Dry Sump Systems

[cms56351]

To those teams that run with a dry sump, I have a question for you. Is it necessary to have baffling in the oil tank? In most racing appreciations foaming is a problem and to combat it baffles are use to separate the air out of the oil. I'm wonder if this problem exists in SAE formula racing.

[cms56351]

To those teams that run with a dry sump, I have a question for you. Is it necessary to have baffling in the oil tank? In most racing appreciations foaming is a problem and to combat it baffles are use to separate the air out of the oil. I'm wonder if this problem exists in SAE formula racing.

[Craig.]

Are you referring to the problem of foaming because of the air and oil mixing in the scavenge pump (pulling a vacuum) or from mixing in the tank itself? The problems I've seen are only due to the scavenge pump and the solutions for that can run from using a centrifuge (more weight so probably bad for a FSAE car) or baffling the tank in a way such that the foamed oil runs over the baffles allowing the air to separate from the oil.

I'm not exactly sure that that is what you are asking though so please feel free to correct me.

Cheers

[cms56351]

Well most oil pumps I've seen are gear or gerotor pumps. What I read about dry sumps is that the scavenge pump pumps a mixture of air and oil from the engine. Since the engines we use are alot smaller than the normal race car engine. Will the amount of air mixed into the oil returning to the engine (Yamaha R6) would effect the engine performance if baffling wasn't used? That's the Question I haven't found a answer to.

[Craig.]

Just to clarify are you concerned about the effect of having air in the oil when fed by the pressure pump to the engine or whether the air will separate just as it sits in the tank waiting to pass to the pressure pump? (Sorry, it's probably just me being a bit slow here...)

My understanding is that if you have an air/oil mixture feeding the oil pressure pump, you will have trouble achieving the required supply pressure and/or have delivery problems further along the lines. I would imagine that bearing would not like being fed with any air in the oil. I'm not sure if there are any other implications when the air is allowed to expand from whatever supply pressure you are running.

Whether the air has time to separate in the tank without baffles probably depends on your oil flow rate and tank size (ie. how long the foamed oil is sitting in the tank for). It could require some testing to see how long it takes to separate on its own.

To be honest, I haven't looked into it properly so be wary of my comments here! I'm sure someone else out there may have something to add.

[cms56351]

Thanks alot Craig

you been a great help

Would you know the type of testing needed?

[DanO]

We have used baffling in our sump resivoir for years without incident.

We do all the macining in house with our own design and only lost one engine due to oiling problems (2003 endurace run at FSAE comp) becuase of a sub par sump build. It helps to have people that know what they are doing..

Now here is my question... How do most of you drive your dry sump? We run ours off the stock waterpump location on our F4i. The internal shaft ratio works perfectly for it.

[cms56351]

I have a question for the teams that run with a dry sump.

What is the size of the your oil tank?

[Dave M]

having a tank that holds about 3-4 quarts should be sufficient. I recomend the 3.2q tank from pace.

[osubeaver]

DanO, we run our dry sump off the crankshaft with a 2:1 gear reduction (ie the pump is turning half the engine speed). We leave the stock oil/water pump assembly intact on the left side of the motor, and mount our scavange pump on the right side of the motor (ZX-6R).

As far as I know, we haven't used any baffling in the oil reservoirs in the past years and everything has worked fine. As far as I know, we haven't had any problems with oil "foaming". Our tank is about 5 quarts, so maybe the oil just has enough time to separate sufficiently before it gravity feeds back into the oil plate. It has been a bit tricky, however, to get a breather working on the tank that doesn't puke oil on cornering.

[Akos]

Chris,

Removing the air from the oil can be done by bringing the oil tangentially into the oil tank. This centrifuges the air out of the oil, provided your oil tank (or at least its top section) is somewhat round.

Check out: http://www.fsae.utoronto.ca/2002/large/eng024.jpg That is the oil tank hanging off the back of the car.

The one thing you have to watch for is the diameter of this section. If its too small it will create a lot of turbulance and splash up to the breather pipe.

A baffle plat is not a bad idea if, especially if your tank is shallow. I always like to put at least one (the seam in the middle of the tank is the baffle plate)

Also be carefull sizing your lines. Too small of an inlet line to the pressure pump can cause it to cavitate. Just as bad as air in the oil.

