Is this valve float?
Is this valve float? I finally finished my heads/cam install on my Z06 and took it to get tuned. There's a nasty dip in the top end of the graph which is puzzling me. Does this look like it would be valve float?
Mods:
ETP 215 Heads 58cc
MS3 Cam
Kooks Headers
Stock LS6 Intake
Vararam
Comp 850-16 Lifters
Comp 8.050" Pushrods
SVO 42# Injectors
Mods:
ETP 215 Heads 58cc
MS3 Cam
Kooks Headers
Stock LS6 Intake
Vararam
Comp 850-16 Lifters
Comp 8.050" Pushrods
SVO 42# Injectors
Looks like spring surge, try shimming for more seat pressure if you have room to do so. Don't ask how I know 
Those are also very long pushrods, you might consider the 3/8" diameter to minimize pushrod flex or possibly tapered pushrods.
Those are also very long pushrods, you might consider the 3/8" diameter to minimize pushrod flex or possibly tapered pushrods.
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Joined: Feb 2005
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Looks like a lot of the graphs for etp heads but if you ask them it's not valve float. What springs did you get? 977's or the PSI's?
I have the 215's also but haven't dyno'd yet.
BTW, did you have to modify your alternator?
I have the 215's also but haven't dyno'd yet.
BTW, did you have to modify your alternator?
What would be the recommended solution to spring surge? I'm not 100% sure on the springs, I'll need to check with the shop since they ordered them to be appropriate for my cam.
As for the alternator, I haven't modified it but i'm still working on a solution. For now I clearanced a valve cover to fit back on, and then unbolted a coil and trimmed the coil pack to fit back on. One coil is just hanging on with a zip tie until I can work out something or relocate them all.
As for the alternator, I haven't modified it but i'm still working on a solution. For now I clearanced a valve cover to fit back on, and then unbolted a coil and trimmed the coil pack to fit back on. One coil is just hanging on with a zip tie until I can work out something or relocate them all.
TECH Apprentice
Joined: Feb 2005
Posts: 395
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Originally Posted by jimmyz80
What would be the recommended solution to spring surge? I'm not 100% sure on the springs, I'll need to check with the shop since they ordered them to be appropriate for my cam.
As for the alternator, I haven't modified it but i'm still working on a solution. For now I clearanced a valve cover to fit back on, and then unbolted a coil and trimmed the coil pack to fit back on. One coil is just hanging on with a zip tie until I can work out something or relocate them all.
As for the alternator, I haven't modified it but i'm still working on a solution. For now I clearanced a valve cover to fit back on, and then unbolted a coil and trimmed the coil pack to fit back on. One coil is just hanging on with a zip tie until I can work out something or relocate them all.
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Originally Posted by jimmyz80
What would be the recommended solution to spring surge? I'm not 100% sure on the springs, I'll need to check with the shop since they ordered them to be appropriate for my cam.
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Verdad Gallardo TECH Apprentice
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Originally Posted by jimmyz80
That would be awesome if you could post up some pics of the setup. Did you need to fabricate anything to move the alternator? What was the belt you ended up using?
I know it's hard to understand now but when I show you the pics you'll see how simple it is. I'll post them tonight.
Kind of sucks that we have to dick around with these heads after you shell out good money for them. For $30 ETP could have these parts made for us vette guys and save us some headaches.
the only time i see this same exact dip is with etp heads..I wish somone would figure out what on these heads is doing it..My opinion is the longer pushrods needed for these heads are just deflecting too much.
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Here's some pics of the alternator mod. Let me know if you have any questions.
http://i106.photobucket.com/albums/m...DSC00334-1.jpg
http://i106.photobucket.com/albums/m...6/DSC00335.jpg
http://i106.photobucket.com/albums/m...6/DSC00337.jpg
http://i106.photobucket.com/albums/m...6/DSC00336.jpg
http://i106.photobucket.com/albums/m...DSC00334-1.jpg
http://i106.photobucket.com/albums/m...6/DSC00335.jpg
http://i106.photobucket.com/albums/m...6/DSC00337.jpg
http://i106.photobucket.com/albums/m...6/DSC00336.jpg
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Joined: Jul 2005
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From: NJ
Originally Posted by vettenuts
Those are also very long pushrods, you might consider the 3/8" diameter to minimize pushrod flex or possibly tapered pushrods.
on pushrods length. im surprised they fit with that much milling you did on the heads. 
http://forums.corvetteforum.com/show...ght=alternator
I made a spacer setup similar to the one Phil used except the brackets are thinner hard steel and the holes are drilled exactly 7/8 on center. I did not want any adjustment to be possible. Also 7/8 vs an inch clears the brake lines under the belt in front of the alternator. If you clamp the brackets together when you drill the holes they will be spaced right. The belt with an ASP pulley is a Gates K060780(78 5/8"). It's a Cad. CTS 2003 3.2L belt. Car Quest has them.
With regard to pushrods the 3/8's will not fit, except with Jesels, according to ETP. I ordered a set of Manton's 5/16 x 8.125 x .118 wall. They should be plenty stiff and that will give me between 3/4 to 1 turn on the rockers or .037 to .050 preload. ETP says more than that may be the problem. I had .062 to .075. with 8.15's. I'll take out 1/2 turn. I'm skeptical that I had too much, but we'll see.
If anyone has cured the problem let us know how.
I made a spacer setup similar to the one Phil used except the brackets are thinner hard steel and the holes are drilled exactly 7/8 on center. I did not want any adjustment to be possible. Also 7/8 vs an inch clears the brake lines under the belt in front of the alternator. If you clamp the brackets together when you drill the holes they will be spaced right. The belt with an ASP pulley is a Gates K060780(78 5/8"). It's a Cad. CTS 2003 3.2L belt. Car Quest has them.
With regard to pushrods the 3/8's will not fit, except with Jesels, according to ETP. I ordered a set of Manton's 5/16 x 8.125 x .118 wall. They should be plenty stiff and that will give me between 3/4 to 1 turn on the rockers or .037 to .050 preload. ETP says more than that may be the problem. I had .062 to .075. with 8.15's. I'll take out 1/2 turn. I'm skeptical that I had too much, but we'll see.
If anyone has cured the problem let us know how.
