track 928 oil pressure drop?????UPDATE FILTER OPEN :>(
04-06-2009, 01:17 PM
#31
Nordschleife Master
Glen,
The I-J crank scraper system is still availible,,,,
But when you order it STAY on top of it, always pester him with emails.
I didnt and I waited 6 MONTHS when I was quoted 4-6 weeks!!!!!
As well he didnt respond to emails until I posted about it on here.
I am not the only one to have had this issue either.
I know of many people in the 944 and 924 group that had this same experiance.
The I-J crank scraper system is still availible,,,,
But when you order it STAY on top of it, always pester him with emails.
I didnt and I waited 6 MONTHS when I was quoted 4-6 weeks!!!!!
As well he didnt respond to emails until I posted about it on here.
I am not the only one to have had this issue either.
I know of many people in the 944 and 924 group that had this same experiance.
04-06-2009, 01:25 PM
#32
Rennlist Member
I have plenty of pressure in all racing situations. 4.5 to 4.7 min. I had this with my 4.7 liter, 5 liter euro, 5 liter holbert and now 6.4 liter . I used to run slightly over the fill line on the dipstick, but now, slightly below. .5quart diff. It now cuts down on the intake blow by.
I dont think the accusump is the answer, unless you are getting real starvation, which would be some pretty irratic oil pressure values. I do think the amzoil can reduce the foaming element, and driving style or gearing can help as well. For my tracks, there are very few sustained high g turns that require more than 5krpm.(usually, turn 2 at T-hill is 4700rpm arount it and up to 5700 up to the next turn after a quick straight. certainly each track will have its own demands on optimizing power and RPM requirements. At sears, the other very fast long carrocel turn, we run 70mph in 3rd gear for a "U" turn, which take about 5 seconds at 4500rpm. Looking at his video at t-hill, he is not doing anything really that different around the turns that would cause any substantial differences in engine oil sloshing. The main difference is that he is going a bit slower than we are (scot and me) and has the different gears. However, scot has the 2.75 gear box and has not seen any issues either. we are talking all out racing where you are pushing the limits of the car for 30min, with no let up.
So, if scot can do this , I dont think the gear ratio issue is a problem. (just thought of that
)
I have a feeling brian might have inherited a problem that he might see if he looks at the bearings, or checks the filter, or sends the oil in. Or, he could just be paranoid. Eitherway, its worth checking out.
mk
I dont think the accusump is the answer, unless you are getting real starvation, which would be some pretty irratic oil pressure values. I do think the amzoil can reduce the foaming element, and driving style or gearing can help as well. For my tracks, there are very few sustained high g turns that require more than 5krpm.(usually, turn 2 at T-hill is 4700rpm arount it and up to 5700 up to the next turn after a quick straight. certainly each track will have its own demands on optimizing power and RPM requirements. At sears, the other very fast long carrocel turn, we run 70mph in 3rd gear for a "U" turn, which take about 5 seconds at 4500rpm. Looking at his video at t-hill, he is not doing anything really that different around the turns that would cause any substantial differences in engine oil sloshing. The main difference is that he is going a bit slower than we are (scot and me) and has the different gears. However, scot has the 2.75 gear box and has not seen any issues either. we are talking all out racing where you are pushing the limits of the car for 30min, with no let up.
So, if scot can do this , I dont think the gear ratio issue is a problem. (just thought of that
) I have a feeling brian might have inherited a problem that he might see if he looks at the bearings, or checks the filter, or sends the oil in. Or, he could just be paranoid. Eitherway, its worth checking out.
mk
Oil level will do you in - a common trick for a stock GT-R (car I have experience with) is to put an extra litre of oil in it before tracking it.
Might not be a good idea with a 928 as I'm not familiar with the engines yet.
Going out on the track half a litre low also not a good idea......
Might not be a good idea with a 928 as I'm not familiar with the engines yet.
Going out on the track half a litre low also not a good idea......
04-06-2009, 01:43 PM
#33
Three Wheelin'
could a smaller pulley ( spinning the oil pump faster ) help anything ?
just a idea, i have no clue myself. And ofcourse the belt would need to be shorter also .... ???
just a idea, i have no clue myself. And ofcourse the belt would need to be shorter also .... ???
04-06-2009, 02:19 PM
#35
Shameful Thread Killer
Rennlist Member
Rennlist Member
This is my favorite 928 topic.
