Just a guess: factory SBC pumps have relief valve capacity well below the volume that needs to be bypassed under high load conditions (oil temperature 0° F, 60 wt. oil, instantly revving the engine to warm it up).
The result is that the pump tries to produce 200 psi (which has almost the same effect as sticking a broom handle between the gear teeth), the valve only dumps 30, and something breaks... if the filter doesn't explode first.
On a dedicated race engine that needs more volume for an external cooler it might help - but then you will be heating the oil before the engine is run, won't you?
Gee, when did they learn to do that?
1st time that I know of: heating castor oil beforehand made it easier to start and increased engine life. The engine was a Liberty V12 - you guess the year.
