what is under the head studs?

[mumpsimus]

I had to drill out a broken cylinder head stud, and some of the drilling swarf went down into the motor through the hole that used to be the stud. Does anybody know what is under this stud in a 21 stud motor? Is it accessible if I pull off the intake manifold? Or did the chips fall between the bores down toward the oil sump? I'd like to clean out the drilling chips, but I'm not sure if they are accessible. It is the top, center stud as shown in the photo.

Thanks,
Pete

 

[J Franklin]

It is the water jacket, seal it when you replace the stud.

 

[Jack E/NJ]

Yeah, just the water jacket. There's prolly so much crap, casting sand and whatnot in the water jacket already so a few extra metal chips, filings and more whatnot won't hurt a thing. Jack E/NJ

 

[51 MERC-CT]

On an 8BA that hole goes into the center exhaust port.
You should be able to feel it thru the exhaust valve.
The one below it is blind above the exhaust port.
And any chips should come out the exhaust port.

 

[34PKUP]

It is the water jacket, seal it when you replace the stud.

Yeah, just the water jacket. There's prolly so much crap, casting sand and whatnot in the water jacket already so a few extra metal chips, filings and more whatnot won't hurt a thing. Jack E/NJ

Maybe if you drill thru the opposite wall of the exhaust port you will hit the water jacket.

 

[mumpsimus]

Thanks guys. It was hard to see inside the hole, but it looked different in there than the water jacket holes that are above and below it. But it if is the exhaust port, then I'm not worried about the chips going down the exhaust pipe. I was worried that they might end up in the cam chest or down into the oil sump! I'm learning these 21 studs one slow, painful step at a time. Now I can finally get the new head gasket into place and get the car back on the road!

 

[Ken/Alabama]

On the 21 stud engine, doesn't that stud hole go into the center exhaust passage ?

 

[JSeery]

Future reference, there are better ways to remove a broken stud if you can weld or get access to someone who can. Isn't that the hole that is used to secure the exhaust dividers when they are installed?

 

[mumpsimus]

That's what it looks like to me, based on what some of the other guys said. The metal isn't rusty colored like it is in the water jackets. I'll see if I can verify that it is connected by opening one ex valve and shining a light through there. (As long as it isn't going to the sump or the cam followers, I'm pretty happy).

On the 21 stud engine, doesn't that stud hole go into the center exhaust passage ?

 

[Brian]

yeah, you'll blow any swarf outta the tailpipe upon firing up your old 21 stud!!

 

[mumpsimus]

Hi guys. I can confirm that the stud hole goes into the exhaust port. Last night I poked a bit of safety wire under the valve head and saw it through the hole. The cylinder head goes back on tonight.