[Z06] LS7 Heads Exhaust Guide Wear Video
07-11-2012, 08:13 PM
#81
Safety Car
Member Since: Nov 1999
Location: S.E. WI.
Posts: 4,243
Received 69 Likes
on
50 Posts
St. Jude Donor '08-'09-'10
I will have to ask if its ok if I mention who told me this......Im sure he will be fine with it but I will keep him nameless for now. Anyways, he has 30 years experience working on heads and knows his ****. Alot of this has been mentioned on the forum before but some was new info to me.
I called to get a couple quotes and to also get his take on the valve issue and here is what I got.......First off, there is nothing wrong with the stock guides. He does install bronze guides only due to fact that he does not have access to OEM guides. The problem is nothing new to him and he has seen the same problem before in Porshe engines as they had a run with sodium filled valves. The sodium valves transfer heat into the guide essentially cooking the oil. Here is the part that I did know before that conversation...... your valves may be seeing the most heat at cruising speeds while in closed loop. I think this may be more likely in tuned cars since tuners will dump the fuel at high RPM and lean it out for fuel mileage in lower RPM. This explains all the "I was cruising at 40mph and dropped a valve" threads.
Anyways, we started talking about the intake side which also has shown signs of wear, but nothing like the exhaust side. My plan for my new car was to only replace the exhaust valves/guides. He recommended changing them out as well as the finish of them are not ideal. If you want to go the cheaper route for them, he has been doing testing with "tumbling" the stock vavles. I believe he said this not only makes them smoother, but also helps make them more porous. <<<<<take that for what its worth as I was trying to do two things at once when he was telling me this. But the "tumbling" option was cheap and he believes it protects the intake side.
I asked him about the concern of weight if I went with SS valves. He disagrees with many that they cause any type of issue. He also highly reccomends a dual spring vs the beehive that many go with. He got into alot more with the different finishes of valves, but I know I will mis-quote him if I try to reiterate.
In conclusion, he knows there is a problem but he has seen heads come back after having SS valves and bronze guides installed and even after mileage and abuse, the guides were in spec. One thing he has not been able to confirm is the tumbling method for the stock intake valves. He just hasn't seen the results after much use yet.
I called to get a couple quotes and to also get his take on the valve issue and here is what I got.......First off, there is nothing wrong with the stock guides. He does install bronze guides only due to fact that he does not have access to OEM guides. The problem is nothing new to him and he has seen the same problem before in Porshe engines as they had a run with sodium filled valves. The sodium valves transfer heat into the guide essentially cooking the oil. Here is the part that I did know before that conversation...... your valves may be seeing the most heat at cruising speeds while in closed loop. I think this may be more likely in tuned cars since tuners will dump the fuel at high RPM and lean it out for fuel mileage in lower RPM. This explains all the "I was cruising at 40mph and dropped a valve" threads.
Anyways, we started talking about the intake side which also has shown signs of wear, but nothing like the exhaust side. My plan for my new car was to only replace the exhaust valves/guides. He recommended changing them out as well as the finish of them are not ideal. If you want to go the cheaper route for them, he has been doing testing with "tumbling" the stock vavles. I believe he said this not only makes them smoother, but also helps make them more porous. <<<<<take that for what its worth as I was trying to do two things at once when he was telling me this. But the "tumbling" option was cheap and he believes it protects the intake side.
I asked him about the concern of weight if I went with SS valves. He disagrees with many that they cause any type of issue. He also highly reccomends a dual spring vs the beehive that many go with. He got into alot more with the different finishes of valves, but I know I will mis-quote him if I try to reiterate.
In conclusion, he knows there is a problem but he has seen heads come back after having SS valves and bronze guides installed and even after mileage and abuse, the guides were in spec. One thing he has not been able to confirm is the tumbling method for the stock intake valves. He just hasn't seen the results after much use yet.
07-11-2012, 08:37 PM
#82
FYI, I lost the motor in my 08 Z in May of 09. Upon tear down, one of the things we noticed was excessive guide wear. I rebuilt and went with new stock heads/stock guides, SS e-valves and roller-tipped rockers (solid roller lifters). We freshened things up last summer and upon checking the guides, found they were perfect.