You're blasting down the straight. A healthy 2-3-4 gear run. And 5 at BIR and RA. Oil rolls from the sump (#3) and up the pan (#4) and draining-back oil does not flow into the sump (#4. This builds at the back of the pan (#5) and goes right into the whirling crank and rods (#6). It creates a huge cloud of oil and hangs there (#6). Now it's time to turn. You brake and that foamy crap whooshes into the sump. You turn and the oil sloshes hard and, again, the liquid rolls out of the pan (#5). The pickup now get a huge gulp of foam and shoots it into the block. The pump doesn't work well with foam and you see low oil pressure. The first gulp of foam flies towards the 2/6 rods (#2) and fills the crank passages. You come out of the corner, and the pickup finally get good oil. That is shot into the block but doesn't displace the foam from 2/6 (#1). The foam continues to feed to 2/6 bearings and is not run out fast enough. The bearings are not lubricated enough and wear metal-to-metal.
You're blasting down the straight. A healthy 2-3-4 gear run. And 5 at BIR and RA. Oil rolls from the sump (#3) and up the pan (#4) and draining-back oil does not flow into the sump (#4. This builds at the back of the pan (#5) and goes right into the whirling crank and rods (#6). It creates a huge cloud of oil and hangs there (#6). Now it's time to turn. You brake and that foamy crap whooshes into the sump. You turn and the oil sloshes hard and, again, the liquid rolls out of the pan (#5). The pickup now get a huge gulp of foam and shoots it into the block. The pump doesn't work well with foam and you see low oil pressure. The first gulp of foam flies towards the 2/6 rods (#2) and fills the crank passages. You come out of the corner, and the pickup finally get good oil. That is shot into the block but doesn't displace the foam from 2/6 (#1). The foam continues to feed to 2/6 bearings and is not run out fast enough. The bearings are not lubricated enough and wear metal-to-metal.
04-06-2009, 04:36 PM
#36
Race Director
Thread Starter
I really hope I'm just paranoid.....I would be VERY happy if I'm just overly cautious..... All I know is the motor makes good power and had 93300 miles when I got it.....
I should have a good idea of the condition of the motor in a few days..... fingers crossed as it is far more fun driving the widow than working on her...
One encouraging fact is I ran within 1 second of my best lap time ever with a passenger during the last session of the day.... I would think if the rod bearings were dying the power would drop off......
04-06-2009, 05:11 PM
#37
Rennlist Member
I dont have experience there, but I dont know of the failure mode regarding power. (knock knock for you and me) . I think they just go and it happens quickly. if they dont blow, they just lock the crank when the rpms get low on a down shift if you dont blip. 
. Ask scot how he knows this.
anyway, let us know as soon as you can! fingers crossed!
mk
. Ask scot how he knows this. anyway, let us know as soon as you can! fingers crossed!
mk
MK
I really hope I'm just paranoid.....I would be VERY happy if I'm just overly cautious..... All I know is the motor makes good power and had 93300 miles when I got it.....
I should have a good idea of the condition of the motor in a few days..... fingers crossed as it is far more fun driving the widow than working on her...
One encouraging fact is I ran within 1 second of my best lap time ever with a passenger during the last session of the day.... I would think if the rod bearings were dying the power would drop off......
I really hope I'm just paranoid.....I would be VERY happy if I'm just overly cautious..... All I know is the motor makes good power and had 93300 miles when I got it.....
I should have a good idea of the condition of the motor in a few days..... fingers crossed as it is far more fun driving the widow than working on her...
One encouraging fact is I ran within 1 second of my best lap time ever with a passenger during the last session of the day.... I would think if the rod bearings were dying the power would drop off......
04-06-2009, 05:23 PM
#39
The widow is a race car. You should really just put in a dry sump.
04-06-2009, 05:24 PM
#40
04-06-2009, 08:13 PM
#41
Race Director
Thread Starter
UPDATE
I just got back from the race shop and saw the cut open oil filter and oil.......there IS small bits of gold colored metal in it....but really not much....the oil is fairly dark indicating it got pretty hot, but does not smell burnt.....
So what do I do now...... my only options are to pull the motor and inspect-replace the rod bearings and install the oil cooler + accusump & scraper-windage......of just install the cooler-accusump and run this engine until it fails.....but I don't like the idea of getting lots of little metal bits in my new accusump and setrab oil cooler....
I just got back from the race shop and saw the cut open oil filter and oil.......there IS small bits of gold colored metal in it....but really not much....the oil is fairly dark indicating it got pretty hot, but does not smell burnt.....
So what do I do now...... my only options are to pull the motor and inspect-replace the rod bearings and install the oil cooler + accusump & scraper-windage......of just install the cooler-accusump and run this engine until it fails.....but I don't like the idea of getting lots of little metal bits in my new accusump and setrab oil cooler....
04-06-2009, 08:25 PM
#42
Intermediate
Join Date: Apr 2009
Location: Maple Ridge, BC, Canada
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It's a lot cheaper to do just bearings than a crank and bearings or fix it once your rod is sticking out the side..........
DO NOT DRIVE IT!!! Things can go wrong in a hurry.........
DO NOT DRIVE IT!!! Things can go wrong in a hurry.........
