HarleyTechTalk

A quick cam change gone wrong. A friend tried drilling to tap the bolt out, bit walked, and now trying to recover the situation.
Is there a jig available to drill and tap these out? Any other suggestions or solutions? Even with it hot, he was not able to extract the bit of bolt that is stuck in there.
Is a timesert a possibility?
Panic has set in of course

Trying to add a pic, will have it up shortly

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I use a Timesert. Get it the Best you can. Get S&S Tappet cuffs. Align it and use a Dremmel to enlarge the hole. Maintain 0.002" between Cuff and Tappet. Next time a good idea is to use a heat gun on the bolt for about five minutes prior to extraction.

Quote from: Pirsch Fire Wagon on April 16, 2022, 10:52:31 AMNext time a good idea is to use a heat gun on the bolt for about five minutes prior to extraction.

https://harleytechtalk.com/htt/index.php/topic,107782.msg1282238.html#msg1282238


you know I'd bee looking at cutting those cuffs off before trying to remove the bolt,
then heat the area to remove the bolt

I may actually go and buy 1 or 2 just to see how hard one would bee to cut with a fine tooth saw

I wasn't here when it happened, I know all about the proper procedures that should have been followed originally, and when it was being drilled for repair, but he was going ho and is now in recovery mode. (Not the first time he has broken stuff, twice, before waiting for help)
Good to know a time sert can be done. We are working on making a jig to drill it out, then figure out a repair. Thinking with jig we can still drill and extract the bolt, then see if enough thread is left to bite, or JB Weld and re-tap. If not, time sert.

Quote from: Hossamania on April 16, 2022, 11:02:09 AMthen see if enough thread is left to bite, or JB Weld and re-tap.

not going to need much

Quote from: FSG on April 16, 2022, 11:04:35 AM

Quote from: Hossamania on April 16, 2022, 11:02:09 AMthen see if enough thread is left to bite, or JB Weld and re-tap.

not going to need much

Nope. Wish us luck, I'll update in a few hours, hunting down material and tools now.

Hoss, consider left hand drill bits.  Small first centred and then larger.  Go slow rpm and even pressure.

Better plug those oil passages with grease before drilling and tapping, etc. But it looks like that's too late as well.

Can't you bottom loud the lifters in the M8? That would preclude the removal of the cuffs.

He has left hand bits, extractors, etc. Currently making a jig out of aluminum block to drill the bolt.
Total garage build machining action going on right now.

Bolt broke because cuffs are being replaced by S&S billet cuffs. He should have started with small bit and stepped up, but he has no patience, gets excited and wants it done. Saving money doing it himself. Now a friend and I are trying to save him the cost of taking it in.
He was going to wait for us, but couldn't, had to start without us.

Success! Garage built jig with scrap aluminum block, cardboard template, hand punched drill marks, actually used a drill press rather than just a hand drill (c'mon, we're not complete neanderthals). Slowly drilled the bolt, picked out the swarf, cleaned with a thread chase (no tap), plenty of thread to grab the new bolt. All good.
Now, the cam install.

  Nice job Hoss.  Great use of hoarded remains.  I like that. You ain't just another pretty face. 

I can see a tool like this getting a little use so here's your next challenge.  Before you forget how you made it, take few more pics or diagrams with instructions on how to make said tool.  Maybe include a flip over option with another hole for the smaller pilot drill.  Then post that baby in the homemade tool section.

Quote from: Hossamania on April 16, 2022, 02:52:06 PMSuccess! Garage built jig with scrap aluminum block, cardboard template, hand punched drill marks, actually used a drill press rather than just a hand drill (c'mon, we're not complete neanderthals). Slowly drilled the bolt, picked out the swarf, cleaned with a thread chase (no tap), plenty of thread to grab the new bolt. All good.
Now, the cam install.

Good work Hoss & if you want to share your jig specs im in

This is the template we made to drill the block, not exactly precision. One of the bolt holes didn't even line up (notice only 3 with bolts in them in the previous pictures), I have no mics or calipers, so no proper measurements, it would be sketchy tape measure  numbers, no help to anybody here. We got lucky. I'll take it.

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The horror of those darn lifter cuff bolts!  I sweat and shake every time I take one out and [now] spend an excessive amount of time with the heat gun on them.  I got bit once and was lucky enough to drill the easy out hole dead nuts on.  Even so, I had to torch heat it, move the easy out a half turn, torch again, move easy out a half turn...and keep doing that until I finally got the broken bolt out.  Nerve racking!

JIMS has a program where you can submit tools for consideration for them to manufacture.  I recommend you sending in your design and maybe there will be a JIMS tool in the future that we can keep in the garage for when the nightmare happens.

Hadn't thought about submitting the idea, but that would be easier than us manufacturing them and selling them, which we had talked about then quickly dismissed.
My contribution here was not so much the actual specs, but the concept that it can be done.

New to the M8 stuff. So these cuffs took the place of the anti-rotation pin on the TC's?

Zach

Quote from: biggzed on April 18, 2022, 01:55:17 PMNew to the M8 stuff. So these cuffs took the place of the anti-rotation pin on the TC's?

Zach

Correct.

And the gorilla strength lockpatch has caused more than a few of those bolts to break while being removed. Heat helps a bunch, as does patience, when removing them

Quote from: rigidthumper on April 18, 2022, 07:01:37 PMAnd the gorilla strength lockpatch has caused more than a few of those bolts to break while being removed. Heat helps a bunch, as does patience, when removing them

If only my friend had read this before breaking his off and adding 4 hours to a cam swap.

Quote from: rigidthumper on April 18, 2022, 07:01:37 PMAnd the gorilla strength lockpatch has caused more than a few of those bolts to break while being removed. Heat helps a bunch, as does patience, when removing them

Funny I've read on here more than once that those lock patches don't do anything. 

On the subject of the lifter cuff bolts...

I'm sort of asking a question, or maybe comments about a technique I use when taking them out.  As mentioned, I use a heat gun and I don't just hit it for a minute or two.  I lay the heat on for a while and switch between high and low to keep the heat reasonable and not turn the plastic cuff into a blob.  I really like to warm up the base metal before using a socket for the first time.

Now, inviting comments...

When I put a socket on the bolt I do not use a back and forth motion as the bolt is coming out.  I only go counterclockwise.  My theory is that going back and forth (which is a technique for removing rusty bolts) "works" the grade 5 bolt too much and can increase the chances that the bolt breaks.  So, I just put only enough pressure on the wrench to keep the bolt moving out.

Comments?  Arguments?  Input to educate me?

BTW, I use this same technique when removing the oil line manifold bolts.