As far as how much vacuum is created... It really doesn't matter. Any vacuum is better than pressure. With that, a vacuum pump will use up some horsepower. A tube type evac system doesn't.
Again, my
you got that right. even tho my vacuum pump only creates 4-5 " I scraped the oil pan and ground a pretty good hole in it after a pass. didn't realize I did this until I shut the engine off in the pit. The vacuum pump was holding the oil in the pan I guess since the leak didn't start until the engine was shut down once I parked the car. After I discovered I was pouring oil out of my pan and got a drain pan under it I retraced where I may have hit something. I found the spot in the return lane over 100 yards away my only guess was the vacuum was holding the oil in the engine What ever caused the oil to not leak until then I was sure glad
