Bowie69 Posted October 12, 2021 Share Posted October 12, 2021 15 minutes ago, monkie said: I would imagine excess would be squezzed out as you tighten the cap down Yep, it should, however I think shells should always be fitted into the rods dry, then assembly lube on the running surface of course. As for cleanliness, I am sure you will make sure everything is even cleaner this time Quote Link to comment Share on other sites More sharing options...
monkie Posted October 12, 2021 Author Share Posted October 12, 2021 Well, I'm certain it was last time as I clean it all up to inspect it all at the kitchen table, but I will double check everything to make sure of no repeat! Quote Link to comment Share on other sites More sharing options...
western Posted October 12, 2021 Share Posted October 12, 2021 Good the engine shop found something wrong on the crank, I'm sure it will be a good strong engine once rebuilt & fitted. 1 Quote Link to comment Share on other sites More sharing options...
David Sparkes Posted October 12, 2021 Share Posted October 12, 2021 4 hours ago, monkie said: ... I can't imagine excess oil caused this on reassembly as I would imagine excess would be squezzed out as you tighten the cap down? When it comes down to it, I only recall fully rebuilding two engines, but on the first one I lubricated the bearing running surfaces, tightened the nuts gradually, checking the crankshaft rotation after each tightening step. At one point the crank locked 'solid'. I slackened the nuts slightly and the crank rotated OK. I then tightened the caps again, but this time I rotated the crank after each cap was tightened. I noticed that, while the crank was slightly stiffer to turn, it eased as the crank rotated. My conclusion was that if 'too much' oil was present it could not easily be 'squeezed out' simply by tightening the nuts, some rotation had to take place to allow the oil to flow out. I followed the same practice on the second engine and all was OK. Regards. Quote Link to comment Share on other sites More sharing options...
monkie Posted October 12, 2021 Author Share Posted October 12, 2021 10 minutes ago, David Sparkes said: When it comes down to it, I only recall fully rebuilding two engines, but on the first one I lubricated the bearing running surfaces, tightened the nuts gradually, checking the crankshaft rotation after each tightening step. At one point the crank locked 'solid'. I slackened the nuts slightly and the crank rotated OK. I then tightened the caps again, but this time I rotated the crank after each cap was tightened. I noticed that, while the crank was slightly stiffer to turn, it eased as the crank rotated. My conclusion was that if 'too much' oil was present it could not easily be 'squeezed out' simply by tightening the nuts, some rotation had to take place to allow the oil to flow out. I followed the same practice on the second engine and all was OK. Regards. This is as interesting observation. The assembly lubricant is also very thick, much more so than engine oil. I am wondering if I over did it with the oil? I will go much more easy this time round; rather than liberally applying oil on and then torque up, I will use less and spread it round carefully then go easy tightening up and check for free rotation. The only other thing I could think of is a blob of white metal on the undersidd of the new shell, but I think I'm clutching at straws there. The guy at the engineering shop agreed with the thoughts of @Bowie69in terms of the odd wear pattern and it seemed to be focused on the thrust side of the bearing. Quote Link to comment Share on other sites More sharing options...
monkie Posted October 12, 2021 Author Share Posted October 12, 2021 4 hours ago, Bowie69 said: shells should always be fitted into the rods dry, then assembly lube on the running surface of course Yes, that is what I did. Shells in place onto the clean dry conrod and cap, oil onto the crank journals then cap put on and tightened down to the specified torque. 1 Quote Link to comment Share on other sites More sharing options...
western Posted October 12, 2021 Share Posted October 12, 2021 Only needs a smear of the assembly fluid on the bearing working surfaces & as suggested rotate after each set is tightened up. IIRC that's what I did 4 years ago. Quote Link to comment Share on other sites More sharing options...
monkie Posted October 12, 2021 Author Share Posted October 12, 2021 The more I think about this; I'm becoming more certain of the cause: Faulty parts? I doubt it as all were purchased from Turners and not elsewhere who supply blue box parts. Something wrong with the engine before it was stripped down? Yes its an old high mileage engine but as it was running well for Ian albeit with a blowing head gasket which I saw on the first strip down, I am certain there is nothing seriously wrong with it. Parts out of spec and not inspected thorougherly? I checked every part very carefully as per the manual and everything was in spec (inc all 4 conrods). The crank did have very light scoring, but was clean and not rough to the touch. This was confirmed by the engineering shop. Silly mistake on rebuild? I think this is most likely, but what? I'm very sure of the following - Everything was thorougherly cleaned and assmebled in a clean environment, pistons were put in correctly with ring gaps spaced as they should be. Conrod right way round and bearing caps matched up to their respective conrod and put on the right way round. All fasteners were torqued to the correct torque using a calibrated torque wrench. I failed to check the clearance in the bearings with plastigage but more importantly and the more I think about this the more certain I am - I think I was far too generous with assembly lubricant on the bearings. The assembley lubricant is thick stuff so won't squish out the way quickly, I think it is quite possible that I tightened that cap down too quickly with too much oil. It distorted the shell which I was oblivious to and before the ladderframe was even on the block the smoking gun had been loaded for that bearing to fail whilst I continued to rebuild the rest of the engine with all due care and attention blissfully unaware I had set up that big end to fail. Lesson here for all - my granny was right: The road to hell is paved with good intentions. I thought I had nicely pre-oiled all bearing surfaces ready for the inital start up when infact I had caused that bearing to distort and become tight. The bearing detroyed itself followed by total loss of oil pressure which thankfully was at no load idle, I noticed the drop off in oil pressure and shut the engine down to investigate before more damage occured. Quote Link to comment Share on other sites More sharing options...