Cheers,

Akos

[cms56351]

Thanks for the info osubeaver and Akos

We may go with 5 quart oil tank and do some testing to see if baffling is needed.

by the way U of Toronto has a cool formula car.

[osubeaver]

cms56351, we tried to do some flow testing on our dry sump pump yesterday and I was somewhat surprised at how aerated the oil was. It wasn't necessaraly foamy, but it did look like it had a lot of little air bubbles in it. I think partially this is because it was shooting out the hose and splashing onto the oil in the temporary reservoir (a 5 gallon bucket). We might try pumping the oil into the bottom of the reservoir instead of letting it splash in from the top. Although, with the current setup, it may be separating out the air enough by the time it feeds out at the bottom of the tank. Anyway, if you do any oil testing, I would like to recommend not securing 4.5 gallons of oil in a bucket by a zip tie. Sometimes they just don't hold http://fsae.com/groupee_common/emoticons/icon_eek.gif.

[Justin Hodge]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by DanO:
We have used baffling in our sump resivoir for years without incident.

We do all the macining in house with our own design and only lost one engine due to oiling problems (2003 endurace run at FSAE comp) becuase of a sub par sump build. It helps to have people that know what they are doing..

Now here is my question... How do most of you drive your dry sump? We run ours off the stock waterpump location on our F4i. The internal shaft ratio works perfectly for it. <HR></BLOCKQUOTE>

That was last year, however, we are having our pump machined outhouse this year with tolerances no greater than .0005 inches. Our pump will provide the same benefits as last years with less drag off of the crank. All friction surfaces will be minimized.

[TommyBoy]

I am looking into possibly fitting our car with a dry sump system this year also but am wondering what size of pump other teams are running and where they might recommend the purchasing of one ?

Any info at all would help a great deal.

Thanks,

[BeaverGuy]

We use a pair of oil pump gear and dies from the motor as our scavenge pumps.

[cms56351]

osubeaver, I visited your teams web sit, did you guys manufacture the scavenge pump and the drive for it in house

[BeaverGuy]

cms56351 <BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> osubeaver, I visited your teams web sit, did you guys manufacture the scavenge pump and the drive for it in house
<HR></BLOCKQUOTE>Yes, The pump housing and drive mechanism was made in house. It required a custom crank trigger to be made. The pump gears and dies are Kawasaki pieces.

[cms56351]

I am working on sizing a dry sump pump are our engine. I not sure of the correct volumetric capacity needed for the pressure pump. I have determined the sock pump to be around 5-6 liters/min/1000rpm and I read that the replacement pump should have a larger volumetric capacity than the sock pump, but I'm not sure of how much.

Any info will be greatly appreciated!

[BeaverGuy]

From a basic control volume analysis you realize that the pumps out of the engine can't really flow more than the pressure pump. There is only so much oil. However, if all that oil was to congregate in one location in the pan you would need to be able to pump at least as much out as in. So if you make it such that each pickup is connected to a sump pump that has at least the same flowrate as the pressure pump you should be fine. So if you have three pickups, have three pumps that have a flowrate equal or greater than that of the pressure pump. Then when the sump pumps are working and they are all pumping oil and not just one you have sump pump system that has a greater flowrate than the pressure pump. As for the pressure pump just use the stock setup and only build a drysump pump. That is the procedure I would go through, and seems to be the reasoning behind the design of drysump system on our car.

[NovaCat2005]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by cms56351:
To those teams that run with a dry sump, I have a question for you. Is it necessary to have baffling in the oil tank? In most racing appreciations foaming is a problem and to combat it baffles are use to separate the air out of the oil. I'm wonder if this problem exists in SAE formula racing. <HR></BLOCKQUOTE>

Hey guys, I've been thinking about this problem but I don't have much experience with these engines.

Would it be possible to lower the air pressure in the oil tank to suck the air bubbles out of solution? I just thought of this idea and wonder if anybody had given it a try. Is there an accessible source of vacuum on these engines? Let me know what you guys think!

I have the engineering curse, I can't stop thinking about a problem until it's been solved http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Dave M]

it is possible on paper, but the baffles and centerfuging (sp) take care of the air/oil separation. you may also have problems with your feed back to the pressure pump when running vacuum in the tank. Just buy a good tank and your problems will be solved. Alot of pump companies make air/oir separators that bolt on to the pump. They arent usually needed unless you are flowing alot of oil and have a small amount of oil (capacity). Its best to use tried and true systems, they work very well, but I have never seen a vacuum on the oil tank.

