2long Posted February 1, 2012 Report Share Posted February 1, 2012 (edited) OK, Here are some shots of the TR in hospital, awaiting open heart surgery. Photos of the engine follow, with the shot showing the stud hole boss for the rearmost stud hole carrying the long stud. My issue is whether the cracks radiating around the stud hole are fatal to my block. You will see the threaded insert that was put in when the long stud broke off down in the hole. The insert allowed a short stud to be used, with the broken piece of stud still residing at the bottom of the hole along with a broken "come along" tool I tried to use to remove the stud remains. This was ten years ago, and now the engine is out, the cracks were noticed during the rebuild, and I need to decide if the block can be salvaged. Opinions? Edited February 1, 2012 by 2long Quote Link to post Share on other sites
Ashley James Posted February 1, 2012 Report Share Posted February 1, 2012 (edited) I'm sure that block is scrap and that the only safe course of action is to find another. However Technilock in Derby specialise in repairing irreplaceable cast iron blocks of all sorts. They do lots of vintage cars and more particularly, ship engines on location. I'm sure they can offer a permanent solution and you should speak to them, but it'll probably cost more than another block. I had a Rolls-Royce block stitched there some years ago and liked them a lot. http://www.cast-iron-repair.co.uk/ Ash Edited February 1, 2012 by Ashley James Quote Link to post Share on other sites
RogerH Posted February 1, 2012 Report Share Posted February 1, 2012 Are we talking about the 'crack' in the last photo running vertically into the water jacket between the liners. If so, it has almost certainly happened because of the short thread length you were using after your rather iffy repair. You should have removed ALL the broken stud and re-threaded all the way down (but you know that). Was the car running before the strip down, Could this crack be the cause of any problem you had to strip the engine down. If the crack wasn't the cause for the engine strip then it could continue in service, but for how long!!! If it was me I would drill out the old broken stud, remove the repair thread and continue the repair thread down as far as possible and insert new repair threads This should give the stud good support and stop the block from cracking further. As for the crack - where is it going. Nowhere Would it cause water leaking - not if sealed adequately. Apply some good jointing compound to the stud thread when fittiing. If necessary apply similar under head nut/washer when bolting down. Your options are limited - repair (either as above or more extensively) or renew. The above will get you on the road quickly and may be very successful (and cheap). Extensive repair may work very well, but!! Renew. There no new engines so you may be buying in more trouble. Roger Quote Link to post Share on other sites
Motorsport Mickey Posted February 1, 2012 Report Share Posted February 1, 2012 Ok, here's a few ideas and no doubt some of the other guys may have different or better options also. If you've not done so check the liner heights, if they are not all comparable ie 3/3/3/3 all around their circumferance (use a depth micrometer to measure) and within the 2-5 thou range recommended you might want to remove the liners and redeck anyway. You don't have to get too anal about this, a variation in heights is likely because of the material and because of the age but obviously you would be better not to have a 3 thou height on one liner alongside a 5 thou height on the neighbouring liner, (this would reduce clamping effort and likely lead to an eventual blown head gasket). If you do remove the liners then game over...scrap the block for the work involved you may as well do it on a sound block, you should be able to find another. If the liner heights are acceptable then you are left with the possibility of repairing the block with liners in situ. If the block wasn't originally cracked in this area (and I doubt it was, otherwise you wouldn't repair it like this ?); the repair of the threaded boss and short stud currently in the head is possibly what cracked the block in the first place, the torque transferring through the stud/boss into the material which flexes because it doesn't have enough support around it. I suspect the boss insert material is steel and not cast which is what I'd have used (trying to be as close as possible to the parent metal to minimise distortion) if trying to carry out the reapair like this. The varying expansion rates wouldn't help the material either possibly the boss may be expanding and hence causing the cracking. Because you have the cracks which are now there I think the option would be to remove the boss and subject to there being enough material deeper into the block along the plane of the stud and before hitting the remains of the broken stud and broken removal tool- drill out the diameter to the max depth possible and retap. I'd suggest about 16mm dia as I remember which is what I used when developing some race engines that broke things, which meant I had a shortish but fat stud in place which did the job. (you would have to enlarge the appropriate cylinder head stud hole). I'd then use some barrs leaks for a couple of weeks to help seal any residual cracks around the repair before flushing out and refilling with your choice of coolant. Hope this helps. Mick Richards Quote Link to post Share on other sites
