The attachment shows 6 quarts of water in the pan with the pan tilted to the side by ~35 degrees. You can gain an appreciation of how much oil is sitting near the rotating assembly. The water line in the forward sump area was ~92mm above the oil pan rail. The lower surface of the water is just at the border to the pickup depression in the casting floor.

This file -- warning large file -- shows how the oil moves in a longitudinal pan while under constant lateral acceleration: http://tiny.cc/znf6x

The picture shown in the attachment with water in the pan would be an example of a neutral attitude. This is perhaps a strong reason why the techniques of any particular driver, in combination with how the car is set up, would affect the amount of oil struck and churned by the rotating assembly and the locale of that churning.

I hope you all find this information helpful.

 

Hi Kevin,

I appreciate this analysis as it is one I started thinking about a few years back. I wrote an bench racing spreadsheet where you put in the torque curve, gears, weight, etc, and it calculated acceleration and velocity. To that I added an analysis of how much oil stays in the pan. The results were surprisingly bad and vary between cars but the volume for mine goes below 4 quarts in 2nd gear. Where's it going? Into the rotating assembly. Another issue is the slightly-sloped pan. Forward acceleration is greater then the acceleration up the pan until I'm in 5th gear.

If only there was a sump cover with trap doors and some better-sloped drain channels.

Wait! That's what I put in from that Ishihara-Johnson operation.

 

Hi Glen,

Yes, of course I remember your analysis. I have another file here that is described by my computer as of unknown type: cover1.75and7qts

Do you need this?

 

I found that the Rennlist will only upload certain types of files. If you want to email the file to me I would be happy to host it and provide a link.

 

lol!

I was just playing with it (got out of bed) and tried but couldn't post the xls. Worried about viruses, I suppose.

With my latest dyno chart punched in 2nd just goes below 4 and in 1st it's worse. Any drag 928 has to be dry sumped.

 

In the mail to "sales."

Thanks, Kevin.

(And would ya stop anticipating my issues and questions? )

The upper graph is interesting in that the pan is sloped at just a few degrees. I measured it at about 5 but that's hard and varies with ride height settings, motor mount compression and just my ability to do it. So the oil rolls form the pan and is pinned against the back of the pan. I was going to add an analysis for how high the oil piled up at the back of the pan but figured it 3 quarts where back there it was feeding liquid directly into the crank and rods.

 

Here is the link to your spreadsheet:

http://tiny.cc/jag2j

 

Thanks, Kevin.

You'll notice the title "with no cover" on the second graph. At one point I was going to make a sump cover. Got the aluminum sheet but got diverted. Before I got a "GTS baffle" I hoped it sealed along the back of the sump. It doesn't. Each inch a baffle sticks out moves the oil pile an inch forwards. It also adds an inch to how far the oil flows before it drops into the sump.

Shelved that project after seizing a rod bearing and put in a full scraper set.

 

I cant really see it in the picture, but I was curious to the level aroud the pick up area. what is being completely disregarded, is what the oil would be doing at the sides of the engine, being that the upper portion of the block would keep the oil from running up the sides. we know Im running near 1.5gs on many turns, some sustained for over 4 seconds, yet I have no oil pressure issues. why is that. its not a style issue, you either pull those gs or you dont. the only "style " factors will be entrance, and exit techniques, which are short lived, AND the choice of rpm into and though and out of those turns.

6 quartrs? how do we know that that is only what is left in the pan? i have a hard time believing that there is near 4 quarts flying around the engine, but thats just a feeling. Probably is the most likely error is showing that the inlet is being uncovered under 1.5gs.

 

Mark,

It's your assertion that you can pull 1.5g that's suspect. What data do you base that on? The best sports cars can muster 1.

And all those things you list is exactly the driving style factors that will affect engine longevity. When going on the track, I carefully select my number font and color, tunes for the stereo, shirt and sunglasses. Those aspects of my driving style do not.

 

This comes from data aquisition of a car i was tailing for multiple laps over a few seasons (and some known levels of g loading from simular performance cars)
PLUS, simple math on the speed and dimensions of the turn. Best sports car performance 1 g?? now are you are talking plain SILLY! Yes, the best sports car from the showroom maybe, but not cars that are modified, and on DOT race rubber, and you know that.

go to trackvision.net ( http://trackvision.net/gallery.php ) and find the video of me racing rylan when he finally put the blower on the S2000. he was tailing me for many laps and had data aqu. that showed 1.5 gs in some turns. 1.3-5 through tun 2 at thunderhill that is between 75 and 80mph for a 6 second duration. for a complete "U" turn. plug in the numbers and its hard, by any stretch, to figure anything less than 1.3gs.

there i even a simple video of the Mazda MX5 cup races where I run around these cars like they are standing still 5mph faster through turn 6 and 9 (more constant Gs) and they are pulling 1.5gs. so, THATs where the info is coming from. you cant run around laguna, sears, and thunderhill at 1:37, 1:46 and 1:59 and not pull 1.5 gs in the hardest, highest duration turns.

 

And here is running with GT3 cup cars from the Pirelli cup series, as well has having a patron cup driver behind me in a GT3RS converted street car, to a almost cup car, but more power, on slicks behind me.

Does it seem like Im taking it easy???


http://www.youtube.com/user/zanick#p/u/13/rKiAu68p8J4

 

This is carlos in a wannabe cup car conversion of a 996. he runs pretty fast and runs DOT race rubber.

Gs look to be in the 1.3-4 range. I also have video of this car in my rear view cam from Thunderhill when we were running 2:00 range.

anyway, his lap time is 1:51. (we run 1:47s at Sears) and watch the G meter. go to about 40 seconds on the time counter.

http://www.youtube.com/watch?v=3HJQe...eature=related

some rear view from thunderhilll of this car a few months earlier
http://www.youtube.com/user/zanick#p/u/27/720woMfitco

 

I thought you might have telemetry of your own car. I watched that video and it flickers to 1.3 or 1.4 a few times. He's not sustaining 1.5 for 4 seconds.

 

Yes, I agree with you that the situation with the bedplate installed would be different. In that situation the bulk of the castings would displace fluid and make the fluid surface come even closer to the rotating assembly as well as flood the rear to a greater extent. This means the oil would be churned full of air. The pickup would be less likely to be uncovered.

Assuming all that you have just said, "why is that" may precisely depend on what you do when driving. This is why the simple fluid device might be useful in determining that.

It is just an educated guess as to the running volume of oil in the sump. (7.9 quarts total less 1.9 quarts in circulation) You must also remember that when oil is churned and aerated (with free air bubbles) that its volume will increase.

Also it has just been determined that the sump casting floor depth has changed. I need to look at some more pics of your engine parts to see if I can determine what sump you have.

Edit: looks like you have the shallow sump