I got a call from a fellow dirt track racer once, about an engine that would start, and then stall immediately. He thought it had carburetor trouble. After several attempts to start it, I told him to keep it running some way to warm it up. He cranked it off, and floored the gas. It shook and stuttered for about 5 seconds, and then the filter housing split, top to bottom. Since I was standing right beside the filter, on an open-wheel race car, I got a bath in 50 weight oil!
He had used a big block oil pump, and then shimmed the relief valve spring down tight. A 100-lb. gauge was pegged at idle speed, and the running pressure was probably close to 1,000 PSI. The stalling was being caused by the hydraulic lock and the engine's inability to turn the pump.
Drop the oil pan and check the pump. You've obviously got a blocked relief valve.
Jerry
