Icarus60 Posted February 28, 2022 Report Share Posted February 28, 2022 Colleagues I have a high port head with both lower outer exhaust manifold studs sheared off below the surface. I plan to drill them out but could benefit by making up a, reusable, drill guide jig to drill them as centrally as possible. Can any body help with accurate dimension for the inlet and exhaust manifold stud centres ? Any help appreciated Regards Rog Quote Link to post Share on other sites
Motorsport Mickey Posted February 28, 2022 Report Share Posted February 28, 2022 (edited) 11 hours ago, Icarus60 said: Colleagues I have a high port head with both lower outer exhaust manifold studs sheared off below the surface. I plan to drill them out but could benefit by making up a, reusable, drill guide jig to drill them as centrally as possible. Can any body help with accurate dimension for the inlet and exhaust manifold stud centres ? Any help appreciated Regards Rog Don't bother, bang a centre punch about central into the stud and use a fluted stud extractor tapped knocked into a drilled hole (that's what the centre punch mark is for) and using a suitable fluted extractor with slip over hex nut just undo the sheared off stud. The extractors look like this Available on Amazon for under £30, comes as a complete kit with drills and centralising bush to drill through and the tap the fluted extractor into the hole. (Amazon now out of stock, just checked and this Neilsen set https://www.ebay.co.uk/itm/172279869503 is what I've got and is fine and does the job, cheaper here on e bay than Amazon ). This is important, these extractors have fluted drive faces that go end to end, there is no stress raiser which is the problem with so called "easy outs" the left hand thread on these where it runs out at the top is weak and will shatter as soon as you put any torque on it. These fluted extractors do not have this problem and you can use a torque wrench on them, I've used 80 lbs on a 3/8th sheared bolt...it came out, no problem. Mick Richards. Edited March 1, 2022 by Motorsport Mickey Quote Link to post Share on other sites
rcreweread Posted February 28, 2022 Report Share Posted February 28, 2022 Mick - the best I could find was this link at £95 not £30 : https://www.amazon.co.uk/s?k=Hazet+841%2F25&crid=30F8AM77PT1MS&sprefix=hazet+841%2F25%2Caps%2C73&ref=nb_sb_noss Have you got a better link/source? Cheers Rich Quote Link to post Share on other sites
Motorsport Mickey Posted February 28, 2022 Report Share Posted February 28, 2022 (edited) 8 hours ago, rcreweread said: Mick - the best I could find was this link at £95 not £30 : https://www.amazon.co.uk/s?k=Hazet+841%2F25&crid=30F8AM77PT1MS&sprefix=hazet+841%2F25%2Caps%2C73&ref=nb_sb_noss Have you got a better link/source? Cheers Rich Here you go Rich, there's a variety on e bay just make sure you pick a fluted set, this one is from US Pro at just under £20. https://www.ebay.co.uk/itm/263601363424?hash=item3d5fdd99e0:g:rJ8AAOSwupRazk77 I have a Neilson set which I bought at just under the £30 from Amazon but the offerings vary as to when you go on. Looks like I waz robbed here on e bay for under £20...it works fine. https://www.ebay.co.uk/itm/172279869503 regards Mick Edited March 1, 2022 by Motorsport Mickey Quote Link to post Share on other sites
John Morrison Posted March 1, 2022 Report Share Posted March 1, 2022 Bought one, thanks Mick. John. Quote Link to post Share on other sites
rcreweread Posted March 1, 2022 Report Share Posted March 1, 2022 Mick -ditto Cheers Rich Quote Link to post Share on other sites
Icarus60 Posted March 1, 2022 Author Report Share Posted March 1, 2022 Thank you Mick but I will still appreciate knowing the stud positions if anybody has the dimensions available. regards Rog Quote Link to post Share on other sites
BlueTR3A-5EKT Posted March 1, 2022 Report Share Posted March 1, 2022 (edited) My brother bought ‘us’ one for Christmas ….just in case. Edited March 1, 2022 by BlueTR3A-5EKT Quote Link to post Share on other sites
stuart Posted March 1, 2022 Report Share Posted March 1, 2022 Ive got the Snapon version of those and they work well though be careful with the smallest one. Stuart. Quote Link to post Share on other sites
Motorsport Mickey Posted March 1, 2022 Report Share Posted March 1, 2022 2 hours ago, Icarus60 said: Thank you Mick but I will still appreciate knowing the stud positions if anybody has the dimensions available. regards Rog Hi Rog, What about using a new inlet manifold gasket for the hole centres ? they have to fit everybodies head so will be made on a jig themselves, and the hole centre should be consistent even if the holes are slightly oversized. Crab the dimensions off there to turn into your jig ? Micky Quote Link to post Share on other sites