RogerH Posted February 1, 2012 Report Share Posted February 1, 2012 Hi Dan, you may need to find somebody with a 'Spark Erosion' machine to burn your 'come along' (easy-out) tool out of the stud. It may too hard and angled to drill. Most airport enigneering areas have them. Roger Quote Link to post Share on other sites
Guest ntc Posted February 1, 2012 Report Share Posted February 1, 2012 It is dead sorry you need to find another block, not easy I know Quote Link to post Share on other sites
Ashley James Posted February 1, 2012 Report Share Posted February 1, 2012 It is dead sorry you need to find another block, not easy I know +1 As I've already said, that one probably is repairable but I'm guessing another block from a club member will be cheaper. Ash Quote Link to post Share on other sites
2long Posted February 1, 2012 Author Report Share Posted February 1, 2012 Thanks for the replies - it seems the cold and logical option is to use a different block, and I do have a spare block from a TR-3 which would have the advantage of the camshaft bearing fitment. But I am a glutton for punishment. I want to give the original block a fighting chance. The liner has now been removed, and the insert removed as well, without any crumbling of the block. I think the only way the block can be salvaged is if a long (or longer) stud is used that pulls from below the surface of the block where the cracks are. But efforts to remove the broken "easy out" tool by welding something to it have failed, so that is a problem. A creative idea came up - remove the remains of the stud and tool by drilling up from underneath, and then welding in a plug. I have never heard of anything like that being done, but if you folks have any thoughts, I am all ears. By the way, I do not mean to be flippant about ignoring the well-reasoned view that it would be better to just use a new block. I ultimately may well have to pay a high price for my efforts. But I do value the thoughtful comments so I can make an informed decision at this critical juncture. Aloha Dan P.S. The damn thing was running pretty good before I pulled the engine apart. Quote Link to post Share on other sites
Ashley James Posted February 2, 2012 Report Share Posted February 2, 2012 Dan If there are cracks they will creep, if you weld, cracks will radiate from the weld and if a specialist welds the block he'll heat the whole thing till it's red hot and then weld the cracks to avoid this happening. However, the block will distort and at least, the camshaft bearings will have to be line bored and the mains afterwards. I suggested Technilock in Derby because they specialise in reclaiming ship engines with horrible cracks and while they are still in the ships! They also do lots of vintage car stuff. If you would like to repair your block, you need to start with advice from real experts, or you may make it worse. They might be able to cold stitch it and effect a permanent fix, but it will probably cost a few hundred. Ash Quote Link to post Share on other sites
RogerH Posted February 2, 2012 Report Share Posted February 2, 2012 (edited) Hi Dan, the advice you have been given is good - if in England or the USA the block would be economicaly scrap. There are plenty around (in a limited sort of way) By attempting to recover the engine you have nothing to lose except a few dollars and if you succeed you will have self satisfaction. The crack was (almost certainly) caused by the short thread length. If a full depth thread can be gained then the existing crack may become relieved to such an extent that it will stop growing. Your problem as you know is the 'easy-out' stuck in the stud. These things are quite hard but not hard enough to easily shatter so attacking with a centre punch and big hammer will have only limited effect. You could drill with a very hard drill - Stellite, Tungsten Carbide tipped etc. B ut these need a flat surface to get into and they can easily break. The guaranteed process is 'Spark erosion' as I stated above. This is a process where a spark is generated between the component and an electrode. The component disintegrates as could the stud if you wish. It is a slowish process but very very effective and fairly reasonable costwise. Once the easy-out is removed you can drill out the stud remains. Make a centring guide that screws into the insert thread of the stud and a hole in the centre for you drill Attacking from the bottom is more hopefully than sensible. I don't think that will work. Should you throw the block away - yes Should you attempt to repair the block - I certainly would. Roger Edited February 2, 2012 by RogerH Quote Link to post Share on other sites
