[Z06] Who makes the BEST rocker arms for the LS7?
02-16-2018, 08:21 PM
#61
Burning Brakes
RPM Engine and Machine
http://rpmengine.com/product/lsra-custom/
http://rpmengine.com/product/lsra-custom/
"There are even services for truing up and polishing the tips of the OEM rockers."
^ Saw this line in that rocker arm overview.
Who offers this service? Does anyone know anything more about it? I found a thread titled "Z06 Micro polishing factory rocker arms" but it didn't really reveal all that much and is pretty much the only thing that pops up regarding this topic in my google search.
^ Saw this line in that rocker arm overview.
Who offers this service? Does anyone know anything more about it? I found a thread titled "Z06 Micro polishing factory rocker arms" but it didn't really reveal all that much and is pretty much the only thing that pops up regarding this topic in my google search.
Last edited by Bad_AX; 02-16-2018 at 08:25 PM.
02-18-2018, 05:32 AM
#62
RPM Engine and Machine
http://rpmengine.com/product/lsra-custom/
https://www.youtube.com/watch?v=y8Pf9cIZevc
http://rpmengine.com/product/lsra-custom/
https://www.youtube.com/watch?v=y8Pf9cIZevc
Last edited by corvettenutz; 02-18-2018 at 05:32 AM. Reason: typo
02-18-2018, 05:47 AM
#63
Le Mans Master
gm endurance tested these rascals and they work. the aftermarket has much stronger pieces, but I don't think they are worth the fold.
put some bushed trunnions in them and polish the tip and check them for cracks
I know you all think the katech is a gm nut swinger but honestly they have "spun the ls7" valvetrain to death and done more to dispel the myths and advise people on the fix
don't get sucked into the "romance" of spending money.
put the heads and fix the problem, it's not the rockers.
02-18-2018, 08:00 AM
#65
Team Owner
Even then, those cams have to be extreme. I run a .652/.652 cam with zero issues with stock rockers. No noticeable wear. So unless you are running something like a GT21 with .680+ lift, stock rockers are not an issue.
02-19-2018, 04:25 PM
#66
Spzany, hope this helps give you a bit better understanding of the overall issue...
Here is the most thorough explanation of the big picture of several factors that lead to the guide wear problem. It is a lengthy read, but it pretty much covers all of the known failure/wear points.
https://www.corvetteactioncenter.com...-engine17.html
After a lot of research myself, and pouring over tons of forum discussions on the subject, I decided on a plan for my 2007 Z06.
1. Replace all 16 guides
2. Have new valve seats cut in heads that are concentric with new giudes
3. (might as well mill the heads 0.030" wile I've got them at the shop. A little free HP never hurts, right?)
4. Replace all exhaust valves. (2006 and 2007 models had a potential failure where the tip of the valve is welded on. Better safe than sorry.) I chose to use Ferrea F1597P
5. Replace LS7 rockers with Yella Terra YT6670 roller tipped rockers.
- Roller tipped rockers eliminate any side loading of valve, which could cause increased guide wear.
- LS7 rockers with trunion upgrade likely would have been fine, but I chose to eliminate side loading as much as possible, regardless of how small that side load may be with OEM rockers.
- Yella Terras come with an extra thick valve cover gasket to offset valve covers just enough to clear the rockers. Or you can add an aluminum valve cover spacer. I chose the aluminum spacer.
6. Replace all Valve springs. YT rockers are heavier than OEM LS7 rockers, so stronger springs are needed. I went with PSI 1511.
BTW, I kept the stock LS7 Cam, but would have chosen the same path with a cam with 0.630 or less lobes. Above that, may have had to make a different spring choice.
Here is the most thorough explanation of the big picture of several factors that lead to the guide wear problem. It is a lengthy read, but it pretty much covers all of the known failure/wear points.
https://www.corvetteactioncenter.com...-engine17.html
After a lot of research myself, and pouring over tons of forum discussions on the subject, I decided on a plan for my 2007 Z06.
1. Replace all 16 guides
2. Have new valve seats cut in heads that are concentric with new giudes
3. (might as well mill the heads 0.030" wile I've got them at the shop. A little free HP never hurts, right?)