Charlie D Posted March 1, 2022 Report Share Posted March 1, 2022 (edited) I didn’t know these things existed!. I’ve never succeeded with the “Easy out” type you mentioned. I’ve always chickened out when I put a bit of pressure on them. It never seems to feel right. What I have done is used TORX bits (and Allen bits) in a similar manner to the fluted items you describe. They work to a degree, but it’s still a bit hit and miss, not really knowing what diameter to drill the hole. Charlie. Edited March 1, 2022 by Charlie D Quote Link to post Share on other sites
BlueTR3A-5EKT Posted March 1, 2022 Report Share Posted March 1, 2022 Yes I would use the gasket for a high port head as the template. Pt no 113122 Just locate it on the existing studs and dowels and scribe through the hole with the missing stud. The original studs are 3/8” unc steel with a copper plating. You will need a couple of gaskets anyway when you come to assemble the engine, so not wasted. Quote Link to post Share on other sites
Icarus60 Posted March 2, 2022 Author Report Share Posted March 2, 2022 Yes I have a couple of gaskets and I’ll give it a go and report back. Thanks and regards Rog Quote Link to post Share on other sites
Trumpy3 Posted March 4, 2022 Report Share Posted March 4, 2022 Mick Just a thought. Why are the two studs broken. I have found that some times these studs are screwed in very tight. As the threaded hole in the head goes through to the cylinder head studs, this brings the stud in contact to them. When you try and extract them, this contact may make it harder to extract. I certainly have came across this issue. Brian Richards Quote Link to post Share on other sites
Trumpy3 Posted March 4, 2022 Report Share Posted March 4, 2022 Oh yes, this also makes it harder to remove the head. Quote Link to post Share on other sites
Motorsport Mickey Posted March 4, 2022 Report Share Posted March 4, 2022 1 hour ago, Trumpy3 said: Mick Just a thought. Why are the two studs broken. I have found that some times these studs are screwed in very tight. As the threaded hole in the head goes through to the cylinder head studs, this brings the stud in contact to them. When you try and extract them, this contact may make it harder to extract. I certainly have came across this issue. Brian Richards Brian, the studs are often used for the engine hook for engine removal complete (certainly the rear one), and are suitable if you hang engine and gearbox off them combined but only if you carefully space the under hook spacer distance. If you just stick any old bigger nut over the the stud it will tighten the lifting hook onto it but also put a bending moment through the stud, which fractures. As for the corner stud holes being drilled deep enough to allow the stud to contact the side of the cylinder head stud, I've seen enough of this "gotcha" to ensure inlet manifold stud removal are my first operations for head removal. On refitting I take 3mm off the stud bottom thread length on the corner fittings to ensure they don't "snub out" against the head studs, the studs are all lubed with a smear of copperslip and wound fully into the head by hand until the thread is used which stops their progress. After this is done there are no further problems with strip downs. One of the benefits of building race engines, you strip down an engine you rebuilt yourself only 7 or 8 months ago and as you find fails or problems starting to occur you can change methods or items to eliminate. It's far harder rebuilding unknown units that were last built when the Beatles were in the charts, some can be a right battle. Mick Richards Quote Link to post Share on other sites
Trumpy3 Posted March 6, 2022 Report Share Posted March 6, 2022 Mick Sorry, my input was meant for Rog. You obviously are aware of the pitfalls. The issue of manifold stud/cylinder stud interference has been found on other members engines I have worked on. There are a lot of non spec studs out there. Brian Quote Link to post Share on other sites
Motorsport Mickey Posted March 6, 2022 Report Share Posted March 6, 2022 No problem Brian, we tend to forget that the hardwon experiences need passing on so it's good to sometimes restate how these wrinkles work. Mick Richards Quote Link to post Share on other sites
Icarus60 Posted March 6, 2022 Author Report Share Posted March 6, 2022 Thanks Brian and Mick I was not aware that the two outer manifold studs are drilled through into the outer head stud bores and I suspect I’m far from being alone on this. I can confirm that this is the case on the head I’m working on but with the correct depth studs fitted they are well short of contacting the head studs. It looks to me therefore that it will only be a problem if incorrect, excessively long, manifold studs are used. I wonder however how many reluctant to move cylinder heads have been caused by over long manifold studs? Onwards and sideways Rog Quote Link to post Share on other sites
