Bad Helicoil/stripped tappet cover

[Tecrekka]

So I got all the stuff to take care of this one stud that was stripped out of the head. I am completely comfortable with cutting off the other studs and making them kosher to fit in to the factory holes but I must admit I am a bit apprehensive about drilling this hole for the Keensert. My main concern is drilling the hole all walleyed and messing up the head. Is it really legitimate enough to just drill this pilot hole by hand? I would assume that maybe I should hit it with a smaller bit first, to make sure the hole stays somewhat true to center, and then hit it with the 11/16 (Keensert calls for 8.8mm, yeah..)?

 

[itrguy]

Where did you find the keensert??

Posted via Mobile

 

[Tecrekka]

A local place , Asheville Bolt & Screw, actually stocks them. Although all they had in stock was the stainless 1, which considerably more expensive than the regular ones, $7/$3.

 

[Halloweenie]

I would assume that maybe I should hit it with a smaller bit first, to make sure the hole stays somewhat true to center, and then hit it with the 11/16 (Keensert calls for 8.8mm, yeah..)?

I don't see why you shouldn't, it would act something like a center drill bit and keep the next bit true.

 

[Tecrekka]

So I hit with the 5/16th first and as Halloweenie said it kept the hole square. Tap ran nice and smooth but I've encountered another unforseen issue. Needed minimum 10 mm depth so the hole did go partially through the head, but not so much as to interfere with the valve spring. The problem is that this doesn't allow for the draft on the end of the tap, causing the actual threading to stop short. I guess my only option at this point is to remove the valve spring to allow the tap to go sufficiently through. I'll keep y'all posted as to my progress.

( sorry my phone tends to upload the photos all wonky)

 

[weekendrider]

You need a bottom tap.

 

[Tecrekka]

You need a bottom tap.

Excellent, thank you! I was thinking I was going to have to remove the head to get this!

 

[Tecrekka]

Success! Didn't have a bottom tap and they are impossible to locate on a Saturday so I made one! I can't thank you all enough. I like the new studs so much better (allen socket) I believe I will change them all. Also only $.75 as opposed to ACE Hardware $2.75/ea.

 

[Tecrekka]

(Duplicate post)

 

[weekendrider]

Good on ya Tecrekka!

 

[5twins]

I like those Allen studs. Where did you get them?

 

[Tecrekka]

I got the studs at a local place: Asheville Bolt & Screw

It definitely made things smoother having those Allen heads. Also, since they are threaded all the way down it was easier to run a die down them after correcting the length. They are 6mm x M1 x 30, which is what is called for if I'm not mistaken, but out of three of them I have had to modify both that were not in the insert.
I haven't started it yet to check for leaks as I decided to redo the wiring harness while I had a little time, but I expect it should be just fine.

 

[itrguy]

I am in need of the same repair. I would like to source the keenserts locally, what size did You get??

 

[Tecrekka]

I got the 6mm x M1.0, which is 10mm x M1.25 OD. It calls for an 8.8mm bit, so I used an 11/16 (which is what the 10mm x M1.25 tap calls for anyway). Be careful, depending on which one you need to replace you may get through the case and need to be concerned about shavings getting inside, and possibly needing a bottom tap.

 

[Tecrekka]

I went back yesterday and realized they refer to the studs as "set screws", if that helps anyone source these guys.

 

[Jon1wdsmen]

How hard was it to drive the securing pins down or did you get the tool for the keenserts? Did they try and bind with out the tool?

 

[Tecrekka]

I think they call for a tool to do it but I didn't really find it necessary. Even with this relatively small diameter, I found that if you hit it nice and square there was no issue. I did have one pin start to lay over but I just straightened it out, gently, and continued to drive it in. Small taps to get it started, then a little more firm once it was about half way down.

 

[Jon1wdsmen]

TX Tec, I end up with the keyserts with 4 pins may need to find a small jeweler a hammer