David Ovenden Posted July 17, 2021 Share Posted July 17, 2021 (edited) I am restoring an old Enya 53-4C engine that has a broken valve (tappet) adjusting screw. It looks very much like a cap head socket screw with the hexagon hole enlarged to a round shape and with the other end slotted (for adjustment). The Enya rocker arm seems to have a standard 3mm thread. I have plenty of cap screws of the correct thread & leng th in stock. Any reason why I can't use a mounted point in my Dremel to grind out the screw head to make the round cup and then slot the other end with a cutting disc? Cap head socket screws are hardened steel so I would have thought they would be ideal for the purpose. Anyone tried it? Edited July 17, 2021 by David Ovenden Quote Link to comment Share on other sites More sharing options...
Don Fry Posted July 17, 2021 Share Posted July 17, 2021 I would be tempted, if you have access, to use a pillar drill, or a mounted drill, and hold your screw in a clamp/vice. It really needs the bits to be mounted square and steady to get a nice job. Or of course a lathe or a mill. To slot in the middle of the screw, one way is to slot a nut, and when you get it right, screw it on, and then you get a start on the workpiece slot. 1 Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted July 17, 2021 Share Posted July 17, 2021 Perfectly good idea. I would if possible reduce / grind down the outside diameter and possibly the depth of the hole in the head of the cap screw head to reduce the weight to match that of the original screw. 1 Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted July 18, 2021 Author Share Posted July 18, 2021 (edited) Thanks 15 hours ago, Don Fry said: I would be tempted, if you have access, to use a pillar drill, or a mounted drill, and hold your screw in a clamp/vice. It really needs the bits to be mounted square and steady to get a nice job. Or of course a lathe or a mill. To slot in the middle of the screw, one way is to slot a nut, and when you get it right, screw it on, and then you get a start on the workpiece slot. Thanks Don, My pillar drill is too slow to grind using very small diameter mounted points. I was going to use my Dremel in its stand. I usually use a piece of wood with a vertical hole (interference fit) bored in it to hold screws while I work on them. Good tip re the nut. If you cut between opposing hex "corners" on the nut you will have a centralised slot. Nice! Edited July 18, 2021 by David Ovenden Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted July 18, 2021 Author Share Posted July 18, 2021 12 hours ago, Engine Doctor said: Perfectly good idea. I would if possible reduce / grind down the outside diameter and possibly the depth of the hole in the head of the cap screw head to reduce the weight to match that of the original screw. Good tip ED about matching the cap screw dimensions to those of the original part. Don't want any extra weight on the end of the rocker arm! Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted July 18, 2021 Author Share Posted July 18, 2021 Well I had a go at making some new adjusting screws. All seemed to work out pretty well. I have tried the new items in the engine and its working fine. Tested the Enya 53 this afternoon. Enya no3 plug; APC 12x6 prop; Model Technics Laser 5% synthetic fuel gave me a reliable 9,700 rpm max, tickover at 2200rpm. At the end the tappet adjusters were fine. No slop no sign of wear or tear. So looking good. Glad I made the effort to make them up. 1 Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted July 19, 2021 Share Posted July 19, 2021 Excellent job and a cheaper alternative than buying new parts . The cups in the screws will probably polish and work harden after some long runs so may need slight adjustment but that should be minimal.? 1 Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted July 20, 2021 Author Share Posted July 20, 2021 23 hours ago, Engine Doctor said: Excellent job and a cheaper alternative than buying new parts . The cups in the screws will probably polish and work harden after some long runs so may need slight adjustment but that should be minimal.? Thanks ED. Next project is to sort out a Saito 115 with a stripped glow plug thread. Looking at buying a Time-sert 1/4-32 thread insert kit. About the same cost as a new Saito cylinder but would give me the chance to repair other engines in the future. Can't find a UK stockist so far though. Anyone know who might stock the Time-Sert 0142SP kit? Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted July 20, 2021 Share Posted July 20, 2021 (edited) There is a chap who regularly advertises glowplug thread repairs on the BMFA Classifieds . A friend used him and was very impressed. He charges around £18 which is a lot cheaper than a kit. I intended to buy a time sert kits some years ago then the price seemed to jump so never did buy it. Have looked recently and can't seem to find the 1/4 x 32 inserts ? His name is Peter Vidgeon ,located in Surrey and he currently has an add in the services section of the classifieds. Edited July 20, 2021 by Engine Doctor 1 Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted July 20, 2021 Author Share Posted July 20, 2021 8 hours ago, Engine Doctor said: There is a chap who regularly advertises glowplug thread repairs on the BMFA Classifieds . A friend used him and was very impressed. He charges around £18 which is a lot cheaper than a kit. I intended to buy a time sert kits some years ago then the price seemed to jump so never did buy it. Have looked recently and can't seem to find the 1/4 x 32 inserts ? His name is Peter Vidgeon ,located in Surrey and he currently has an add in the services section of the classifieds. Thanks ED. Been in contact with Peter and the cylinder is packed up to send for him to fit an insert. