I stand behind what I said. the question was opening a line and have some air. If you are starting a new engine, that requires much more. you have air in your cooler it goes out real fast when the thermostat opens. I never worried about that. I have my new engine at 500hrs and the old one went about 2200hrs. never an issue and yes I have the lockwood thermostat, have had it forever on both engines. I also believe the air in the cooler goes right into the tank not the engine on flow. correct me if I'm wrong. still I've never had an issue with this. If there is air in the system, the oil pressure will be none. this is for sure.