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Hi,
I just lost my 2nd motor to a similar failure. The #3 rod exited the case in a dramatic way.

Motor specs.

103 by 80 bore/stroke
Ham LE200 heads, 6800rpm limit
Dual oil coolers on a full flow system
Sequential fuel and ignition.
tuna can sump with 1/2 quart over fill level.
windage tray modified with holes at the push rod ends to aid flow back to the sump.
Large vented breather with both heads ducted

Since my first motor let loose, I have added the 2nd oil cooler and the sequential fuel and ignition Motor was balanced, with the crank turned -.010 for the new build. I also changed the rod length to a longer rod and reduced the bore by 1mm.

I am wondering if I was sucking air or it is a lack of return flow (still sucking air) that could cause the damage. The other option is RPM causing some sort of failure on a weak oil film. Looking for ideas as I don't want to go through this a 3rd time.

Sorry for the carnage . # 3 rod bearing is the furthest away from the oil pump , was the engine fully warmed up when the failure happened ? what can happen when the oil can't flow fast enough ( cold thick oil) is the centripetal force of the spinning crank flicks the oil out of the crank oil passages faster than the oil pump can push oil through the galleys and main bearings to replace it . your gauges will still see full pressure but there will be no oil at the big ends .

A friend had a Mighty Mouse 1640 seize because of this , after an oil down and clean up at the drag strip the driver started the engine and did a burn out with the engine not up to temp . he was lucky , just the #1 main bearing picked up and stopped the engine at idle and no major damage was done .

I've a 103x78 that is limited to 7000 , I won't rev it till the oil (10w50)reaches 70C , I've adjusted the pressure relief to give 60psi instead of the factory 43psi . when the oil is cold the oil pressure is over 60psi because the oil can't flow through the relief valve/galleries fast enough . once up to temp I've an idle pressure of 14psi and max at 60psi even at high revs .

Could it be that you are sucking all of the oil out of the sump and into the coolers?

You aren't running a big extra sump or dry sump tank, so it might be vacuuming everything up and into the coolers and heads or..?

Was it having real troubles with oil temp?

I'm not a fan of oil coolers; most temp issues can be brought under control with judicious tuning IMHO.

Pics are broken for me; not really sure I want to see them, though. Sorry for your loss.

I am not sure why your pics aren't showing, so here.
Who's rods are those and whats the name on the head of the bolts.
I would like to see a picture of the head of the bolts.
I don't think it's an oiling issue

The rod journal isn't blued from lack of oil/overheating, I agree more information on the rods and bolts would be good