4. Replace all exhaust valves. (2006 and 2007 models had a potential failure where the tip of the valve is welded on. Better safe than sorry.) I chose to use Ferrea F1597P
5. Replace LS7 rockers with Yella Terra YT6670 roller tipped rockers.
- Roller tipped rockers eliminate any side loading of valve, which could cause increased guide wear.
- LS7 rockers with trunion upgrade likely would have been fine, but I chose to eliminate side loading as much as possible, regardless of how small that side load may be with OEM rockers.
- Yella Terras come with an extra thick valve cover gasket to offset valve covers just enough to clear the rockers. Or you can add an aluminum valve cover spacer. I chose the aluminum spacer.
6. Replace all Valve springs. YT rockers are heavier than OEM LS7 rockers, so stronger springs are needed. I went with PSI 1511.
BTW, I kept the stock LS7 Cam, but would have chosen the same path with a cam with 0.630 or less lobes. Above that, may have had to make a different spring choice.
I was unaware of the articles that had been written or the available aftermarket roller tip rockerarms !
Now down to business tall Texan what material guides did you use and what intake valves (the Katech coated ) or stock ? Also how long has it been since you fixed the heads (milage ) and have you checked the valve guide clearances since it has been done ? Thank you for your time and information !
02-19-2018, 04:53 PM
#67
Pro
I wanna start off by saying thank you to everyone for your responses ,shared knowledge and input ! It is greatly Appreciate as my frustration when I came here was about what I thought was a on going problem with little information about but as it seems some of have found some solutions !
I was unaware of the articles that had been written or the available aftermarket roller tip rockerarms !
Now down to business tall Texan what material guides did you use and what intake valves (the Katech coated ) or stock ? Also how long has it been since you fixed the heads (milage ) and have you checked the valve guide clearances since it has been done ? Thank you for your time and information !
02-19-2018, 04:59 PM
#68
Le Mans Master
I have about 15K on my setup at this point, I have a set of gold-plated Katech covers to mount, I will report what I find when I pulll them. And of course if everything checks out, I will be told "yeah, and you'd see the same result with stock rockers", and that is certainly a possibility. 
02-19-2018, 06:02 PM
#69
Also I will state I have fixed my heads and will be soon checking them again as well there is about 7000 miles since I fixed mine I used Manley solid stanless steel valves on the exhaust side factory titanium on the intake side ! My set up is stock cam stock rockers with comp cams trunion bearing up grade ! Stock springs ! I will report my findings as well again thanks for everyone’s effort in reporting ! I sure hope mine lives another 80,000 Miles or so ,I used che bronze guides as well !
Last edited by Spzany; 02-19-2018 at 06:06 PM.
02-19-2018, 06:28 PM
#70
Team Owner
again thanks for all the data ! I will be curious to hear your findings ! @tall Texan I was asking about the intake valves you used and any special treatment there ?
Also I will state I have fixed my heads and will be soon checking them again as well there is about 7000 miles since I fixed mine I used Manley solid stanless steel valves on the exhaust side factory titanium on the intake side ! My set up is stock cam stock rockers with comp cams trunion bearing up grade ! Stock springs ! I will report my findings as well again thanks for everyone’s effort in reporting ! I sure hope mine lives another 80,000 Miles or so ,I used che bronze guides as well !
02-19-2018, 06:53 PM
#71
Pro
02-19-2018, 07:32 PM
#72
thank you for that bit of info will do for sure ! I can assure you if the rocker bearings show signs of where it will get yellow yellow terra with up graded springs as tall Texan has or the bronze brass bushing that replaces the bearing all together as every engine I have ever seen with stupid high spring pressures such as Diesel engines have a rocker arm bushing no bearing !
Last edited by Spzany; 02-19-2018 at 09:35 PM.
02-20-2018, 04:58 PM
#73
Le Mans Master
again thanks for all the data ! I will be curious to hear your findings ! @tall Texan I was asking about the intake valves you used and any special treatment there ?
