When I was in High School my dad gave me the Opel Kadett that Mom had burnt up the engine in. Being a kid with very little money I scrimped on the rebuild and didn't put new cam bearings. As a result it held very poor oil pressure when it was hot. So, I kept putting washers behind the oil pump bypass spring to jack up the pressure. When it was cold it would pump out 80 psi or better, hot it was down to about 15psi. One winter night I jumped in it and headed out for a date. I was late and the weather was cold.... I never noticed the oil pressure until I heard a load "POP" about a 1/4 mile down the road from home. I then saw 0 psi. I shut it down immediately and stopped the car. Behind it I saw a solid trail or oil for about 100 yards. Upon closer inspection I found that the oil filter (spin-on) had exploded and the entire filter can was gone. I'll never know how high the pressure was but it had to be pretty good to blow-up a filter.