[Brodyj]

BeaverGuy and osubeaver,

Our trusty dry sump gears are actually made my Linn Gear. They are not Kawasaki parts.

I would validate the oil pump speed one of these days. The stock oil pump runs off some gears so, it might be running at a different speed than you think. In other words, the dry sump to stock oil pump ratio might be different than you are expecting and communicating to this thread.

Brody
'04 Engine Team Captain
OSU FSAE

[BeaverGuy]

Brody, the oil pump die and gear, the actual pump pieces, are Kawasaki pieces, The actual engine speed to Oil pump speed is just the primary reduction ratio which is 2.022:1. The engine speed to drysump ratio is 2:1.

[Dave M]

for those teams that have ran dry sumps in comp. What do the judges ask and say about the system. Do they want specific details or a more general idea.

thanks

[Brodyj]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by BeaverGuy:
Brody, the oil pump die and gear, the actual pump pieces, are Kawasaki pieces, The actual engine speed to Oil pump speed is just the primary reduction ratio which is 2.022:1. The engine speed to drysump ratio is 2:1. <HR></BLOCKQUOTE>

Really? What were the gears used for originally? So on our motor, was the dry sump to stock oil pump speed ratio ~1:1?

[James Waltman]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Dave M:
for those teams that have ran dry sumps in comp. What do the judges ask and say about the system. Do they want specific details or a more general idea. <HR></BLOCKQUOTE>

They want you to prove that your decision was valid. You prove this by showing them all pros & cons of your choice. We had a pretty cool dry sump but no data to back it up. I was asked specifically about how much power the scavenge pump and alternator were drawing off of the engine. I didn't have a clue.

If your argument is that you can get a lower CG because you made the pan shorter then you better have data that shows how much lower it actually got (for the entire car with driver) and how that is going to help your car handle better. If your argument is that you are trying to prevent oil starvation in constant lateral acceleration then you need data that shows you were starving the engine during cornering and that the dry sump solved it. Could baffles have done the same thing?

When we started the Design competition in 2004 I gave the judges a quick run through of our car. I pointed out this picture to show how much lower we were able to get the engine because of our dry sump:
http://dot.etec.wwu.edu/fsae/HostedPics/DrySump/oils_pans_F3_F2mod_V35.JPG
On the left is a stock F2/F3 pan. Center is the same pan with the tabs cut off of the bottom. On the right is our pan from last year. Doug Milliken was standing behind me when I explained all this. When I watched the video later it was pretty cool to see how big his eyes got when he saw our pan. But even though it is impressive we didn't have any justification for it and that is what the Design competition is all about. I've been telling our new guys that if we showed up with Schumacher's Ferrari we would get destroyed in Design because we couldn't back it up with justification.

[Dave M]

Thanks, Thats what I wanted to hear. Any other teams?

[BeaverGuy]

Depending on the judges you could get a different response as to what you say when you talk about a dry sump system. Last year we were asked about the oil pressure vs. lateral acceleration, we said we didn't have that data but at the same time we tried to explain that that wasn't the reason for the dry sump. We have a dry sump to lower the engine. When we tried to say that, they interupted and asked again about oil pressure vs. lateral acceleration.

Brody, I think we might have a little bit of miscomunication here. The gears driving the dry sump were made by Linn Gear, however the pump die and gear, the parts that pump the oil are Kawasaki pieces. And yes the dry sump to oil pump ratio is about 1:1 but the dry sump could theoretically pump twice as much oil as the stock pump.

[Brodyj]

BeaverGuy, yeah that sound right. Just checking.

Hey send me some stuff that you and the other teams are working on (team weekly presentations). I want to see what the intake and chassis will look like this year.

Josephbrody_no spam_yahoo.com

[Nizmo95911]

No, you don't need it at all, a tank is just fine!

[Atoidi]

Anyone have any problems mounting their pumps onto the engine? Or with attaching required fittings to feed the engine. We just received our pump and we have not been able to design a proper mounting bracket that will not interfere with the engine or any of the major components.

Any ideas?

[Dave M]

Some teams have mounted their pumps infront of the motor and driven off the generator shaft. this is ok but you need to have a realy well built cover. Talk to some of the washington guys about this setup. The best way is to run the pump off the water pump shaft. Remove the water pump (run an electric water pump) and make a housing that adapts the pump to bolt on to the old water pump location. What pump/manurfacturer do you have?