Also I will state I have fixed my heads and will be soon checking them again as well there is about 7000 miles since I fixed mine I used Manley solid stanless steel valves on the exhaust side factory titanium on the intake side ! My set up is stock cam stock rockers with comp cams trunion bearing up grade ! Stock springs ! I will report my findings as well again thanks for everyone’s effort in reporting ! I sure hope mine lives another 80,000 Miles or so ,I used che bronze guides as well !
02-20-2018, 05:32 PM
#74
it’s subjective its a matter of opinion at this point ! If we are listening to Katech they did a valve train stability article stated this set up is fine for a street car !
i can see your concerns with the comp trunnion up grade only time will tel there ! I have no concerns with stock springs or the exhaust valves ! Performs as it should with this set up no valve float with or without the after market limiter ! Not to mention it has a ignition cut off limiter set at 6500 the factory engine makes no power after 6300 and only one to 2 more hp over 5900 so it doesn’t need to be turned any harder not mention its not tracked , and it has only ever seen those kinda rpm less than a hand full of times it’s a driver not a race car ! Mine is any how
i can see your concerns with the comp trunnion up grade only time will tel there ! I have no concerns with stock springs or the exhaust valves ! Performs as it should with this set up no valve float with or without the after market limiter ! Not to mention it has a ignition cut off limiter set at 6500 the factory engine makes no power after 6300 and only one to 2 more hp over 5900 so it doesn’t need to be turned any harder not mention its not tracked , and it has only ever seen those kinda rpm less than a hand full of times it’s a driver not a race car ! Mine is any how
02-20-2018, 05:35 PM
#75
it’s subjective its a matter of opinion at this point ! If we are listening to Katech they did a valve train stability article stated this set up is fine for a street car !
i can see your concerns with the comp trunnion up grade only time will tel there ! I have no concerns with stock springs or the exhaust valves ! Performs as it should with this set up no valve float with or without the after market limiter ! Not to mention it has a ignition cut off limiter set at 6500 the factory engine makes no power after 6300 and only one to 2 more hp over 5900 so it doesn’t need to be turned any harder not mention its not tracked , and it has only ever seen those kinda rpm less than a hand full of times it’s a driver not a race car ! Mine is any how
02-20-2018, 06:03 PM
#76
Team Owner
From my notes...
C6Z Exhaust Valve Weight:
Ferrea F1597p - 104g
Manley - 103g
REV - 98g
Ferrea F2042p - 84g
OE - 74g
Also, here's good recent thread on spring and retainer data:
https://www.corvetteforum.com/forums...fo-w-pics.html
C6Z Exhaust Valve Weight:
Ferrea F1597p - 104g
Manley - 103g
REV - 98g
Ferrea F2042p - 84g
OE - 74g
Also, here's good recent thread on spring and retainer data:
https://www.corvetteforum.com/forums...fo-w-pics.html
02-20-2018, 06:56 PM
#77
Pro
Correction - MTP's postpwith valve weights made me re-check. I initially ordered the solid F1597P, but returned them and ordered the hollow stem ones. I used the Ferrea F2042P hollow stem exhaust valves. I went back and edited my original post accordingly.
Last edited by long_tall_texan; 02-20-2018 at 07:07 PM.
02-20-2018, 07:01 PM
#78
From my notes...
C6Z Exhaust Valve Weight:
Ferrea F1597p - 104g
Manley - 103g
REV - 98g
Ferrea F2042p - 84g
OE - 74g
Also, here's good recent thread on spring and retainer data:
https://www.corvetteforum.com/forums...fo-w-pics.html
C6Z Exhaust Valve Weight:
Ferrea F1597p - 104g
Manley - 103g
REV - 98g
Ferrea F2042p - 84g
OE - 74g
Also, here's good recent thread on spring and retainer data:
https://www.corvetteforum.com/forums...fo-w-pics.html
thanks everyone for there data and shared information ! Lol this is madness ! I just can’t even I’m done lol
ita kinda like the more you buy the more you save smh
what a conundrum lol
ita kinda like the more you buy the more you save smh
what a conundrum lol
Last edited by Spzany; 02-20-2018 at 07:04 PM.
02-20-2018, 07:31 PM
#79
Team Owner
