SOMEONE drilled out my 1915 block head bolt hole to .5 I was going to put a Z head on when I discovered this. When I removed the head bolt there was a heli-coil setting there flopping in the breeze. Wrong size coil.
Suggestions on returning this to the original size or do I need to "bite the bullet" and just oversize this one head bolt?
i have made bolts with a larger thread on 1 end and a reduced diameter and smaller thread on the other...decide what thread fill work with your oversize hole in block and the depth of the finished thread in block ...the portion above the block deck surface will be made the same as a standard cyl. head stud ...hope this helps ...always an optimist...gene french
spelling correction "fill" is WILL ...also if the stud is currently solid and functional ,why not just re-drill the hole in the new cyl. head ?
John: Look up Stevens Head bolt repair insert. I made some on these tools a while back. Someone near you may have one. This would fix your problem in a NY minute. Dan
P.S. I may still have one set of this tool.
Here is a link to T 235 Toolhttp://www.mtfca.com/discus/messages/506218/522248.html?1425415180
John, there are ready made inserts for this job. Here one brand is called Key-serts. They are cylindrical inserts with the required thread on the inside, 7/16"unc for a head bolt, and a larger thread on the outside. They come in more than one outside diameter for a given inside diameter, so you can tailor the job to the size of the hole you drill.
Tapping the thread in your drilled hole uses a standard sized tap which you may already have or some sizes require the purchase of a special tap.
I once replaced 15 oversized head bolt holes in a 1913 block to bring it back to standard.
Hope this helps.
Allan from down under.
I think that you probably mean Keensert Allan:
They were designed to fix a hole that is too big to use a Heli-Coil in.
I get them here:
http://www.mscdirect.com/browse/tn/Threading/Thread-Repair-Reinforcement/Threade d-Inserts/Thread-Locking-Inserts/?011=keensert&009=e&pcrid=635446144&006=6354461 44&005=6075344242&004=428715944&002=2167518&mkwid=eP613YjBM&cid=ppc-bing-Product +-+Threading_eP613YjBM_keensert_e_635446144_c&025=c&navid=12106001
You are right Royce. The other brand I could not recall at the time is Thread-sert. I use them in the lower eyes of front axles too.
Allan from down under.
Thanks one and all for the advice. I guess I am on the right track.
Leaving for a week so will work the issue when I return.
Thanks Royce for your follow up.