Brian Eldred Posted April 8, 2022 Report Share Posted April 8, 2022 (edited) On 2/28/2022 at 11:10 PM, Motorsport Mickey said: Here you go Rich, there's a variety on e bay just make sure you pick a fluted set, this one is from US Pro at just under £20. https://www.ebay.co.uk/itm/263601363424?hash=item3d5fdd99e0:g:rJ8AAOSwupRazk77 I have a Neilson set which I bought at just under the £30 from Amazon but the offerings vary as to when you go on. Looks like I waz robbed here on e bay for under £20...it works fine. https://www.ebay.co.uk/itm/172279869503 regards Mick Hi Mick, I have a head stud sheared off at the block face. Do you think one of these kits would be up to the job? They state they go up to a 16mm stud. Thanks, Brian Edited April 8, 2022 by Brian Eldred Quote Link to post Share on other sites
Motorsport Mickey Posted April 8, 2022 Report Share Posted April 8, 2022 (edited) 5 hours ago, Brian Eldred said: Hi Mick, I have a head stud sheared off at the block face. Do you think one of these kits would be up to the job? They state they go up to a 16mm stud. Thanks, Brian Hi Brian, There are 2 ways of the stud removal, drill out using a drill stand to keep the hand drill square in both planes (assuming it's a short stud) from a dead centre mark increasing drill size until it reaches just below the stud thread root at which point the stud just collapses and a correct tap gently entered into the hole should pick up the thread and clean the remaining material out leaving an unmarked thread. Or if it's a long stud (or even a short stud) use a set like these pictured, when you drill the core dia ready for the flute drive decide upon what torque you think can be applied for the dia used. For example I've used a flute in a 3/8th sheared bolt and set a torque wrench at 80 lb ft and after leaning on the wrench (without it clicking off) the bolt let out a scream (my heart sank !) and started undoing finally winding out after a little toing and froing. Give it a dowsing in a superior unseizing fluid first for a day or two, I think it's your best chance of removing the stud without having to retap. Mick Richards Edited April 8, 2022 by Motorsport Mickey Quote Link to post Share on other sites
Brian Eldred Posted April 9, 2022 Report Share Posted April 9, 2022 Thanks Mick, I've ordered the US Pro set from eBay, though at £19.35 including postage I don't think it comes from the US...I like the idea of a drill stand if I can find a way of clamping it - would probably have to remove some more studs. The studs are 1/2 in. so can probably take a bit more torque. I also have a centre stud sheared at the top - the one sheared at the block is the rear one that hides behind the heater valve, and I didn't know this was gone until taking the head off. I've been thinking of leaving the centre one but just as well I didn't.... I've made a little well of blu-tac around the two studs and filled with plus gas. I'm away for a few days so will be attacking it next weekend. Brian Quote Link to post Share on other sites
BlueTR3A-5EKT Posted April 9, 2022 Report Share Posted April 9, 2022 (edited) To hold the drill press Try to secure with a couple of ratchet straps around the complete engine, or buy/borrow a magnetic drill press stand https://m.vevor.co.uk/magnetic-drill-c_11000/brm35-240v-35mm-mag-drill-magnetic-drill-drilling-machine-10000n-rotabroach-type-p_010336829731?msclkid=978061b9c9bd126b338803e8a338d62d&utm_source=bing&utm_medium=cpc&utm_campaign=PLA-All高-UK-All-GMC-Ecpc-20201118-20220119reset-mxy&utm_term=4587162517923890&utm_content=Electrical Edited April 9, 2022 by BlueTR3A-5EKT Quote Link to post Share on other sites
Lebro Posted April 9, 2022 Report Share Posted April 9, 2022 11 hours ago, Brian Eldred said: the one sheared at the block is the rear one that hides behind the heater valve, and I didn't know this was gone until taking the head off. I've made a little well of blu-tac around the two studs and filled with plus gas. I'm away for a few days so will be attacking it next weekend. Brian I had huge problems getting my cylinder head off early 2020 see below: It was stuck on the stud nearest the heater tap. Eventually it came off, but I could not remove the stud, so left that one in. Later that year I stripped the engine for a re-build, & so had to remove it (out of the car now) it took three head nuts wound on as tightly together as I could & a ring spanner on the lowest one with a scaffold pipe approx 4 ft long over the spanner. I was convinced the stud would break, but it eventually unscrewed. I hate to thing what torque I was putting on it. so for yours to have sheared it must have had some abuse !, also given the above, I don't rate much chance of getting it out with an extractor, even the fluted type, I suspect you will end up drilling it out. Bob Quote Link to post Share on other sites
Brian Eldred Posted April 9, 2022 Report Share Posted April 9, 2022 Thanks Bob, that's filled me with confidence I do wonder what caused one stud to shear at the block face and another at the head face? I've bought another tool with a serrated cam to hopefully shift that one. As it happens the engine was running fine, but for how long is anyone's guess.... Quote Link to post Share on other sites
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