[Z06] Here goes nothing: My take on the root cause and "the fix"...(long read)
#21
Le Mans Master
Thread Starter
Don't agree with this and I think its a bad analogy. Just being honest. Vendor does not equal corrupt. Id love to see independent also but I think a lot of the testing we get here (free of cost) is indeed, accurate. I can smell a rat just as good as anyone but lets be honest with ourselves, did you honestly think, and Ill use Katech as an example, that a 98g valve wouldn't have any bounce and would be stable at 7,000 RPM? The results made sense. If they showed less bounce than a stock setup, I'm assuming you'd have backed the results.
#22
Burning Brakes
this is one of those moments when I just want to be kind. You need to read the wiki, I won't even mention basic chemistry.
http://en.wikipedia.org/wiki/Temperature_dependence_of_liquid_viscosity
Last edited by The_Raging_Bull; 11-27-2013 at 09:33 PM.
#23
Pro
#24
Le Mans Master
Thread Starter
#25
While I appreciate feedback on the original topic, I do not want my thread to turn into anything other than a focus on the topic listed. Vendor involvement in scientific or engineering based research is another topic for another thread. Please keep this thread on topic. Thank you for reading it if you did...and thank you for considering my stance.
Yep found it:
What did you find the over the tip weight of the Yella Terras to be? I have heard they range in the 20g area whereas stock is around 8-9g.
Last edited by forg0tmypen; 11-27-2013 at 09:47 PM.
#27
Le Mans Master
Thread Starter
ALL!!!
My apologies for the listed oil weight! Total typo...I meant to recommend a 0W-30 NOT 0W-20! Guess with all that typing, I overlooked that detail...sorry.
My apologies for the listed oil weight! Total typo...I meant to recommend a 0W-30 NOT 0W-20! Guess with all that typing, I overlooked that detail...sorry.
#28
Le Mans Master
Thread Starter
When I put in my new 2013 LS7 motor, one thing I liked was the new style oil cooler GM uses on the ZR1s. Before the car would take me the whole drive to work to get to 150F (about 20 mins). Now, it takes half that and is in the 200-215F range for MOST of the drive. I do use 5W30 oil, I will be switching to 0W40 at next change. I dont know about 0W20, Id like to see some in here first put serious miles with it before I switch..
What did you find the over the tip weight of the Yella Terras to be? I have heard they range in the 20g area whereas stock is around 8-9g.
What did you find the over the tip weight of the Yella Terras to be? I have heard they range in the 20g area whereas stock is around 8-9g.
I did not measure the "tip-weight" of the YT's. This really is irrelevant to valve train function in the operating conditions we deal with. It has the equivalent affect as say...a mouse fart in a tornado.
#29
oil temps on the oem Z06 with the air oil cooler IS something that needs improving. I have my cooler covered and the dry sump tank. I drive 12 miles to work. Oil temps with a 5w/30 pennzoil ultra oil never gets close to 200F. This is in 50-60 F weather. It may see for a few minutes only....170F.
Remember also this is NOT the temp of the oil going into the engine. That oil is about 20-25F COOLer than the oem sensor shows. You think you have 200F---nope--you have 175F. You think you have 125F--nope to have 100 and so forth.
I would love to see the temps in the pan.
I have been curious as to why uoa are not showing wear when people's valve guides are obviously getting worn?
I do like the fix for the side loading--regardless.
Remember also this is NOT the temp of the oil going into the engine. That oil is about 20-25F COOLer than the oem sensor shows. You think you have 200F---nope--you have 175F. You think you have 125F--nope to have 100 and so forth.
I would love to see the temps in the pan.
I have been curious as to why uoa are not showing wear when people's valve guides are obviously getting worn?
I do like the fix for the side loading--regardless.
#30
Le Mans Master
Thread Starter
oil temps on the oem z06 with the air oil cooler is something that needs improving. I have my cooler covered and the dry sump tank. I drive 12 miles to work. Oil temps with a 5w/30 pennzoil ultra oil never gets close to 200f. This is in 50-60 f weather. It may see for a few minutes only....170f.
Remember also this is not the temp of the oil going into the engine. That oil is about 20-25f cooler than the oem sensor shows. You think you have 200f---nope--you have 175f. You think you have 125f--nope to have 100 and so forth.
I would love to see the temps in the pan.
I have been curious as to why uoa are not showing wear when people's valve guides are obviously getting worn?
I do like the fix for the side loading--regardless.
Remember also this is not the temp of the oil going into the engine. That oil is about 20-25f cooler than the oem sensor shows. You think you have 200f---nope--you have 175f. You think you have 125f--nope to have 100 and so forth.
I would love to see the temps in the pan.
I have been curious as to why uoa are not showing wear when people's valve guides are obviously getting worn?
I do like the fix for the side loading--regardless.
