Crankshaft connecting rod repair

What experience do you have with crankshaft repairs while maintaining the same diameter, e.g. hard chrome/technical chrome etc.

I assume you mean the big-end journal of the crankshaft?

I haven't, personally, but I know many have had the journals built up and reground to size, successfully.

Wire welding or spray welding/deposition seem to be the go-to methods. First thing, though, is to have the crankshaft checked carefully for bends, cracks, or other damage that may prevent a sound repair, or make them unreasonably expensive compared to a new or good used one.

I don't know what the machine shops are like in your country, or part of, but if there's a heavy machinery dealer in your area you could call them and ask who does their work, because heavy machinery is EXPENSIVE and repairs like that are not-uncommon on a cost-efficient basis.

Yes, of course I mean the crankshaft journal. I do this on Ducati cranks because the connecting rods often get stuck and there are few used cranks for sale.

The mechanic who deals with it says that it is usually done on racing cars.

I am also attaching photos of how it looks after application and processing. I'm a little worried about the porous surface. Do you think it could have a negative effect on longevity? The machinist declared that he didn't have any and that it had a hardness at least as high as the 69HRc hardened surface

Sorry about the delay.

Personally, while that finish may be fine for many other applications, such as strup pins, I would be cautious about using a journal pitted like that, but overall I think it should be fine, if the clearances are correct - which is the usual reason for bearing failure.

One might expect the pits to be areas where the hydro-dynamic wedge's pressure might be slightly lower, but the oil is effectively incompressible, but on the other hand, they may have potential as oil reservoirs.

If you do run it, please update on results?

Well, I've already done 3 engines this way and I'll admit that one left after one day on the circuit

But the problems the engine had at this moment could also have had an effect, it overheated, the oil pressure at high revs was from 4 bar but at idle only up to 1 bar at about 106°. The mounting clearance of the connecting rods was 0.040mm. What minimum oil pressure is permissible at idle for powerful engines?