oil deaeration 2

[40caliber]

Does anyone have any suggestions for effectively removing the air from engine oil in a dry sump oiling system? I have tried dry sump tanks from many aftermarket manufacturers and none of them are very good at removing the air from the oil. Most of them splash the oil from the sump over one or more perforated plates. Any help would be appreciated.

 

[patprimmer]

Make sure the return oil is directed to a curved plate, at the inside of the curve at a tangent to it so the oil has a very gentel impact and swirls around. This will not remove air, but will stop further entrapment. Sufficient capacity of oil to alow time to seperate is the only method. All other techniques are aimed at reducing inclusion rather than removal.

The more gently the oil swirls around and down the tank, the more air will escape.

The position and design of the pick up also helps to reduce picking up aereated oil.

Adequate, but not excessive oil flow also helps, as does a good scraper system to reduce windage inside the engine.

Also look to keep oil returning from the overhead gear and valvtrain from impacting the crank, by scavanging it from the rocker box or by directing it to the sump by a path that is clear of moveing parts.

Regards
pat

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Tmoose]

I vaguely recall the older Chevy Power books or one of the Czrroll Smith books talking about that. Maybe both.

 

[Azmio]

40 caliber

Have you tried sucking out the air from the oil tank. The idea is to create some 'vacuum' above the swirl pot. This will minimize the air near the swirl pot from further 'enriching' the oil with air.

At the same time, it is crucial to minimize oil vapor or splashes from being sucked out as well. If the sucked out vapor or splashes is too much, you may need to return the oil back to the oil tank through catch tank or other devices.

It is also helpful to find the right oil for your application. We have tried different oil over the same engine application and we learned that oil specification, additives, life, etc. really influence the oil aeration.

Much like what Pat has mentioned, oil scrapper is really helpful in minimizing oil aeration and to decrease pumping losses.

 

[Carbuncle]

Look for a pump that incorporates a centrifuge. This actively forces the air rather than the passive separation other systems use.

 

[sprintcar]

One of the D/S oil pump brands incorporates an air separator into the scavenge side. Check the aftermarket listings. Try

http://www.performanceracing.com

and do a search in there for PUMPS - you get a vendor list - click thru those. Most have weblinks on their page

Keep the wheels on the ground
Bob
showshine@aol.com

 

[KevinJohnson]

Ed Pink has one.

 

[evelrod]

For an interesting read on this exact subject, along with lots of nice photos for us older folks, look up, I think, the Oct. and Nov. issues of Circle Track magazine.
I have been hooked on this mag since, well, a long time, because Smokey was their tech guy. I like the pictures!

Rod

 

[carnage1]

another good source of info (if you want to custom build one) is "Metal Fabricators Handbook by Ron and Sue Fournier"
great book if you like fabricating stuff, or if you don't still has a lot of info on dry sump oil tanks.

 

[rbmc1968]

One other thing you may want to try is stepping your scavange and return lines down one size. We found that switching from -12AN to -10AN scavange and return lines had a drastic effect on the amount of aerated oil seen in the dry sump tank while on the dyno. It also helped eliminate oil surging in the scavange lines.

Just my .02

 

[KevinJohnson]

rbmc 1968,

What inspired you to try that? Or was it serendipity?

Kevin

 

[evelrod]

Kevin, it was common practice in many smaller road race applications. You simply don't need AN -012 scavenge and -010 delivery lines on a <1 litre engine in most cases. I have seen several with -010 scavenge and -08 pressure delivery lines on 948 Lotus 7A's that functioned perfectly well. It's really old school.

Rod

 

[rbmc1968]

Kevin,
We decided to run smaller hoses on one of our small block Chevy dyno mules just to see what kind of results we could get. We had been in the process of studying windage. We ran clear -8AN, -10AN, & -12AN lines with an oil pan that had a Lexan window in it and video taped the results.

 

[KevinJohnson]

rbmc 1968,
Now that would be an interesting video to see. I have a spare Suzuki G10 engine (993cc -- tiny) that I am thinking of mounting on a platform that I can tilt side to side and fore and aft. In addition to the pan, I was also considering sectioning out several areas on the side of the block to be able to see in there as well (no dyno loading -- just windage studies).

Did you mount an internal light or was external illumination sufficient? Another interesting idea might be to add a fluorescent tracer and use UV illumination. Not sure if a standard video camera would be able to pick that up under low ambient light conditions, though. Be wild to watch directly in any event.

Just to make sure I am interpreting correctly, you are speaking only of the scavenge (from the pan, valve cover, etc.) and return lines to the holding tank versus pressure lines to the galley? (Different circuit in the latter, I'd think.)

 

[sprintcar]

Ditto on the video... it would make a good website link in here (hint)

Moroso did that study a few years ago and found smaller suction lines did work best. (Or is this the same one?)
I ran their dry sump pump with the smaller lines with excellent results.

Keep the wheels on the ground
Bob
showshine@aol.com