I have had 216 Chevy engines that held 11psi at highway speeds and zero at a hot idle that ran for years. High pressure pumps are hard on drive gears, both cam and distributor, and high volume pumps give the oil less time to lose heat before being back on hot metal again. Now with that said about regular engine we HAVE to run 200psi hot on our blown tractor engines if they are at maximum boost---45psi. They have a dry sump system with 24 quart capacity and a Gilmer belt driven external oil pump with three scavenger rotors and one pressure rotor. The screens in the return port on the oil tank kept showing both metallic and copper particles, a sure sign of bearing problems. We tried different bearing materials and clearances ranging from 0.015 to 0.006 without success. A drag racer friend that ran a blown fuel car clued us onto going to ultra high oil pressure and the problem was solved. All our wet sump engines run in the 40psi range without problems so what we have theorized (not proven) is that the extreme oil pressure is so high that there is a pressurized oil cushion (that can't escape) between the rod journal and the crank pin that cushions the firing impulses. Whatever is happening it took us from a rebuild after every show, with a maximum of three pulls, to six shows before rebuild.

Evan