Oiling situation (gauge spoof) on the race track (nothing to see here)
07-18-2011, 03:18 PM
#16
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Yes, all great points. But to re explain, ONLY on the hard lefts, does the temp jump. rights turns no change at all , no matter the g forces. so, after reading all that was said here, i had to go out, run the car to temp and then try and simulate the phenom. even pulling the temp dipstick out, takes a while for the temp sensor system to get to the actual lower temps. so, this phenom might be due to some thing else, because in the left turns, it snaps to 350degree max and stays there until the car is straightened out. right turns, no issues, the temps stay right at 260F during a race. what if the dipstick gets uncovered and the ambient in pan air is searing hot, and it gives the resistance of full short or open circuit (I dont remember which it works by) could there be some wire that is grounding out during those turns? if so, why cant it be simulated on the street.
I got excited about seeing this because it would be the first time we could possibly see how much oil is left in the pan and has it migrated away from the pick up, causing starvation and being a probable cause for bearing failures. With all the Greg Brown talk of the oil being pumed up to the heads and not returning, as a major cause of the oiling issues, this could have been proof that its happening, but the engine is still ok because the levels are still high enough to feed the pump. But, I think it might be some other issue that is causing the meter to go nuts on left turns at race speeds and temps.
even if the temp was high enough to peg the temp sensor,then why does it fall back so quickly to normal temps the instant the car is not turning left.
Ill do some more experienmenting this weeken at the race track
Mark
I got excited about seeing this because it would be the first time we could possibly see how much oil is left in the pan and has it migrated away from the pick up, causing starvation and being a probable cause for bearing failures. With all the Greg Brown talk of the oil being pumed up to the heads and not returning, as a major cause of the oiling issues, this could have been proof that its happening, but the engine is still ok because the levels are still high enough to feed the pump. But, I think it might be some other issue that is causing the meter to go nuts on left turns at race speeds and temps.
even if the temp was high enough to peg the temp sensor,then why does it fall back so quickly to normal temps the instant the car is not turning left.
Ill do some more experienmenting this weeken at the race track
Mark
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......
07-18-2011, 03:29 PM
#17
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Yes, that is a good point. my "Max" RPM is factory redline, so very close to 6500rpm on each shift.
Ill have to check the telemetry,
, but my RPM range is 4500 to 6500rpm for an entire 30mins, not just 1 min. shifting constantly, does give the engine a 4500rpm breather , but there are sections where im in one gear and it averages 5500rpm for longer than a min. im thinking turn 3 all the way turn 11, I can be in one gear, with maybe a 6000rpm blip for 2nd at the corkscrew and a 3rd shift on the exit, where the rpm might be above 5000rpm for over a min.
certainly i trust your findings, and probably would not want to run our cars at 6500 on an open road race for 20mins
maybe the way i use the car is exactly at the limit of its design sure seems that way, rulling out luck and rabbit's feet.
Mark
Ill have to check the telemetry,
, but my RPM range is 4500 to 6500rpm for an entire 30mins, not just 1 min. shifting constantly, does give the engine a 4500rpm breather , but there are sections where im in one gear and it averages 5500rpm for longer than a min. im thinking turn 3 all the way turn 11, I can be in one gear, with maybe a 6000rpm blip for 2nd at the corkscrew and a 3rd shift on the exit, where the rpm might be above 5000rpm for over a min.certainly i trust your findings, and probably would not want to run our cars at 6500 on an open road race for 20mins
maybe the way i use the car is exactly at the limit of its design sure seems that way, rulling out luck and rabbit's feet.
Mark
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.
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.
07-18-2011, 04:54 PM
#18
Former Sponsor
Yes, that is a good point. my "Max" RPM is factory redline, so very close to 6500rpm on each shift.
Ill have to check the telemetry,, but my RPM range is 4500 to 6500rpm for an entire 30mins, not just 1 min. shifting constantly, does give the engine a 4500rpm breather , but there are sections where im in one gear and it averages 5500rpm for longer than a min. im thinking turn 3 all the way turn 11, I can be in one gear, with maybe a 6000rpm blip for 2nd at the corkscrew and a 3rd shift on the exit, where the rpm might be above 5000rpm for over a min.
certainly i trust your findings, and probably would not want to run our cars at 6500 on an open road race for 20mins
maybe the way i use the car is exactly at the limit of its design sure seems that way, rulling out luck and rabbit's feet.
Mark
Ill have to check the telemetry,
, but my RPM range is 4500 to 6500rpm for an entire 30mins, not just 1 min. shifting constantly, does give the engine a 4500rpm breather , but there are sections where im in one gear and it averages 5500rpm for longer than a min. im thinking turn 3 all the way turn 11, I can be in one gear, with maybe a 6000rpm blip for 2nd at the corkscrew and a 3rd shift on the exit, where the rpm might be above 5000rpm for over a min.certainly i trust your findings, and probably would not want to run our cars at 6500 on an open road race for 20mins
maybe the way i use the car is exactly at the limit of its design sure seems that way, rulling out luck and rabbit's feet.
Mark
It would have been really interesting to have put in some Amsoil in this engine, right after we saw the first traces of oil ejection.
Without testing, one never knows.....
07-18-2011, 07:31 PM
#20
Race Director
However the scavenging system you created should fix the problem.....basically 1/2 a drysump!!!
07-18-2011, 10:59 PM
#21
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Thread Starter
nah, the sensor is well out of the tube as it barely touches the level area of the oil. because there is such a rapid swing of full scale on the left turns, it must be a shorting wire or something that is giving the full scale reading on left turns
07-19-2011, 12:19 AM
#22
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That is what I was thinking as well.....
