[Z06] LS7 Engine Failures On CF....The Breakdown
08-12-2009, 11:02 AM
#681
Team Owner
Thread Starter
Regardless of the condition of the oil the known shortcomings in the system are:
1. lack of pan baffle
2. lack of tank baffle
3. lack of scavenge pump capacity
4. lack of return line capacity from scavenge pump to tank
5. restriction due to oil filter placement.
6. possibly lack of system capacity
7. any others that we havent heard about yet
You folks can discuss all you want but if GM had done their homework properly this thread wouldnt even exist.
Damn........ I swore I wasnt going to read this thread anymore and would go get a life
1. lack of pan baffle
2. lack of tank baffle
3. lack of scavenge pump capacity
4. lack of return line capacity from scavenge pump to tank
5. restriction due to oil filter placement.
6. possibly lack of system capacity
7. any others that we havent heard about yet
You folks can discuss all you want but if GM had done their homework properly this thread wouldnt even exist.
Damn........ I swore I wasnt going to read this thread anymore and would go get a life
Besides, after you peruse the "What color should I get" and "Should I buy a Camaro or a Z06 or just do a wide body or wide booty coversion" threads, this is one of the only "meat and potatoes" informative threads in here.
The items you mention above, what would be your estimate in terms of costs, for an owner to address them?
Last edited by '06 Quicksilver Z06; 08-12-2009 at 11:05 AM.
08-12-2009, 11:05 AM
#682
Le Mans Master
This brings up a point: Variables.
Oil LEVEL at the time of and prior to failure.
Oil CONDITION; temperature, number of miles.
The track itself; banking, off camber, bumps, dips.
Prior HARD use or abuse.
As several people have pointed out, not every engine that failed was driven all that hard, and not every car that was driven hard had its engine fail.
E.
Oil LEVEL at the time of and prior to failure.
Oil CONDITION; temperature, number of miles.
The track itself; banking, off camber, bumps, dips.
Prior HARD use or abuse.
As several people have pointed out, not every engine that failed was driven all that hard, and not every car that was driven hard had its engine fail.
E.
Jim
08-12-2009, 11:27 AM
#683
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Location: Lehigh Valley PA
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And added!!
E.
Last edited by E's Z(D'oh!)6; 08-12-2009 at 11:30 AM.
08-12-2009, 11:31 AM
#684
Pro
I am curious as to how you feel that such an "experiment", even if "successful", would prove that "THE CAR IS FLAWED".
If you were to hold someone's head in a bucket of water for 10 minutes until they drowned, would that mean that the human respiratory system is flawed?
All it would prove is that you were able to create a set of extreme and unlikely circumstances under which the system could not stand up.
You know, really, I don't get it with these guys who just love to complain. They seem to wallow in a "the bastards, they done me wrong" world. They live to complain.
People love to argue that the "system is flawed" when things don't go their way. They love to argue that the "entrance exam or the qualification exam was flawed" when they can't pass it.
They live to complain about "flaws".
And then, like above, they try and do everything they can in an attempt to show others that they were "justified in their complaining". Not realizing that it doesn't change a thing.
At the end of the day, and I have asked you this before, at the end of the day, what are YOU going to do?????
"Flawed" or not, what are YOU going to do?????
After you are done bitching, what are YOU going to do???? What??? Bitch some more????
In continuing my answer to your above question, as I think you deserve an answer to it, it is possible that Dreamin's scenario of >1g and for >4 seconds on left handed sweeping curves, has happend in a few stock cars. No one has said that it was impossible.
This could explain why a few stock cars have failed on stock tires. Thus I don't think that anyone can declare the scenario his efforts indicated "impossible" in a stock car.
Indeed, most here who have commented on it, myself included, have been careful not to say that it is impossible.
However, it would appear to be the exception, and certainly not the rule, as few completely stock oil starvation related failures have been reported.
Furthermore, a discussion between Jimman and Dreamin which ronsc1985 joins, it starts about here and is where Jimman brings up a valid point.
In addition, Dreamin's work, as appreciated as it was, simply tells us what he observed under the conditions he reported. He shows us the results of his experiments and shows us his conclusions. Someone else may come along and observe something slightly, or even much different. Or even may have already.
As Jimman points out, there could be other variables. He doesn't say it, but there could even be a slight variability in the stock suspensions of a few cars which may allow a handful of cars to achieve Dreamin's scenario on stock tires.
