KMP259 Aero Testing

[1ntCobra]

Did you order that fancy bottle from the McCormick racing catalog?

Originally Posted by patrickt

This is not up on the level of Morris' stuff but my oil level investigation makes for a fun game nonetheless. Here are two pics. The first is my oil pan when the car is standing normally on my reasonably level garage floor. This is the condition under which I usually check my oil, fill the sump, check how much is being used, etc. The second pic is when I have the back of the car jacked up so that the magnetic level on the bottom of the Canton pan has its bubble in the middle of the level's window (it's jacked up a good bit). Now, when Danbury Competition calibrated my dipstick when they built my engine it was on an engine stand, not when it was sitting in my ERA. Now you can't really see my dipstick all that well but it's directly behind my fancy coolant overflow catch bottle. See if you can guess what the oil level difference is on the dipstick when you check the oil under the first photographed condition as opposed to the second. Why it's important should be obvious.

[patrickt]

Originally Posted by 1ntCobra

Did you order that fancy bottle from the McCormick racing catalog?

Very astute. The glass in that bottle is actually quite thick and heavy, but if you don't catch your overflow you never know how much you're overflowing. So, on a reasonably well built FE, what does fuel level, coolant level and oil level all have in common? Answer: Your FE will tell you what level it likes if you just leave it alone and listen to what it's saying. With my Holley, if I set the fuel level as per every instruction ever written in the last sixty years (to the bottom of the bowls' site holes) she'll perc it out the boosters and leak it out the butterfly shafts, create scary fuel clouds and refuse to start when she's hot (and the bowls don't sit level either). If I fill the coolant surge tank up half way she'll spit coolant out the overflow tube until it settles to her sweet spot, which is always at the same level about an inch and a quarter off the floor. If I try and top her off she just spits it out again. And what if I overfill my Canton oil pan? Same thing. Even with my windage tray, the overfilled oil gets aerated and vanishes without a trace. The difference in my two pictured dipstick readings above is a good 1/8th to 1/4th of a quart of oil. And because of the tilt of the pan, if I fill my sump up to the "FULL" mark I'm really overfilling it by at least that much. For years I always filled my oil to the "FULL" mark and noticed that the first eighth of a quart of oil seemed to disappear relatively quickly, but then consumption seemed to slow down. If I topped it off, it did it again. Finally, when I did absolutely nothing and just let it go, oil consumption came to a crawl when it was about halfway down the dipstick. It never occurred to me that the dipstick markings weren't actually wrong, they were just wrong for an engine that sits tilted in the engine bay. What really tipped me off was when I installed a Wagner adjustable PCV a few years ago and I plumbed in a Moroso Oil/Air Separator expecting to catch a ton of oil. It catches a couple of ounces, but not all that much. How can oil just vanish for a while and then stop vanishing? My engine was simply telling me "I don't like to be filled to the brim with oil -- especially when your marks are wrong to begin with." So how did I reduce my oil consumption down to almost nothing? Just by putting a notch in the middle of the dipstick and keeping the level there.