#31
Burning Brakes
2) Poor exhaust rocker arm side loading. Now I actually measured the deflection on my car when the rockers were swapped for Yella Terra's. How does .382 grab you? (This was the extreme case, as there was typically between .250 - .300 on the others) That’s almost half an inch of deflection.
Thanks, Ernie
#32
Another reason to get the ZR1 style oil cooler. Just did a 25 min drive at 60mph w/ZR1 style cooler, oil temps were 167 at 12 miles and 179 when I parked in the garage. And BTW the OAT was 34F (low humidity).
#33
#34
Le Mans Master
Thread Starter
Man, I wish I took pictures. Basically, a rocker arm is a pivot that needs to open and close the valve. True perpendicular motion is ideal. The way the factory has it, the motion of this pivoting action is not a true open and close. There is a measured amount of "side-load" that creates another range of motion that makes the valve not open in just an open and shut manner. It opens, but it has a force pushing on it sideways (due to the improper geometry) that forces it to exert additional force into the wall of the valve guide which causes excessive wear when coupled with the other issues mentioned. Does that make sense?
#35
The Consigliere
Member Since: May 2006
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Interesting thoughts, OP.
#36
Team Owner
Then that would be just about never for me. It takes a real hot day coupled with stop and go driving to get there. I am however planning to go the Dewitt's route with intergrated oil/water cooler once my GMPP is up in 2016.
#37
Le Mans Master
Member Since: Dec 2004
Location: AZ
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St. Jude Donor '06-'08-'10-'11-'12-'13 '14-'15-'16-'17-'18-'19
this is one of those moments when I just want to be kind. You need to read the wiki, I won't even mention basic chemistry.
http://en.wikipedia.org/wiki/Tempera...quid_viscosity
http://en.wikipedia.org/wiki/Tempera...quid_viscosity
The way I read all this information, the viscosity of a 0W-30 oil at 75°F will be, lets say 40 for the sake of argument. A 0W-40 oil will ALSO have a viscosity of 40 at 75°F. True?
If this is true, then why would one prefer a 0W-30 weight oil over a 0W-40 weight oil since at operating temps of 200°F the viscosity of a 40 weight oil will be higher than a 30 weight oil?
#38
Le Mans Master
Thread Starter
Quick, (wasn't sure if you're okay with me mentioning your name)
I kind of put forgotmypen on blast earlier...it wouldn't be fair if I didn't request the same of you. I'm asking to keep the thread on topic. I know you weren't specifying anything to the contrary other than a response...but I would like this thread to be based purely my inputs without influencing other previous vendor tests. I completely agree that it would be awesome for someone to test my theory that was neutral...but, can we please save that for another thread.
Thanks man. FWIW, your compilation of data inspired me to really look into potential causes of our issues. And I appreciate your efforts on this board...please continue on compiling your information.
I kind of put forgotmypen on blast earlier...it wouldn't be fair if I didn't request the same of you. I'm asking to keep the thread on topic. I know you weren't specifying anything to the contrary other than a response...but I would like this thread to be based purely my inputs without influencing other previous vendor tests. I completely agree that it would be awesome for someone to test my theory that was neutral...but, can we please save that for another thread.
Thanks man. FWIW, your compilation of data inspired me to really look into potential causes of our issues. And I appreciate your efforts on this board...please continue on compiling your information.
#39
Man, I wish I took pictures. Basically, a rocker arm is a pivot that needs to open and close the valve. True perpendicular motion is ideal. The way the factory has it, the motion of this pivoting action is not a true open and close. There is a measured amount of "side-load" that creates another range of motion that makes the valve not open in just an open and shut manner. It opens, but it has a force pushing on it sideways (due to the improper geometry) that forces it to exert additional force into the wall of the valve guide which causes excessive wear when coupled with the other issues mentioned. Does that make sense?
#40
Quick, (wasn't sure if you're okay with me mentioning your name)
I kind of put forgotmypen on blast earlier...it wouldn't be fair if I didn't request the same of you. I'm asking to keep the thread on topic. I know you weren't specifying anything to the contrary other than a response...but I would like this thread to be based purely my inputs without influencing other previous vendor tests. I completely agree that it would be awesome for someone to test my theory that was neutral...but, can we please save that for another thread.
Thanks man. FWIW, your compilation of data inspired me to really look into potential causes of our issues. And I appreciate your efforts on this board...please continue on compiling your information.
I kind of put forgotmypen on blast earlier...it wouldn't be fair if I didn't request the same of you. I'm asking to keep the thread on topic. I know you weren't specifying anything to the contrary other than a response...but I would like this thread to be based purely my inputs without influencing other previous vendor tests. I completely agree that it would be awesome for someone to test my theory that was neutral...but, can we please save that for another thread.
Thanks man. FWIW, your compilation of data inspired me to really look into potential causes of our issues. And I appreciate your efforts on this board...please continue on compiling your information.
I look forward to you carrying on in your efforts, and will do all that I can to help and encourage you in that endeavor.