So named because the sump, in the case of the rotary is just a flat
plate, is not used for storing spent engine oil. Two or more scavenge lines
remove oil from above the flat plate and pressurize it through two or more
scavenge sections of the pump. The pressurized oil is then pushed to the
storage tank. It may also be forced through one or more coolers on the
way to the storage tank, and have no affect on oil pressure.
The pressure section of the pump pulls oil from the bottom of the oil
storage tank, pressurizes it and sends it to a filter and then an additional
cooler. If the cooler is known to be clean, then cooler and filter may be
reversed. From the cooler/filter then to the engine. In this case an extra oil
line from oil in to the front bearing gallery is shown, that is not required
on aircraft.
While the most expensive/complex and heavy of all oiling systems, the dry
sump system allows for a wide range of options, in locating stored oil. In the
amount of oil pressure to be used. In providing for additional coolers to be
installed in a wide range of locations. And in providing oil with the smallest
amount of foam included. The primary cost is in the pump, as they run about
$1,500.00 new for a three section. Weaver Brothers, Peterson, Moroso, and
Stock Car Products are brands that come to mind. The SCP pieces seem to
be the lowest priced.
An alternative, is to use the engine pump for oil pressure, and run an
aftermarket pump for scavenging oil to a storage tank. Slightly less complex
and cheaper, and very effective.
Not needed for airplanes, but like all brainstorming, fodder for the
mill..................
Lynn E. Hanover