western Posted October 12, 2021 Share Posted October 12, 2021 Think you may be right, bit of a hard lesson to learn, but you will be sure not to fall in that hole again, looking forward to the rebuild commencing. Quote Link to comment Share on other sites More sharing options...
monkie Posted October 12, 2021 Author Share Posted October 12, 2021 Yes this is a hard (and expensive) lesson to learn, but I look on the bright side: No one died/got hurt, I was able to pull the engine out and find the cause with the help of this forum and the engineering shop. I shall have the engine rebuilt and running a lot sooner than I thought possible when I came to terms that something had gone very wrong requiring it to be taken out and pulled apart again. I wanted to post the findings on here to stop someone else making this mistake in the future and maybe not realising as quickly resulting in much more serious and expensive damage. 4 Quote Link to comment Share on other sites More sharing options...
cackshifter Posted October 12, 2021 Share Posted October 12, 2021 Don't beat yourself up for using a lot of assembly lube, that may have minimised damage. But do take your time. I'd advise filling the oil filter as much as reasonably possible before fitting, and initially spin it over for a few seconds with the stop solenoid disconnected. You should see oil pressure build quite quickly. Then you know oil has got round before combustion happens. Though don't run the starter for long periods without a rest in between. Quote Link to comment Share on other sites More sharing options...
Maverik Posted October 13, 2021 Share Posted October 13, 2021 13 hours ago, monkie said: - I think I was far too generous with assembly lubricant on the bearings. The assembley lubricant is thick stuff so won't squish out the way quickly, I think it is quite possible that I tightened that cap down too quickly with too much oil. It distorted the shell which I was oblivious to and before the ladderframe was even on the block the smoking gun had been loaded for that bearing to fail whilst I continued to rebuild the rest of the engine with all due care and attention blissfully unaware I had set up that big end to fail. Lesson here for all - my granny was right: The road to hell is paved with good intentions. I thought I had nicely pre-oiled all bearing surfaces ready for the inital start up when infact I had caused that bearing to distort and become tight. The bearing detroyed itself followed by total loss of oil pressure which thankfully was at no load idle, I noticed the drop off in oil pressure and shut the engine down to investigate before more damage occured. Did you put lubricant behind the bearing shell? surely putting the lub between the shell and crank shaft should only help to push the shell into place. The manual I posted up on here about bearings the other week has a really interesting section talking about the mechanism of how the bearings are designed to seat, and its the end to end compression that squeezes the bearing into the saddle of the conrod - its like your shell didn't seat properly like it was slight undersized in its effective "length" perhaps. I guess we can speculate until he cows come home, still a really interesting topic with some valuable learning points. Ultimately you need to remember you're working with precision parts and you need to adjust your working behavior to match. I have everything crossed for you for the next phase. 1 Quote Link to comment Share on other sites More sharing options...
Popular Post monkie Posted October 15, 2021 Author Popular Post Share Posted October 15, 2021 Retrieved the crank, conrods and new bearing shells from the engineering shop at lunchtime. New seals etc from Turner's arrived yesterday. I shall start rebuilding the engine tomorrow. 6 Quote Link to comment Share on other sites More sharing options...
monkie Posted October 22, 2021 Author Share Posted October 22, 2021 Been a while since I've got anywhere with this. The new shells supplied were the wrong type (12J engine) so that delayed me while they were swapped for the correct type. The engine is now built up and hopefully be put back in tomorrow. The crank turns really smoothly so all should be good. I've changed my mind on the cause. I don't think too much oil on the bearings was the issue, although I did use engine oil this time rather than assembly lubricant. I think there was an issue with the big end cap. I carefully rechecked them all once again before assembly. Fingers crossed the oil pressure will be good this time. 4 Quote Link to comment Share on other sites More sharing options...
reb78 Posted October 22, 2021 Share Posted October 22, 2021 Good luck Phil! 1 Quote Link to comment Share on other sites More sharing options...
