Roger Posted December 6, 2023 Report Share Posted December 6, 2023 (edited) Hi All, Only posting this in case it might be useful information for someone else. Most of us have struggled with seized and rusty cylinder head studs. I have been trying (for a long time) to dismantle a 2000 Mk II engine without success. I have bought, tried and destroyed every special tool you can think of. I have used phosphorous acid, citrus acid, and many other chemicals. I started with the double nut technique and removed a few of the twelve studs that way. Then I removed another few of them by using special stud removal tools. Welding a nut on the stud removed yet another few. But finally I had two studs that simply did not move no matter what I tried. Welding a washer on the stud, and a nut on the washer created a very strong weld. So the stud snapped… Finally I only had a few mm of the stud above the cylinder head. I tried to apply heat with a small propane burner but it did not have the power to heat enough. Then I found this gas burner in my local store, picture below. It burns 2 kg of gas / hour and I managed to heat the cylinder head to approximatey 350 degrees Celcius. As you can see on the pictures, I lifted the enging holding on to the cylinder head, so the weight of the engine was trying to pull the block away from the cylinder head. Then I tapped the stud with a hammer and at this temperature the engine started to move downwards. I managed to create a 5 mm space between the cylinder head and the block. Then I got a hacksaw blade in between the block and the head and and cut one of the studs. Now there was only one stud remaining and it was in the corner of the cylinder head. Since it did not move up or down, I tried to move it sideways by kicking the opposite side of the cylinder head. That worked, and I could turn the head around the axis of the last stud, and by turning it back and forth, the weight of the engine finally separated the cylinder head from the block. I don’t know which of the tools or chemicals that was the most effective. I would say that stubbornnes is probably the most important tool of them all in these cases. I have been at war with those two studs for more than a year… Some picture of the operation... Edited December 6, 2023 by Roger Link to comment Share on other sites More sharing options...
Roger Posted December 6, 2023 Author Report Share Posted December 6, 2023 I bought a temperature gauge that was very useful, it took a lot longer than I expected to reach 300+ degrees (about half an hour) Link to comment Share on other sites More sharing options...
Pete Lewis Posted December 6, 2023 Report Share Posted December 6, 2023 many years back i had a Mk1 2000 jacked off the deck with a tube in a port and not a murmur from the offending stud so with a small gap did as you have cut through the stud the threaded remains undid with fingers the sledge hammer needed to slog the stud out the head Have just rebuilt a Mk2 head and all studs came out with our extractor chuck and there were signs on the head face that a stud had been sawn in its previous life a long time ago . so stud cutting is not as rare as you might think ha ! Pete Link to comment Share on other sites More sharing options...
JohnD Posted December 6, 2023 Report Share Posted December 6, 2023 Roger, I think your report, and that Pete "needed a sledge to slog the stud out of the head" after he had cut it, should make it clear to everyone! When a head is stuck, it is the studs that are seized in the head, never that the head is somehow glued to the block! Thank you both! Makes me wonder if a sleeve of something - Teflon tube? - around the stud, in the head, might be helpful for another time. 12mm PTFE heat shrink tube is very cheap! PTFE/FEP Heat Shrink Tubing 1.7:1 1.3:1 Ratio Heatshrink Sleeving Φ 0.5-40mm | eBay John Link to comment Share on other sites More sharing options...
johny Posted December 6, 2023 Report Share Posted December 6, 2023 What mystifies me is that the head starts to move so as to give a gap for cutting the stud but then refuses to go any further! You would think any movement and the bond between stud and head has been broken😤 Link to comment Share on other sites More sharing options...
JohnD Posted December 6, 2023 Report Share Posted December 6, 2023 I think it's corrosion in the gap between stud and head. Rust occupies more volume than iron, so they sieze. But moving the 'joint' compresses the rust even more, making the seizure worse. Hence a sleeve to keep them apart? John 1 Link to comment Share on other sites More sharing options...
