Cam cap bolt hole problem.

So I broke a cam cap bolt off in the head, then broke an extractor off in the bolt. The extractor was off center and cut into the wall of the bolt hole. I don't know by how much... haven't seen it since the shop I took it to was able to remove the extractor and bolt.

Is this head possibly salvageable or should I take a chance on a used head on eBay?

Thanks.

Almous71, they can do wonders with a head. It's a common problem with stripping threads in alloy heads.
They have things like "bigserts" and can always weld the hole up and re-tap.
If it a good head, other than the recent damage, I would run with it!
RegardZ.

Thanks Garn. That's good to know. Hopefully it won't cost me too much more to get it fixed (I'm embarrassed to say how much it cost me to get the broken bolt and extractor extracted).

In the future be sure to use a torque wrench to properly tighten bolts to the factory torque spec as shown in the Kawasaki Service Manual. Also, when removing bolts, if they seem to be too stubborn, soak them for a couple days with Kroil and they will come out without damaging anything. Ed

Don't use the factory torque spec if it says anything higher than 80 INCH pounds of torque. I stripped the threads on three of my caps using the 12 FOOT pound torque specification from the factory manual.

When a steel bolt goes into aluminum it is a good idea to use anti-seize (don't locktite) on the bolts

Thanks for the tips guys. I did use an inch lb torque wrench on all but that 1 bolt. That bolt went in really hard, and stupid me just kept wrenching it down till it was seated. My 1st mistake was not figuring out why the bolt came OUT so hard the 1st time, or doing anything about it before trying to put it back in. An expensive learning experience.

If you want a 'do it yourself' solution, look for Timeserts. It will require you to drill a relatively big hole where your bolts used to go, but is a superior solution to Helicoils in that it's a full collar instead of just a thread shaped spring. From the sounds of where you are now, it is probably your only reasonable solution short of filling the holes with new aluminum and machining them.

If you want a shop to do this, it would still be a good solution. Get their best price for doing all of the bolt holes, just in case.

Remember to include the guide pin holes to make sure you get a solid alignment of the cam covers and bolts.

Another option for you is to move up from 6mm bolts to 7mm or 8mm. Putting in new threads on oversized holes will require machine shop support, but is another reasonable solution.

Thanks Cynjut.
Would the fact that I cut into the wall a little bit with the extractor affect the viability of the timesert, or would that pretty much get taken care of when drilling the larger hole?

My 'a little bit' might be different than yours, but generally no. Having a shop do it might be a good choice - I don't know your limits, and this does require some precision.

Yeah, I'm not going to risk screwing it up any more than I already have. I'll have to find a shop. Thanks again for the advice.

So the cycle shop I took it to for the extraction said it would have to be welded and re-tapped because the hole is now off center. It doesn't seem like it to me, but I don't know how to really tell. The threads are completely gone now after they got the bolt and and extractor out, except for a little bit below where the bolt reaches without the dowel in place. I think I should take it to a good machine shop anyway to see what they say.