I purchased a used/ rebuilt cylinder head for my '93 960 wagon and found all of the threads for the cam/valve cover are stripped out (I think there are 42 of them). I am thinking of heli-coiling all of these threads. Does anyone think this is a bad idea? What other options to repair threads? Thanks

 

I had to do that very thing, all 42 of them, plus many others including the main head bolts, in all, there were maybe 20 bolt holes that did not need to be repaired on my replacement engine. Not a fun job, but well worth it, after you are done you will never have to worry about stripping them again.

I would practice on the old head for a few before doing the good head.


DanR '94 964 353,000 miles (119,000 on the new engine)

 

Is head used or reconditioned? how expensive? Can it be returned (42 stripped cam cover threads is defective)? I have replaced bad heads with fully reconditioned ones in the 500 to 700 dollar range with warranty. If interested I will look up the information.

 

I have had to do many of heads like this. But on the ones I did I had to double up on the heli coils per hole(What a pain!)
If I did not use 2 when I went to torque the cam cover it would pull them out of the head. But that might also have been because we could not get the longer ones only the shorter ones.

If I had my way I would have used what is called time serts. They are a full steel insert that you thread into the head and it stays there.

 

Thank you all for the reply. No warrnty on this head- purchased on EBAY 4 months ago. Head was reconditioned- but stripped threads were overlooked at machine shop. After pricing out Helicoill, I decided to take all the threads up to the next size metric thread. Tapped them all last night and the new threads look great. Had to resize the clearance holes in the top cover for passage of larger bolts......just a shaving. Anything I should be concerned about?

 

You should be fine doing it that way.