onetenor Posted July 23, 2018 Share Posted July 23, 2018 Somebody has stripped a thread in a crankcase and is talking of plastic metal and M2 tap. Not my first, or come to that. my last My choice is recoil kit a la Helicoil or similar--see here--https://www.google.co.uk/search?q=Small+size+re+coil+kits+like+Helicoil&oq=Small+size+re+coil+kits+like+Helicoil&aqs=chrome..69i57.12574.9j1j1&sourceid=chrome&ie=UTF-8 Failing that drill and tap for a brass machine screw or bolt.Loctited in . Then drilled and tapped for the correct size bolt. Use the biggest diameter brass plug you can.. If I was up and about I would offer to do it for you. Make sure you centre the dot punch accurately.. If you do get it a faction out enlarging the clearance hole a bit should get you out of trouble.If you need a way to centre the punch mark use a bolt /nail or rod that just goes down the hole and turn a point on it with a lathe or in a drill Assemble the cylinder/ cyl head to the crankcase before punching the hole. Quote Link to comment Share on other sites More sharing options...
onetenor Posted July 23, 2018 Author Share Posted July 23, 2018 Further my thread thread to coin a phrase --CCCCCCChttps://www.voelkel.com/en/produkte-en/gewindereparatur-en/gewindeeinsaetze-en.html and https://www.voelkel.com/en/produkte-en/gewindereparatur-en/zapfenbrecher-en.html .. It is the only one so far that I could find with 2 Mm insert. All required tools are available on this site if you scroll through it. Cheaper than a new crankcase I'm sure. You will of course require the correct tap to insert the thread insert which will be on the site. The method can be found on Instructables or Facebook. Google will help you find it Regards John Mantova O/T Edited By onetenor on 23/07/2018 20:19:06 Edited By onetenor on 23/07/2018 20:27:23 Quote Link to comment Share on other sites More sharing options...
kc Posted July 23, 2018 Share Posted July 23, 2018 A quick and easy repair might be to use a stud ( or part of a bolt) with a nut so that the bit in th alloy crankcase is not turned when finally tightening but it's just the steel nut on the steel bolt instead. I learned that trick in 1963 when the thread in the alloy fuel pump of my old Austin Devon gave up and the small country garage bodged it up for half a crown ( 12.5 pence) - lasted for many months until I sold the car! A good half crowns worth of info which worked on a few glow motor exhausts etc. Quote Link to comment Share on other sites More sharing options...
Mike T Posted July 23, 2018 Share Posted July 23, 2018 I'm not at all confident that the studding would not turn in the alloy when doing that final 'nip up'. I've done that kind of thing in the past, but I've epoxied the stud in first... Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted July 23, 2018 Share Posted July 23, 2018 In this instance, there is usually no metal to spare But in most other cases, you can go up .5mm For example 3mm silencer bolt, go to 3.5mm thread and new bolt Quote Link to comment Share on other sites More sharing options...
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