[Z06] Down and dirty valve drop info
02-06-2015, 09:49 PM
#21
It is marginal for the application. Even the GM engineers admit that. Also high temp evaporation issues (the exhaust valve guide is a very high temperature environment... just covering some obvious bases).
Other oils have better high temp performance/stability, but I would not consider/use any of the mainstream 5W30's (Pennzoil, etc) since they are all EPA oils not specifically designed for engine protection.
Other oils have better high temp performance/stability, but I would not consider/use any of the mainstream 5W30's (Pennzoil, etc) since they are all EPA oils not specifically designed for engine protection.
02-06-2015, 10:18 PM
#23
Drifting
It is marginal for the application. Even the GM engineers admit that. Also high temp evaporation issues (the exhaust valve guide is a very high temperature environment... just covering some obvious bases).
Other oils have better high temp performance/stability, but I would not consider/use any of the mainstream 5W30's (Pennzoil, etc) since they are all EPA oils not specifically designed for engine protection.
Other oils have better high temp performance/stability, but I would not consider/use any of the mainstream 5W30's (Pennzoil, etc) since they are all EPA oils not specifically designed for engine protection.
02-06-2015, 10:26 PM
#24
The Pennzoil is one of the lightest 30wts out there. Higher psi does not equate to a higher capability for reduced engine wear. Simply one variable in the equation.
02-06-2015, 10:51 PM
#25
Melting Slicks
Time to vote to get an Official Reply from GM on this issue:
https://www.corvetteforum.com/forums...ead-issue.html
https://www.corvetteforum.com/forums...ead-issue.html
But use this link to go right to the poll, and vote..
https://www.corvetteforum.com/forums...post1588902085
02-07-2015, 12:11 AM
#26
Instructor
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Tons of good info guys. I think my most likely course of action would be to have the heads done along with the valves/guides. Probably a FAST as well. Seems like this could be done reasonably thru American Heritage or a similar vender. It's just something that I have to factor into purchase price when shopping. Anybody know if there was any major revamp to the heads/valve train for the Z/28 cars? Would be interesting if something was obviously done to prevent the failure without acknowledging all the Z06 owners who have had to pay out of pocket.
02-07-2015, 08:29 AM
#27
Team Owner
No, z28 heads are the same.
02-07-2015, 09:01 AM
#29
Drifting
02-07-2015, 09:06 AM
#30
Drifting
Oh yes, I'm well aware. Was just the first time I've ever seen such a noticeable change in oil pressure from switching brands.
02-07-2015, 06:50 PM
#31
Le Mans Master
A "master design flaw"...you're kidding right?
IF it were a design flaw there wouldn't be some LS7s running 200,000 miles and more without a failure. I could go on and on about how wrong the idea is of there being a "design flaw" but just don't have the energy.
It IS a QC issue which once rectified properly will mean there is nothing to fear in the future.
Cheers, Paul.
IF it were a design flaw there wouldn't be some LS7s running 200,000 miles and more without a failure. I could go on and on about how wrong the idea is of there being a "design flaw" but just don't have the energy.
It IS a QC issue which once rectified properly will mean there is nothing to fear in the future.
Cheers, Paul.
How many LS7's running 200,000 miles with out failure ?-- Maybe 1 and that's an anomaly. How many over 100,000 miles maybe 2 or 3.
02-08-2015, 08:02 AM
#32
Pro
Only two things really need to be done:
1. Replace the valve guides. American Heritage probably has the best or least risky (deviation from original design) approach on this -- a supposedly better version of the OEM guide.
2, Replace all the exhaust valves (in case any have suffered damage due to running in incorrectly machined heads). Use OEM parts.
Original springs can be reused if pressures measure within spec.
1. Replace the valve guides. American Heritage probably has the best or least risky (deviation from original design) approach on this -- a supposedly better version of the OEM guide.
2, Replace all the exhaust valves (in case any have suffered damage due to running in incorrectly machined heads). Use OEM parts.
Original springs can be reused if pressures measure within spec.
It is marginal for the application. Even the GM engineers admit that. Also high temp evaporation issues (the exhaust valve guide is a very high temperature environment... just covering some obvious bases).
Other oils have better high temp performance/stability, but I would not consider/use any of the mainstream 5W30's (Pennzoil, etc) since they are all EPA oils not specifically designed for engine protection.