04-06-2009, 08:28 PM
#43
Shameful Thread Killer
Rennlist Member
Rennlist Member
You've got two things to do here. Remedial, is to inspect and replace as necc the rod bearings. Then you have the proactive job of insuring you get good quality liquid oil to the galleries. It could be several of the things posted before, or a dry sump system, or all of the above.
04-06-2009, 08:33 PM
#44
Rennlist Member
I agree with rc & doc -- you're much better off fixing it now than running it to destruction. YOu'll have to be sure to get all of the metal fragments out. If you wait and try to Kibort it you may end up ventilating the block and picking the rods up off of the track. Also think about what having oil spraying under the car and onto the back tires will do for you in a high-speed turn.
04-06-2009, 08:36 PM
#45
Rennlist Member
like panning for gold type bits or just a shimmer in the oil? (like metal flake paint). pieces you could feel with your finger?
If so, bearings. you could had it damaged by the PO, so who knows. I dont think the accusump or scraper will help much. I think you put it together with new bearings and see how it runs. You might have fixed the oil pressure issue, and then migth be ok. then, if temps are gettting too high, you can put on an oil cooler. crank scraper also trying to solve a problem that may or may not exist. the main problem is the way our cranks are drilled. we know the oil you are using is good, but we dont know the shape of the engine when you got it. PO could have been using a lesser oil or who knows.
Having 6 928 engines with good oil pressure and no temps over 250F on the oil in race conditions seems to show that engine can run well without the cooler. Heck, scot doesnt even have the radiator oil cooler! (and he is running 2:04s at Thunderhill and 250F oil temps on a hot day during a race)
Remember, scots "unknown" engine did grenade, probably PO's fault as there was a lot of sludge in the oil pan. it lasted 2 race days and then grenaded in lap 10 of our race at laguna. we thought we could just drop it in the car, but we should have taken it apart. you never know what you got from a PO. It could have been damaged and took this long to make the problem worse. Did you ever see how clean the Holbert oil pan was after 7 years of racing? spotless. Looked brand new. thats what scots looked like too, after the engine WE built was pulled for the 5 liter.
I dont know how hard pulling the pan is, but that might be a good idea so that you can change out the rod bearings and see what is up. do you really have to, or want to pull the engine? I guess if you want to do the scraper, spacer and rod bearings, it might be an easier way. I cant even imagine pulling the pan with the engine in the car. How hard is that?? Anyone??
mk
If so, bearings. you could had it damaged by the PO, so who knows. I dont think the accusump or scraper will help much. I think you put it together with new bearings and see how it runs. You might have fixed the oil pressure issue, and then migth be ok. then, if temps are gettting too high, you can put on an oil cooler. crank scraper also trying to solve a problem that may or may not exist. the main problem is the way our cranks are drilled. we know the oil you are using is good, but we dont know the shape of the engine when you got it. PO could have been using a lesser oil or who knows.
Having 6 928 engines with good oil pressure and no temps over 250F on the oil in race conditions seems to show that engine can run well without the cooler. Heck, scot doesnt even have the radiator oil cooler! (and he is running 2:04s at Thunderhill and 250F oil temps on a hot day during a race)
Remember, scots "unknown" engine did grenade, probably PO's fault as there was a lot of sludge in the oil pan. it lasted 2 race days and then grenaded in lap 10 of our race at laguna. we thought we could just drop it in the car, but we should have taken it apart. you never know what you got from a PO. It could have been damaged and took this long to make the problem worse. Did you ever see how clean the Holbert oil pan was after 7 years of racing? spotless. Looked brand new. thats what scots looked like too, after the engine WE built was pulled for the 5 liter.
I dont know how hard pulling the pan is, but that might be a good idea so that you can change out the rod bearings and see what is up. do you really have to, or want to pull the engine? I guess if you want to do the scraper, spacer and rod bearings, it might be an easier way. I cant even imagine pulling the pan with the engine in the car. How hard is that?? Anyone??
mk
UPDATE
I just got back from the race shop and saw the cut open oil filter and oil.......there IS small bits of gold colored metal in it....but really not much....the oil is fairly dark indicating it got pretty hot, but does not smell burnt.....
So what do I do now...... my only options are to pull the motor and inspect-replace the rod bearings and install the oil cooler + accusump & scraper-windage......of just install the cooler-accusump and run this engine until it fails.....but I don't like the idea of getting lots of little metal bits in my new accusump and setrab oil cooler....
I just got back from the race shop and saw the cut open oil filter and oil.......there IS small bits of gold colored metal in it....but really not much....the oil is fairly dark indicating it got pretty hot, but does not smell burnt.....
So what do I do now...... my only options are to pull the motor and inspect-replace the rod bearings and install the oil cooler + accusump & scraper-windage......of just install the cooler-accusump and run this engine until it fails.....but I don't like the idea of getting lots of little metal bits in my new accusump and setrab oil cooler....