monkie Posted October 24, 2021 Author Share Posted October 24, 2021 Well after alot of jiggling around on the engine hoist, it's in. I've connected up the wiring and fuel pipes but I've started to feel rubbish so off for a PCR swab. No more on the 110 until I feel better Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted October 24, 2021 Share Posted October 24, 2021 Huge cliff hanger Phil ! 😳 Hopefully your PCR will be negative and you'll recover quickly 👍 Mo Quote Link to comment Share on other sites More sharing options...
simonr Posted October 24, 2021 Share Posted October 24, 2021 On 10/13/2021 at 12:02 PM, Maverik said: Did you put lubricant behind the bearing shell? surely putting the lub between the shell and crank shaft should only help to push the shell into place. The manual I posted up on here about bearings the other week has a really interesting section talking about the mechanism of how the bearings are designed to seat, and its the end to end compression that squeezes the bearing into the saddle of the conrod - its like your shell didn't seat properly like it was slight undersized in its effective "length" perhaps. I agree with this. If the bearings cannot seat in the saddle, the only thing it can do is deform / ripple to take up the extra length. This will manifest as a gap between the crank bearing face & the shell, possibly wide enough to loose oil pressure. I've seen this on other types of high tolerance sleeve bearings. If you lubricate the sleeve (to make it easier to slide in to the hole) it actually makes it not fit at all! Quote Link to comment Share on other sites More sharing options...
Mossberg Posted October 24, 2021 Share Posted October 24, 2021 Firstly I hope you are ok. Secondly a huge thanks for posting this up here. It's great that you are willing to help others by sharing your experience. I look forward to you reporting your fantastic running engine shortly. Quote Link to comment Share on other sites More sharing options...
Popular Post monkie Posted November 8, 2021 Author Popular Post Share Posted November 8, 2021 Been alittle while since an update. I caught a rotten cold that plauged me for a while and stopped me progressing with this project - luckily negative for dreaded Covid19, probably just man flu. Anyway, the engine is in, all connected up, I turned it over a number of times without power to the stop solenoid on the injection pump to circulate the oil.Once the wire was put on, It fired up straightaway and registered healthy oil pressure on my gauge. Just need to put the front grill on and the inside back together then get it booked in for an MOT. As for the cause of the issue; I think @Bowie69was right, there was something not right about that bigend on #2, the engineering shop confirmed that it was out of round. I consider myself to be lucky that I spotted the low oil pressure and switched off the engine to investigate before damage started to spread as a result. The oil pressure gauge has certainly paid for itself. 5 Quote Link to comment Share on other sites More sharing options...
Peaklander Posted November 8, 2021 Share Posted November 8, 2021 Whoop! Deep sighs of relief I expect. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted November 8, 2021 Share Posted November 8, 2021 Very pleased, good result in the end Quote Link to comment Share on other sites More sharing options...
western Posted November 8, 2021 Share Posted November 8, 2021 Excellent news on the engine & good you recovered as well. Quote Link to comment Share on other sites More sharing options...
smallfry Posted November 8, 2021 Share Posted November 8, 2021 Good news indeed. I have rebuilt/reconditoned/bodged up probably 75 -80 engines over my lifetime, and 45 -50 of them were Rover V8s, not that it has any BEARING on your problems, which are now hopefully sorted ! I reckon what happened was either the upper bearing was not properly seated, or displaced slightly when you installed the piston and conrod into the bore. Its easily done ! Never had, or heard of, any problem with overdoing the engine building lube, however, the bearing seats MUST be scrupulously clean. Also, ALWAYS rotate the crank after each journal (both main and big end) is tightened, to see if it locks up, then its obvious which one is a problem Obviously it will get progressively stiffer as more caps are on ! As an aside, back in the 80s I used to do some Triumph engine tuning, (car, not motorcycle) and back then, King bearings were to be avoided at all costs because of the high incidence of failure. Came from Israel ISTR, and IIRC, they didnt have the oversizes stamped on the back ? Vandervell were the must have bearings for these, but of course you cannot get them any more. Clevite 77 for the V8s. Quote Link to comment Share on other sites More sharing options...
monkie Posted November 8, 2021 Author Share Posted November 8, 2021 Having thought a lot about it and spoken to people, I don't think it was over doing the lube, nor do I think it was dirt or anything behind the shell. I think it was most likely misalignment of the cap somehow or as you say the shell moved or did something as I inserted the piston in the bore, I guess I'll never know. On the second time round I did rotate the crank by hand after each big end cap was installed to double check. Im still frustrated that although I've narrowed it down to that big end on number 2, I can't be certain exactly what caused it. But I'm now very confident that I have a good engine. I'd say the lesson here is to double check everything on a rebuild. 1 1 Quote Link to comment Share on other sites More sharing options...
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