However, the fact that oil starvation does not appear to be a huge problem, except possibly under the conditions described by Dreamin, as well as the observations of many, Painrace, and including Jason at Katech and his remarks about starvation issues in these cars, and their relationship to sticky tires and/or suspension mods, well none of that suggests any engineering "screw up" or "mistake" or "coverup" scenario in which "they knew that the system was flawed."
If you were to hold someone's head in a bucket of water for 10 minutes until they drowned, would that mean that the human respiratory system is flawed?
All it would prove is that you were able to create a set of extreme and unlikely circumstances under which the system could not stand up.
You know, really, I don't get it with these guys who just love to complain. They seem to wallow in a "the bastards, they done me wrong" world. They live to complain.
People love to argue that the "system is flawed" when things don't go their way. They love to argue that the "entrance exam or the qualification exam was flawed" when they can't pass it.
They live to complain about "flaws".
And then, like above, they try and do everything they can in an attempt to show others that they were "justified in their complaining". Not realizing that it doesn't change a thing.
At the end of the day, and I have asked you this before, at the end of the day, what are YOU going to do?????
"Flawed" or not, what are YOU going to do?????
After you are done bitching, what are YOU going to do???? What??? Bitch some more????
In continuing my answer to your above question, as I think you deserve an answer to it, it is possible that Dreamin's scenario of >1g and for >4 seconds on left handed sweeping curves, has happend in a few stock cars. No one has said that it was impossible.
This could explain why a few stock cars have failed on stock tires. Thus I don't think that anyone can declare the scenario his efforts indicated "impossible" in a stock car.
Indeed, most here who have commented on it, myself included, have been careful not to say that it is impossible.
However, it would appear to be the exception, and certainly not the rule, as few completely stock oil starvation related failures have been reported.
Furthermore, a discussion between Jimman and Dreamin which ronsc1985 joins, it starts about here and is where Jimman brings up a valid point.
In addition, Dreamin's work, as appreciated as it was, simply tells us what he observed under the conditions he reported. He shows us the results of his experiments and shows us his conclusions. Someone else may come along and observe something slightly, or even much different. Or even may have already.
As Jimman points out, there could be other variables. He doesn't say it, but there could even be a slight variability in the stock suspensions of a few cars which may allow a handful of cars to achieve Dreamin's scenario on stock tires.
However, the fact that oil starvation does not appear to be a huge problem, except possibly under the conditions described by Dreamin, as well as the observations of many, Painrace, and including Jason at Katech and his remarks about starvation issues in these cars, and their relationship to sticky tires and/or suspension mods, well none of that suggests any engineering "screw up" or "mistake" or "coverup" scenario in which "they knew that the system was flawed."
I am a bitcher and complainer because I dont believe in your conclusion that the oil system is 100% with stock tires? I am just expressing my opinion.
If the oil system was doing its job at 100% you wouldnt even have to say there was a possiblility that in some scenario you might see Dreamins problem with stock tires. Infact we wouldnt even be having this discussion.
The oil level theory is a good one, I would love it to be something that simple.
If the oil system cant handle stock car variables it goes back to my "If the oil system is maxed out that is terrible because of the variables and the unknowns especially in track situations and that alone I would call it flawd."
I am not a bitcher and complainer, go back and do a search on me, the only time I have put this much effort into a thread is when someone called me un American because I use to drive a Supra also. But as strong as you feel that there is no wrong with the ZO6 stock is as strong as I feel that the oil system is lacking even in stock form.
I dont expect GM to do anything about my car, I dont expect GM to admit there is a falt in the oil system and I dont expect GM to fix cars that are modded. I am simply expressing my opinion just like you are.
08-12-2009, 11:37 AM
#685
Pro
I think this is a great point. Also, as a 5w30 gets gets thinner under track conditions, could it be getting sucked out faster from the tank and maybe going with 15w50 would keep more oil in the tank or it wouldnt make that much of a difference with the level of oil?
Last edited by dbhajek; 08-12-2009 at 11:43 AM.
08-12-2009, 11:52 AM
#686
Team Owner
Thread Starter
Look folks the reality of the Z06 dry sump system is is was never designed to alleviate oil pickup starvation in continuous high G turns at a race track. Anyone who has a clue can tell you a dry sump system with one scavenge section is there only to a. allow the motor to be lower in the car and b. to cut down on the oil windage and possibly pick up a little horsepower. This is just fine for street driven cars which is what a Z06 was designed for.
