232+ duration XER lobe, what valve spring...
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Re: 232+ duration XER lobe, what valve spring...
I don't know if this counts, but mine is a 229 duration cam with .578 lift. I run the isky 295D and they have about 7000 miles on them without any problems. My rev limiter is at 6800 right now so I might not spin them as high as others.
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Re: 232+ duration XER lobe, what valve spring...
I have a 228/236 XER cam in my car and I use the isky dual springs. 6000 miles and climbing with no problems. I would just use 918s if I did it again. They seem to work fine for just about any cam.
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Re: 232+ duration XER lobe, what valve spring...
I replied to your other post. From what I am told, you need Comp Dual 977 springs for anything over 232+ duration. I think the spring pressure was 400# open and I am guessing 170# closed.
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Re: 232+ duration XER lobe, what valve spring...
I've got comp 987's in my ls6 heads from absolute that I'll be using with big cam (236+). I know that they've been used successfully with the g5x2 (232/240). I think the problem with going to 978's or 977's is that you could run the risk of lifter pump at higher rpm... that's a lot of spring for a hydraulic roller. I guess I'll find out soon enough if the 987's can take it.
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Re: 232+ duration XER lobe, what valve spring...
I have 232/236 and I am running 918's. As of now I am not having any issues, but I have considered going with duals for my next setup..
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Re: 232+ duration XER lobe, what valve spring...
FDLS6 - Did you get the heads yet? Installed? I would double check with Jay. In testing, I am told the 987's went into valve float with a cam with a 232+ duration. I have a XE-R 236/240 with the 987's and my top end is flat. Jay thinks i and going into valve float. You are right, with the stiffer springs, you will need Comp R lifters...
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Re: 232+ duration XER lobe, what valve spring...
I've got comp r's... Jay felt that anything stronger than 987's might cause lifter pump even with the comp-r's that I have. I'm still putting the motor together, so nothing's set in stone. If I get nervous, I might go 978, which is in the middle I believe.
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Re: 232+ duration XER lobe, what valve spring...
I like 918s and the only problem with them is that they are a single spring and everyone knows what happens when they break. Even though the spring pressures arent real high, they are a lighter setup and therefore can sacrifice some pressure and still be effective. The Crane duals seem decent, but there arent too many people using these. As for the REVs...I've seen too many reports of broken ones, but I havent seen any blue stripe 918s that have broken. I'm also not sure why people say its duration that necessitates a higher spring pressure. Its ramp rate and lift. Doesnt matter how long you hold the valve open...its how fast and how far you are opening and closing it.
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Re: 232+ duration XER lobe, what valve spring...
Comp 977 or 978's. I am getting a set of stage 2 heads and a 230/236 cam from Absolute Speed and Jay insisted that he use 977's. He said that he has seen some valve float recently with G5X-2 and similar cams. They are a lot stronger than 987's.
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Re: 232+ duration XER lobe, what valve spring...
I have had 2 different tuners setup 987s and both times they have had valve float/bounce with CC 987s. I am very fustrated because I think my floating valves are now bent again with only a couple of hundred miles.....
Phillip
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