Maverik Posted October 7, 2021 Share Posted October 7, 2021 Which bearing is which from your picture? just looking at them the one on the right it hasn't worn the free ends of the bearing, could something like this have happened? 1 Quote Link to comment Share on other sites More sharing options...
monkie Posted October 7, 2021 Author Share Posted October 7, 2021 2 minutes ago, Maverik said: Which bearing is which from your picture? just looking at them the one on the right it hasn't worn the free ends of the bearing, could something like this have happened? I've think you are on the money there. The one on the right is the shell fitted in the cap, the one on the left was fitted into the conrod. Now I look closely the one fitted into the conrod had been squeezed in the middle (it slightly buldges out and is thinned in the middle than the ends. I have an ovaled conrod big end I'd say. If so, that is good news as an ovaled big end would be the gun smith of this smoking gun. I will measure and get a new one from Turners. Quote Link to comment Share on other sites More sharing options...
Nonimouse Posted October 7, 2021 Share Posted October 7, 2021 13 minutes ago, monkie said: I will take the shells and conrod with me when I drop off the crank later on so they can see the full picture. I was wondering "had I got confused and measured the crank wrong and ordered the wrong size bearings?". I double checked and no I hadn't done that; also if that was the case and all 4 were tight surely they would all have been chewed up, the rest (inc main shells) do have some slight scuffing (I assume from the drop off in pressure) but other than that they are fine and no copper is visable. Excuse the question, but did you lube them up during fitting? Quote Link to comment Share on other sites More sharing options...
monkie Posted October 7, 2021 Author Share Posted October 7, 2021 Yes I did. I use Millers assembly lube. 1 Quote Link to comment Share on other sites More sharing options...
monkie Posted October 7, 2021 Author Share Posted October 7, 2021 If you look carefully at this closeup of the shell fitted to the conrod (not the cap) you can see how it has been squeezed out in the centre if you compare it to the material arrowed. Quote Link to comment Share on other sites More sharing options...
Maverik Posted October 7, 2021 Share Posted October 7, 2021 Good spot - it could also be a defective shell too... I'd definitely be looking at the conrod quite carefully. Quote Link to comment Share on other sites More sharing options...
cackshifter Posted October 7, 2021 Share Posted October 7, 2021 Might be an idea to take one of the other conrods to the engineers as a reference too. I'm not sure plastigauge would be a complete answer; it proves the fit when you put it in, but then you have to refit the bearing cap when you have removed it. It would show up ovality though. I can't believe the crank was that oval originally, it had run like that before and the crank surfaces were all fine, and are now still on the others. Did you turn the engine over as you fitted the big ends? It's interesting you are down to the copper near the tab, I think maybe the shell wasn't right in place. But the measurement will tell all I'm sure. 1 Quote Link to comment Share on other sites More sharing options...
monkie Posted October 7, 2021 Author Share Posted October 7, 2021 1 hour ago, cackshifter said: Might be an idea to take one of the other conrods to the engineers as a reference too. I'm not sure plastigauge would be a complete answer; it proves the fit when you put it in, but then you have to refit the bearing cap when you have removed it. It would show up ovality though. I can't believe the crank was that oval originally, it had run like that before and the crank surfaces were all fine, and are now still on the others. Did you turn the engine over as you fitted the big ends? It's interesting you are down to the copper near the tab, I think maybe the shell wasn't right in place. But the measurement will tell all I'm sure. That's a good point about takeing a known good conrod too. I will do and report back on what they say. 1 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 7, 2021 Share Posted October 7, 2021 What caused the damage to the tab, here: As mentioned above, this damage is weird: Really makes it look like it didn't seat properly for whatever reason. 1 Quote Link to comment Share on other sites More sharing options...
monkie Posted October 7, 2021 Author Share Posted October 7, 2021 UPDATE: I have dropped off the crank to my local engineering shop (Perrett Engineering, Henstridge, Somerset) along with the offending conrod #2 and one of the good conrods (#3). He inspected the chewed up shells and I pointed out my observation of the flattened top bearing. He thought that it wasn't the cause, but more a symptom of once the bearing started to fail the thrust of the piston being forced down hammered it flat at the top as it hit the crank. He confirmed the other shells showed very little wear so I had saved the engine from further damage by switching it off in plenty of time following the loss of oil pressure. Whilst I was there he checked the oil galleries in the crank; all were clear so ruled out oil starvation. Their view was that it is down to either a tight big end bearing or oval crank journal. They checked the journal and it was fine. They visually checked the conrod and said it looked fine on first inspection but noted once it was tightened up the cap didn't appear to correctly align, leaving a lip that could distort the bearing shell. I left it with them and they will investigate more closely. I said that I regretted not getting the crank reground before, he said that wasn't the problem as the other journals don't look that bad at all. They are all currently 010 thou under, he is going to take them all down to 020 thou under and supply new shells (either glycol or King for both main and big end). If the conrod can be saved, he will. If not he'll call me to let me know to add it to my order from Turners for a replacement. He then said, yes plastigage is always a good idea but in this case it might not necessarily showed anything up. I think the lesson here is to pay much more close attention to the big ends without any shells in; I think this is the cause of the problem. 2 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 7, 2021 Share Posted October 7, 2021 Sounds like you got a good chap there, worth his weight I expect. Quote Link to comment Share on other sites More sharing options...