IMO, it's is a combination of side load from poor geometry (reduced or eliminated by the roller rockers) and excessive temp. Only changes that were made last time were new springs and solid Ti exhaust valves.
IMO, it's is a combination of side load from poor geometry (reduced or eliminated by the roller rockers) and excessive temp. Only changes that were made last time were new springs and solid Ti exhaust valves.
07-11-2012, 09:03 PM
#83
Safety Car
FYI, I lost the motor in my 08 Z in May of 09. Upon tear down, one of the things we noticed was excessive guide wear. I rebuilt and went with new stock heads/stock guides, SS e-valves and roller-tipped rockers (solid roller lifters). We freshened things up last summer and upon checking the guides, found they were perfect.
IMO, it's is a combination of side load from poor geometry (reduced or eliminated by the roller rockers) and excessive temp. Only changes that were made last time were new springs and solid Ti exhaust valves.
IMO, it's is a combination of side load from poor geometry (reduced or eliminated by the roller rockers) and excessive temp. Only changes that were made last time were new springs and solid Ti exhaust valves.
Did you mean to say you replaced the OEM sodium-filled exhaust valves with OEM guides and stainless exhaust valves?
Glad to hear there was no noticeable wear - how many miles (and what kind of miles: track, street?) on the rebuild when you checked them over?
07-11-2012, 09:21 PM
#84
Is that a type-o?
Did you mean to say you replaced the OEM sodium-filled exhaust valves with OEM guides and stainless exhaust valves?
Glad to hear there was no noticeable wear - how many miles (and what kind of miles: track, street?) on the rebuild when you checked them over?
Did you mean to say you replaced the OEM sodium-filled exhaust valves with OEM guides and stainless exhaust valves?
Glad to hear there was no noticeable wear - how many miles (and what kind of miles: track, street?) on the rebuild when you checked them over?
07-11-2012, 09:38 PM
#85
Melting Slicks
Nail on the head. OP, I am interested in a "redneck" way of checking my OWN valves: ie a way I can estimate guide wear in MY garage - since I have no high quality micrometers to measure stem diameter and the inner diameter of the guides themselves.
In other words, you showed us a video of the "wiggle test," stating that this is an effective way of approximating valve guide wear. But how much wear is this representative of? I don't know how much the wiggle in your video correlates to actual guide wear - which is why I was trying to be rather polite in asking you to corroborate your initial demonstration with actual measurements (ie 0.005" wear, etc) from the valve you demonstrated to us.
Doing things without measurements or related measurements is what I coin "redneck," kind of like porting heads but not bothering to flow-test before or after your work: how would anyone know it was effective or know how to match the cam/components? Of course you flow test, which is why you mentioned going for 380cfm earlier in this thread - it's the scientific, reproducible method to ensure accuracy.
Looks like someone else posted a video in this thread, so I need to check it out.
Good post. I agree a more accurate measurement and documentation would be better. In the seat would be better as well. This would show if the wear is within limits or not.
I believe he stated if it moves at all "Its toast" I don't know if that is true based on how much it was pulled out and how much wiggle is considered toast. I am by far NOT an expert at all on the subject I just think if you are going to make the effort go all the way.
07-11-2012, 09:56 PM
#86
Safety Car
cold start = most wear, thus cold oil = more engine wear, thus GM changed the oil coolers and now engine oil gets to temps extremely fast.
If the oil is "too cold" then it may not get into the guides like it should until it is much voter. My Z06 barely got to 150* in the 98* heat from my house to my work (15 miles of mild traffic doing 45) and barely to 125 in winter (temps in the 30's low 40's)
In contrast my 2011 ZR1 gets to 200 by the time I get to work, and is right at about 160 by about 3 miles with one traffic light. In the Z06 I'd be lucky to get to 100.
It will be interesting to see the results on wear with the new oil cooler.
If the oil is "too cold" then it may not get into the guides like it should until it is much voter. My Z06 barely got to 150* in the 98* heat from my house to my work (15 miles of mild traffic doing 45) and barely to 125 in winter (temps in the 30's low 40's)
In contrast my 2011 ZR1 gets to 200 by the time I get to work, and is right at about 160 by about 3 miles with one traffic light. In the Z06 I'd be lucky to get to 100.
