mg midget 1500, Drilling out the centre oil feed to main bearing and 2 and 3 big ends.
Drilling out the oil feed to the known weak point on these 1500 engines.
This gives a better oil supply to the centre main bearing and the two big end bearings that can often fail.
The racers used to do this years ago to prevent failure.
The oil supply to the centre and big ends was not enough under hard driving.