[Z06] so who is spraying with a cam and stock valves?
#21
Safety Car
Thread Starter
This longblock isn't getting used for the next phase of the life of my Z06, so I don't care all that much. Yes, it'd suck to grenade it, but things happen.
#22
Drifting
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You could buy a heck of a lot of performance upgrades and forged parts for the $14-20K it would cost you to replace your motor. That's why I am hitting all of the exposed weak points before tracking (valve springs, oiling system, etc.). I was planning on replacing valves until Jason (Katech) more or less said don't bother - not needed. Pistons, OTOH, are a definite must if you go over a certain power range or go forced induction. Cheap insurance relatively speaking.
What cam are you running if you don't mind me asking?
#23
Le Mans Master
#24
You could buy a heck of a lot of performance upgrades and forged parts for the $14-20K it would cost you to replace your motor. That's why I am hitting all of the exposed weak points before tracking (valve springs, oiling system, etc.). I was planning on replacing valves until Jason (Katech) more or less said don't bother - not needed. Pistons, OTOH, are a definite must if you go over a certain power range or go forced induction. Cheap insurance relatively speaking.
#25
Le Mans Master
#27
Premium Supporting Vendor
I was saying that we run the stock intake and exhaust valves in almost everything.
#29
Pro
#30
Former Vendor
Well, time for an Exhaust fix SPECIAL...right?
How about this: exhaust porting and milling, installing new SS exhaust valves with all new springs, retainers, seals, keepers and locks for with new gaskets and bolts for... Any interest?
Thanks,
Carlos
How about this: exhaust porting and milling, installing new SS exhaust valves with all new springs, retainers, seals, keepers and locks for with new gaskets and bolts for... Any interest?
Thanks,
Carlos
#31
Bad valves or bad seats??
I popped the heads off my new crate LS7, and lapped 2 exhaust valves using Dykem blue to determine valve seat flatness. Both seats had only half of the blue removed. Most probable conclusion: seats from GM not leaving the factory very flat.
If seats aren't completely flat when valve closes, exhaust valve can't dissipate all the heat efficiently and will most likely be the main culprit of broken valves due to excessive heat build up and fatigue.
If seats aren't completely flat when valve closes, exhaust valve can't dissipate all the heat efficiently and will most likely be the main culprit of broken valves due to excessive heat build up and fatigue.
#32
Melting Slicks
Member Since: Dec 2002
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I replaced my exhaust valves with Ferrea Inconel super alloy valves. Just added insurance imho.
Seen too many engine failures with these 2 pc stock sodium valves and if you plan on making some serious power, it is really a cheap addition...
Anything can happen though, it's all mechanical....
Seen too many engine failures with these 2 pc stock sodium valves and if you plan on making some serious power, it is really a cheap addition...
Anything can happen though, it's all mechanical....
Last edited by BADZ; 01-10-2010 at 12:06 AM.
#33
Bad Z
If anyone knows about LS7's, it's Katech. They don't seem to be the least worried about the stock valves. I was considering the Ferrera valves, but they weighed over 30% more than the stock ones, and decided against them as they could potentially upset the valve train dynamics.
I'm going to check all my seats and have them machined as needed so that the maximum transfer of heat from valve to seat will take place. I really believe the stock valves are good as long as they don't get over heated.
Since I'm not a pro-racer, I've also decided to limit my rpm to 6500 as an extra measure of safety and longevity for the motor.
I'm going to check all my seats and have them machined as needed so that the maximum transfer of heat from valve to seat will take place. I really believe the stock valves are good as long as they don't get over heated.
Since I'm not a pro-racer, I've also decided to limit my rpm to 6500 as an extra measure of safety and longevity for the motor.
#34
Melting Slicks
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I'm not questioning Katech's findings but I would want the added insurance when making big power as I am. I'm now not worried about the heat and the added 18/20% weight added to my valvetrain when your making 900+ to the tires.
IMHO if your wanting to make big power, this cost is cheap insurance to eliminate what can turn into a very costly mistake.
Just my .02
IMHO if your wanting to make big power, this cost is cheap insurance to eliminate what can turn into a very costly mistake.
Just my .02
#35
Melting Slicks
#36
#37
If anyone knows about LS7's, it's Katech. They don't seem to be the least worried about the stock valves. I was considering the Ferrera valves, but they weighed over 30% more than the stock ones, and decided against them as they could potentially upset the valve train dynamics.
I'm going to check all my seats and have them machined as needed so that the maximum transfer of heat from valve to seat will take place. I really believe the stock valves are good as long as they don't get over heated.
Since I'm not a pro-racer, I've also decided to limit my rpm to 6500 as an extra measure of safety and longevity for the motor.
I'm going to check all my seats and have them machined as needed so that the maximum transfer of heat from valve to seat will take place. I really believe the stock valves are good as long as they don't get over heated.
Since I'm not a pro-racer, I've also decided to limit my rpm to 6500 as an extra measure of safety and longevity for the motor.
#38
Melting Slicks
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#39
Safety Car
Thread Starter
I'm going to be doing this with Richard at WCCH... but I'm also cutting 0.040" off the heads. Might have him do the 400cfm intake profile too... may as well!
#40
Melting Slicks
If I could venture a guess I'd say Katech has probably seen far more pistons fail than exhaust valves...so why they haven't offered a "Piston fix SPECIAL" is beyond me, seems like a great marketing opportunity is being missed
Cheers, Paul.
Cheers, Paul.