What's scary is when some doofus shims the relief valve spring down tight. One of my competitors on the dirt track in California called me up one day to help him get his freshly-assembled 350 stroker engine running. It would run about 10 seconds, shudder, and stall, repeatedly. I was tinkering with the carburetor, standing right behind the left front wheel on the open-wheel car. He was in the driver's seat. After several tries, he got frustrated and kicked the throttle wide open as soon as the engine started. The engine loaded up, shook a little, and split the side of the oil filter from top to bottom. I got a bath in slightly warm 50 weight Valvoline!
It turns out he had installed a big block oil pump, and then added several flat washers behind the relief valve spring. The engine was pegging a 100# pressure gauge at idle, and the stalling on startup was caused by a solid hydraulic lock in the oil passages because the relief valve couldn't move. With 500+ horsepower driving the pump at wide open throttle, the pressure was at least several hundred pounds, and the filter let go before the pump drive shaft or the distributor gear had a chance to fail!
Now, that's too much oil pressure, for sure!
Jerry
