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Discussion Starter · #1 ·
I am braking inner springs and sec springs on two - four passes . These are nextek 448 and 449 . What other spring can i use with better life in them .
P.S or is this maybe just a bad bunch . :confused:
Thank for the help
 

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I have NEVER broke a Nextec.

I have broken KMotion, comp and PSI.

Are you breaking the same cylinders everytime?
 

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Discussion Starter · #3 ·
No i am breaking diff . I not even rev this thing , cam is big . but the lobe is not that aggressive .
 

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Discussion Starter · #5 ·
int 277at .50 , ext304 at.50 9000 rpm int rocker 1.8 lobe lift 515.
ext 1.7 490lobe lift Center line 115
 

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I broke one inner on a set of nextecs and found most of them were down on pressure after about 50 passes or so. We attributed it to two factors. #1 a heavy stainless valve, switched to a Ti valve to help that out. #2 At max lift we were below the recommended open height which we believe was causing spring surge and premature failure. We set the springs up about .060" shorter and that put us in the ball park when open no further issues.

Craig
 

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we use alot of the 448 and 449p spring with good results. somtimes you do get a bad batch so to speak. that said, what i see most often is retainer diferences. check to see the step is correct for the inner springs. somtimes it will make the inner go solid. you may have already checked it but i thought i would throw it out there.

good luck
 

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Discussion Starter · #8 ·
Is there anyone using the PAC 1355 dual spring , if so are you having good luck with them ? The are exspensive !
 
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