I read this somewhere on a "24 hours of lemons post":
"If there are 6 quarts of oil in an I6, about 4 quarts are flying around the sump past 4000 rpm, and piston, head gasket and rod failure are more related to a steady rise in oil temperature from cavitation from a oil pickup sucking air than anything else.
In the early days of Aussie sedan racing, people were looking to having to run an oil cooler often looked at better sump windage trays and baffles and when they ran spark inducing 40 thou clearance windage trays, crank scrapers and baffles, they could loose 50 deg F oil temperature, more power, and a sudden reduction on engine scrappage. Ford Production race engineers cut a perspex window into the passanger firewall in 1972, and viewed the oil sump pickup via a glass plate in the sump. Much to their horror, they found that on a certain race track, the sump pickup on the Falcon sedan got air 50% of the time doing 90 mph average speed laps on a certain 3.8 mile circuit. Their engine scrappage rate was huge, and the key was to build sumps that ensured the pickup was always submerged."