We ran a negative pressure on our circle track engines by having a tube with baffles in it mounted to the factory fuel pump location. Can't get any closer to the oil supply than that but never a wisp of blue smoke. Rather than engine vacuum, which wasn't much with both valves open most of the time, we had a tube in the exhaust collector with the end angled so the high velocity exhaust passing over it drew a high vacuum. Baffled tube was about a foot long, vertical, and at least eight overlapping baffles at a 45* angle. Early sbc had a baffle (they called a condenser) in the lifter gallery that was simply a smaller tube inside a larger one. It doesn't take much to draw air and not liquid/vapor but a bit of thought to do so. For sure, you and the whole neighborhood will know if it's wrong.
Last edited by coilover; 01/07/2022 8:41 PM.
