Valve spring sitting on top locator?
#11
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iTrader: (7)
I agree unless for a stock cam. I had those in a build years ago and tossed them. Wasn’t much more than a 420 cam.
Definitely check the installed height on all and compare as unlimited mentioned. Even with the light pressure a seat could still go out or get driven up in the head resulting in even much less pressure to allow the spring to flop around.
Last edited by getrdunn; 02-01-2021 at 12:16 PM.
#12
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iTrader: (8)
I agree unless for a stock cam. I had those in a build years ago and tossed them. Wasn’t much more than a 420 cam.
Definitely check the installed height on all and compare as unlimited mentioned. Even with the light pressure a seat could still go out or get driven up in the head resulting in even much less pressure to allow the spring to flop around.
Definitely check the installed height on all and compare as unlimited mentioned. Even with the light pressure a seat could still go out or get driven up in the head resulting in even much less pressure to allow the spring to flop around.
#13
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I spoke to my head guy (JimV) tonight about this.
Conversation...
Jim: Probably from valve float and asked if an inner spring was broken.
Me: No broken inner spring
Jim: Weak springs.
Me: Springs are Comp 911 120/309 (140/338)
Jim: Hydraulic Flat tappet in a 496?
Me: Hydraulic Roller
Jim: Those are light on pressure
I showed him a pic of the spring out of location
Jim: Why is he using spring cups and not locators? Locators are to center the spring to the valve guide.
FWIW
Conversation...
Jim: Probably from valve float and asked if an inner spring was broken.
Me: No broken inner spring
Jim: Weak springs.
Me: Springs are Comp 911 120/309 (140/338)
Jim: Hydraulic Flat tappet in a 496?
Me: Hydraulic Roller
Jim: Those are light on pressure
I showed him a pic of the spring out of location
Jim: Why is he using spring cups and not locators? Locators are to center the spring to the valve guide.
FWIW
Last edited by Rookie; 02-01-2021 at 07:19 PM.
#14
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The 911 spring does not have an "inner" spring. It is a single spring with a damper. Not much more than a stock BBC spring. Certainly not what i would use on a Hydraulic Roller. What does Comp call for on your cam ? They usually want at least 130 seat and close to 400 open.
#15
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iTrader: (4)
The 911 spring does not have an "inner" spring. It is a single spring with a damper. Not much more than a stock BBC spring. Certainly not what i would use on a Hydraulic Roller. What does Comp call for on your cam ? They usually want at least 130 seat and close to 400 open.
#16
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Thanks again for the help. Valve float and weak springs it is.
Comp actually recommends the 911 spring for their smaller hyd roller 8.1 grinds. The 924 and 930 for the XM284HR which is pretty close to my cam.
I called CamMotion about my grind and they rec'd 145-160 seat and 360-390 open.
Need to look a lil more but the Comp 929 looks to fit my needs nicely. I believe it was also the stock valve spring on Merc's 500EFI.
Comp actually recommends the 911 spring for their smaller hyd roller 8.1 grinds. The 924 and 930 for the XM284HR which is pretty close to my cam.
I called CamMotion about my grind and they rec'd 145-160 seat and 360-390 open.
Need to look a lil more but the Comp 929 looks to fit my needs nicely. I believe it was also the stock valve spring on Merc's 500EFI.