Motorsport Mickey Posted February 2, 2012 Report Share Posted February 2, 2012 Dan, I agree with Roger, the bottom up drilling I don't think will work because although you may suceed in drilling out the stud (if able to centre accuarately which will be a good trick in itself) when you get to the broken Easy out (a mis named item if ever I heard one) its harder than the hobs of hell (which is why it broke in the first place) and any drill even stellite or carbide is likely to wander around like a drunk chavelling up the softer side walls of the block ! The spark erosion process should be guaranteed, and give a precision finish, from my now hazy days of Toolroom engineering in my youth they make up a tool some thous smaller than the dia to be eroded .The tool doesn't erode to a dead size but a clearance on the tool which varies by dimension and they pass a positive charge through the tool and a negative charge into the item to be eroded (I think Roger ?) which is submerssed under paraffin !!**%+ ? which then causes a spark to be emitted from the tool which erodes the item being attacked. I think the absence of oxygen which prevents the machine and operator (who normally sits alongside it drinking coffee and reading the Sun ! its a slow process) being engulfed in a fireball of combusting paraffin (if I remember correctly). Once the Easy out is gone then drilling out the stud to depth is relatively easy especially because the spark eroder (the operator) will likely go past the Easy out and you'll have a flat or centred surface to attack with the drill, I'd recommend the engineering firm does that as well whilst they are at it ! Good luck. Mick Richards Quote Link to post Share on other sites
vivdownunder Posted February 3, 2012 Report Share Posted February 3, 2012 Dan, I've seen very good results with spark erosion removal of broken head studs. You probably don't have Metalock out in Hawaii who could stitch repair the crack, but someone in aviation welding might be able to help. Having been through the drama of saving a hopelessly written off block myself, I fully understand why you want to try and retain your original engine. Regards, Viv Quote Link to post Share on other sites
RogerH Posted February 3, 2012 Report Share Posted February 3, 2012 Hi Dan, just to cheer you up. When I stripped down one of my spare 4 pot engines last year I found the crank had a beautiful crack at the #4 big-end /web (it's where they go). The length of the crack is apprx 1/4 circumference. No idea on depth. I know it is not repairable but I can't find the enthusiasm to throw it away. One day there will be a process for sorting it. But until then it sits in my garage tripping me up occassionally. Roger Quote Link to post Share on other sites
BrianC Posted February 3, 2012 Report Share Posted February 3, 2012 ...the crank had a beautiful crack at the #4 big-end /web (it's where they go). ... I know it is not repairable but I can't find the enthusiasm to throw it away. Once upon a time the club was full of 'crankshaft tossers' at the IWE. Are you sure it's TRuly lack of enthusiasm and not another instance of energy deficiency? Quote Link to post Share on other sites
RogerH Posted February 3, 2012 Report Share Posted February 3, 2012 Hi Brian, If I were to throw it it ceryainly wouldn't go far. Roger Quote Link to post Share on other sites
2long Posted February 3, 2012 Author Report Share Posted February 3, 2012 Roger: I guess I would feel a LITTLE better hearing your story IF your cracked block weren't a spare. A little dose of schadenfreude is good for us all, I suppose. My block may yet end up as a stout doorstop. Or if the whole thing goes pear shaped I might try jumping into the Pacific with it tied to my ankle. The shop is looking into spark erosion, but the tool they have will not work down in the confines of the stud hole. Looking for another shop. I have actually learned a bit about machine work and metallurgy in the process. I guess spark erosion will work on the hardened easy-out, but I am not sure. That easy-out sure put me in a tough spot. Those things should come with a disclaimer! Dan Quote Link to post Share on other sites
RogerH Posted February 3, 2012 Report Share Posted February 3, 2012 Hi Dan, spark erosion works very well on any (most) conductive materials - steel is a very good conductor. Keep looking for a good spark eroding shop, depth shouldn't be an issue. Another form of spark erosion is 'wire cutting'. This uses the side of a wire to spark from. This is used to cut shapes around or into conductive material. It works as well on Tungsten as it does on steel Don't use the engine block as a weight if you thorw yourself into the 'oggin. It will rusty away before you hit the bottom. Roger Roger Quote Link to post Share on other sites
pinky Posted February 5, 2012 Report Share Posted February 5, 2012 hi i have enjoyed reading this post really interesting i phoned the father in law, he is a retired tool maker i told him about the sparker he agreed this would do the job but being an easy out he would clamp the job down and use a location plate/bush to centralize the drill then drill the easy-out out using a special drill he also said the sparker can harden the adjacent material which could cause problems regards pink Quote Link to post Share on other sites
