Anyone Use Rail-style Roller Rockers?

Discussion in 'Ranchero Tech Help' started by colnago, Mar 27, 2019.

  1. colnago

    colnago In Fourth Gear

    Messages:
    409
    Location:
    Ridgecrest, CA
    Long story short, I'm needing to get a set of rail-style rocker arms. I was wondering if anyone has used roller rockers on an engine/head that used the rail-style rockers, and if you noticed any difference (good or bad) between the roller rockers and the non-roller rockers.

    Thanks,

    Joseph
     
  2. Basstrix

    Basstrix In Maximum Overdrive BRONZE MEMBER

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    Location:
    Phoenix, AZ
    The closest I've come is to use a set of roller tipped rockers on a 302 I built for a 70 bronco I wish I'd never sold. It used guide plates, so can't comment on the rail aspect. I think the main benefit of roller tips is the reduction in fore to aft loading of the valve stem as the rocker sweeps an arc through it's range of motion. By only changing to roller rockers, I doubt you'd get a significant change, if any, in horsepower from that alone.

    I will say, that by not using guide plates, the alignment load is reacted through the valve stem, thus you'll still get the same guide wear (in that direction) with rail guided rockers.
     
    pmrphil likes this.
  3. colnago

    colnago In Fourth Gear

    Messages:
    409
    Location:
    Ridgecrest, CA
    What?!? But Comp Cams said I could pick up 15 - 30 HP! Darn them marketers!

    Yeah, I don't think I'll pick up anything. I'm just thinking about decreasing the wear on the valve stems themselves, and overall reliability, if I go with roller rockers. I had the valve covers off on my 289 (with 302 heads) the other day, and noticed that it SHOULD have rail rockers, but doesn't. So, since I have to get a set anyway …

    Joseph
     
  4. Basstrix

    Basstrix In Maximum Overdrive BRONZE MEMBER

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    Location:
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    If it should have rail guided rockers and it doesn't, it has to have something keeping the rockers on top of the valve stems. Sounds like you may be OK as is...or at least until you're ready for a rebuild and upgrade to came and valvetrain.
     
  5. colnago

    colnago In Fourth Gear

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    409
    Location:
    Ridgecrest, CA
    A hope and a prayer, maybe. I need to dive into the girl this weekend, and find out more about how the PO put things together. There seems to be a lot of slop in the push rods and rocker arms. I'll see if I can find some part numbers or casting dates somewhere.

    Joseph
     
  6. pmrphil

    pmrphil In Overdrive GOLD MEMBER

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    Take a picture. It may reveal a lot of info that others have seen or know.
     
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  7. colnago

    colnago In Fourth Gear

    Messages:
    409
    Location:
    Ridgecrest, CA
    Well, I popped into the valves again today. Looks like the PO used rail rockers after all. Dunno why I didn't recognize them before. I did notice that it seemed to be easier to push the rockers in one direction vs the other direction. I assUme that is due to wear of either the rocker tips or the valve tips. Either way, I probably don't want to reuse these rockers on a rebuild ... right?

    Joseph
     
    Last edited: Apr 1, 2019
  8. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

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    Everett, WA
    Yeah, not a good idea. Listen, you definitely want newer heads. Later Windsor engines have the pedestals machined to accept the square base of the trunnions (that's the arm's 'fulcrum') to prevent side-to-side movement of the arms. Now, IIRC, not only are there stamped arms with a roller tip that fit the factory trunnion, there should also be aluminum roller-trunnion arms with roller tips that are adjustable, and have the square bottom that fits the pedestals on the heads.
     

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