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C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
I just acquired a '09 Z with 6.7k miles on the clock from the original owner. It's bone stock and I'm worried about the valves dropping so I decided to get the heads fixed.
Looks like a lot of people on this forum went with American Heritage Performance headers package #4:
I noticed that they use Ferrea Competition Plus Exhaust Valves F2042p which weigh 85 grams, compared to the stock exhaust valves that weigh 74 grams. Katech did an article on drive train stability and noted that when you increase the weight of one part of the system, if the rest of the system is not balanced with that new weight, it causes drivetrain instability:
The weight is not a concern with proper valve springs. Most people run solid valves without issues and these are quite a bit lighter. They are a good compromise between weight and strength. You don’t need to worry about guide weight.
I just acquired a '09 Z with 6.7k miles on the clock from the original owner. It's bone stock and I'm worried about the valves dropping so I decided to get the heads fixed.
Looks like a lot of people on this forum went with American Heritage Performance headers package #4:
I noticed that they use Ferrea Competition Plus Exhaust Valves F2042p which weigh 85 grams, compared to the stock exhaust valves that weigh 74 grams. Katech did an article on drive train stability and noted that when you increase the weight of one part of the system, if the rest of the system is not balanced with that new weight, it causes drivetrain instability:
So my question is, are those heavier exhaust valves safe?
Also, are the hardened valve guides they offer going to add weight too that I should be aware of?
many many are using the Ferrea hollow valves with great success. Kohle from AHP sets them up perfect. The guides don’t add weight. You honestly can’t go wrong with AHP. Call them you’ll be happy you did.
Even Spintron testing (everything else is just an educated guess) proved that the stock GM springs can control the hollow stem exhaust valve to stock redline.. Plenty of other things to worry about, this isn't one of them..
Last edited by Dan_the_C5_Man; 09-18-2018 at 01:03 AM.
Swapping the OE beehive for a PSI 1511ML spring more than offsets the slight increase in weight with the Ferrea F2042P exhaust valve. Throw in a Ti retainer, even more so. When AHP uses their Moldstar 90 valve guides they only use (or strongly reccommend) the Ferrea exhaust valves.
Thanks for the responses everyone. Also, that thread is incredibly useful. I think I'll end up going with the Ferrera valves and compensate for the weight with some 1511's as was suggested.
Thanks for the responses everyone. Also, that thread is incredibly useful. I think I'll end up going with the Ferrera valves and compensate for the weight with some 1511's as was suggested.
Thats what i did...AHP heads w/ treated OE Ti intakes, Ferrea F2042p ex valves, MS90 guides, PSI 1511 springs w/ Ti retainers, and CHE rocker trunions. Still on stock cam, doubt I'll ever change my combo...I want this car to live a long, reliable life.
I'm sure the Ferrea is a great valve. I just had my heads inspected and repaired and decided to keep the stock OEM because of weight and the sodium fill it has.
09-17-2018, 05:55 PM
Ferrea Exhaust valves on AHP heads safe?
