Al, I understand there is a difference between "spray bars" and "spring oilers". I understand the "spray bars" oil the rockers primarily. "Spring oilers" are tubes welded inside the valve covers that spray oil directly on to the valve springs. We began doing this during our oval track days(20 years ago)---it worked for us---still do it on our drag engines. As Ronny said, they help to prevent spring breakage during warm up. BTW, some people(including the Direct Connection people) thought we were crazy for wanting to build "spring oilers"

We have never used "spray bars".