Quote:
Originally Posted by tims210
Quick question. Like others, I have the Moroso low profile oil pan on my 1st gen Coyote engine. Moroso advertises it as a 9.5 quart capacity. They claim I should add another 1/2 quart for a dry filter. That's 10 quarts total obviously. I followed their instructions and the dipstick reads above the "full" range. I called them and they instructed me that I need to re-calibrate a new fill mark to compensate for their pan. Didn't make sense to me. I feel that whatever the pan capacity is the dipstick tells the true story. Am I wrong? I don't know what dipstick was used at install. Is it Ford OEM, aftermarket, etc.? All I know is the dipstick has a plastic yellow ring on the top. Hopefully this helps for identification purposes.
Thanks in advance. |
The dipstick does not indicate
oil volume in the
oil pan. It only indicates the oil level the engine manufacturer does not want you to exceed for windage purposes. When you exceed the normal fill level (above the full mark on the dipstick), the additional oil is whipped into an aerated foam by the rotating assembly. This foamy oil must lose its air bubbles before it is a suitable lubricant. You determine pan volume by how you build or buy your pan.
For the purpose of illustration, let's say you have an oil system that can move 5 gallons of oil per minute, you have an 8-quart oil pan, you have ½ quart of oil in suspension in the crankcase at operating engine speeds, and it takes 1 minute for the oil to degas, leaving just lubricant to be recycled through the oil system; the following is what will happen.
You will cycle the oil in the pan 2.5 times in the first minute. You will deposit ½ quart of aerated oil into the oil pan sump that will be recycled through the engine. The oil with the trapped air bubbles will begin a progressive erosion of the most highly loaded bearings in the engine first and progress up the bearing load lineup until non-aerated oil is once again available.
The bearing damage is like arsenic poisoning. Unless you overdose on the poison, it is a slow and cumulative process that takes place over time until it eventually extracts its final full measure of destruction.
Dry sump manufacturers work hard on the problem to protect their customers' engines — which is why we buy dry-sump oil systems. Sometimes a picture is worth the thousand words equivalence, so here is a pic of what oil looks like in an aerated vs non-aerated form. Click here =>
Aerated vs Non-Aerated Vid The video takes about 2 minutes but is visually quite informative.
The larger capacity oil pans do two very important things. The first is to provide a larger quantity of oil in the oil sump that will take longer to heat and therefore run cooler than a smaller quantity. The second is the use of baffling around the pickup and also between the rotating assembly and the oil in the sump.
The pickup baffling prevents uncovering the pickup and drawing air — which is bad for bearings. The second baffling is a windage tray or windage tray and crank scraper, which sheds oil off the crank and quickly gets it to the sump with a minimum of aeration by the rotating assembly. In the sump, you need a large enough sump capacity to allow the oil time to de-aerate before being drawn into the pump for recirculation to the various lubricated bearings.
The next video is not intended to encourage you to run dangerously low on oil. It does, however, show you two important dynamics. The first is how poorly many pans, OEM included, protect the oil from windage. The second is how much power is consumed whipping the oil that the rotating assembly can get at into a foamy mess.
For reasons I can't fathom, I can not find the Engine Masters session where they kept decreasing the oil volume in the pan. My memory tells me they went from 6 or 7 quarts down by a quart at a time and found best power at four maybe five quarts.
This is not a endorsement or a suggestion to reduce your pan capacity to gain power. Their power imporvement was small but measurable — my memory wants to peg it at 5 or 10 HP.
What it is showing us that is significant is, the benefit of getting the sump oil level as far away from your rotating assembly as possible. The best way to do this is a windage tray and a crank scraper. A deep pan will also give you a cooler oil supply and provide additional time for existing oil to de-aerate.