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted August 29, 2021 Share Posted August 29, 2021 Just found your thread David, I have a small lathe if next time you need to borrow one ,, As for the plug insert, I hope that you have more luck than Pierre, his OS 120 was sent to the french bloke and the first time he took the plug out the thread came with it,,,? Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted August 29, 2021 Author Share Posted August 29, 2021 All good with the Saito. The repair was A1 and fast. The time-sert thread inserts are a "solid" insert not just a wire thread like "Helicoil" and they have a flange at the top for the glowplug to set against. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted August 29, 2021 Share Posted August 29, 2021 Not a rubbish Helicoil then,,,, A club member bought one of those kits with a special tap and like yours a threaded flanged insert, for a 55cc petrol engine. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted August 29, 2021 Share Posted August 29, 2021 I used one of those on my Zenoah 38 after literally ripping the plug out after an unfortunate incident. It’s worked ok but isn’t locked in like a Helicoil and has loosened on one occasion. I reinserted it with a smear of high temperature epoxy and it’s been fine since. I’m not sure why you’re so against helicoils although I haven’t any direct experience of them in spark plug threads but some years ago, I had a pair of threaded inserts installed “professionally” during work to gas flow a Fiat cylinder head. They didn’t seal properly and the escaping gases melted the aluminium around them so proceed with caution! Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted August 29, 2021 Share Posted August 29, 2021 I have only seen 2 helicoils fitted to models to replace the plug thread and both failed, I made a couple of inserts in brass and they are still going strong,,, Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted August 29, 2021 Share Posted August 29, 2021 The chap who advertises on the BMFA site fits "timeserts" I believe. Once installed a tool is screwed through them that expands the bottom of the thread to seal and lock it in position, preventing it from unscrewing with the plug . Helicoil repairs can unscrew and leak , they also need fixing with a suitable adhesive to seal them in some applications Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted August 30, 2021 Share Posted August 30, 2021 12 hours ago, Engine Doctor said: The chap who advertises on the BMFA site fits "timeserts" I believe. Once installed a tool is screwed through them that expands the bottom of the thread to seal and lock it in position, preventing it from unscrewing with the plug . Helicoil repairs can unscrew and leak , they also need fixing with a suitable adhesive to seal them in some applications Have you his address and what sort of prices,A club member needs a couple fitting one in an OS 20 AX the other a Saito 100,, Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted August 30, 2021 Share Posted August 30, 2021 1 hour ago, Paul De Tourtoulon said: Have you his address and what sort of prices,A club member needs a couple fitting one in an OS 20 AX the other a Saito 100,, Hi I donthave his address but he regularly advertises on the bmfa classifieds website. Look in services in the classifieds for current add . He charges £18 Inc post and packing for most engines in uk. Hope you get sorted. Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted August 30, 2021 Share Posted August 30, 2021 (edited) Timesert, try Wurth... I am saving for a set, 10 X 1.25 motorcycle repair... Edited August 30, 2021 by Rich Griff Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted August 30, 2021 Share Posted August 30, 2021 (edited) Hi Rich check out other makes as Wurth sets inc taps an insert tools cost from around £170 . OK if your doing loads of repairs but a bit steep for a one off ? Sealy make 10 x 1.25 inserts for car glowplug repair. Might be a bit cheaper than a Wurth set ? Also look at Nielsen kit. Edited August 30, 2021 by Engine Doctor Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted August 30, 2021 Share Posted August 30, 2021 Thanks, Willcox.... Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted August 30, 2021 Author Share Posted August 30, 2021 Paul I'll send you the details re repairs Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted September 1, 2021 Author Share Posted September 1, 2021 (edited) Well here's something to make you laugh. Having spent some time making and fitting new tappet adjusting screws for my Enya 53-4C today I was looking in my engine spare parts box. There I found some parts from an old restoration of an Enya 40-4C. Guess what - I spotted a sealed packet with a genuine Enya tappet adjuster - the exact part number I needed. OK I did need 2 of them and only had 1 in stock - so I would still have had to make one anyway. But I should have looked properly first! At least I now know that I have a spare one. Unless, of course, I forget again. Edited September 1, 2021 by David Ovenden Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted September 1, 2021 Share Posted September 1, 2021 What is it's exact size, Michel has a couple of old OS four stroke heads,, Ordered the bearings for a Saito FA 100 today, funny sizes, one 6903 = 17mm x 30mm x 7mm the other R6 0.38 x 0.88 x 0.28,, which I have no idea how they get that for a 9.53mm x 22.23mm x 7.14mm bearing,,, Quote Link to comment Share on other sites More sharing options...
Martin Fraser Posted September 1, 2021 Share Posted September 1, 2021 I sent my two Saito FA60T heads to Peter Vidgeon for his copper coated steel inserts and he did a first class job on them. They returned a couple of days later all cleaned up and looking like new. Top job! Cheers, Marty Quote Link to comment Share on other sites More sharing options...
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