Dry sump systems that are really designed to ensure oil pickup under most all cornering conditions have multiple scavenge sections and multiple pick up points. Look at any race system. Some have up to 5 scavenge sections with multiple pickup points dedicated one to each scavenge section. Why so many scavenge sections? Simple they allow one or more pickup points to be sucking air while other pick up oil. A single section with it's input plumbed to several pick up points doesn't do you any good as when one pick up point uncovers it sucks air, reducing or eliminating the pumps ability to pick up anything. That's why real race dry sump systems have several independent scavenge sections. If you don't believe this you can see it for yourself if you have any kind of pump. Just make a Y connection to the pump with one leg in the liquid and the other leg in the air. Unless you have a high head type pump, which dry sump scavenge sections are not, you will notice a large decrease or total elimination of the pump function vs both lines in the liquid.
All this bitching about the oil system being defective is idle chatter by people who don't understand much about how a dry sump system operates and how it has to be designed if it is to ensure oil pickup under all loading conditions. The current system does what it's design intended. Lower the engine and reduce oil windage. Anything else is iffy at best.
Should GM make a foolproof system? I think not. Most people drive the cars on the street and the current system is just fine. If you want to go to the track there are several options to ensure proper oiling depending on how fast (what G load) you put on the oil.
Expecting GM to build in cost for the small minority who want to run HPDE's is foolish. Those people can make their own modifications. It does kind of suck that the very oil system modifications that will keep the engine alive may void your warranty but on the other hand if done properly you shouldn't have to use the warranty for oil starvation problems anyway.
For the purpose I bought a Z06, a street driven car, the current oiling system is just fine. I've had all kinds of race cars over the years and no stock passenger car does anything for me at a track.
I guess I'm performance spoiled.
Dry sump systems that are really designed to ensure oil pickup under most all cornering conditions have multiple scavenge sections and multiple pick up points. Look at any race system. Some have up to 5 scavenge sections with multiple pickup points dedicated one to each scavenge section. Why so many scavenge sections? Simple they allow one or more pickup points to be sucking air while other pick up oil. A single section with it's input plumbed to several pick up points doesn't do you any good as when one pick up point uncovers it sucks air, reducing or eliminating the pumps ability to pick up anything. That's why real race dry sump systems have several independent scavenge sections. If you don't believe this you can see it for yourself if you have any kind of pump. Just make a Y connection to the pump with one leg in the liquid and the other leg in the air. Unless you have a high head type pump, which dry sump scavenge sections are not, you will notice a large decrease or total elimination of the pump function vs both lines in the liquid.
All this bitching about the oil system being defective is idle chatter by people who don't understand much about how a dry sump system operates and how it has to be designed if it is to ensure oil pickup under all loading conditions. The current system does what it's design intended. Lower the engine and reduce oil windage. Anything else is iffy at best.
Should GM make a foolproof system? I think not. Most people drive the cars on the street and the current system is just fine. If you want to go to the track there are several options to ensure proper oiling depending on how fast (what G load) you put on the oil.
Expecting GM to build in cost for the small minority who want to run HPDE's is foolish. Those people can make their own modifications. It does kind of suck that the very oil system modifications that will keep the engine alive may void your warranty but on the other hand if done properly you shouldn't have to use the warranty for oil starvation problems anyway.
For the purpose I bought a Z06, a street driven car, the current oiling system is just fine. I've had all kinds of race cars over the years and no stock passenger car does anything for me at a track.
I guess I'm performance spoiled.
http://forums.corvetteforum.com/c6-z...post1571057069
Oil pressure is usually set by the manufacturer. A true dry sump pump has a pressure adjustment on it. Either system will work on the street. When you start doing road racing a proper dry sump system will always supply the oil needed at the right amount of pressure all the time. Wet sump engines can get the oil sloshed away from the oil pickup with high side or braking G-Force loads and the bearings get smeared which eventually causes failure. I prefer dry sump but most of the time on the highway it does not matter. I think the C6Z is an outstanding performance car that is well engineered.
Jim
Jim
I am a bitcher and complainer because I dont believe in your conclusion that the oil system is 100% with stock tires? I am just expressing my opinion.
