Oil pan baffle design? 1

[Hooligan22]

I have been reading posts on this site for a good time now and I'm astounded by what I've been able to learn here. It's now my turn to ask a question and I'd really appreciate any help that anyone has to offer.

I am designing an oilpan to be used in a very small racecar to be powered by a Suzuki GSX-R 600cc motorcycle engine. Due to placement of the engine on the chassis and the desire to maintain the stock oiling system's volume, the external dimensions of the pan are set in stone. This means that the vast majority of this project is the design of any sort of baffling/oil control system. Dry sump is out of the question due to the relative complexity of the system, cost, and weight. Crank scrapers and windage trays are virtually impossible to implement due to the geometry of the engine casings.

Is there any good literature out there about oil pan design? From what I've been able to see, it seems to be somewhat of a "black science." The racecar is capable of 1.4G of lateral acceleration, and this has occasionally caused problems with previous designs (not mine, thankfully).

Thanks for the assistance.

 

[Azmio]

Hooligan

I have designed oil pan, scrappers, windage trays, oil pick up strainer, etc. for high performance cars.

One thing that you really need is a 3D CAD and the 3D models for crankcase, oil pick up and moving components 3D locus. Once you have the 3D models, you will be able to simulate oil movement at say 1.4 g. This oil volume shape must be defined by the shape of the crankcase and the rough oil pan that you are designing. You will need to subtract the oil using the 3D models of oil pick up and the moving component locus. You will have to do this for all four directions to simulate braking, acceleration, right cornering and left cornering.

You will notice that the oil volume is not the same for all 4 lateral acceleration. All you need to do is to iterate the position of the oil pick up and to also iterate the oil pan shape. At the end you will arrive to the oil pan shape that looks similar to the aftermarket oil pans.

One thing that I can share with you is that, to design an oil pan is very easy but to get it optimized to all the functional and performance requirements require at least few weeks assuming you have a 3D CAD.

Anyway, give it a go and post more questions once you run into difficulties.

AO

 

[Tmoose]

Like Azmio said, the oil will try to assume >45 degree angle in the sump.

The older Mopar Direct Connection (Chrysler factory performance division) books talk about modfying wet sump oil pans for oval track and drag racing use.

The Bill Jenkins "Chevrolet Racing engine" describes a lot of 70s technology

I think the older "Chevrolet Power" books had some lube system design info

http://www.accusump.com/acc_products/acc_units.html

 

[Azmio]

Tmoose,

During the development, we installed the engine to a tilting rig and tilt the engine at more than 42 degree in all direction. This will simulate, acceleration, braking, right and left cornering.

Regular baffle plate design that works well in stopping an instantaneous splash may not be able to work well at the tilt rig at continuos engine operation. We found out that the best way to prevent oil starvation is to carefully place the oil pick up point in the middle of the oil pan.

 

[crashyummy]

hey, i have seen some designs that completely eliminate the oil pan as a whole, they just modify inside the crankcase by using sheet metal to create an angle on the walls then they modify the pickup for the oil pump and just seal the bottom of the crankcase.

i dont know what angles to put it at or how but there are two ways to do it that work. they are basicaly to just put the sheet metal at differnt angles

EX: |= wall /= Sheet metal either A. |\ or B. |/
when you do B you would want a small (less than 1 cm) gap underneath the angle from the bottom of the pan (or whatever you use) so that the transmission can still get the propper amount of oil (but this also prevents too much oil from getting to it)

i hope that made sense, im not the best at explaining things, sorry

 

[rpmag]

accusump?

 

[Tmoose]

It's an accumulator that stores a volume of oil under pressure. Does a nice job of filling holes when the pump sucks air due to acrobatics on the track or rules that prevent serious lube system designs. Can really be quite simple, but the commercial ones are pretty nice. Can be scary to get "charged up" initially.