07-19-2011, 09:16 AM
#23
Craic Head
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Originally Posted by MK
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
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
I think this is consistent with the oil starvation that has been described before. The dipstick is at the front right side of the engine, right? So when you turn left and slow just slightly, the oil goes to the right side of the engine, more level or to the front than it would be during acceleration, so the temp sensor (which you said barely touches the oil when on level ground and topped off) is submerged more fully with hot oil and the oil is now not on the left bottom side where the oil pickup tube is located.
To me it makes perfect sense.
260=barely submerged (or possibly the 'sweet spot' of the sensor is just in the air above the oil)
350=when the oil washes up there during long left turns. (although 350 seems a bit on the warm side, I'm sure it's spiking and the calibration of the sensor and display unit might need to be checked and verified).
Your theory that the air above the oil is hotter than the oil and that that is reading on a temp sensor more quickly in air than in hot oil doesn't make intuitive sense to me.
07-19-2011, 12:05 PM
#24
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Given that it ..." because in the left turns, it snaps to 350degree max " and "must be a shorting wire or something that is giving the full scale reading " The gauge is reading MAXIMUM it is PEGGED it is NOT reading 350 degrees but is exceeding the range of the gauge...... Move along nothing of any interest here....
07-19-2011, 03:08 PM
#25
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Thread Starter
"There is nothing to see here, these arent the droids we are looking for"
Ill do some more experimenting this weekend at thunderhill. it would be interesting to use the float system or make another float system that could accurately detect changing oil levels in the pan, while racing on the track.
one thing of interest, is that i have a fully functioning oil level gauge. it has never gone on. proving the levels at least stay above the warning level, and this is a binary switch, so if you ever even splashed down on the oil level, it would trigger and give you a warning light. this has never happened. Ill have to recheck how low that level is, with the sensor, since i have an engine appart right now with Petty's motor.
Ill do some more experimenting this weekend at thunderhill. it would be interesting to use the float system or make another float system that could accurately detect changing oil levels in the pan, while racing on the track.
one thing of interest, is that i have a fully functioning oil level gauge. it has never gone on. proving the levels at least stay above the warning level, and this is a binary switch, so if you ever even splashed down on the oil level, it would trigger and give you a warning light. this has never happened. Ill have to recheck how low that level is, with the sensor, since i have an engine appart right now with Petty's motor.
Given that it ..." because in the left turns, it snaps to 350degree max " and "must be a shorting wire or something that is giving the full scale reading " The gauge is reading MAXIMUM it is PEGGED it is NOT reading 350 degrees but is exceeding the range of the gauge...... Move along nothing of any interest here....
07-23-2011, 03:27 AM
#26
Rennlist Member
Mark,
Is your sensor wire moving over and resting on something hot? This could heat up the wire and raising your wire resistance and this causes the sudden up and down in temp reading. Wire has a low mass so it would quickly cool again and go back into spec.
Is your sensor wire moving over and resting on something hot? This could heat up the wire and raising your wire resistance and this causes the sudden up and down in temp reading. Wire has a low mass so it would quickly cool again and go back into spec.
07-23-2011, 04:41 AM
#27
Drifting
would the atmosphere in crankcase be hotter than the oil....if so it would surely take longer than a second or two to raise the temp while uncovered as the heat transfer ability is a lot more with oil than air.
what do you think:?
what do you think:?
07-23-2011, 11:30 AM
#28
928 Collector
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Mark, clearly it's your gearing that does the trick
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.
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.
07-23-2011, 11:41 AM
#29
928 Collector
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My on-track experience with hard lefts suggests that oil gets forced to the right and held there, starving the pickup. Yes I know, we all agree. Additionally, I believe that the crank whips oil up into the passenger (right) head at the same time, causing that head to "drown" in oil, while the driver's head starves.
Because there are NO BREATHERS on the left head (on an S4), the extra oil in the right head gets ingested via the breather there. In cars with an equalising breather, that oil can flow to the left head, possibly cooling that head, lubricating it, and draining down to the pan and pickup. IMHO, there should not be an exit breather hose on the right head, just on the left.
Why is your dipstick sensor reading max during hard lefts?
Anybody's guess. Why not put a small camera there instead of a temp sensor? At a guess, I'd say you may be getting superheated oil right at that spot, possibly because there is no cooling (from oil and perhaps even from water) at the left head. Not a lot of research or thought has gone into the question whether coolant gets forced in one direction or another under cornering. Something to look at perhaps.
Because there are NO BREATHERS on the left head (on an S4), the extra oil in the right head gets ingested via the breather there. In cars with an equalising breather, that oil can flow to the left head, possibly cooling that head, lubricating it, and draining down to the pan and pickup. IMHO, there should not be an exit breather hose on the right head, just on the left.
Why is your dipstick sensor reading max during hard lefts?
Anybody's guess. Why not put a small camera there instead of a temp sensor? At a guess, I'd say you may be getting superheated oil right at that spot, possibly because there is no cooling (from oil and perhaps even from water) at the left head. Not a lot of research or thought has gone into the question whether coolant gets forced in one direction or another under cornering. Something to look at perhaps.
07-23-2011, 11:54 AM
#30
Captain Obvious
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Originally Posted by mark kibort;8724791o[B
ne thing of interest, is that i have a fully functioning oil level gauge[/B]. it has never gone on. proving the levels at least stay above the warning level, and this is a binary switch, so if you ever even splashed down on the oil level, it would trigger and give you a warning light. this has never happened. Ill have to recheck how low that level is, with the sensor, since i have an engine appart right now with Petty's motor.