If the oil system was doing its job at 100% you wouldnt even have to say there was a possiblility that in some scenario you might see Dreamins problem with stock tires. Infact we wouldnt even be having this discussion.
If the oil system was doing its job at 100% you wouldnt even have to say there was a possiblility that in some scenario you might see Dreamins problem with stock tires. Infact we wouldnt even be having this discussion.
The oil level theory is a good one, I would love it to be something that simple.
If the oil system cant handle stock car variables it goes back to my "If the oil system is maxed out that is terrible because of the variables and the unknowns especially in track situations and that alone I would call it flawd."
I am not a bitcher and complainer, go back and do a search on me, the only time I have put this much effort into a thread is when someone called me un American because I use to drive a Supra also. But as strong as you feel that there is no wrong with the ZO6 stock is as strong as I feel that the oil system is lacking even in stock form.
I dont expect GM to do anything about my car, I dont expect GM to admit there is a falt in the oil system and I dont expect GM to fix cars that are modded. I am simply expressing my opinion just like you are.
If the oil system cant handle stock car variables it goes back to my "If the oil system is maxed out that is terrible because of the variables and the unknowns especially in track situations and that alone I would call it flawd."
I am not a bitcher and complainer, go back and do a search on me, the only time I have put this much effort into a thread is when someone called me un American because I use to drive a Supra also. But as strong as you feel that there is no wrong with the ZO6 stock is as strong as I feel that the oil system is lacking even in stock form.
I dont expect GM to do anything about my car, I dont expect GM to admit there is a falt in the oil system and I dont expect GM to fix cars that are modded. I am simply expressing my opinion just like you are.
But I'll tell you, some of the responses in this thread have me frazzled. One guy has even suggested that I collect people's VINs and check the authenticity of their claims of having warranty work.
Others want to argue that the Z06 as a track car. It is first and foremost a street car, which can be used on the track, as can many other cars.
My post was directed primarily in response to Captain454s "challenge" and chatter about "IF I DO THIS, WILL YOU ADMIT YOU ARE TOTALLY WRONG, FINALLY ADMIT THE CAR IS FLAWED, AND BEG FOR FORGIVENESS FOR THE NEXT THOUSAND YEARS?" horsecrap.
Wasn't directed at you, nor your eloquently expressed opinions vs what he wrote above.
Last edited by '06 Quicksilver Z06; 08-12-2009 at 12:14 PM.
08-12-2009, 01:45 PM
#687
Le Mans Master
There are a couple of posts you may want to look at.
http://forums.corvetteforum.com/c6-z...post1570970530
http://forums.corvetteforum.com/c6-z...post1571057069
See above posts by ron and Painrace.
I don't want to give the impression that I don't appreciate your opinion and if I did, then that was not my intent.
But I'll tell you, some of the responses in this thread have me frazzled. One guy has even suggested that I collect people's VINs and check the authenticity of their claims of having warranty work.
Others want to argue that the Z06 as a track car. It is first and foremost a street car, which can be used on the track, as can many other cars.
My post was directed primarily in response to Captain454s "challenge" and chatter about "IF I DO THIS, WILL YOU ADMIT YOU ARE TOTALLY WRONG, FINALLY ADMIT THE CAR IS FLAWED, AND BEG FOR FORGIVENESS FOR THE NEXT THOUSAND YEARS?" horsecrap.
Wasn't directed at you, nor your eloquently expressed opinions vs what he wrote above.
http://forums.corvetteforum.com/c6-z...post1570970530
http://forums.corvetteforum.com/c6-z...post1571057069
See above posts by ron and Painrace.
I don't want to give the impression that I don't appreciate your opinion and if I did, then that was not my intent.
But I'll tell you, some of the responses in this thread have me frazzled. One guy has even suggested that I collect people's VINs and check the authenticity of their claims of having warranty work.
Others want to argue that the Z06 as a track car. It is first and foremost a street car, which can be used on the track, as can many other cars.
My post was directed primarily in response to Captain454s "challenge" and chatter about "IF I DO THIS, WILL YOU ADMIT YOU ARE TOTALLY WRONG, FINALLY ADMIT THE CAR IS FLAWED, AND BEG FOR FORGIVENESS FOR THE NEXT THOUSAND YEARS?" horsecrap.
Wasn't directed at you, nor your eloquently expressed opinions vs what he wrote above.
