Cylinder head recondition question


(Gary Grant) #1

Hi everyone,

I have a spare 3.4 cylinder head which I am considering trying to recondition.
The valve guides are worn, and I will have to eventually take the head in to a machine shop to have the valve guides replaced, or more likely to have the guides lined with, I think, K- liners.

My question is: do the studs which hold the camshafts in place have to be first removed from the head, so that the valve guides can then be worked on?
I got the cams out, but these studs are stuck. The cam studs are not bent or mangled, the exposed threads look good.
So, if it is even possible to have the head fixtured, and machined, with the cam studs still in place?

It would save a lot of effort if I didn’t have to try removing the cam studs.
Thanks in advance for any help.


(Rob Reilly) #2

What methods have you tried for removing the studs? Is it a corrosion case?
Double nutting and penetrating oil usually works. Propane torch helps.
The answer to your question is probably no, but the machine shop will probably remove them anyway to make it easier.


(Gary Grant) #3

Hi Rob,
Well, so far the only thing I have done is to just sit there and look at the studs. Have applied penetrating oil a few times to the studs, which have light surface rust showing. The engine hasn’t run since 1967.

Maybe I will get lucky and they will unscrew with little effort, although such a thing doesn’t happen often. They say they every dog has its day, so maybe I should at least try double nutting and see what happens.


(Jag-ur) #4

WOOF! meooooow! HISSSSSSSSSS. :wink:


(Gary Grant) #5

Well guys, I cannot believe that 3 of the studs have come out already by just double nutting them and unscrewing. They, so far, haven’t needed nearly as much torque as I had imagined, to unscrew.

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Rob, thanks for the encouragement, this clearly confirms that I should get your advice before starting any project.

Regards, Rover


(Robin O'Connor) #6

I would do due diligence on the K line inserts, standard guides will probably outlast your stewardship.


(Rob Reilly) #7

Delighted to hear its working. One thing that should be mentioned with the double nut method is you want to limit your torque to what you would normally use on the thread in question, in this case 5/16-18 UNC in the aluminum head, which would be 8 foot pounds. Any more might break the stud.
https://www.boltdepot.com/fastener-information/bolts/US-Recommended-Torque.aspx
If that doesn’t loosen it, stop and apply some oil or heat.