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Some parts too look at (Valvetrain)

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  • Mars
    replied
    Originally posted by tejohnson
    Do they fit the valve guides snug? What is the ID? Part number please?
    I brought the valves, seals, seats, everything to my machine shop. He threw them together for me. Reputable shop, they know their stuff, and didn't have any trouble with anything fitting. Stock GM parts.

    (12) LS1 spring shim (seat) 12565118

    Keep in mind I also used :

    (6) 1991 3.1L valve stem seals (exhaust)
    (6) 1991 3.1L vavle stem seals (intake)

    Leave a comment:


  • tejohnson
    replied
    Originally posted by Mars
    They fit pre 2000 heads. they are copper coloured.
    required no mods at all on my 1999 3400 heads.
    Do they fit the valve guides snug? What is the ID? Part number please?

    I bought a set of Comp, but they are .570 ID (worried about chatter against the valve guide), so I am dumping them cheap.

    BTW, if anyone is interested in Comp ID locators (4785-16):

    Leave a comment:


  • Mars
    replied
    They fit pre 2000 heads. they are copper coloured.



    Assembled.



    required no mods at all on my 1999 3400 heads.

    Leave a comment:


  • SappySE107
    replied
    Do those gold seats work? They dont fit any of the heads I have tried them on so im wondering if you have had any luck with them.

    Leave a comment:


  • Mars
    replied
    I can confirm the valve float at high RPM with stock Gen III springs. With a centrifugal blower, it is even more noticeable beause the higher the revs get, the more boost is produced, consequently, the more valve float you get.

    Just to compare, the LS6 style is quite a steup up from the stock 3X00 spring...

    Leave a comment:


  • tejohnson
    replied
    Shop I am workin with feels up to .475 would be safe...

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  • SappySE107
    replied
    That says .580 lift which would be .480 lift on our setup.

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  • geoffinbc
    replied
    Woops 26915

    Edited old post

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  • tejohnson
    replied
    Originally posted by betterthanyou
    Springs are 16915-16 (or-1 order 12 times)
    Retainers are 787-16

    The Comp springs were also cheeper than the LSx springs and I get Cost+10% on GM parts. So thats good news.
    Is it 16915-16, or is it 26915-16? Also, for the LS6 Springs, Lingenfelter is purdy cheap:



    But I figure you get them cheaper...

    Leave a comment:


  • torq455
    replied
    Lets not forget what types of lifters we are using. Rollers are heavier. If I had the rollers and bigger cam, I'd want the LS2/6. For the hybrids, I don't see why one couldn't use the LS1 on the 272 with 1.6 rockers. Oh, and great find on the retainers and springs!!

    Leave a comment:


  • torq455
    replied
    Lets not forget what types of lifters we are using. Rollers are heavier. If I had the rollers and bigger cam, I'd want the LS2/6. For the hybrids, I don't see why one couldn't use the LS1 on the 272 with 1.6 rockers.

    Leave a comment:


  • tejohnson
    replied
    I have LS6 springs, SI valves, stock retainers and keeps, and viton seals. Just lookin for something to serve as a good seat. Was eyeing the Crane valve cups for the LS1 (144460-16) which Pace sells them for $~28, but I will need to open the ID up from .505 to .550.

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  • SappySE107
    replied
    Id use the stiffer spring with boost.

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  • AaronGTR
    replied
    Stock LA1 springs are 75lb @ 1.701" and 230lb @ 1.260". Thats .441" of measured compression, and the LA1 has .436" of valve lift. Stock LS1 springs are 76lb @ 1.8" and 220lb @ 1.32". Thats .480" of measured compression, and the LS1 has .472/.479" of valve lift. So basically an LS1 spring at an LA1 installed height and lift would have slightly higher closed pressure and about the same open pressure. Not a whole lot of difference though. I have a set of LS1 springs left over if you want 'em.



    Thats interesting info on the retainers. I assume they made them so they also sit on the valve at the same height so they don't interfer with the rocker? Using those would lower your spring pressure a tiny bit too (if thats what you wanted). I don't see much use for them though since we've pretty much determined the LS6 springs will let us run plenty of lift still even at our lower height.

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  • tejohnson
    replied
    How about stock cam with forced induction? 5200RPM @ 11 PSI did a pretty good job at practically pushing my valves open with the stock springs. The valve float was very noticable. What keeps do ya use with those retainers? Finally, what seats are you looking at? ID locaters, or OD cups?

    Leave a comment:

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