Roger Posted December 6, 2023 Author Report Share Posted December 6, 2023 1 hour ago, JohnD said: Makes me wonder if a sleeve of something - Teflon tube? - around the stud, in the head, might be helpful for another time That’s a great idea John! I used to work for many years in an extrusion company and we produced all kinds of tubing for the medical device industry. Including heat shrink tubing. PTFE has very impressive properties with extremely low friction, and very heat resistant (it’s in your frying pan…). That extrusion company is only 20 minutes away from my home and I know they scrap kilometers of tubing every week (I was quality manager, I scrapped it if it was not up to spec…). I will contact them and see what I can find in the scrap bin. I learned a lot about quality control there. Failure is not an option if you make components for pacemakers. I still have some tools in my garage from my years in the medical device industry that must be very familiar to John. I use IV catheters to apply small amounts of phosporic acit on rusty bolts and nuts. I even have a few meters of petrol tubing that I extruded myself (can’t remember what polymer, but it handles ethanol very well). Link to comment Share on other sites More sharing options...
johny Posted December 6, 2023 Report Share Posted December 6, 2023 Probably just a good coating of copaslip or similar would do as thats exactly the use its intended for... 1 Link to comment Share on other sites More sharing options...
JohnD Posted December 6, 2023 Report Share Posted December 6, 2023 Well .... Copperslip helps prevent seizing, when high friction causes galling, actual fusion and damage to surfaces in contact. That's not what is happening here. Hut I think I did use "seizing" above, so I was in error! More likely is that corrosion fills the narrow space between stud and head. I would hope that a PTFE sleeve could either prevent that, or prevent the corrosion jamming the gap between them when you try to slide them apart. But I'm no metallurgist! And the research program to check if it does work mightvtake 40+ years! But I hope it might be useful. Experimental Group B - Copperslip! John Link to comment Share on other sites More sharing options...
johny Posted December 7, 2023 Report Share Posted December 7, 2023 This is what their website says and it sounds pretty useful to me... Link to comment Share on other sites More sharing options...
Pete Lewis Posted December 7, 2023 Report Share Posted December 7, 2023 (edited) at least its not a weekly or monthly job just a now and again in the life of classics would a plated stud work better ?? so long as its not hydrogen enbrittled I was surprised the mk2 head we took off last week did not have the slotted thread to save hydraulicing the block . but as the head has been off previously maybe low quality aftermarket studs got refiited small but very important design . or was it only the mk1 /3/8" studs that had the slot ???? pete Edited December 7, 2023 by Pete Lewis Link to comment Share on other sites More sharing options...
JohnD Posted December 7, 2023 Report Share Posted December 7, 2023 1 hour ago, johny said: This is what their website says and it sounds pretty useful to me... To quote Ms Rice-Taylor, "They would say that, wouldn't they?" Definition of "to seize" in engineering: to cohere to a relatively moving part through excessive pressure, temperature, or friction But I don't want to say that your suggestion has less merit than mine, just that we should define our terms. And if you want to quote another manufacturer on the uses of their product, see ROCOL's site: What is Anti-Seize? | ROCOL 3. Where should Anti-Seize be Applied? • Plain, unthreaded sections of the bolt or stud if they will be inside the assembly So all we need is at least three people about to rebuild an engine, and someone to dismantle them in 40 years time! John Link to comment Share on other sites More sharing options...
johny Posted December 7, 2023 Report Share Posted December 7, 2023 Think I know what I'll be using when I next take my head off but yes hopefully it'll be someone else who finds out whether Molyslip have lied😄 Link to comment Share on other sites More sharing options...
dougbgt6 Posted December 7, 2023 Report Share Posted December 7, 2023 (edited) 29 minutes ago, JohnD said: To quote Ms Rice-Taylor, "They would say that, wouldn't they?" Rice-Davies I think. I thought you'd know that? When I had to summon the Luton Guru to my stuck head bolts we struggled with the impact driver. But finally got them off with the impact driver jaws and the pair off us swinging on a 3 foot breaker bar. Interestingly not one of the studs or the block had any rust. We concluded they had been installed by a gorilla. We retired to "The Lands End" and had a good afternoon of pies, ale and fish and chips. Sadly "The Lands End" is now "The Heron by the Ford" and serves overpriced ready meals. Doug Edited December 7, 2023 by dougbgt6 Link to comment Share on other sites More sharing options...
trigolf Posted December 7, 2023 Report Share Posted December 7, 2023 1 hour ago, dougbgt6 said: We retired to "The Lands End" and had a good afternoon of pies, ale and fish and chips. Sadly "The Lands End" is now "The Heron by the Ford" and serves overpriced ready meals. So, are you implying that the "Heron by the Ford" does not serve meals of high enough stodge (calorific) levels to enable you to remove a siezed Mk 2 cylinder head?!😜 Link to comment Share on other sites More sharing options...
Pete Lewis Posted December 7, 2023 Report Share Posted December 7, 2023 yes studs and Pies made a good combination the impact gun should be up to 330lbft but like the owner the batteries are getting stuffed so two old gits on the breaker bar and not a song between them Pete Link to comment Share on other sites More sharing options...