[Andycostin]

Sump pics are impressive, but just looking at them, I'm pretty sure that we've managed to make a flatter wet sump, will try to get some pics posted, but wouldn't this be better that adding the weight of a second pump??

[Denny Trimble]

Andy,
Are you sure you saw the 1/2" plate on the right? I'd like to see a wet sump shorter than that http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Travis Garrison]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Andycostin:
Sump pics are impressive, but just looking at them, I'm pretty sure that we've managed to make a flatter wet sump <HR></BLOCKQUOTE>

...for your sake I sure hope not http://fsae.com/groupee_common/emoticons/icon_smile.gif The sump plate for the dry sump is the shiny thing on the far right...its only as thick as the heads of the bolts used to retain it.

-Travis Garrison

[GTmule]

Denny/Travis:

Where do yall plumb the scavenge lines/pickups into the sump? In otherwords, with (obviously) no fottings on the pan, how does the oil get out? Are yall using an external two stage scavenge and the internal pump for pressure? or a 3 stage external?

Also, I havb't looked THAt hard yet (not sur eI can sell the team on it) but does any one have pic of the Honda F3, F4(i) arrangement with the oil pump running of the waterpump drive? I cna't picture how it'd all come together, at the moment.

Thanks,
Chuck.

[Jarrod]

http://www-personal.monash.edu.au/~fsae/pastcars/2001/01car/197.jpg

this is the only pic i could find that is on the web of our setup, ran in 01 and 02, removed in 02 comp after a few issues, make sure you use a radius in the slot off the tongue and groove drive, use good steel, and put a mesh gauze over your oil pickups(we found out the hard way). Toronto have a neat setup, maybe there is some better pictures of theirs floating around.

[Travis Garrison]

GTmule,

That setup had the lines plumbed through the case...

-Travis

[GTmule]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Travis:
GTmule,

That setup had the lines plumbed through the case...

-Travis <HR></BLOCKQUOTE>

so you drilled holes in the case with bulkhead fittings or something? I thought about that, where you do it? front of the engine?

[Travis Garrison]

I wasn't the engine guy when I was there, so I can't take credit for it...but if I remember correctly we ran the two pickup tubes through the front next to the oil cooler, and we fed the stock pump directly from the oil resivior via a fitting in the right side (?) of the case.

Our particular fittings were just aluminum barb fittings for push lock hose welded onto the case...and on the inside we used aluminum tube bent to shape...

-Travis

[James Waltman]

GTmule,
Follow these links to get some more information about how we did it and how some other teams have done it.
link 1 (http://fsae.com/eve/forums?q=Y&a=tpc&s=763607348&f=125607348&m=3446023614&p=1) & link 2 (http://fsae.com/eve/forums?a=tpc&s=763607348&f=125607348&m=5026026005&r=5026026005#5026026005)

[Atoidi]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dave M:
Some teams have mounted their pumps infront of the motor and driven off the generator shaft. this is ok but you need to have a realy well built cover. Talk to some of the washington guys about this setup. The best way is to run the pump off the water pump shaft. Remove the water pump (run an electric water pump) and make a housing that adapts the pump to bolt on to the old water pump location. What pump/manurfacturer do you have? </div></BLOCKQUOTE>

We're running the pump off the water pump shaft but having mounting problems with our housing plate. The main issue is the location of the pump in reference to the frame. PACE made our pump. We're dealing with really low tolerances for the placement of this pump.

[Dave M]

Is your frame having conflicts with the pump? Make a snout that adapts to the water pump provision, then mount your pump to that plate.

[Atoidi]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dave M:
Is your frame having conflicts with the pump? Make a snout that adapts to the water pump provision, then mount your pump to that plate. </div></BLOCKQUOTE>

We got it mounted! We were having trouble with that spot but we were able to mount the pump and it looks hot. Thanks for the advice though

C

[Justin Hodge]

Check out the LTU car at competition. It is one of the better dry sump designs.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Atoidi:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dave M:
Is your frame having conflicts with the pump? Make a snout that adapts to the water pump provision, then mount your pump to that plate. </div></BLOCKQUOTE>

We got it mounted! We were having trouble with that spot but we were able to mount the pump and it looks hot. Thanks for the advice though

C </div></BLOCKQUOTE>