I just took mine apart and what would you know, It is pressure operated, Thanks to twincam.org for telling me the age bigport sandwich plate is temp operated when I was looking into oil feeds for the turbo and it might surprise some people to know that one of the ones that had said that was JP, I am sick of getting told something and then relaying it on to others to find out it is bullshit, No wonder the net is full of crap.