It will be interesting to see the results on wear with the new oil cooler.
07-11-2012, 10:01 PM
#87
Drifting
Thread Starter
Member Since: May 2011
Posts: 1,337
Likes: 0
Received 0 Likes
on
0 Posts
Update
Some of you asked me to show the movement with the valves closer to the seat so here you go. I work for myself and if the guides on a set of heads need to be replaced then I have a local shop that takes care of it for me. If your guides get to a point that the movement can be seen on video it is evident that the guides need to be changed. I don't claim to know all the answers but in my experience with other heads there should not be any kind of wiggle room.
LS7 Bud....this is what was accomplished today. Sorry for the video quality. I ran out of light and literally just walked in. Tomorrow when I have daylight I should be able to get a better shot.
2006 Z06 Vengeance RHS 454
2010 Bone Stock SS Camaro[/QUOTE]
LS7 Bud....this is what was accomplished today. Sorry for the video quality. I ran out of light and literally just walked in. Tomorrow when I have daylight I should be able to get a better shot.
2006 Z06 Vengeance RHS 454
2010 Bone Stock SS Camaro[/QUOTE]
07-11-2012, 10:05 PM
#88
Race Director
With a worn guide, the valve will seat slightly off center. This work hardens the valve at the weld. Eventually it can break.
Interesting video, just not sure what it shows that we haven't already seen. Pulling the valve out nearly 2" and it rocking doesn't mean much, IMO. Though I don't doubt there may have been some excessive guide wear with a head from 06-08'.
Interesting video, just not sure what it shows that we haven't already seen. Pulling the valve out nearly 2" and it rocking doesn't mean much, IMO. Though I don't doubt there may have been some excessive guide wear with a head from 06-08'.
I guess for those who don't understand the thread where this is discussed, this is helpful to watch
Well, we have to be careful lumping every failure in to the same category and then assessing cause - of course rarely are things ever black and white.I personally have assumed heat/fuel/tune related issues given the propensity of wear in modified vehicles: many cammed cars have problems - is it from the tune (which is invariably tweaked for max HP and thus leaner A/F, and higher EGT's), the valvetrain changes/cam/lift modifications, or is it just dumb luck? Of course many cammed cars are reporting worn guides... because the heads come off for other reasons and this is checked out of curiosity (whereas far less stock vehicles will just pull the heads for the hell of it).
But stock vehicles also have richer WOT tunes - but as you point out, this is NOT the case while cruising at the highway where the ECM is going for stoich A/F. The problem is, at lower RPM and load the EGT (heat) is also significantly less in almost all situations, and the time for heat transference between combustion cycles is also increased (increased valve seat time, oil flow, etc) versus WOT runs with a richer mixture.
And again, we have to allow for the possibility of supplier defect or poor quality control: 27,000+ cars with 8 exhaust valves a piece is only 216,000 parts. Since NOTHING is ever perfect, an error rate of 0.2% would correlate to over 500 blown engines (one broken valve = LS7 doorstop) - something we haven't seen. This 0.2% quality control error rate also ignore any other cause (like tunes, cam or heavy abuse); even though these sources significantly wittle down our existing Blown LS7 list.
Again - the sky probably isn't falling. But that doesn't mean that there aren't potential risks or ways of improving the existing engine for reliability depending on the application.
People tighten their axle nuts, use premium oils, do meticulous engine break-in procedures, use $200 waxes twice a year, swap the diff fluid every 5K miles, have a glorified leaf blower for washing the car without messing up the paint, worry about our door hinges splitting, etc etc - all in the name of longevity. Doesn't mean the car is a POS; it just means we all try to protect our investments in different ways and inevitably Murphy's Law will bite some of us in the ***.
IMHO, the exhaust valve issue is yet another variation: but unfortunately ONE bad valve takes out a $15,000 motor, so it's perfectly natural to take greater lengths to protect our investments. But that doesn't mean it's necessarily a "design" flaw inherent to the system - perhaps due to the higher HP output, the inherent flaws of mass production (quality control) are just more manifest in much more noticeable ways?