 

[evelrod]

"Can be scary to get charged up...".
Not if you if you take care in setting up a new engine and accumulator system to begin with.
With an "Accusump", open the Schraeder valve next to the guage port and push the piston all the way in and pour in a couple qts of oil before you install the Accusump. Prior to starting the engine pressurise the unit to 45 to 55 lbs. with air and turn on the valve (I assume you will be using the electrical assembly as it is WAY superior to the manual valve).
Once the engine is started and the oil pressure has stabalized, turn off the Accusump switch and stop the engine to check the oil level. Once I have everything up to proper levels (usually a qt. or so low in a properly built wetsump pan), I turn on the accumulator and let it discharge completely so that I may set the air pressure to the required setting---I use 35# but the mfgr. lists pressure as low as 7#. I also use a 50# pressure switch for the solonoid actuator as my normal pressure hot is in the neighborhood of 85# . Next, just start 'er up and the Accusump will fill at a rate that will not starve the engine for oil. After a proper warm up to check everything, stop and check oil level one final time. This all takes just a few minutes and well worth the extra effort. Accusumps have saved my bacon on more than one engine.

Rod

 

[rpmag]

Rod, you sound a fan of them and thanks for that clear explanation. Do you think such a device would be a solution for Hooligan22 in addition to a different sump design?

 

[Hooligan22]

I am familiar with the Accusump product line and it's advantages, however, it has a few disadvantages in my application. It is too large and too heavy for my use. Sump design is pretty much the only way I can make changes to the motor in my advantage.

 

[patprimmer]

When designing sumps and baffles, i have been known to sit in a swimming pool on a sunny day, with a sump and some bits of plastic and tape, and slosh things around to see where the water ends up, and how it splashes and surges.

Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[evelrod]

rpmag---Yup! I don't use the gargantuan brass piece that is supplied with the solonoid valve --- I drill and tap a AN -010 aluminum fitting to take a somewhat expensive Autometer, normally closed, 50# pressure switch on the Mini Cooper and a 35# switch on the Lotus Cortina. The multi purpose pressure switch that is supplied OEM does not meet my requirements.

H...22--- I use the 3 qt. "Accusump" on my cars but, I find it difficult to imagine a car so small that I could not find room for an accumulator. If I could not use my first choice of a dry sump system and, even if I had to make a one quart version up on my lathe (patent infringements?) out of two inch tubing, I'd even have one on a go kart!!!

Pat, Pat, Pat... I just knew that you would have found the "proper" engineering approach. (-:

Rod

 

[patprimmer]

Rod

But it works, and it's fun to boot.

No patent infringement if you do it only for your own use. It is only an infringement if you sell it, or sell something made with it.

I agree, make a tiny little accusump if you can't use a dry sump or a very deep sump.

Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[rpmag]

I believe they already make a 1qt one or is the pre-oiler a different thing?
evelrod I am interested in seeing what your modification looks like.
Hooligan22 I have seen one used on a 600cc hillclimb car locally, perhaps for the same reason (as well as the reduced engine wear at startup)? I hope to see it at the Aust Hillclimb Champs next weekend, if I do I will make sure I take some photo's if it of interest...can do the same for other bike engines if I see modded sumps.

 

[evelrod]

It's not much of a mod. Just a 45 degree AN - 010 to male 1/2" NPT elbow with a hole tapped to 1/4 NPT in the center "flat" or a 1/8" NPT tapped hole for the Autometer switch. One other version uses a -010 to 1/2" male 90 but, any AN fitting with sufficient area for a 1/4 " hole could be used, I suppose. Not rocket science. Just looks better..

Rod

 

[rpmag]

I am sorry to report that there were no modified sumps that I was able to see clearly. The two MC engined cars I did see and inspect closely were dry-sumped.

 

[djko]

I am designing a baffle for the sump in Yamaha YZF-600 (Thundercat): 599cc since we have oil surge problem. How can I calculate the G-force in the oil pan and simulate the oil surge?