Dry Sump Question

[csatte02]

I want to mount a retangular/square dry sump, but have heard that round baffling is better because it creates less air bubbles. Wanted opinions on square/rectangular tanks and baffling.
Thanks
Chris

[RussMcB]

I think at some point above the level of oil (even in a square tank), you'd want curved walls to encourage oil-air separation. I've seen some square tanks with upper round sections.

It probably helps to think about the in-rushing oil. Try to give it a path that does not cause splashing, which would add even more bubbles.

[HayesCages]

We put a rectangular one in a vintage Crossle' FF with no issues at all. It's still doing fine 4 years down the road.
Lawrence

[kea]

If you want to run a small (Crossle) size dry sump tank, you need to use an oil cooler to help separate the air from the oil on its returns to the tank. The round tanks, with return oil coming in at an angle to the round sides, do this as the oil drops down off the vertical wall. I've know some Crossle owners, who tried to do without the standard style air/oil cooler (tried water to oil) and had lubrication issues with their motors.

[problemchild]

The smaller the tank, the more critical the design is. I had a state-of-the-art Saldana sprint car tank that I modified ..... and I was amazed that I could tell the difference in oil pressure stability between 5 and 6 qts. I was also using my own design oil pump that had more than 50mm length of scavenge pump gear or about double what most people have .... so I was doing a better job of getting oil from the engine. If you are going to use a rectangular tank, it will need to be larger and well designed to minimize aeration.
I have heard about (but not seen) a tiny round tank designed by Adrian Reynard that had less than 2 qt capacity. I would like to see that if someone has one.

[HayesCages]

That makes good sense.
Lawrence

[kea]

Years ago, one of the Reynard Indy (CART) cars, had an engine oil capacity of 5 quarts, using an oil tank located between the engine and drive train. What couldn't be seen from the outside, was the swirl-tank located inside the oil tank, to de-aerate the returning oil.

[Bill Bonow]

The Evolution now uses a 2 1/2" x 5 1/2" x 24" tank with no baffles or anything special. It holds 4 to 4.5 quarts and never flickers on oil presure (via DA) regardless of level. Saves a lot of space over round tanks and it costs less. If you have the room, build it tall.

Here is a link to a photo:

http://www.apexspeed.com/forums/show...72&postcount=9

[Purple Frog]

The round tank that Greg speaks of can be seen on most 83-84 Reynard FC cars. It's a nice little unit with built in swrill properties.

[CAM]

Chris,

As Bill stated above we originally started with a baffled Pace Tank from Pegasus.

http://www.pegasusautoracing.com/pro....asp?RecID=134

They are really nice units but they are now $ 539.00 . Bill ran all last season with a rectangular tank made to fit the Evolution FST. It has no baffles or de-aeration of any sort and the oil pressure data is the same between both our cars. I still run the pace tank and did so for a comparison.

Greg and Keith are also right as you try and make the tank smaller de-aeration and cooling for our air/oil cooled cars will become more important. I think if you had everything right you could get by with a 3 to 4 quart total system, it does not leave much room for error or cooling on those hot summer days however.


Carl.

[winsmith]

How much aeration occurs has to do with the RPM that is turned, the pressure you are pumping in to the engine and how much vaccum you are pulling oil out with. With the First motors and the most common dry sump pump neither is high enough to get into any aeration issues.
Tall and narrow is almost always the best. Baffles slow down the return of the oil to the pickups. If you do not need them, do not have them. Get a tank that you can fit to your car or have one custom made to fit. (it is cheaper that you might think) The tank should be 2/3s full with the motor running. However much oil it takes for this to occur is capacity of your system.

Win Smith

[provamo]

at one time they ran a nearly conical resevior

[lawyerbob]

As long as we're on this subject - what kind of oiling does Gomez Adams have? If it's a dry sump - where is the tank located and wwhere was it purchased? Any other Adams FST's with dry sumps?

My new motor is a dry sump set-up but I'll need to get and fit a tank. Those familier with the Adams know that the fuel tank is behind the main hoop, in fornt of the motor, so things are already a little tight up there, but relocating the fuel tank is not really an option, both from the space standpoint and the cost standpoint.


Second question - how large or small a tank can we use? Would that small Reynard tank (or something that size) be adeqaute for our cars?

Thanks

[Bill Bonow]

Bob,

The Gomez tank was fabricated at SRacing. Good chance that they can help out again as Gomez is currently sitting in their shop, makes for easy duplication. I'd bet Jim can take a photo or two for you.

[lawyerbob]

Bob,

The Gomez tank was fabricated at SRacing. Good chance that they can help out again as Gomez is currently sitting in their shop, makes for easy duplication. I'd bet Jim can take a photo or two for you.

Excellent - thanks - I'll call Jim monday

[roofus]

oil used to come pretty much exclusively in round one quart "cans", which meant it was happier in round sump tanks.

today's oil comes in containers with "corners" which means it can be happy in other than round sump tanks.

these facts are often over looked . . .

it is also important to consider whether one is located in the northern or southern hemisphere when designing a swirl pot.

when in doubt about swirl direction, just employ the direction your toilet flushes for sump tank design.

roofus

[provamo]

spot on Rufus, those arcane facts you alluded to are often over-looked by the current generation of cyber based design engineers