Regardless, the more we know, the more we can protect our vehicles. I also plan on checking the heads at some point, but I remind myself that for the thousands of Z06's in my state, probably less than 2 dozen will ever have a significant issue. Naturally, I don't want to be one of them.
But stock vehicles also have richer WOT tunes - but as you point out, this is NOT the case while cruising at the highway where the ECM is going for stoich A/F. The problem is, at lower RPM and load the EGT (heat) is also significantly less in almost all situations, and the time for heat transference between combustion cycles is also increased (increased valve seat time, oil flow, etc) versus WOT runs with a richer mixture.
And again, we have to allow for the possibility of supplier defect or poor quality control: 27,000+ cars with 8 exhaust valves a piece is only 216,000 parts. Since NOTHING is ever perfect, an error rate of 0.2% would correlate to over 500 blown engines (one broken valve = LS7 doorstop) - something we haven't seen. This 0.2% quality control error rate also ignore any other cause (like tunes, cam or heavy abuse); even though these sources significantly wittle down our existing Blown LS7 list.
Again - the sky probably isn't falling. But that doesn't mean that there aren't potential risks or ways of improving the existing engine for reliability depending on the application.
People tighten their axle nuts, use premium oils, do meticulous engine break-in procedures, use $200 waxes twice a year, swap the diff fluid every 5K miles, have a glorified leaf blower for washing the car without messing up the paint, worry about our door hinges splitting, etc etc - all in the name of longevity. Doesn't mean the car is a POS; it just means we all try to protect our investments in different ways and inevitably Murphy's Law will bite some of us in the ***.
IMHO, the exhaust valve issue is yet another variation: but unfortunately ONE bad valve takes out a $15,000 motor, so it's perfectly natural to take greater lengths to protect our investments. But that doesn't mean it's necessarily a "design" flaw inherent to the system - perhaps due to the higher HP output, the inherent flaws of mass production (quality control) are just more manifest in much more noticeable ways?
Regardless, the more we know, the more we can protect our vehicles. I also plan on checking the heads at some point, but I remind myself that for the thousands of Z06's in my state, probably less than 2 dozen will ever have a significant issue. Naturally, I don't want to be one of them.
Bingo! Especially in bold. While it's been identified that there is an issue on some engines with Valve Guides or valves on the exhaust side... noone can say with total certainty (or any logic) that all the failures listed here are a result of that..sure some maybe, but the others have also failed for other reasons.Not enough is known, or enough info to say to every Z06 owner who has a stock motor and tune...run run go pull your heads and get them checked and re-done otherwise your motor will in fact blow!
Edit, nice work on the heads you have done in the post above mine here..just watched it.
Last edited by FrankTank; 07-11-2012 at 10:09 PM.
07-11-2012, 10:11 PM
#89
Drifting
Thread Starter
Member Since: May 2011
Posts: 1,337
Likes: 0
Received 0 Likes
on
0 Posts
07-11-2012, 10:33 PM
#90
Some of you asked me to show the movement with the valves closer to the seat so here you go. I work for myself and if the guides on a set of heads need to be replaced then I have a local shop that takes care of it for me. If your guides get to a point that the movement can be seen on video it is evident that the guides need to be changed. I don't claim to know all the answers but in my experience with other heads there should not be any kind of wiggle room.
LS7 Bud....this is what was accomplished today. Sorry for the video quality. I ran out of light and literally just walked in. Tomorrow when I have daylight I should be able to get a better shot.
2006 Z06 Vengeance RHS 454
2010 Bone Stock SS Camaro
LS7 Bud....this is what was accomplished today. Sorry for the video quality. I ran out of light and literally just walked in. Tomorrow when I have daylight I should be able to get a better shot.
2006 Z06 Vengeance RHS 454
2010 Bone Stock SS Camaro
Are you certain that it was this movement which you demonstrate, which caused the other valve to break?
Also, if you see this kind of movement, and since no measurement of the movement is stated, we don't know how much we actually are seeing, what would you say are the chances of valve breakage, in the typical head with the same mileage on it, and with the amount of movement you are showing?
100% certain, 50% certain? 25% certain, 10% certain, or something less than that?
I ask because I think of some of the very high mileage LS7s out there.
