How long should a bottom end last?

Had a second hand K series fitted to my car last September after my first engine dropped a cylinder liner. Didn’t really check the provenance and have since done 1.5 trackdays and 600 miles in total and the bottom end bearings appear to have gone

Take it on the chin for not checking the oil or enquire further?

So you’ve done 1 and a half track days and 600 miles without checking the oil? And you also had an engine fitted without knowing its provenance? Can’t see you having a leg to stand on. Sorry.

The oil was checked on 17th Feb and was a-ok, I meant that I hadn’t checked the oil before/during the second trackday

Edited to add, 2nd trackday was under a month after that oil check

The oil was checked on 17th Feb and was a-ok, I meant that I hadn’t checked the oil before/during the second trackday

Edited to add, 2nd trackday was under a month after that oil check

My VHPD-K can drink up to a litre of oil on a good track day and perhaps 150mL of oil per 100km of spirited road driving. They can drink oil when pushed hard, usually through the valve guides so it’s entirely possible that if it was low-ish on the dipstick, over the course of a trackday it could have gotten so low that oil surge became an issue.

When it started knocking (or whatever led you to believe a bottom end was gone) what was the oil level in it then?