Bent con rods? Never actually come across one in a car/light van, although I did have to recover broken down vehicles with many and various engine problems including one with a sizeable hole in the crankcase where a rod had done it's best to make a bid for freedom! Seen a few in lawnmower engines particularly though especially rotary cutters where the operator has run the machine over a large obstruction which has stopped the blade dead. The flywheel's momentum tries to keep the crankshaft turning so something has to give. Usually this will be the flywheel woodruff key which shears allowing the flywheel to turn on it's taper - Briggs engines are particularly prone to this which results in an engine which kicks back fiercely, painfully tearing the starter cord out of your fingers when you subsequently try to start it because the timing is now "out". OUCH! If the key doesn't shear, the crankshaft nose will usually bend which then presents the problem as to whether it's bent enough to be unsafe to straighten (straightening the shaft leads to fatigue which may cause it to shear off completely at some indeterminate later time. That gets "exciting" when you consider the blade is sharp and running, typically 3 to 3.5 thousand RPM! very occasionally you may find a con rod bent too. I don't believe in straightening shafts that are any more than very slightly bent and it's very difficult to get one straightened so it exhibits no run out at all. Best done in a lathe so you can use the tool post to push against it and then check for runout with a dial gauge. This requires a complete strip down of the engine so only worth doing if there's no labour content (like when I'm working on one of my old vintage machines for my hobby) Commercially a replacement engine is usually a better option if the rest of the machine is in good enough condition. If you ever feel tempted to straighten one with a large hammer, and there's plenty of you tube videos extolling this method, I implore you not to. I've seen the result of one breaking off after being "straightened" in this way. Luckily no-one got injured, and no, it wasn't me who "straightened" it.
If you do take the risk, Ok, it may work and obviously many get away with it but, as "Dirty" Harry said, "Are you feeling lucky today punk"? (or words to that effect).
I said above that I'd not seen a shell with this sort of failure but
@puntodad19 mentioning above about "white Metal" reminds me that one of the first car engines I ever took to pieces was the engine from my second ever car - a 1936 Morris 8 - This must have been back in the very early 60s so I hope you'll forgive me for forgetting. One of the big end bearings displayed similarities to those in the OP's picture. Of course this was engine didn't have shell bearings, the white metal being melted directly onto the "eye" of the big end itself. My guess would be a combination of poor preparation and me mercilessly thrashing it round the fields and private estate roads was to blame.
His mention of "dodger" rings also brought back memories of the first engine I ever completely overhauled. It was my 105E Ford Anglia with the 997cc OHV "Kent" engine. I believe it was the first Ford to get the, then new, Kent engine which, of course, went on to be a whole family of very reliable engines found in many Fords and in many different guises and capacities for many years. Anyway, back to my, very second hand, Anglia. I was near the end of my college course and I mentioned to the engine shop lecturer that my engine was very "tired". He asked if I could afford the parts to overhaul it, which I thought I could, so he told me I could use the department facilities to do it as a project. This was great as I got to use the professional cleaning bath etc and was allowed to use stuff like Plastigauge
https://www.hpacademy.com/technical...vwFxY9SII1Wp3UoKcqErPiJcYh8XTigRoCfusQAvD_BwE for free. I got the crank reground but the bores were pretty good, showing very little taper etc so, as I was not building it for high performance, he recommended I save the money a rebore would have cost. Anyway, took my time over it, got to use a glaze buster in anger for the first time and reassembled everything meticulously with great care and feeling very proud of myself fired it up for the first time. Got very worried by the smoke which came off it! but, of course that's not unusual with a newly assembled engine as it burns off oil on the manifold etc. Anyway, it ran really well and I felt "Pure dead chuffed" with myself. I think the instructor was quite pleased too that all he'd taught me had been put to good use. I then noticed, after running it in gently for about a week, that when I gave it a bit more throttle, ie. put the engine under some real load for the first time, that it had a small, but definite, knock. I was desolate! Went back to my mentor, the lecturer, and asked his opinion. To cut a long story short, after trying several possibilities, we decided to strip the engine and examine everything carefully. At first there was absolutely nothing obvious but, after going over everything at least three times he finally said, "you know what I think it is"? Of course I said no. "Look at the ridge on the top of that bore" There was just the slightest hint of a wear ridge on the top of the bores, pretty insignificant though. "I think, he said, it's the new rings, maybe just one of them, contacting the lip of the ridge at TDC". Of course I'd fitted new standard rings when I built it up and it was then that he went on to tell me about ridge dodgers and that I should buy a set of Cords Rings which have this "feature"
https://www.vintagecarparts.co.uk/m/help_and_instructions/Later Cords Piston Rings Vehicles searchable.pdf So I bought a set, reassembled the engine and it ran great with no trace of the noise. I haven't rebuilt many car engines, although I've done a number of Imps, a couple of VW flat 4 and others, and, although I find crankshafts nearly always benefit from a regrind or polish - the shop I send cranks to is very good about recommending just a polish if they feel a regrind is not required. I buy the shells from them too so they make the money on them anyway and it ensures I get a perfectly matched set of shells without having to worry. I always now check very carefully for any ridge on the top of bores before ordering rings if the engine is not to be rebored. I haven't rebuilt anything other than horticultural engines for many years but I find you can often get away with a set of ridge dodger rings and no rebore and still end up with a reliable engine. Of course any bore scores or appreciable top ridge and it will need a rebore.
I'd forgotten all about that "incident" with my Anglia, so long ago now. Funny how mention of something like that brings back the memories. I now vividly remember feeling absolutely gutted hearing that slight knock after all that work.
Edit. The Anglia went on to give me many years of good service until the MOT inspector failed it. MOTs back then were nothing like as strict as they are now and it took that long for the newspaper and glass fibre repairs to the sills to be noticed!
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