RogerH Posted February 5, 2012 Report Share Posted February 5, 2012 Hi Pinky, I don;t think there would be a hardening of surrounding material due to the large mass of metal and the electrolyte used in the process. Drilling out using an alignment guide etc is understandable but the cost of the drill would be more than the spark erosion. Roger Quote Link to post Share on other sites
Ashley James Posted February 7, 2012 Report Share Posted February 7, 2012 (edited) It looks as though there's another crack from the metal around the next stud on as well. Edited February 7, 2012 by Ashley James Quote Link to post Share on other sites
littlejim Posted February 7, 2012 Report Share Posted February 7, 2012 Can I demonstrate my ignorance by asking if the crack in a normal block would have meant 'scrap it', but in an engine with wet liners not quite the same problem?? Quote Link to post Share on other sites
RogerH Posted February 7, 2012 Report Share Posted February 7, 2012 Hi LittleJim, it is not so much the engine that dictates the scrapnocity but the crack. Where is it, where is it going, how fast, what happens when it gets there, what caused it - that sort of thing. These big steel lumps don't like welding etc so leaving the crack may be a better option Roger Quote Link to post Share on other sites
Ashley James Posted February 7, 2012 Report Share Posted February 7, 2012 Cast iron is what blocks are made from, it's very brittle and very difficult to repair because if you try to weld it, cracks will radiate from the weld. Almost always, the only safe course of action is to buy another, but if it's irreplaceable there are experts who can repair, but at a price, and they use two methods. 1. Cold stitching. This is a process of drilling and tapping along the line of the crack and screwing studs into it and also drilling at right angles as, every 1/4' pr so and pressing in a steel tie that pulls the crack edges together. It's highly skilled and used to save marine engines more than anything, because they won't usually come out of the ship they were built into. It's very strong and effective, but expensive and needs a highly skilled person to do it. Sometimes they even stitch in new metal. 2. Welding. This is a difficult and very risky operation because localised heat will cause distortion and may start off a chain of cracks. Therefore it is normal practice to put the whole block into a furnace and raise it to a dull cherry red over 24 hours or so and then gas weld the cracks. Once the repair has been made, cooling has to be carefully controlled and make take a day or two. Usually, if this is successful, some distortion will have occurred and line boring of the mains and camshaft bearings and surface grinding the top of the block will be necessary. Warnings. Old blocks tend to fatigue, so if cracked in one place, may be about to go in others. At the time the TR engine was designed, blocks weren't rigid and if run at high revs for any time, the main bearing caps would move around on the joint face and sump bolts would loosen, so lots of stress. In the case of this one, old age and very large studs with 100 Lbs ft of tension on them, have caused the metal to give way, so it's probably scrap. Ash Quote Link to post Share on other sites
RogerH Posted February 7, 2012 Report Share Posted February 7, 2012 (edited) This is a most interesting thread. We have two camps - the scrappers and the fixers ( a bit like Westside story, but without the music). If the crack/damage had happened with the stud inserted at full depth then the crack would be the product of general stresses (if engine operated under normal conditions) and would/may be seen in other engines. This would give us some history to work on. The block would probably be scrap as any repair may not remove the stresses. If the crack has been caused by partial insertion of the stud then we know what caused it (within reason). Repairing the stud hole (with a helicoil) to allow full stud insertion will overcome the initial cause for cracking. Whether this eliminates any further cracking will become evident in time. However the crack did travel to the weakest point - shortest route to a corroded rough edge. (it would be interesting to see what direction the crack grew - stud to edge or edge to stud) Actually repairing the crack itself is extremely difficult (as explained by Ashley). A water tight seal could be accomplished by either gasket material or a brazing process (I would prefer the gasket material) I would still go for the full depth stud hole repair. Now, back to the crank - solder and a couple of 2BA screws I think Roger Edited February 7, 2012 by RogerH Quote Link to post Share on other sites
Ashley James Posted February 7, 2012 Report Share Posted February 7, 2012 Roger If you go back the photograph of the block and look at the adjoining stud hole, I think you'll see a crack radiating from it as well. Ash Quote Link to post Share on other sites
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