XE268H fitment

Discussion in '96-04 - 2V Specific' started by NMB3, Mar 18, 2014.

  1. NMB3

    NMB3 New Member

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    I've done a bunch of reading on cams when searching for a used set and came across a set of 268h's for sale and picked them up. From all of my reading they will drop in and clear fine with my PI heads on NPI engine, but what I can't seem to get a definitive answer on is valve springs. Most of what I read leads me to believe the stock 02 PI springs will handle the xe268's fine, but I just want to make sure before I do this, as I don't have time to mess around.... (I work 4weeks on 2 weeks off rotation, and I'm doing this next week on weeks off).

    I know they are a cheapish upgrade but this PI swap snowballed with mods and what started as heads and intake turned into that plus cams, injectors, headers, exhaust, tune...so on and so forth so I'm running a bit low on funds.

    Thanks in advance,

    Justin
     
  2. DropTopPony

    DropTopPony Administrator Staff Member Admin SN95 Supporter

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    Should be ok with clearance IIRC those cams were the stage 2 NPI cam and spring upgrade was suggested. To be honest though I have seen so many people pop in more aggressive cams than those with stock springs and not run into any issues. You could always upgrade later if you do a port job.
     
  3. NMB3

    NMB3 New Member

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    I will eventually be building that 02 shortblock and do a turbo build.

    Thanks for the quick response.
     
  4. NMB3

    NMB3 New Member

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    I was trying to find a cam card so I could see ramp rates, and I also don't know what the springs are like stock. When I built my 5.0 in my buggy I used gt40p heads and I was told with the XE258 grind they would be fine..... they didn't bind, but with the aggressive ramps it caused them to float slightly, and I had to pull it apart to swap an Alex's kit in.

    Just wanted to make sure this wasn't the case here, which it doesn't sound like it is.
     
  5. 96blak54

    96blak54 Legend

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    Droptoppony nailed it!
    Ptv contact will be reduced because of lower lift with a specific npi cam. I cant see the reason springs are required with these cams in a npi head, because of spring installed height. I cant remember what the actual heights are but their is over a .100" difference between the two. Pi having the taller install height and if pi can get away with thumpy cams with stock springs then npi should be ok. I think most of the valvespring upgrade is hype. I see junkyard 4v's pulling out a 7000rpm drop and shift points with basically the same stock valve springs but shorter.. Im rambling on here...sorry. Youll be fine. Besure to degree the cams in or you WONT be fine.
     
  6. four.six

    four.six Member

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    I have those cams in my PI swapped 98 GT.... DEGREE DEGREE them... When I first put them in I has PTV issues, didn't degree them.. After fixing everything I degreed them and no issues those cams have a 4 degree advance ground into them combine that with the slop in the key way on the bolt on cam gears one bank was advanced over 8 degrees. It's not the lift that's the killer its the duration. Also still running the stock valve springs in mine.
     
  7. Wichers123

    Wichers123 Well-Known Member

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