monkie Posted October 7, 2021 Author Share Posted October 7, 2021 6 minutes ago, Bowie69 said: Sounds like you got a good chap there, worth his weight I expect. Wasn't you was it?!!! You aren't that far from Henstridge if you are in Blackford. Perrett have done other work for me previously (inc the 19J I rebuilt a few years back), I totally recommend them. Lots of the garages I know in South Somerset all send their engineering work to them. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 7, 2021 Share Posted October 7, 2021 Just now, monkie said: Wasn't you was it?!!! Nope, I tend to go to Precision Engineering | Engine Reconditioning | Hamlins & Co. Hamlins Engineering in Bridgwater Quote Link to comment Share on other sites More sharing options...
cackshifter Posted October 7, 2021 Share Posted October 7, 2021 I'd check there's definitely an oil feed to the main that feeds the no.2 big end, it could be the oil is not getting to there, maybe that main bearing is much less stressed so would not pick up as soon as its big end buddy has. But it does sound like you are on the way to getting it sorted.👍 Quote Link to comment Share on other sites More sharing options...
Nonimouse Posted October 7, 2021 Share Posted October 7, 2021 2 hours ago, Bowie69 said: Nope, I tend to go to Precision Engineering | Engine Reconditioning | Hamlins & Co. Hamlins Engineering in Bridgwater One of my favourite places. I played rugby with Mark in my youth Quote Link to comment Share on other sites More sharing options...
western Posted October 7, 2021 Share Posted October 7, 2021 Pleased to see you have a decent engineering place & they can & have given good advice/info, hoping the can get you engine back to a fully serviceable unit. 1 Quote Link to comment Share on other sites More sharing options...
monkie Posted October 7, 2021 Author Share Posted October 7, 2021 37 minutes ago, western said: Pleased to see you have a decent engineering place & they can & have given good advice/info, hoping the can get you engine back to a fully serviceable unit. Thanks Ralph, I'm feeling confident that with a nice reground crankshaft, new shells and a refurbed/replacement conrod the engine will be a good'un soon. Thank goodness I had the pressure gauge and watched the pressure fall off. 2 Quote Link to comment Share on other sites More sharing options...
western Posted October 7, 2021 Share Posted October 7, 2021 Well caught once all the machiing is done, it will go back together easily & be a good solid workhorse. 1 Quote Link to comment Share on other sites More sharing options...
monkie Posted October 12, 2021 Author Share Posted October 12, 2021 UPDATE: I had a call with the engineering shop to see if I needed to order a new conrod. They have inspected them and initially wondered if the one that failed had the wrong cap fitted but on checking the other 3 ruled it out. The big end on number 2 was out of round a little. They have honed it back into spec and have ordered the new shells for me. Hopefully the crank will be ready for collection on Friday. 2 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 12, 2021 Share Posted October 12, 2021 That sounds like quite good news then? Quote Link to comment Share on other sites More sharing options...
monkie Posted October 12, 2021 Author Share Posted October 12, 2021 1 minute ago, Bowie69 said: That sounds like quite good news then? I think so, yes. Finger pointed to a certain source of failure and all able to be put back right. I'm happy with that. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 12, 2021 Share Posted October 12, 2021 Cool, perhaps it was OK with the worn old shells in it due to the increased clearance, but once you stuck new bearings in this tightened it up and started on the road to destruction? However it happened, a smoking gun is always a pleasing thing to find. 👍 Quote Link to comment Share on other sites More sharing options...
steve b Posted October 12, 2021 Share Posted October 12, 2021 So it was No2 rod then , good clear fault and of course you can now rest easy that your build was good . A good clean of the block oilways and other related parts and it'll be getting bolted in soon enough . Steve Quote Link to comment Share on other sites More sharing options...
monkie Posted October 12, 2021 Author Share Posted October 12, 2021 Yes, I think you are right. I checked the con rods myself on the strip down and all seemed fine. The only thing I didn't do was check the clearances with Plastigage when assembling with the new shells. I know I didn't assemble the caps backwards or mix them up. The only other possibility as I can see is as you suggested where maybe a bit of dirt got trapped between the shell and conrod? I used a torque wrench to tighten and 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? Quote Link to comment Share on other sites More sharing options...
monkie Posted October 12, 2021 Author Share Posted October 12, 2021 1 minute ago, steve b said: So it was No2 rod then , good clear fault and of course you can now rest easy that your build was good . A good clean of the block oilways and other related parts and it'll be getting bolted in soon enough . Steve Indeed. I plan to have all items in hand for next week, then take a day off work so I have distraction to rebuild it back up. I have thoroughly washed the block and all parts to remove any traces of chewed up bearing shell. Quote Link to comment Share on other sites More sharing options...
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