08-12-2009, 02:25 PM
#688
Le Mans Master
What I do know is you need 40-50 weight oil when you get to 270-280 degrees oil temperature to protect the bearings. I learned that about 100 years ago by blowing motors. I also know you want to keep as little oil in the engine as you can after the oil has done it's work of lubricating and cooling. The more time it has in the dry sump tank to get air out the better quality oil will be sent to the engine. 
Jim
08-12-2009, 02:30 PM
#689
Cruising
Member Since: Aug 2009
Location: Los Angeles California
Posts: 11
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I am curious as to how you feel that such an "experiment", even if "successful", would prove that "THE CAR IS FLAWED".
If you were to hold someone's head in a bucket of water for 10 minutes until they drowned, would that mean that the human respiratory system is flawed?
If you were to hold someone's head in a bucket of water for 10 minutes until they drowned, would that mean that the human respiratory system is flawed?
For marketing purposes, GM is eager to sing the C6Z's praises, and they are right to do so: it's a marvel of human ingenuity. But this is an American car, and in America we have no reverence for boundaries. We push every possible limit (including the sky), and GM knows we will. I think they would do well to lead other car manufacturers by example and state not only what the car can do, but what it can't.
08-12-2009, 03:37 PM
#690
Team Owner
The bottom line here Howie, is if you want to run the car on the track using sticky tires, suspension and brake modifications, then you may want to upgrade your oiling system, as it was not tested by the manufacturer using these items.
I don't know whats hard about that. Seriously, you're making this harder than it has to be.
No one is putting a gun to anyone's head and making them track their cars on sticky tires, and modded suspensions and brakes.
I don't know whats hard about that. Seriously, you're making this harder than it has to be.
No one is putting a gun to anyone's head and making them track their cars on sticky tires, and modded suspensions and brakes.
I do feel that the arguments they make about the oil system being inadequate with these minor upgrades is fair in view of their experience with the C5Z06 using similar mods without the same problems of engine failure.
I know from experience that one can get over 1 G on city streets/high ways with the stock GY. I have read many postings and have seen my G meter max out too. Wether its over 4 seconds is another issue. And keep in mind that although I value Dreamin's findings they are not necessarily conclusive or correct .... that would take further testing on different vehicles to be scientific.
I do feel that me or another driver on new stock GY's could definately get 1G for more than 4 seconds.......and I'm sure you could too. Unfortunately we might only want to do this turning to the right, not to forget that the exact same turn to the left could leave engine parts cluttering the highway or track.
DH
08-12-2009, 03:47 PM
#691
Le Mans Master
I can put together a whole list of do's and don'ts so you'll be as good as can be, Howdie - although driving slow is protection enough. 
08-12-2009, 03:56 PM
#692
Drifting
They avoid left turns in NJ by having "teacup" intersections - you turn right to enter a little cloverleaf and end up heading left on the cross-street. Also, just make 3 right-hand turns on the street and you'll be going left. See, no problem (I'm just trying to be helpful) . . . I can put together a whole list of do's and don'ts so you'll be as good as can be, Howdie - although driving slow is protection enough.
I can put together a whole list of do's and don'ts so you'll be as good as can be, Howdie - although driving slow is protection enough. 
:-)
08-12-2009, 04:23 PM
#693
Team Owner
If I was tracking my stock Z06 and had 15-50 oil in it and the engine failed. They could attribute the problem to poor lubrication on multiple start ups with that syrup in there !!!!
DH
08-12-2009, 04:37 PM
#694
Team Owner
For the most part I respect all the time and effort in this exercise you have invested.
I don't agree with your hardline position any more than the guys who want GM to cover their car with insane mods. I have tried to have intelligent disagreement and throw wood into the fire in order to have some debate.
But your above statement causes me to call you an A$$
I suggested you could check the vin with the permission of the poster because you refused to add his stock car onto your list claiming you were concerned it was a fraudulent example
You made no effort to verify his claim and now bash me for suggesting you do so ........... 
DH
08-12-2009, 04:42 PM
#695
After reading this thread, I have to say that I'm glad I waited to buy an '09 ZO6. But, I have also read many threads over the years about people like Ranger who track their cars regularly without incident.
About 4 weeks ago, I was at the Palm Beach International Raceway to watch some drag racing. It was a compact car day at the track. There were some great looking cars there, all modded to the max including Porsches.
