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Paging anyone that has had trouble with double springs and rockers

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Old 08-21-2002, 01:43 PM
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Default Paging anyone that has had trouble with double springs and rockers

Guys,
Can you describe what happens when you had your springs hitting the rockers?
Describe your dyno and AF ratio etc when this happens. How much did you clearance the rockers?
Cheers,
Chris
Old 08-21-2002, 01:48 PM
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Default Re: Paging anyone that has had trouble with double springs and rockers

you'll get some extra valvetrain noise and your retainers will be screwed up.

<img src="https://ls1tech.com/howto/infopics/rockerclearance01.jpg" alt=" - " />
<img src="https://ls1tech.com/howto/infopics/rockerclearance02.jpg" alt=" - " />
Old 08-21-2002, 03:08 PM
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Default Re: Paging anyone that has had trouble with double springs and rockers

Email Vince, he can tell you ALL about this <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Old 08-21-2002, 03:14 PM
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Default Re: Paging anyone that has had trouble with double springs and rockers

Chris,

When the valve closes, it wants to bounce off the seats. This gets worse at higher rpm (bigger bounce). If your rocker to retainer clearance is too tight (less than .050"), the valve can bounce up knocking the retainer into the bottom of the rocker arm, seriously upsetting the dynamics of the valve spring.

When this contact happens, it will make your motor seem just like it's experiencing valve float...but it's not. Mine occured at 6400 rpms. Wouldn't pull higher than 6500. My springs are good to at least 7500 rpms with the light valves and retainers I'm running. Something was FUBAR. Thanks to Vince and JMX for solving my problem. It kicked my *** for about 5 months!!!
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Old 08-21-2002, 03:21 PM
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Default Re: Paging anyone that has had trouble with double springs and rockers

This is what the stock rocker looks like with a 944-17 double.

<img src="http://www.sigma-epsilon.org/steve/images/performance/headcam/day4/MVC-163S.JPG" alt=" - " />

This is all the material I've removed.
<img src="http://www.sigma-epsilon.org/steve/images/performance/headcam/day5/MVC-178S.JPG" alt=" - " />
<img src="http://www.sigma-epsilon.org/steve/images/performance/headcam/day5/MVC-179S.JPG" alt=" - " />

I've had the covers off since then and I have no scratches in the retainers (after about 3000 miles on the car). So I guess I cleared them enough!

<small>[ August 21, 2002, 03:21 PM: Message edited by: derty ]</small>
Old 08-21-2002, 03:26 PM
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Default Re: Paging anyone that has had trouble with double springs and rockers

Cool thanks guys!
Cheers,
Chris

<small>[ August 21, 2002, 03:30 PM: Message edited by: Chris ARE 360 ]</small>
Old 08-21-2002, 03:46 PM
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Default Re: Paging anyone that has had trouble with double springs and rockers

Is the rocker arm mod needed with the Comp 987 double springs or just the 944?
Old 08-21-2002, 04:14 PM
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Default Re: Paging anyone that has had trouble with double springs and rockers

Chris give me a shout.. I can tell you all about it..
Old 08-21-2002, 04:18 PM
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Default Re: Paging anyone that has had trouble with double springs and rockers

I just cleared mine until I got about .040" clearance or more. Whatever you can do to move that away from the spring and the retainer the better. It only takes about an hour or two to do them all. I used a dremel tool with a grinding tip. Worked great and was very easy. Just don't breathe the dust!




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