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Thread: 0.100" preload Caddy Race Lifters?

  1. #1
    Advanced Tuner GapRider's Avatar
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    0.100" preload Caddy Race Lifters?

    I have searched, read, called and I only see one reference to the recommended preload for Caddy Race lifters which I installed with my CAM MOTION cam - 0.050" to 0.100" on the BTR website.
    I read one guy on a forum that stands out saying he runs 0.100" or greater preload on those lifters, most stay closer to the 0.060 to 0.080 range.

    I have right at 0.100" preload with my aftermarket stock length 7.850"pushrods.

    I really feel like I should replace them with 7.825" to reduce my lifter preload closer to the middle of the recommended range.

    Can someone chime in on this to help me decide?
    2019 C7 Stingray M7 - long tube headers, 6.30/6.22 226/238 cam, supporting stuff, DOD and VVT delete.
    Stock everything else

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    For whatever it's worth I do not have any experience with those particular lifters, but I can say that .030" extra "too much" preload is enough to float valves even at idle on shorter travel stiffer spring lifters. On the other side of that I have seen weaker internal spring lifters require more preload - I've personally run 1.5 turns on some like that years ago with adjustable style rockers, so if that is indeed what "those" lifters call for, then....
    2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
    2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80

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    Advanced Tuner GapRider's Avatar
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    Quote Originally Posted by GHuggins View Post
    For whatever it's worth I do not have any experience with those particular lifters, but I can say that .030" extra "too much" preload is enough to float valves even at idle on shorter travel stiffer spring lifters. On the other side of that I have seen weaker internal spring lifters require more preload - I've personally run 1.5 turns on some like that years ago with adjustable style rockers, so if that is indeed what "those" lifters call for, then....
    thanks so much for your insight, more to think about.
    Your 1.5 turns is another relatable data point for me as mine are at 1.25 turns.
    With the M8 rocker bolt with 1.25mm pitch and a 1.8 rocker ratio that comes out to 0.095" preload if my calculation is right (1.25/25.4 x 2.8/1.8 x 1.25 turns) - so I feel a little better.
    I wish I could find actual GM documentation that tells me the dimensions and full plunger travel of those lifters - GM 88958689
    2019 C7 Stingray M7 - long tube headers, 6.30/6.22 226/238 cam, supporting stuff, DOD and VVT delete.
    Stock everything else