Nothing to do with surge in my case, mine baffled, I couldn't be arsed with filling with oil every 100 miles or so with a worn engine, so put more into start with, didn't cause any issues at all.
I won't do this when I put me new engine in, as I think the oil/air cooler will add another litre, and so help anyway, with the small capacity, just need to find room for the oil cooler and the steering fluid cooler, got me eye on a lecky steering column hybrid using cossie/sierra and corsa parts, or MGF as these are much cheaper!!
tabetha