Other oils have better high temp performance/stability, but I would not consider/use any of the mainstream 5W30's (Pennzoil, etc) since they are all EPA oils not specifically designed for engine protection.
All this calls for testing those 0W40 and 5W30 Corvette Z06 oils, as well as testing 0W30 oils, to see how they all compare. Then Z06 owners and the Bob Forum guys can take a look at actual hard numbers that will show the facts. With that information in hand, they can make an informed decision when it comes to selecting an oil that will truly provide them with the best wear protection.
So, I tested the following motor oils:
0W40 and 5W30 Pennzoil Ultra
0W40, 5W30 and 0W30 Mobil 1
0W40, 5W30 and 0W30 Castrol Edge with Syntec (in the black bottle)
NOTE: Castrol’s top of the line 100% Edge motor oil, comes in the gold bottle.
The Wear Protection reference categories are:
• Over 105,000 psi = INCREDIBLE wear protection
• 90,000 to 105,000 psi = OUTSTANDING wear protection
• 75,000 to 90,000 psi = GOOD wear protection
• 60,000 to 75,000 psi = MODEST wear protection
• Below 60,000 psi = UNDESIRABLE wear protection
Here is how these oils ranked just among themselves, according to their Wear Protection Capability. All wear protection capability testing was performed at 230* F, and the higher the psi value, the better the wear protection. I also included values for the onset of thermal breakdown for comparison (the thermal breakdown values were rounded to the nearest 5* increment):
1. 5W30 Pennzoil Ultra, API SM synthetic = 115,612 psi, which puts it in the INCREDIBLE wear protection category.
The onset of thermal breakdown = 280* F
2. 5W30 Mobil 1, API SN synthetic = 105,875 psi, which puts it in the INCREDIBLE wear protection category.
The onset of thermal breakdown = 265* F
3. 5W30 Castrol Edge w/Syntec, API SN (black bottle, formerly Castrol Syntec) synthetic = 85,179 psi, which puts it in the GOOD wear protection category.
The onset of thermal breakdown = TBD (I did not test this particular oil for this when I had it on hand)
4. 0W40 Mobil 1, API SN, European Formula, made in the U.S., synthetic = 82,644 psi, which puts it in the GOOD wear protection category.
The onset of thermal breakdown = 285* F
5. 0W40 Pennzoil Ultra, API SN, synthetic = 81,863 psi, which puts it in the GOOD wear protection category.
The onset of thermal breakdown = 260* F
6. 0W30 Mobil 1, API SN, Advanced Fuel Economy, synthetic = 81,240 psi, which puts it in the GOOD wear protection category.
The onset of thermal breakdown = 290* F
7. 0W40 Castrol Edge with Syntec (black bottle), API SN, European Formula, made in Belgium and sold in the U.S., synthetic = 69,307 psi, which puts it in the MODEST wear protection category.
The onset of thermal breakdown = 290* F
8. 0W30 Castrol Edge with Syntec (black bottle), API SL, European Formula, made in Germany and sold in the U.S., synthetic = 69,302 psi, which puts it in the MODEST wear protection category.
The onset of thermal breakdown = 290* F
As you can see from these actual test values, all the 5W30 oils provide better wear protection than any of the 0W oils. But even so, any of these oils would be acceptable for normal daily driver use. However, for highly loaded High Performance applications where the best possible wear protection is desired, the obvious choice would be 5W30 Pennzoil Ultra or 5W30 Mobil 1, which are the only oils in this test that provide INCREDIBLE wear protection.
So, GM got it right about which oil to recommend in their U.S. Z06 Corvette’s. One can only speculate that perhaps they expect the U.S. cars to be run harder, so they call for the best protection in those engines. Although, general availability in Canada and Europe may also play a part in what oil they recommend. Whatever the case, both oil viscosities had to meet GM’s endurance testing requirements.
So, I tested the following motor oils:
0W40 and 5W30 Pennzoil Ultra
0W40, 5W30 and 0W30 Mobil 1
0W40, 5W30 and 0W30 Castrol Edge with Syntec (in the black bottle)
NOTE: Castrol’s top of the line 100% Edge motor oil, comes in the gold bottle.
