CBR600RR Oiling

[Composites Guy]

Teams that have run this engine with the stock sump (which is very deep in comparrison to other engines)... do you have engine oiling problems?

I'm thinking of adding the accu-sump that is mentioned in a recent thread... and Pat Clark's FSGermany article. I would like to know if the stock sump is "good enough" given how deep it is.

[Composites Guy]

Teams that have run this engine with the stock sump (which is very deep in comparrison to other engines)... do you have engine oiling problems?

I'm thinking of adding the accu-sump that is mentioned in a recent thread... and Pat Clark's FSGermany article. I would like to know if the stock sump is "good enough" given how deep it is.

[Ian M]

By my analysis (which you may want to take with a grain of salt) you should be fine with the super deep stock pan, but your engine is going to be REALLY high in the frame!!!

We use a modified pan, and have made a windage tray / baffle to try to prevent oil starvation. If you cut the pan than the accu-sump may be a good idea, but in my opinion it would be a waste with the stock pan.

[Composites Guy]

That's kinda what I figured... since my personal car is for fun, and will be slightly larger than the average FSAE car and unrestricted, I figured that I would bite the bullet and use the higher engine CG to avoid the complexity of modifying the oil system.

So "your analysis"... is that just considering the oil at a 60 degree angle in the bottom of the pan and seeing if the sump gets uncovered?

[Ian M]

Yes, I believe the angle that I calculated for the oil at 1.5 g's was 48 degrees from horizontal. I then figured up how much oil VOLUME I would be carrying with the modified pan. Then through the Solidworks engine model (using the shortened oil pan in the drawing) I cut away the rest of the engine at this 48 degree angle until the amount of engine model left not cut away equaled the VOLUME of oil that I would be carrying.
This analysis then took into account the oil sloshing into the side casings.
The model showed that by doing this with the pan cut approx. 2 inches the oil line is right on the verge of pulling away from the pickup. So I made a windage tray that keeps the oil in the pan from sloshing into the side casings as much.
Then, just to make sure we weren't starving the engine, I installed a pressure sending unit in place of the stock pressure switch (dumby light) and logged the data to the Aux. Voltage on the Motec. This showed that even in a long sharp corner the engine was never losing oil pressure, although approaching 1.2 g's a slight 10 psi pressure drop could be seen, but rarely.

Hope this helps. Sounds like a big / fun project to build one by yourself.

[Horace]

Hi Ian,

We're using the 600RR for our engine also and have this same problem of putting the engine in the air. We did this for our first year car and if you look at the threads for the photos there is a photo of our car on two wheels, and not by a little bit but clearly!

There are two ways we can fix this. One is to lower the CG, which is what we want to do. The other is make the track wider, which means 200% more issues when it comes to storing the car since we're based in downtown Brooklyn and space is priceless.

So we're pretty much forced to do something with our oil pan if we want to fix this 2 wheeling issue. I have a few questions for you since you did this before.

1) How much safety factor do you have? It sounds like it's right on the edge from your analysis.

2) Did you take energy into consideration? Tilting the engine slowly to the # of degrees equivalent to 1.5g is different to tilting it quickly as far as where the oil line is.

3) You modified the stock pan instead of making a new oil pan that would be wider, like the F4i oil pan. What's the reason behind that?

4) What does the windage tray look like?

Happy 4th of July

[Wesley]

When it comes to oiling issues, I see way too many people focus on lateral-g's versus oil pressure, when in reality, it isn't steady state g's that cause low pressure. I didn't have a lateral-g vs psi plot at competition because, really, it's irrelevant. You've either uncovered the pickup or not.

Transient oil slosh is the largest cause of low oil pressures. Exiting a high-g corner, sudden braking or acceleration, basically any large changes in acceleration, or "jerk" is what we have found to be the largest cause for low pressure.

In our case, with the F4i, we started with a really crude method. We hooked up a dummy light to the stock switch. This gave us an indicator as to which parts of the course would be most problematic. In our case, braking and entering tight hairpins generated the most lights.

With that in mind we looked at our pan (the shape of which was just an extension of the crankcase) and tried to determine why and where the oil was sloshing. Using this, we designed our first iteration of the windage tray.

It was enough to keep the stock light from coming on, so we decided to switch to an oil pressure transducer. While the light didn't flicker, looking at the generated pressure plots over the course of an autocross course, it was clear that the pressure dipped below the stock curve considerably. Running a few quick numbers, it was trivial to determine the proper oil pressure and volume to generate a sufficient hydrodynamic bearing film thickness and maintain proper film pressure.

From there, we broke our analysis down into two categories - low pressure events, in which oil pressure fell to 85% of nominal output, but which still met the lubrication needs of the engine, and starvation events, when oil fell below 75% pressure, failing to meet pressure requirements at higher RPM.

The number of events that we saw was used to gauge the effectiveness of our oil baffle. (windage tray is a bit of a misnomer, as it is there not to prevent crank windage, but to keep the oil from sloshing away from the pickup.)

After iteration our final design resulted in no starvation pressure events (and a handful of low-pressure events) averaged over several varying test autocross laps, whereas with no baffle we had over 8 low pressure and 5 starvation events.