that's me. There's an art to welding cast iron, also. But Im no welder. Maybe one will chime in. How much are Magnum heads going for? Is it worth possible damage to your bottom end?
 
It worries me that there is a broken piece that looks stripped and heli coils. Some one was either heavy handed, didn't know what they were doing or had some F'd up valve geometry issues, retainer hitting guides, or all the above. I'd have these looked over by a good shop before rebuild.

Just so everyone knows there are not production magnum heads off an R/T, they are Mopar over the counter performance heads.
 
In my poorer, younger days, with that amount of threading available, I would have run it. If you could clean out the rust on the 2 surfaces with a really fine wire brush and if they mate tightly, put some high temp superglue in between the 2 surfaces and quickly lock it down with a bolt to set up. (Just don't get it in the threads!) Very tiny spaces is where those cyanoacrylate glues are strong. Just put it in there as a stable surface for the rocker.
 
The broken part has been drilled out. So no threads. They aren't stock magnum heads. They're Mopar performance R/T heads. I got them cheap. I could probably eBay the one head and make my money back, but I would love to use them! Finding a single matching head would be pretty tough I think.

The previous owner passed away and I bought them from the "garage sale" along with some other goodies. His son seemed decently knowledgeable but didnt remember how or why the mount broke. Judging by the repaired threads, there had to have been some issues. I have the full set of valves from the heads. None are bent or bad from what I can see.
 
Forget all that JB Weld and super glue stuff.

Remove any existing thread repairs.

Degrease it with alcohol, acetone, and brake cleaner, then degrease again and let it dry.

Break out your tig welder, and build it back up with 316 rod. The idea is to add more metal than what's lost, so you can mill it back flat. There nothing precise about it, just get the porosity out and make taller than what you need. Be sure to fill the bolt hole too. If your welder buddy can't do this, get a new welder buddy.

Now take it to your machinist buddy. If he takes more than an hour to fixture it, deck it, drill it and tap it, he's good. If he takes two hours, he's bad. He should use existing holes to determine the location.

This should be a cake walk repair if I'm looking at correctly. I did the same process on the cast arm on this wrench a while back. It's been used daily since.

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bevel the edges of both pieces, run a bolt down with upper piece sandwiched, now weld it with 3/32 cast rod. do not preheat!! it can be welded and done correctly it will hold. use machinable cast rod. we stick weld cast iron.
 
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