The Wear Protection reference categories are:
• Over 105,000 psi = INCREDIBLE wear protection
• 90,000 to 105,000 psi = OUTSTANDING wear protection
• 75,000 to 90,000 psi = GOOD wear protection
• 60,000 to 75,000 psi = MODEST wear protection
• Below 60,000 psi = UNDESIRABLE wear protection
Here is how these oils ranked just among themselves, according to their Wear Protection Capability. All wear protection capability testing was performed at 230* F, and the higher the psi value, the better the wear protection. I also included values for the onset of thermal breakdown for comparison (the thermal breakdown values were rounded to the nearest 5* increment):
1. 5W30 Pennzoil Ultra, API SM synthetic = 115,612 psi, which puts it in the INCREDIBLE wear protection category.
The onset of thermal breakdown = 280* F
2. 5W30 Mobil 1, API SN synthetic = 105,875 psi, which puts it in the INCREDIBLE wear protection category.
The onset of thermal breakdown = 265* F
3. 5W30 Castrol Edge w/Syntec, API SN (black bottle, formerly Castrol Syntec) synthetic = 85,179 psi, which puts it in the GOOD wear protection category.
The onset of thermal breakdown = TBD (I did not test this particular oil for this when I had it on hand)
4. 0W40 Mobil 1, API SN, European Formula, made in the U.S., synthetic = 82,644 psi, which puts it in the GOOD wear protection category.
The onset of thermal breakdown = 285* F
5. 0W40 Pennzoil Ultra, API SN, synthetic = 81,863 psi, which puts it in the GOOD wear protection category.
The onset of thermal breakdown = 260* F
6. 0W30 Mobil 1, API SN, Advanced Fuel Economy, synthetic = 81,240 psi, which puts it in the GOOD wear protection category.
The onset of thermal breakdown = 290* F
7. 0W40 Castrol Edge with Syntec (black bottle), API SN, European Formula, made in Belgium and sold in the U.S., synthetic = 69,307 psi, which puts it in the MODEST wear protection category.
The onset of thermal breakdown = 290* F
8. 0W30 Castrol Edge with Syntec (black bottle), API SL, European Formula, made in Germany and sold in the U.S., synthetic = 69,302 psi, which puts it in the MODEST wear protection category.
The onset of thermal breakdown = 290* F
As you can see from these actual test values, all the 5W30 oils provide better wear protection than any of the 0W oils. But even so, any of these oils would be acceptable for normal daily driver use. However, for highly loaded High Performance applications where the best possible wear protection is desired, the obvious choice would be 5W30 Pennzoil Ultra or 5W30 Mobil 1, which are the only oils in this test that provide INCREDIBLE wear protection.
So, GM got it right about which oil to recommend in their U.S. Z06 Corvette’s. One can only speculate that perhaps they expect the U.S. cars to be run harder, so they call for the best protection in those engines. Although, general availability in Canada and Europe may also play a part in what oil they recommend. Whatever the case, both oil viscosities had to meet GM’s endurance testing requirements.
02-08-2015, 08:12 AM
#33
Burning Brakes
My guides were fine on a modified engine at 7500 miles. Had the heads reworked anyway and there was a flaw discovered and fixed with one head from what I can remember.
02-08-2015, 10:12 AM
#35
Team Owner
Mark, pretty sure those numbers are old. They stopped making the pennzoil plat like they use too and it ranks far lower now when you look at the updated numbers.
From the blog/testing"
"NOTE:
5W30 Pennzoil Ultra, API SM synthetic = 115,612 psi
zinc = 806 ppm
phosphorus = 812 ppm
moly = 66 ppm
calcium = 3,011 ppm
TBN = 10.3
This oil was ranked in this position for about a year and a half. But, it is no longer ranked at all, because it has now been replaced by the newer API “SN” version. See below for the “SN” version’s ranking position."
They changed from SM to SN version and now it is rated at
25. 5W30 Pennzoil “Ultra” Platinum, Pure Plus Technology, made from pure natural gas, API SN = 99,039 psi
This oil was introduced in 2014, and comes in a dark gray bottle with a blue vertical stripe on the label.
From the blog/testing"
"NOTE:
5W30 Pennzoil Ultra, API SM synthetic = 115,612 psi
zinc = 806 ppm
phosphorus = 812 ppm
moly = 66 ppm
calcium = 3,011 ppm
TBN = 10.3
This oil was ranked in this position for about a year and a half. But, it is no longer ranked at all, because it has now been replaced by the newer API “SN” version. See below for the “SN” version’s ranking position."