NO S8NT at 182,000 miles as of May 30th of this year. Jimman at over 155,000 miles. Winzerguy at 148,000 miles. Peelingout 120,000 miles in an '07, MrVette1 at 106,000 miles on a 2007.
Those and a long list of other cars out there with 75,000-80,000 miles on them.
If one were to examine the heads from those cars, in that 100,000 mile club, would it be reasonable to expect to see NO movement such as that which you demonstrate in the videos?
Finally, as we don't know if there was any lateral movement such as that shown in the video when the head was actually "brand new", do we know to attribute all of the movement which we see here to "wear"?
In other words, how do we know that this lateral movement, or some of it, or most of it, seen in the video, wasn't going on when that head was brand new?
That question brings us back to the prospect of a QC issue.
One other thing which would help bring some clarity to this matter as well, and if you happen to have any similar mileage LS2, LS3, or LS9 heads in?
It would help if we could see something like a comparison video of those heads demonstrating an absence of movement such as that shown in the LS7 videos.
Last edited by '06 Quicksilver Z06; 07-11-2012 at 11:20 PM.
07-11-2012, 10:37 PM
#91
Drifting
Thank you very much ZOsickTanner... We both agree we're done trying to convince people... Do what you want people... All the info is out there for the people but it's up to them if they wanna use it...
07-11-2012, 11:22 PM
#92
Drifting
Thread Starter
Member Since: May 2011
Posts: 1,337
Likes: 0
Received 0 Likes
on
0 Posts
We know that the 2006 had a valve break, correct?
Are you certain that it was this movement which you demonstrate, which caused the other valve to break?
Also, if you see this kind of movement, and since no measurement of the movement is stated, we don't know how much we actually are seeing, what would you say are the chances of valve breakage, in the typical head with the same mileage on it, and with the amount of movement you are showing?
100% certain, 50% certain? 25% certain, 10% certain, or something less than that?
I ask because I think of some of the very high mileage LS7s out there.
NO S8NT at 182,000 miles as of May 30th of this year. Jimman at over 155,000 miles. Winzerguy at 148,000 miles. Peelingout 120,000 miles in an '07, MrVette1 at 106,000 miles on a 2007.
Those and a long list of other cars out there with 75,000-80,000 miles on them.
If one were to examine the heads from those cars, in that 100,000 mile club, would it be reasonable to expect to see NO movement such as that which you demonstrate in the videos?
Finally, as we don't know if there was any lateral movement such as that shown in the video when the head was actually "brand new", do we know to attribute all of the movement which we see here to "wear"?
In other words, how do we know that this wasn't going on when that head was brand new?
That question brings us back to the prospect of a QC issue.
One more request too, and would help bring some clarity to this matter as well.
Would you happen to have any similar mileage LS2, LS3, or LS9 heads in?
It would be good if we could see videos of those heads demonstrating an absence of movement such as that shown in the LS7 videos.
Are you certain that it was this movement which you demonstrate, which caused the other valve to break?
Also, if you see this kind of movement, and since no measurement of the movement is stated, we don't know how much we actually are seeing, what would you say are the chances of valve breakage, in the typical head with the same mileage on it, and with the amount of movement you are showing?
100% certain, 50% certain? 25% certain, 10% certain, or something less than that?
I ask because I think of some of the very high mileage LS7s out there.
NO S8NT at 182,000 miles as of May 30th of this year. Jimman at over 155,000 miles. Winzerguy at 148,000 miles. Peelingout 120,000 miles in an '07, MrVette1 at 106,000 miles on a 2007.
Those and a long list of other cars out there with 75,000-80,000 miles on them.
If one were to examine the heads from those cars, in that 100,000 mile club, would it be reasonable to expect to see NO movement such as that which you demonstrate in the videos?
Finally, as we don't know if there was any lateral movement such as that shown in the video when the head was actually "brand new", do we know to attribute all of the movement which we see here to "wear"?
In other words, how do we know that this wasn't going on when that head was brand new?
That question brings us back to the prospect of a QC issue.
One more request too, and would help bring some clarity to this matter as well.
Would you happen to have any similar mileage LS2, LS3, or LS9 heads in?
