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I need help from someone with some expertise. I had a rocker stud fail in the 327 on my 64. It is threaded (originals were press-fit) and cracked beneath the surface of the head. My intent is to drill a hole and get an extraction tool in there to remove it, but it was a complete fail. The drill didn't go anywhere. Obviously I'm not doing this right. Can anyone suggest an effective way to get this stud out?
The way my favorite machine shop would approach this: Fixturing the head securely on a Bridgeport, they would run a tiny end mill into the stud and move it around in a circular path. That will make the stud just a thin shell which can then be collapsed on itself and extracted..... possibly in pieces. The threads will not be damaged by this process.
There may be other ways of extracting what's left of that stud, of course.
There's nothing but stud in that hole? Get good drill bit. An American made high speed steel or cobalt. Drill carefully starting with a small drill the drill it to 1/4" making sure to stay centered and true. Get a good stud extractor again American made no Harbor Freight here. With the extractor in the hole use a little heat to loosen any Loctite. The stud should not be that tight as there's no nut and you could only tighten it so much.
There's nothing but stud in that hole? Get good drill bit. An American made high speed steel or cobalt. Drill carefully starting with a small drill the drill it to 1/4" making sure to stay centered and true. Get a good stud extractor again American made no Harbor Freight here. With the extractor in the hole use a little heat to loosen any Loctite. The stud should not be that tight as there's no nut and you could only tighten it so much.
ok, I think I might need to upgrade the drill bit and extractors then. That picture is how I found it so I am assuming that it's only stud in there. Thanks for the tip.
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I would try a good quality extractor as well,
BUT.....maybe my eyes are getting old but that looks like a helicoil in that hole. Anyone else see that?.....if that's the case it's no wonder an undersized screw in stud broke. I've never even heard of a screw in stud snapping off like that. That's the reason we take out the press fit ones....to avoid stuff breaking.
Who put the studs in?......I'd like to ask him if someone was messing with them before somehow.
BUT.....maybe my eyes are getting old but that looks like a helicoil in that hole. Anyone else see that?.....if that's the case it's no wonder an undersized screw in stud broke. I've never even heard of a screw in stud snapping off like that. That's the reason we take out the press fit ones....to avoid stuff breaking.
Who put the studs in?......I'd like to ask him if someone was messing with them before somehow.
Kerrmudgeon I see what you're seeing now, it could be a helicoil. I bought the car last year so I don't know who did this work. I just want to get the thing fixed to get me to later this year when I do an engine rebuild and get a set of new heads.
When you say this is how you found it does that mean it was running fine and a stud broke or you got it like this? Sure looks like an eazy out in there to me. That's why a drill won't touch it. I hope I'm wrong.
The easiest way to get those out if the drill an easy out fail is to place a nut on top of the stud and someone with good welding skills weld the nut to the top of the stud let it cool and back it out with a wrench the same way you would do exhaust manifold studs that break off the weld does not stick good to the cast-iron but will stick good to the stud if done properly.
It is best to use a "left hand" fluted drill bit when drilling to remove a "right hand" threaded bolt. The "left hand" drill bit with the drill in reverse helps loosen the bolt and in some cases will even back it out. The "left Hand" drills are not cheap, especially good quality stainless or cobalt bits, but last.
That valve looks like the top end of the stem is dome shaped rather than flat suggesting the rocker was run loose or the rocker is cracked in the seat?
If that's true, the head needs to come off to repair the valve.
Not an expert but should the top of the boss the stud screws into have been milled smooth so it could seat properly?
The type of stud he has doesn't have an integral nut, it's just a threaded stud. This is how these studs are installed. There's nothing t seat so no need for a square surface.
I think looking at the pic there is JB Weld around the stud making it look like a Helicoil. There's a piece of it off to the left as well. Don't panic just drill it straight and pull it out. Snap On sells a set of extractors that are square, they are very tough and a good bit harder to break. There's no way I would even consider pulling that head. I would have that stud out before you got the exhaust off to remove the bottom row of head bolts.
When you say this is how you found it does that mean it was running fine and a stud broke or you got it like this? Sure looks like an eazy out in there to me. That's why a drill won't touch it. I hope I'm wrong.
To clarify, the car was running well, then I started hearing a ticking noise. Still running well. Valve adjustment/rocker was probably getting loose but the stud was still intact and engine still seemed ok. As I was trying to locate the origin of the noise, the ticking noise remained and all of a sudden the car was missing. This is probably when the stud had broken apart. I did a compression test to isolate the bad cylinder and took the cover off to find the broken stud.
The type of stud he has doesn't have an integral nut, it's just a threaded stud. This is how these studs are installed. There's nothing t seat so no need for a square surface.
I think looking at the pic there is JB Weld around the stud making it look like a Helicoil. There's a piece of it off to the left as well. Don't panic just drill it straight and pull it out. Snap On sells a set of extractors that are square, they are very tough and a good bit harder to break. There's no way I would even consider pulling that head. I would have that stud out before you got the exhaust off to remove the bottom row of head bolts.
I will check the Snap-On site for the extractors you refer to, thanks.
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Replace threaded rocker stud