It took well over an hour just to get through the first 11 cars during their qualifying rounds. This was because 5 of them blew their engines, and the track had to be cleaned of debris and spilled fluids. I heard some missed shifts beforehand, and I'm sure many of them had their turbos maxed out. But, in the end, I came to the conclusion that racing your cars is a just a very risky proposition and expensive sport for the average driver on a track.
I wonder how many ZO6 engines have failed because of driver error, poor preparation, and/or poor track conditions? I also wonder what percentage of all cars of any kind, experience blown engines from driver error or from just participating in racing events?
About 4 weeks ago, I was at the Palm Beach International Raceway to watch some drag racing. It was a compact car day at the track. There were some great looking cars there, all modded to the max including Porsches.
It took well over an hour just to get through the first 11 cars during their qualifying rounds. This was because 5 of them blew their engines, and the track had to be cleaned of debris and spilled fluids. I heard some missed shifts beforehand, and I'm sure many of them had their turbos maxed out. But, in the end, I came to the conclusion that racing your cars is a just a very risky proposition and expensive sport for the average driver on a track.
I wonder how many ZO6 engines have failed because of driver error, poor preparation, and/or poor track conditions? I also wonder what percentage of all cars of any kind, experience blown engines from driver error or from just participating in racing events?
08-12-2009, 04:57 PM
#696
Le Mans Master
If you can run your car hard enough to get the oil temperature up to the 270 degree range you should know enough to put heavier oil in the engine. The first thing you should do is increase the cooling if oil tempertures are getting this high. If you have 50 weight oil in your engine at zero degrees, start it up and take it to 6,000 RPM you deserve what you get.
I am not defending GM but they cannot give you a book with everything you should do in every situation. Every once in a while we are required to use experience or common sense. Sorry, I forgot, this is America, it is always someone elses fault!
Your stock Z06 will not fail because you have 15W50 in it if you get the oil temperature up to 150 degrees before you hammer it! No, I will not warrant your car if it does blow up but GM might, particularly if you keep your foot in it and let parts come out of the pan because all the oil will come out also.
I run 5W30 in my car on the street and 15W50 in my car on the track. Sometimes I have to throw oil away before the end of it's useful life but it is no big deal. Tracking a car is not cheap. If you take a car to a track you should expect they worst and hope it does not happen. If you can't afford the worst you should not go to the track.
Just my 3 cents.
Jim
08-12-2009, 05:02 PM
#697
Melting Slicks
Any car lubrication system I have ever seen is kind of like a pump to a distribution system with leaks all over the place. Oil goes to the lifters, cam, crank to main bearings, rod bearings and up the rods to the wrist pins (usually, some wrist pins are splash oiled). It leaks out around the edges of the bearings or in the case of lifters goes up the pushrod holes and sprays all around the valve train. If you ever see an engine running on a dyno with a transparent oil pan and valve covers it looks like an oil shower. When the viscosity goes down there is less oil pressure pressure between things the oil is supposed to keep separate such as the crank and the crank bearings, big end of the rods and the crank journals, small end of the rods and the wrist pins etc.
That however is not the end of the story. This additional spray puts more oil on the the cylinder walls making the oil control function of the rings more difficult. Lower viscosity also makes it easier to suck some up through the valve guides and tends to put more mist into the crankcase evac system which you eventually have to put in the combustion temperature with the fuel. Why do you care?
If the oil isn't controlled on the cylinder walls you get oil burning but worse then that you may cause detonation. Pure synthetic oil don't lower the octane rating of the gasoline but these days most synthetic oils are primarily made with grade 3 dino oil (I think that's what they call it) which will lower gasoline octane. A quick and dirty test is to try and see if you current oil will burn. If it does you may have a problem.
Is this a problem since the ECU (or whatever GM calls it) does react to the knock sensor activating? Yes because it does not however predict knock, it only reacts after sensing detonation knock. That is one reason you don't want to put 87 octane fuel in your Z06 because it will knock and although the ECU will try to correct it can't adjust for the first knock after you increase cylinder pressure, like when going up a hill even in normal street driving. Every time this happens you are giving the bearings a whack. Enough whacks and you will get a failure. Reading bearings is/was a primary method of detecting detonation in race engines (no mufflers you can't hear anything) before knock sensors,data recording of various engine functions etc. became available.