It would be good if we could see videos of those heads demonstrating an absence of movement such as that shown in the LS7 videos.
07-11-2012, 11:26 PM
#93
Drifting
Thread Starter
Member Since: May 2011
Posts: 1,337
Likes: 0
Received 0 Likes
on
0 Posts
07-11-2012, 11:48 PM
#94
Drifting
Thread Starter
Member Since: May 2011
Posts: 1,337
Likes: 0
Received 0 Likes
on
0 Posts
We know that the 2006 had a valve break, correct?
Are you certain that it was this movement which you demonstrate, which caused the other valve to break?
Also, if you see this kind of movement, and since no measurement of the movement is stated, we don't know how much we actually are seeing, what would you say are the chances of valve breakage, in the typical head with the same mileage on it, and with the amount of movement you are showing?
100% certain, 50% certain? 25% certain, 10% certain, or something less than that?
I ask because I think of some of the very high mileage LS7s out there.
NO S8NT at 182,000 miles as of May 30th of this year. Jimman at over 155,000 miles. Winzerguy at 148,000 miles. Peelingout 120,000 miles in an '07, MrVette1 at 106,000 miles on a 2007.
Those and a long list of other cars out there with 75,000-80,000 miles on them.
If one were to examine the heads from those cars, in that 100,000 mile club, would it be reasonable to expect to see NO movement such as that which you demonstrate in the videos?
Finally, as we don't know if there was any lateral movement such as that shown in the video when the head was actually "brand new", do we know to attribute all of the movement which we see here to "wear"?
In other words, how do we know that this lateral movement, or some of it, or most of it, seen in the video, wasn't going on when that head was brand new?
That question brings us back to the prospect of a QC issue.
One other thing which would help bring some clarity to this matter as well, and if you happen to have any similar mileage LS2, LS3, or LS9 heads in?
It would help if we could see something like a comparison video of those heads demonstrating an absence of movement such as that shown in the LS7 videos.
Are you certain that it was this movement which you demonstrate, which caused the other valve to break?
Also, if you see this kind of movement, and since no measurement of the movement is stated, we don't know how much we actually are seeing, what would you say are the chances of valve breakage, in the typical head with the same mileage on it, and with the amount of movement you are showing?
100% certain, 50% certain? 25% certain, 10% certain, or something less than that?
I ask because I think of some of the very high mileage LS7s out there.
NO S8NT at 182,000 miles as of May 30th of this year. Jimman at over 155,000 miles. Winzerguy at 148,000 miles. Peelingout 120,000 miles in an '07, MrVette1 at 106,000 miles on a 2007.
Those and a long list of other cars out there with 75,000-80,000 miles on them.
If one were to examine the heads from those cars, in that 100,000 mile club, would it be reasonable to expect to see NO movement such as that which you demonstrate in the videos?
Finally, as we don't know if there was any lateral movement such as that shown in the video when the head was actually "brand new", do we know to attribute all of the movement which we see here to "wear"?
In other words, how do we know that this lateral movement, or some of it, or most of it, seen in the video, wasn't going on when that head was brand new?
That question brings us back to the prospect of a QC issue.
One other thing which would help bring some clarity to this matter as well, and if you happen to have any similar mileage LS2, LS3, or LS9 heads in?
It would help if we could see something like a comparison video of those heads demonstrating an absence of movement such as that shown in the LS7 videos.
07-11-2012, 11:50 PM
#95
Also, we know of the engine failure in LS7 Bud's car, the 2006.
But if I'm following the progression right, his block was cracked. He bought a long block from out of a 2008, and the heads from it are the heads you are working for him?
But did the '08 also suffer an engine failure? What happened to the motor in the '08 that caused the dealership to have to pull it and sell it?
Apparently it didn't drop a valve and destroy the block.
Last edited by '06 Quicksilver Z06; 07-12-2012 at 12:01 AM.
07-12-2012, 12:16 AM
#96
Safety Car
I will have to ask if its ok if I mention who told me this......Im sure he will be fine with it but I will keep him nameless for now. Anyways, he has 30 years experience working on heads and knows his ****. Alot of this has been mentioned on the forum before but some was new info to me.
