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Looking for opinions....

Discussion in 'The Garage' started by SUBFAN, Aug 24, 2003.

  1. SUBFAN

    SUBFAN 1/2 ton status

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    Variable duration lifters:

    Why don't I see more about these on here? In theory, their benifits should be a win / win situation for those of us trying to get these heavy rigs moving.

    I'm just looking for opinions or experience with these, Thanks....
     
  2. Beast388

    Beast388 1/2 ton status

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    Kelly, I ran a set of Rhoads lifters in my last 350 with a Comp 270H cam. I didn't really notice any improved low end over regular lifters. The worst part was that I was often asked what was wrong with my valvetrain because they ticked so annoyingly.

    A buddy of mine ran Crane's version, the ones that are variable duration but much quieter than "Brand R", and was not that impressed either. They were much quieter, but we both felt that they did little for the low end power of his 350 powered '80 Regal. /forums/images/graemlins/deal.gif /forums/images/graemlins/thinking.gif /forums/images/graemlins/thinking.gif
     
  3. SUBFAN

    SUBFAN 1/2 ton status

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    I realize they don't reduce the duration by much in the lower RPM's, but putting in a new cam, how could you really tell if they worked or not? Did you pull those lifters and replace with the regular kind? ( I know this isn't recommended )

    I would imagine seat of the pants feel would be difficult to feel at this level....

    If that 350 you built had your gear-drive, those are some noisy lifters to hear them over all that racket /forums/images/graemlins/thumb.gif
     
  4. rodzzilla

    rodzzilla 1/2 ton status

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    A freind had a set in a 402 powerd 77 2wd about 10yrs ago. It ate the cam. It was a 280H Comp. I think it was probably the cams fault. That was during comp's SOFT yrs. Before it commited suicide, it did tame the cam down for some respectable low end.
     
  5. Beast388

    Beast388 1/2 ton status

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    The whole idea behind a variable duration lifter is to bleed off duration at low RPMs to help make low-end power. Once you get the RPMs up, there is no time to bleed off so thay act like a regular lifter.

    While I never ran a different lifter with that cam, that engine didn't come alive until 2500-3000 RPM. The ads for Rhoads lifters made it seem that I could run a larger than recommened cam and still make power down low. That wasn't the case. They probably made some improvement, but were no where near what I expected.

    I ran a regular double roller in that engine, so no whine. /forums/images/graemlins/thumb.gif In fact that engine still had a good lope at idle, so the lifters didn't bleed off enough to smooth that out. /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif
     
  6. Beast388

    Beast388 1/2 ton status

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    [ QUOTE ]
    It ate the cam. It was a 280H Comp. I think it was probably the cams fault.

    [/ QUOTE ]

    Funny you should say that. That was the same demise as my 350. After about 5 years of running the Comp270H/Rhoads combo, I lost two lobes off the cam. /forums/images/graemlins/angryfire.gif /forums/images/graemlins/eek.gif /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif
     
  7. SUBFAN

    SUBFAN 1/2 ton status

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    And a 270M really isn't that big....

    I'm still listening, thanks Roddzilla for the reply too....
     
  8. Z3PR

    Z3PR Banned

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    270H is about as big as you can go and use a stock torque converter. Or so Comp said.
     

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