Rhoads lifters

Discussion in 'Street/strip 400/430/455' started by 41speciman, Oct 11, 2019.

  1. 41speciman

    41speciman Well-Known Member

    Crazy question I never have pushed on rockers after engine has sat a few days and I can push down on all lifters real easy with fingers even after starting it not sure what might be going on ?
     
  2. Bens99gtp

    Bens99gtp Well-Known Member

    Rhoades are anti pump up/bleed down lifters........they are made to not be fully bumped up at lower rpms, this shortendvthe lift and duration to make the car idle and drive better............but when running rpms there isn't enough time to bleed down so the cam performs closer to spec.


    So yes when the engine is off and there is 0 oil pressure they will bleed off and have a touch of play in them

    Totally normal for rhoades lifters
     
  3. agetnt9

    agetnt9 Agetnt9 (Dan)

    YEP...
     
  4. Stevem

    Stevem Well-Known Member

    Working as designed they are as Yoda would say!
     
  5. BQUICK

    BQUICK Gold Level Contributor

    Make sure you have plenty of oil pressure....Rhoads bleed pressure off
     
  6. 41speciman

    41speciman Well-Known Member

    Pressure gauge says 80 lbs oil comes out of rocker shafts so what is a touch of play ? Seems I can push them down till they bottom out after they sit awhile when I check them right after I shut it down most are tight and a couple on each head I can move on rocker shaft if the lobe is not opening the valve and the ticking noise is annoying. How much lift can cam have and not use those lifters. I have a set with lifter cup further down but they are melling lifters the cam is a Kenne Bell MK3 with adjustable pushrods
     
  7. Bens99gtp

    Bens99gtp Well-Known Member

    Is this a street car that needs the extra vacuum to have smooth idea.......if not there is not much need for them.

    I know some ppl use the to run a bigger than allowed cam in class racing.

    You still need to have proper pushrod lengths.

    I ran and still have a set........not in my race motor.........never had any issues with them
     
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Has nothing to do with lift. It's the duration that matters when it comes to overlap, low vacuum, and rough idle. The Rhoads lifters bleed down at idle reducing the duration so you have more vacuum and smoother idle. Then they pump up at higher RPM delivering full duration. If you want a cam recommendation, you'll have to provide more information like your static compression ratio and exactly what you expect from the engine and how the car will be used.
     
  9. 41speciman

    41speciman Well-Known Member

    I have a KB MK 3 In it now and seems ok so far seems ok and compression is 9-1 and decked almost zero piston is 009 in the hole
     
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Kenne Bell MK 3HB?
     
  11. 41speciman

    41speciman Well-Known Member

    Just has KB MK3 stamped on end it was purchased around 1982-83
     
  12. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    The only specs I have are for the KB MK3H. It is 252*/252* on a 106* LSA. That's pretty big and would be a good candidate for Rhoads lifters.
     
  13. BQUICK

    BQUICK Gold Level Contributor

    Like I said be wary of low oil pressure.....the cars I've seen them with have very low idle oil pressure. One motor had 5-10 at HOT idle and 25-30 after putting stock lifters back in. But I guess if it goes up to 60-80 when revving HOT it's ok. Sounds horrible at low speeds as well.
     
  14. 41speciman

    41speciman Well-Known Member

    I put adjustable pushrods in and it smoothed thing out some still is noise at idle at 20 lbs pressure. I have a lunati sp1228 cam but dont know what specs are was thinking of trying that one come spring
     
  15. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Probably SP1 cam. Lunati 33302?

    This is an old catalog from Buick1. They used to sell a variety of Buick cams,

    Buick1BBCams1.jpg Buick1BBCams2.jpg
     
    Last edited: Oct 14, 2019
    Darron72Skylark likes this.
  16. 41speciman

    41speciman Well-Known Member

    Thank you for posting that information Larry
     

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