I called to get a couple quotes and to also get his take on the valve issue and here is what I got.......First off, there is nothing wrong with the stock guides. He does install bronze guides only due to fact that he does not have access to OEM guides. The problem is nothing new to him and he has seen the same problem before in Porshe engines as they had a run with sodium filled valves. The sodium valves transfer heat into the guide essentially cooking the oil. Here is the part that I did know before that conversation...... your valves may be seeing the most heat at cruising speeds while in closed loop. I think this may be more likely in tuned cars since tuners will dump the fuel at high RPM and lean it out for fuel mileage in lower RPM. This explains all the "I was cruising at 40mph and dropped a valve" threads.
Anyways, we started talking about the intake side which also has shown signs of wear, but nothing like the exhaust side. My plan for my new car was to only replace the exhaust valves/guides. He recommended changing them out as well as the finish of them are not ideal. If you want to go the cheaper route for them, he has been doing testing with "tumbling" the stock vavles. I believe he said this not only makes them smoother, but also helps make them more porous. <<<<<take that for what its worth as I was trying to do two things at once when he was telling me this. But the "tumbling" option was cheap and he believes it protects the intake side.
I asked him about the concern of weight if I went with SS valves. He disagrees with many that they cause any type of issue. He also highly reccomends a dual spring vs the beehive that many go with. He got into alot more with the different finishes of valves, but I know I will mis-quote him if I try to reiterate.
In conclusion, he knows there is a problem but he has seen heads come back after having SS valves and bronze guides installed and even after mileage and abuse, the guides were in spec. One thing he has not been able to confirm is the tumbling method for the stock intake valves. He just hasn't seen the results after much use yet.
I called to get a couple quotes and to also get his take on the valve issue and here is what I got.......First off, there is nothing wrong with the stock guides. He does install bronze guides only due to fact that he does not have access to OEM guides. The problem is nothing new to him and he has seen the same problem before in Porshe engines as they had a run with sodium filled valves. The sodium valves transfer heat into the guide essentially cooking the oil. Here is the part that I did know before that conversation...... your valves may be seeing the most heat at cruising speeds while in closed loop. I think this may be more likely in tuned cars since tuners will dump the fuel at high RPM and lean it out for fuel mileage in lower RPM. This explains all the "I was cruising at 40mph and dropped a valve" threads.
Anyways, we started talking about the intake side which also has shown signs of wear, but nothing like the exhaust side. My plan for my new car was to only replace the exhaust valves/guides. He recommended changing them out as well as the finish of them are not ideal. If you want to go the cheaper route for them, he has been doing testing with "tumbling" the stock vavles. I believe he said this not only makes them smoother, but also helps make them more porous. <<<<<take that for what its worth as I was trying to do two things at once when he was telling me this. But the "tumbling" option was cheap and he believes it protects the intake side.
I asked him about the concern of weight if I went with SS valves. He disagrees with many that they cause any type of issue. He also highly reccomends a dual spring vs the beehive that many go with. He got into alot more with the different finishes of valves, but I know I will mis-quote him if I try to reiterate.
In conclusion, he knows there is a problem but he has seen heads come back after having SS valves and bronze guides installed and even after mileage and abuse, the guides were in spec. One thing he has not been able to confirm is the tumbling method for the stock intake valves. He just hasn't seen the results after much use yet.
This is absolutely correct, I agree 100% with Richard . Ferrari guys have had the same problems too with the sodium fills, they heat up the oil and cook inside the guide.
07-12-2012, 12:18 AM
#97
Drifting
Quicksilver - I've posted all these answers in my own thread about my car failing... At this point I have no interest in repeating myself... I've really lost all interest in caring what anyone thinks about the whole situation... You guys have really just killed the whole thing for me... At this point I'm just worried about finishing my engine build and driving my car...
07-12-2012, 12:38 AM
#98
Quicksilver - I've posted all these answers in my own thread about my car failing... At this point I have no interest in repeating myself... I've really lost all interest in caring what anyone thinks about the whole situation... You guys have really just killed the whole thing for me... At this point I'm just worried about finishing my engine build and driving my car...
There are still plenty of unanswered questions here, and if people are reluctant to answer them , then that doesn't help anybody.
