Bolw By ???

hi, here is a story about no vacuum in a motor. four stock eliminator motors were built with the total seal gapless top rings. two were put on a dyno for break in. the motors were sealed and a blow by meter installed. when running motors, there was no blow by, yet they smoked out the exhaust profusely!
both were torn down, rings thrown out. another stocker had same results. same fix, throw out rings. last guy had no problems with oiling at all. the comman thing the 3 had was, a PVC valve installed. the rings created so much vacuum in motors, was pulling oil through motor. total seal says, to plug the PVC or have a .060 hole in line to prevent oiling. these motors pulled
oil at wide open throttle. the piston /ring does provide a vacuum. the last motor was tested and pulled 19" of vacuum at 1500 RPM. this is with a very long duration cam. when tested with regular rings was only 9"