If I was going to run around a road course I would be sure to use higher weight oil and pay attention to the oil and water temperature and how much oil I was burning. The engine is not designed to really use much oil and excessive oil consumption is surely going into the combustion chamber. If it's being vaporized by heat it still ends up in the combustion chamber via the crank evac system.
This kind of trouble could be more prevalent in places like California where the best available pump gasoline is 91 octane and you are using normal pump gas. Any input charge contamination by oil could take the ECU outside of it's possible correction range when the cylinder pressure is running near it's maximum value (as in when you are at full throttle).
The above is not meant to scare anyone it's just a simple explanation of cause and effect.
All those who at certain the engine is poorly designed please feel free to use the above as another reason to bytch and moan.
08-12-2009, 05:51 PM
#698
Team Owner
I cannot tell you why GM does things, can you??
If you can run your car hard enough to get the oil temperature up to the 270 degree range you should know enough to put heavier oil in the engine. The first thing you should do is increase the cooling if oil tempertures are getting this high. If you have 50 weight oil in your engine at zero degrees, start it up and take it to 6,000 RPM you deserve what you get.
I am not defending GM but they cannot give you a book with everything you should do in every situation. Every once in a while we are required to use experience or common sense. Sorry, I forgot, this is America, it is always someone elses fault!
Your stock Z06 will not fail because you have 15W50 in it if you get the oil temperature up to 150 degrees before you hammer it! No, I will not warrant your car if it does blow up but GM might, particularly if you keep your foot in it and let parts come out of the pan because all the oil will come out also.
I run 5W30 in my car on the street and 15W50 in my car on the track. Sometimes I have to throw oil away before the end of it's useful life but it is no big deal. Tracking a car is not cheap. If you take a car to a track you should expect they worst and hope it does not happen. If you can't afford the worst you should not go to the track.
Just my 3 cents.
Jim
If you can run your car hard enough to get the oil temperature up to the 270 degree range you should know enough to put heavier oil in the engine. The first thing you should do is increase the cooling if oil tempertures are getting this high. If you have 50 weight oil in your engine at zero degrees, start it up and take it to 6,000 RPM you deserve what you get.
I am not defending GM but they cannot give you a book with everything you should do in every situation. Every once in a while we are required to use experience or common sense. Sorry, I forgot, this is America, it is always someone elses fault!
Your stock Z06 will not fail because you have 15W50 in it if you get the oil temperature up to 150 degrees before you hammer it! No, I will not warrant your car if it does blow up but GM might, particularly if you keep your foot in it and let parts come out of the pan because all the oil will come out also.
I run 5W30 in my car on the street and 15W50 in my car on the track. Sometimes I have to throw oil away before the end of it's useful life but it is no big deal. Tracking a car is not cheap. If you take a car to a track you should expect they worst and hope it does not happen. If you can't afford the worst you should not go to the track.
Just my 3 cents.
Jim
I'm not arguing with you. I used to use 15-50 all the time in my C5 Stroker.
This was in context of the discussion regarding GM waranty issues and modifications to their specifications in which they could include fluids.
And my car never sees over 3K (usually 2-2.5) rpm until the temps are up to 150*
And I can afford to take my car to the track. I'm filthy rich. That should be evident by all the time I can spend here .........
DH
08-12-2009, 06:25 PM
#699
Team Owner
The oil pumps can be accurately described as constant volume pumps i.e. they pump the same volume every revolution. As such they don't much care what the viscosity of the oil is. That is why you can notice the oil pressure go up when you rev the engine when you are below the pressure the oil pump is regulated to. That however doesn't mean that low viscosity doesn't at some time become a problem.
Any car lubrication system I have ever seen is kind of like a pump to a distribution system with leaks all over the place. Oil goes to the lifters, cam, crank to main bearings, rod bearings and up the rods to the wrist pins (usually, some wrist pins are splash oiled). It leaks out around the edges of the bearings or in the case of lifters goes up the pushrod holes and sprays all around the valve train. If you ever see an engine running on a dyno with a transparent oil pan and valve covers it looks like an oil shower. When the viscosity goes down there is less oil pressure pressure between things the oil is supposed to keep separate such as the crank and the crank bearings, big end of the rods and the crank journals, small end of the rods and the wrist pins etc.
That however is not the end of the story. This additional spray puts more oil on the the cylinder walls making the oil control function of the rings more difficult. Lower viscosity also makes it easier to suck some up through the valve guides and tends to put more mist into the crankcase evac system which you eventually have to put in the combustion temperature with the fuel. Why do you care?
