CC 981 Valve Springs
CC 981 Valve Springs Anybody have any experience with the 981 Dual Springs. I have a set and would like to install them. Do the heads need any mods. I want to use the for either a hotcam or cc503.
Thanlks
Thanlks
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comp specs say they have 105 seat and 273 open....sounds like a pretty light spring for a 503...and the seat pressure was at 1.700 installed height"...which is tighter than stock so you would need to use shims or the pressure would be less at 1.75x" installed height
I would look into another spring
I would look into another spring
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Joined: Apr 2008
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they will work if you cut the valve stem outer guide down to .500 and machine the spring pockets to allow a 1.800" installed height...so yes. You need to buy .500 valve guide seals, no problem getting those.
I ran those springs years ago on a H/C 350 with a mild cam. Had 10 degree locks/retainers.
Since you have them they would "work", just not what most would run today given other choices
I ran those springs years ago on a H/C 350 with a mild cam. Had 10 degree locks/retainers.
Since you have them they would "work", just not what most would run today given other choices
Ok Ok, what would you recommend running. It's my DD so I'm not looking for anything radical. I just want a little extra out of it, that's why I was thinking on running either the hotcam or the 503.
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Verdad Gallardo TECH Veteran
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you can buy a tool to grind down the guides while head is on car. Don't think there is one to do the pockets though with head on car. I would be super **** though on capturing all metal shavings
Fortunately there are good spring choices now where you don't have to do that.
The dual 987's, yes you do have to. At the very least do the guides as the inner spring will hit the valve stem seal. If you don't grind down the spring pockets the installed height would then be 1.75x so the open and seat pressure would be more than spec for the 987's installed at a shorter height. Depending on the lift of the cam you could be at or close to coil bind so you would have to check for that
Fortunately there are good spring choices now where you don't have to do that.
The dual 987's, yes you do have to. At the very least do the guides as the inner spring will hit the valve stem seal. If you don't grind down the spring pockets the installed height would then be 1.75x so the open and seat pressure would be more than spec for the 987's installed at a shorter height. Depending on the lift of the cam you could be at or close to coil bind so you would have to check for that