Street thumper - how much can GM rollers take? Are LS lifters better?

Discussion in 'Engine Topic' started by fstarocka, Jan 29, 2021.

  1. fstarocka

    fstarocka Member

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    On the final leg of my 383 build, comp beehive springs, 1.6 full roller comp rockers, 2.02/1.6 aftermarket ALU heads (+- 265 cfm intake at 600 lift), comp xr288 cam, vic jr, 850 holley, 373 rear, 3k stall, LT headers 1-5/8 or 1-3/4..

    Wondering if the LS lifters are the same as the GM L31 ones? If they are indeed better then I will use them -

    Otherwise if the same and the LS can rev almost to 7k stock then the L31 lifters will be fine- trying to determine if and by what margin its necessary to spend $ on exotic lifters now or later-

    BTR has a set of LS lifters for $135 or there abouts iirc..

    Thoughts?

    Its possible I might have the intake off for testing - so no biggy to swap lifters at a later stage..
     
    Last edited: Jan 29, 2021
  2. hoppy

    hoppy New Member

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    Sbc L31 lifters and ls lifters are the same
     
  3. biker

    biker Veteran Member

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    You do raise a good question though. All things being equal, what allows an LS engine to handle 6800 rpm without floating the valves? Lighter valves than a roller lifter SBC?
     
  4. fstarocka

    fstarocka Member

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    In my very inexperienced guess - its probably the spring setup.. I cant see much of a difference between 11/32 and 8mm stem valve making so much difference - they are about the same.. My 2 dollar bet would be the springs are why.. The beehive with its progressive action vs regular coiled ones on the L31/hot rods.

    fwiw this is the reason I bought beehives - superior action in every way-

     
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  5. biker

    biker Veteran Member

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    Thanks man. I've been considering my valve springs as a potential weak point since they came with my heads and while I know the specs, I dont know who makes them. Everyone says how great the beehive style is, so it might be a wise upgrade.
     
  6. sandlapper

    sandlapper Veteran Member

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    Lifter belt & suspenders.
    Depending on how you'll use it: Johnson 2110 or reduced travel 2110R; surrender wallet.
    Check geometry/measure pushrod length ... again.
     
  7. Rustbucket350

    Rustbucket350 Veteran Member

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    I've successfully revved a stock bottom end 350 with stock valve springs to 7500 rpms with no problem. What makes the LS lifters better? Probably luck.
     

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