They changed from SM to SN version and now it is rated at
25. 5W30 Pennzoil “Ultra” Platinum, Pure Plus Technology, made from pure natural gas, API SN = 99,039 psi
This oil was introduced in 2014, and comes in a dark gray bottle with a blue vertical stripe on the label.
Last edited by Unreal; 02-08-2015 at 10:17 AM.
02-08-2015, 10:36 AM
#37
Mark, pretty sure those numbers are old. They stopped making the pennzoil plat like they use too and it ranks far lower now when you look at the updated numbers.
From the blog/testing"
"NOTE:
5W30 Pennzoil Ultra, API SM synthetic = 115,612 psi
zinc = 806 ppm
phosphorus = 812 ppm
moly = 66 ppm
calcium = 3,011 ppm
TBN = 10.3
This oil was ranked in this position for about a year and a half. But, it is no longer ranked at all, because it has now been replaced by the newer API “SN” version. See below for the “SN” version’s ranking position."
They changed from SM to SN version and now it is rated at
25. 5W30 Pennzoil “Ultra” Platinum, Pure Plus Technology, made from pure natural gas, API SN = 99,039 psi
This oil was introduced in 2014, and comes in a dark gray bottle with a blue vertical stripe on the label.
From the blog/testing"
"NOTE:
5W30 Pennzoil Ultra, API SM synthetic = 115,612 psi
zinc = 806 ppm
phosphorus = 812 ppm
moly = 66 ppm
calcium = 3,011 ppm
TBN = 10.3
This oil was ranked in this position for about a year and a half. But, it is no longer ranked at all, because it has now been replaced by the newer API “SN” version. See below for the “SN” version’s ranking position."
They changed from SM to SN version and now it is rated at
25. 5W30 Pennzoil “Ultra” Platinum, Pure Plus Technology, made from pure natural gas, API SN = 99,039 psi
This oil was introduced in 2014, and comes in a dark gray bottle with a blue vertical stripe on the label.
1. Prolong Engine Treatment added to 5W30 Pennzoil Ultra, API SN synthetic = 136,658 psi
This oil on its own WITHOUT the Prolong Engine Treatment added to it, has a wear protection capability of 92,569 psi. With the recommended amount of Prolong added per qt, its wear protection capability “WENT UP 48%”. But, compared to the previous API “SM” version of this oil, this mixture’s capability went up 18%.
02-08-2015, 12:32 PM
#38
The "reputed" type of testing Rat does has been disputed. He does not use the testing method his detractors have assumed he uses.
M-1 is what I use. No need or zinc in these engines.
Also don't be too quick to move to a heavier weight.
M-1 is what I use. No need or zinc in these engines.
Also don't be too quick to move to a heavier weight.
02-08-2015, 01:06 PM
#39
Pro Mechanic
Pro Mechanic
It is marginal for the application. Even the GM engineers admit that. Also high temp evaporation issues (the exhaust valve guide is a very high temperature environment... just covering some obvious bases).
Other oils have better high temp performance/stability, but I would not consider/use any of the mainstream 5W30's (Pennzoil, etc) since they are all EPA oils not specifically designed for engine protection.
Other oils have better high temp performance/stability, but I would not consider/use any of the mainstream 5W30's (Pennzoil, etc) since they are all EPA oils not specifically designed for engine protection.
My LS7 coverage located elsewhere in the Internet does not make those statements about Mobil 1 5W30. Nowhere in my LS7 coverage is any GM Engineer quoted as saying...
"Mark 2009" needs to stop making stuff up.
I'll also suggest that "Mark2009" should stop posting inaccurate information about engine oils.
Characterizing Mobil 1 5W30 as...
...is a gross distortion of fact.
While I believe there are better choices in engine oils for LS7s used in severe duty, Mobil 1 5W30 is perfectly adequate for an LS7 used in a normal duty cycle.
To say that Mobil 1 products are...
...demonstrates significant lack of knowledge about engine oils.
02-08-2015, 01:54 PM
#40
This day and age it is laughable to claim that factory fill oil has engine performance as a primary goal, so I'll not restate conventional wisdom to address your other comments.