mark kibort

Quite by accident, i found a way to determine what the oil leve does in the 928 pan. GB has discussed the packign of the oil in the heads, and this leads to oil starvation of the pick up. other theories include the oil being whipped up by the crank.

I wont even go into the success I have had with the bone stock system, with slightly raised and bowed up breather lines as the only slight mod.

So, why the success? Who knows. I peg near the rev limiter on every shift, I blip down shift on each downshift and the rpm doesnt go lower than 4500rpm for 30mins on most race sessions.

as many know, i have a dipstick tempurature sensor, and never noticed an interesting phenominom when taking right turns ONLY. the temp would immediately go to over 350 degrees during hard left hand turns, from its stable 260F temp range during all other points on the race track.
keep in mind, this dipstick temp sensor barely sits in the oil at rest. meaning, if its a quart low, it wont even touch the oil in the pan. so, under acceleration. no issues (straight). under braking. no issues. right turns, 1.4 g loading, no problem, BUT, take a moderate left hand turn, and the temp sensor gets uncovered and makeing the sensor temp skyrocket. since the dipstick is WELL above the oil return ladel, "bucket" or inlet, its safe to assume that the oil level is sound on the track. the since the pressure stays firm even on right turns, and only varies a little on lefts, (e.g. turn 2 at thunderhill, going from 5 bar to 4 bar) , it is pretty safe to say that there is enough oil feedng the system with sticky tires, high g loading and some pretty high engine RPM.
if there was a big issue why would the dip stick that ends up near the center of the crank area, still be submerged under high g loading letf turns?

something to consider, and think about.

I still think the amzoil viscosity characteristics and anti foaming might be the answer.

Ninespub

Let me be one of the first to welcome you back Mark but you sure do make an entrance already. There is probably some who would think that Mobile 1 has the same attributes....what do you think?

Gretch

Hi ya Mark..........

Good to see you back.......... really.

blown 87

Hey, glad your back Mark, we got all the gearing and oil stuff figured out while you were gone, sorry you missed it.

Set in stone now though.


Really, glad your back.

James Bailey

OK so hard left and temp jumps , moderate right and temp jumps, hard right no jump ? It would be unsual for a temp sensor to react very quickly to changes. It might be a good experiment to stick your room temp sensor into boiling water and time how long it takes to show 212 degrees or some 300 degree cooking oil (it is cheaper than Amsoil). Your theory that it is an uncovered sender which spikes the temp is interesting......

karl ruiter

Whoo, Hooo. Mark's back!

Mike Frye

Welcome back Mark. The place wasn't the same without you.

I think Jim's suggestion is a great one. I'd like to know how fast the reaction to changes is and what could potentially cause an identical set of circumstances.

Isn't it also a possibility that the thermometer is in the air above the hot oil under most circumstances but only during right turns you're exposing the sensor area (or a more sensitive part of it?) to hot oil?

You said that under normal circumstances it barely touches the oil and if you're a quart low it doesn't touch.

Also is the whole thing verified with an IR thermometer or something so you have a pretty good idea that it's accurate?

GregBBRD

Welcome back, Mark.

Just for clarity, what do you use for a maximum rpm? "Running it to "redline every shift" might mean something different to different people....I'm running my latest engine above 7500.

I also think that comparing your car with my test might not be quite the same, and drawing an "absolute" conclusion about the oil might not be sage advice for everyone....

If you recall, I didn't see any issues, either, until the engine was run at 5,500rpms for about a minute. I doubt that you are doing anything like this, with a stick shift car, on relatively short continuously changing race tracks, like you run.

I'd suggest that you might see different things happen on tracks that have long sweeping turns, if you ran those at high rpms and held it. Willow Springs, Cal Speedway, Road America come to mind.

Don Ashe

Boy, that's an understatement!
These guys are pretty dull without you around to keep 'em riled up!
I bet we missed you more than you missed us!

As to your theory, do you think if you were driving on the other side of the equator, it would be the left side that gets exposed?
Or are you using only left-handed amsoil?
-don

76FJ55

I am aa little curiorious about all this as well. you say, "temp would immediately go to over 350 degrees". how fast will the temp return back to the 260 reading after corner exit? It seems od to me that you would get such a rapid fluctuation by the temp sensor when it where removed form the oil. this would only leave the hot oil mist and crank case gasses to transfer heat to the sensor where as when it is submerged you would have the liquid oil to conduct the heat. seems to me that you should get the rapid temp indication change when the sensor became submerged and a slower change when the probe was uncovered, not the other way around (the way your initial description reads).

could you extend your sensor deeper into the pan to ensure it stays covered by liquid oil, and see how it react in comparison?

Randy V

As soon as you get back you start right back up.

Man, some guys just don't get it.

F451

So just wondering if are you yanking our chains in a light hearted way, or are you really posting like the thread topic says?

"Oiling situation proof on the race track"

And not trying to be antagonistic, but like many here, I'm really interested in the oiling issues with the 928, so to see a post that mentions something like your thread title, naturally I'm going to read it.

As far as I can see, you mention your favorite brand of oil as "the answer", but I'm not really understanding what you're saying.

If you're just jumping back into the forum in a light hearted way, cool, no worries, I get it, no further explanation needed.

If not, that is cool too, just trying to figure out what the message is. -Ed

mark kibort

Thanks!
I know we may never find out what is really happening w the oiling of our engines , but it seems with each discussion we learn something new
The only difference I saw w mobile 1 was a substantial difference in oil pressur at temps of 240 to 260f. 0 bar at some points on the track w the pressure light illuminating. Vs always 5 bar w amzoil. Same car same temps

RFJ

Randy, i think you don,t get it. He is talking ,so what? You know what they say talk is cheap but it sparks debate, what america is about,Ray

IcemanG17

This is interesting data.....MK and I discussed it during his "break".... I don't notice temp spikes in the Estate, since I tapped the plugs where the oil cooler attaches for my pressure and temp gauges....I do see drops in oil pressure in the corners....typically when I am in the lower RPM ranges....but never below 50psi...at say 3000rpm....even hot it tends to stay 75psi+ with slight dips at turn in.....then it recovers and climbs with RPM as it should