Hey, its all in the name of performance// er, science, right?
They make thermal wraps for oil tanks and hoses can be insulated.
Actually, if there is any
chance the engine CAN fill up the valve covers or have a large qty of oel not in the tank, it IS an excuse for more oil, and you need room to store it when its all home.
No oil in tank == very very bad, under absolutely any circumstances.
(Thus the danger of a full case on startup and related need for oil level interlock and electric pump or cutoff valve etc)
I have been eyeing a competing deareating unit likely similar to that, looks
Its really just an intentionally internally leaky centrifugal pump, particularly on the air outlet side.
I posted a vid of it awhile back, cutaways were shown for some reason...
Connects to scavenge:Liquid is heavier, gets flung to OD and out, bubbles "rise" to center outlet.
The scavenge pump still does the oil/air movement work.
I doesn't look like it would take much power or be hard to fab, but you could probably run it too fast and have it act as a fine blender.
May need an additional stage to push the oil or air to the tank? (probably not)
Haven't built one. Yet.
There's probably an ideal RPM rnge based on oil viscosity/temperature.
I've been doing some reading. One of the considerations is how much air needs to be removed from a dry sump system. Another is time that oil can collect in the engine before getting scavenged.
I found this rule of thumb: Longest corner in seconds x 2 x volume of oil moved per second = minimum capacity of reservoir.
For the 3.6 Gal/Min that is 14.4 qts/min or .24 qt/sec
15 second corner x 2 x 0.24 = 7.2 qts
10 second corner x 2 x 0.24 = 4.8 qts
7 second corner x 2 x 0.24 = 3.4 qts
Looking at laps of the local road course no corner is longer than 9 seconds from turn-in to track out, so maybe 70% of that time pulling enough G's to hold oil away from the pickup.
Another consideration that is somewhat related to air separation requirements is how much air needs to come out. For a V8 with 3-4 scavenge pumps (2 pan + 1 each valve cover) and each pump sized to scavenge 100% the total scavenge capacity is 3-400% of total flow. i.e. for every qt pumped into the engine 3-4 qts of air/oil is coming back to the tank. The return is more air than oil.
In the single scavenge section we are using and assuming both sides are 100% the ratio is 26/21 or 124% return not 300%. For 26mm = 4.2 gal/min 21mm = 3.4 ga/min so we need to remove 0.8 gal/min of air. In airflow terms that is about 0.10 CFM. .1 CFM is not much. A 3/8" hose 3ft long flows .1 CFM with 0 pressure loss.
So ... In the interest of science ...
The oil sump in the case has these dimensions 9"L x 10"W x 1.5" to full mark on dipstick 2.5" to bottom of PR tube openings. G loads can be estimated by tilting the engine. When engine is tilted so the oil pick up and PR tubes are level, oil will start draining into the valve cover. There is a volume of oil in the case that is below both the PR tube and the pickup as shown by the red line below. (green is normal oil level). This is about a .5 G load.
This trapped volume is at most 9" x 5" x 2" = 90 cu in or 1.5 qts
As more oil is added the pickup can scavenge it limiting the amount that pools in the valve cover when the g load is over .5 or so.
I'f the car pulls over .5 g for the entire 7 seconds it will have pumped 1.75 qts of oil into the engine. 1.5 is trapped away from the pickup so .25qt can make it into the valve cover.
Lets say we have 1.75 qts in the engine after a long corner. We still have oil in the tank and the scavenge pump will pump those 1.75 qts back into the tank in 6.25 seconds.
I can see a quart of oil remaining in the case sloshing around past the pickup during an autocross run. The design of the engine with a flat case floor is a challenge. On the race course the idea is to have maximum G's all the time so the system will never work as if the engine is level. The question becomes the amount of time the car is pulling enough g-force to starve the pickup and how much oil is trapped by those forces. The oil level in the tank will drop by that amount and return to normal when the g-forces are removed.
I'm going to assume that 1.5 quarts will stay in the engine while racing. So the tank has to work over that range. Adding tank volume makes all of this less critical ...
I still think I'll be okay, but your concerns got me to investigate further. Thanks!
The 2qt Accusump will cover 100% loss of oil flow from the tank for 8.3 seconds based on the .24 qt/sec rate.
Maybe just don't drive it hard?
You do not have the required permissions to view the files attached to this post.