If the oil isn't controlled on the cylinder walls you get oil burning but worse then that you may cause detonation. Pure synthetic oil don't lower the octane rating of the gasoline but these days most synthetic oils are primarily made with grade 3 dino oil (I think that's what they call it) which will lower gasoline octane. A quick and dirty test is to try and see if you current oil will burn. If it does you may have a problem.
Is this a problem since the ECU (or whatever GM calls it) does react to the knock sensor activating? Yes because it does not however predict knock, it only reacts after sensing detonation knock. That is one reason you don't want to put 87 octane fuel in your Z06 because it will knock and although the ECU will try to correct it can't adjust for the first knock after you increase cylinder pressure, like when going up a hill even in normal street driving. Every time this happens you are giving the bearings a whack. Enough whacks and you will get a failure. Reading bearings is/was a primary method of detecting detonation in race engines (no mufflers you can't hear anything) before knock sensors,data recording of various engine functions etc. became available.
If I was going to run around a road course I would be sure to use higher weight oil and pay attention to the oil and water temperature and how much oil I was burning. The engine is not designed to really use much oil and excessive oil consumption is surely going into the combustion chamber. If it's being vaporized by heat it still ends up in the combustion chamber via the crank evac system.
This kind of trouble could be more prevalent in places like California where the best available pump gasoline is 91 octane and you are using normal pump gas. Any input charge contamination by oil could take the ECU outside of it's possible correction range when the cylinder pressure is running near it's maximum value (as in when you are at full throttle).
The above is not meant to scare anyone it's just a simple explanation of cause and effect.
All those who at certain the engine is poorly designed please feel free to use the above as another reason to bytch and moan.
Any car lubrication system I have ever seen is kind of like a pump to a distribution system with leaks all over the place. Oil goes to the lifters, cam, crank to main bearings, rod bearings and up the rods to the wrist pins (usually, some wrist pins are splash oiled). It leaks out around the edges of the bearings or in the case of lifters goes up the pushrod holes and sprays all around the valve train. If you ever see an engine running on a dyno with a transparent oil pan and valve covers it looks like an oil shower. When the viscosity goes down there is less oil pressure pressure between things the oil is supposed to keep separate such as the crank and the crank bearings, big end of the rods and the crank journals, small end of the rods and the wrist pins etc.
That however is not the end of the story. This additional spray puts more oil on the the cylinder walls making the oil control function of the rings more difficult. Lower viscosity also makes it easier to suck some up through the valve guides and tends to put more mist into the crankcase evac system which you eventually have to put in the combustion temperature with the fuel. Why do you care?
If the oil isn't controlled on the cylinder walls you get oil burning but worse then that you may cause detonation. Pure synthetic oil don't lower the octane rating of the gasoline but these days most synthetic oils are primarily made with grade 3 dino oil (I think that's what they call it) which will lower gasoline octane. A quick and dirty test is to try and see if you current oil will burn. If it does you may have a problem.
Is this a problem since the ECU (or whatever GM calls it) does react to the knock sensor activating? Yes because it does not however predict knock, it only reacts after sensing detonation knock. That is one reason you don't want to put 87 octane fuel in your Z06 because it will knock and although the ECU will try to correct it can't adjust for the first knock after you increase cylinder pressure, like when going up a hill even in normal street driving. Every time this happens you are giving the bearings a whack. Enough whacks and you will get a failure. Reading bearings is/was a primary method of detecting detonation in race engines (no mufflers you can't hear anything) before knock sensors,data recording of various engine functions etc. became available.
If I was going to run around a road course I would be sure to use higher weight oil and pay attention to the oil and water temperature and how much oil I was burning. The engine is not designed to really use much oil and excessive oil consumption is surely going into the combustion chamber. If it's being vaporized by heat it still ends up in the combustion chamber via the crank evac system.
This kind of trouble could be more prevalent in places like California where the best available pump gasoline is 91 octane and you are using normal pump gas. Any input charge contamination by oil could take the ECU outside of it's possible correction range when the cylinder pressure is running near it's maximum value (as in when you are at full throttle).
The above is not meant to scare anyone it's just a simple explanation of cause and effect.
All those who at certain the engine is poorly designed please feel free to use the above as another reason to bytch and moan.
DH
08-12-2009, 06:35 PM
#700
Le Mans Master