If this presentation is going to be submitted as a piece of the puzzle, well then every attempt ought to be made to answer questions posed by the audience you're presenting it to.
The materials used in Z0sicktanner's presentation, belong to you.
If it died, then what killed the '08 motor?
And if it died of something other than a dropped valve, then who knows how long it would have gone before it finally did drop one, even with this degree of lateral movement using the wiggle test?
Furthermore, if it failed due to something else, then that could give some indication as to how it was used and in turn give some idea as to why it's valve guides are in the shape that they are in.
For example, if it in fact failed, and the cause of failure was oil starvation and bearing failure, then that could give an indication that it saw some, or a lot of, track duty, and that could account for some of the reason why the guides are in the condition that tanner's video indicates that they are in.
Last edited by '06 Quicksilver Z06; 07-12-2012 at 12:40 AM.
07-12-2012, 01:29 AM
#99
Team Owner
Member Since: Apr 2001
Location: Elmhurst, IL (West Suburb of Chicago) & Home of MEGA Horsepower
Posts: 26,714
Received 584 Likes
on
399 Posts
St. Jude Donor '06
Gentleman,
Can we get an answer whether the 2008 heads on the video were actually on a LS7 engine when it failed, and if yes do we know what failed (and was the engine stock)?
I am not mechanic but know enough that any engine is going to have valve guide wear as the engine starts getting used more and more, accumalating mileage on it, and being subjected to normal wear and tear as it ages and the mileage increase.
Are there LS7 engines out there that have this exact type of movement on the valve guides that will live to 100,000 miles with normal usage?
It would be real interesting to see LS1/6/2/3/9 heads with similar mileage on them and do the exact same type of testing on those heads.
Keep up the great work gentleman.
Can we get an answer whether the 2008 heads on the video were actually on a LS7 engine when it failed, and if yes do we know what failed (and was the engine stock)?
I am not mechanic but know enough that any engine is going to have valve guide wear as the engine starts getting used more and more, accumalating mileage on it, and being subjected to normal wear and tear as it ages and the mileage increase.
Are there LS7 engines out there that have this exact type of movement on the valve guides that will live to 100,000 miles with normal usage?
It would be real interesting to see LS1/6/2/3/9 heads with similar mileage on them and do the exact same type of testing on those heads.
Keep up the great work gentleman.
07-12-2012, 01:36 AM
#100
Former Vendor
Some of you asked me to show the movement with the valves closer to the seat so here you go. I work for myself and if the guides on a set of heads need to be replaced then I have a local shop that takes care of it for me. If your guides get to a point that the movement can be seen on video it is evident that the guides need to be changed. I don't claim to know all the answers but in my experience with other heads there should not be any kind of wiggle room.
LS7 Bud....this is what was accomplished today. Sorry for the video quality. I ran out of light and literally just walked in. Tomorrow when I have daylight I should be able to get a better shot.
2006 Z06 Vengeance RHS 454
2010 Bone Stock SS Camaro
LS7 Bud....this is what was accomplished today. Sorry for the video quality. I ran out of light and literally just walked in. Tomorrow when I have daylight I should be able to get a better shot.
2006 Z06 Vengeance RHS 454
2010 Bone Stock SS Camaro
Mr. Z0sickTanner,
Great job all around
Love your comment(s) regarding the 5.0 heads from back in the day in one of your earlier replies; I remember those days. As a quick side note, just got your PM, sorry for the late response; I've been busy dealing with health issues.
Regarding this entire valves and guides issues, yes, there is a problem-taking place and yes, some people will fight you tooth and nails blaming this issue on such things as cams, tuning and other modifications, but little do they know that this mess is happening to BONE STOCK cars as well.
Hey, everyone is entitled to his or her own opinion…right? All I've been saying for a while now is: if you’re 100% confident on the state of your vehicle, its tune (stock or not), your dealership/GM over even your warranty (GM or otherwise) then leave the car alone and hope that nothing happens – who knows, you may get lucky. But if you’re not and want to be proactive then visit a trusted machine shop/tuner and do something about before a big ugly mess occurs...it is that simple!!!
I don't think I need a flame suit, but have one on just in case
Thanks,
Carlos