Wagger Posted December 7, 2023 Report Share Posted December 7, 2023 20 hours ago, johny said: What mystifies me is that the head starts to move so as to give a gap for cutting the stud but then refuses to go any further! You would think any movement and the bond between stud and head has been broken😤 I thought that I had unseized a bike brake cable some while ago. It would operate once, then jam again. Using a cable oiler did not improve the situation. The rust just kept compacting and jamming. It is a similar situation. Link to comment Share on other sites More sharing options...
johny Posted December 7, 2023 Report Share Posted December 7, 2023 Ah but that probably had broken strands of wire which yes act like ratchets so no amount of lube is going to work.... Link to comment Share on other sites More sharing options...
dougbgt6 Posted December 7, 2023 Report Share Posted December 7, 2023 38 minutes ago, trigolf said: So, are you implying that the "Heron by the Ford" does not serve meals of high enough stodge (calorific) levels to enable you to remove a siezed Mk 2 cylinder head?!😜 You may think so, but I couldn't possibly comment! Doug Link to comment Share on other sites More sharing options...
JohnD Posted December 7, 2023 Report Share Posted December 7, 2023 2 hours ago, dougbgt6 said: Rice-Davies I think. I thought you'd know that? When I had to summon the Luton Guru to my stuck head bolts we struggled with the impact driver. But finally got them off with the impact driver jaws and the pair off us swinging on a 3 foot breaker bar. Interestingly not one of the studs or the block had any rust. We concluded they had been installed by a gorilla. Doug Ooops, yes, but then it was a pretty murky episode on the family history - best forgotten! I cracked a block (!!!) by in stalling the studs and torquing them in - my wrench had lost calibration and was underreading by about 50%. Only then I learned that they are best installed finger tight! If yours were that tight, then you were lucky to keep the block from the scrap. John 1 Link to comment Share on other sites More sharing options...
dougbgt6 Posted December 7, 2023 Report Share Posted December 7, 2023 The head was last off 30 years previously. My brother helped on the rebuild, my recollection is hazy but during his amateur motor maintenance career he has sheared the sump drain bolts of no less than 3 of his cars by overtightening them. Just saying. Doug Link to comment Share on other sites More sharing options...
JohnD Posted December 7, 2023 Report Share Posted December 7, 2023 (edited) There are ways ... and ways! That's FOUR hydraulic jacks! See dismantling a RussianT34 tank engine.: youtube.com/watch?v=icMzlpzfraQ Edited December 7, 2023 by JohnD 1 Link to comment Share on other sites More sharing options...
PeteH Posted December 7, 2023 Report Share Posted December 7, 2023 (edited) By the late 60`s, "we" where using a product from a spray can called "mollycote". (or molicote?) This was applied to the body of injectors before the where refitted to marine engines. It did appear to have some effect as we experienced less problems removing then subsequently. As for "Sticking" cylinder heads, I had a few recalcitrant ones, Mostly Ford Pinto`s? My worst experience though, was having to remove and reinstall the cylinder liner of a 870mm bore x1500mm stroke engine, after the fitters removing the head neglected to fit the clamps designed to prevent this happening. As the head was being lifted, the studs jambed and liner started to come with it, which distrubed the sealing "O" rings and would have created a liner leak. Had my 3rd Engineer not noticed it, we may well have been lifting the whole kit and caboodle at sea! over 1/2ton of single cylinder head and a ton+ of liner are nasty beasts to work with on a rolling vessel. Pete Edited December 7, 2023 by PeteH Link to comment Share on other sites More sharing options...
Wagger Posted December 7, 2023 Report Share Posted December 7, 2023 4 hours ago, johny said: Ah but that probably had broken strands of wire which yes act like ratchets so no amount of lube is going to work.... No broken strands at all. Just powdered rust all through when I eventually pulled the inner out. It had been standing for years before I acquired the bike. It is a BSA folding one from about 1984. Replaced the cable after a long fight. The tyres are the next job. Tyre slime worked for a while until they cracked. This was all experimental stuff trying not to spend anything on it. It never works does it? Hopefully, I'll never have to remove my cylinder head. Link to comment Share on other sites More sharing options...
Pete Lewis Posted December 7, 2023 Report Share Posted December 7, 2023 41 minutes ago, Wagger said: Hopefully, I'll never have to remove my cylinder head. dont say that you know these little cars sit outside and listen to you Pete 2 Link to comment Share on other sites More sharing options...
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