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Thread: roller rocker use?

  1. #1
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    Question roller rocker use?

    can I use used roller rockers? I 'm sure I'd want to replace the pushrods

  2. #2
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    Yes you can use roller rockers, and you can replace the pushrods if you want to but it isn't necessary unless changing the cam to one with a smaller base circle.

    BTW..why are you wanting to install roller rockers ?

    David
    1991 SC AOD 4.2..2.3 Whipple..........10.910 @ 125.61
    2016 SRT Challenger Hellcat.............10.597 @ 135.78

    My Garage

  3. #3
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    I haven't gotten an answer to this from either owners, manufacturers, shops, etc.
    A roller tip effectively lengthens the valve stem by the roller radius (compared to an OEM rocker with the same contact point), which may be as much as 3/16" (3/8" roller tip is common).

    The question: is compensation for this built in to the rocker design (viz. the rocker axle is located lower)?

  4. #4
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    Aside from the reduced friction and corresponding temperature drops, roller rockers are precisely machined to maintain exact ratio. Try and say that about the factory stamped sled rockers.

    Unlike sled rockers, the ratio does not change through the range of motion either. Seems like good reasons to me.

  5. #5
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    Thumbs up

    They free up hp in the upper rpm's and just less friction better on valvetrain. They are a much better design. But unfortunatly very expensive for these cars brandnew.
    Last edited by stempak; 09-22-2007 at 08:46 PM.

  6. #6
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    Quote Originally Posted by Flex View Post
    Aside from the reduced friction and corresponding temperature drops, roller rockers are precisely machined to maintain exact ratio. Try and say that about the factory stamped sled rockers.

    Unlike sled rockers, the ratio does not change through the range of motion either. Seems like good reasons to me.
    If doing ported heads and a more agressive cam, yes I would upgrade the rockers and pushrods too. But just doing rockers and pushrods for increased HP on an otherwise stock motor isn't something I would reccomend. Mainly because it's not going to make any noticable increase in power.

    There are many other things that can be done to increase power before pulling the rocker covers.

    David
    1991 SC AOD 4.2..2.3 Whipple..........10.910 @ 125.61
    2016 SRT Challenger Hellcat.............10.597 @ 135.78

    My Garage

  7. #7
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    David,

    I have heard that argument before and I say bull. These are the same stamped steel rockers Ford used on the 351C/M/400 and 429/460. They suck. My Clevelands had over 20 thou variation in lift across the set. Your .500 lift cam is now a .480 on one cylinder and only a handful were actually 1.73. The ratio on a sled rocker also changes as it moves through it's arc. Not so with a roller.

    Stempak,

    Search the boards for lightly used ones. I just bought a set of 1.8's that are adjustable CSP pieces for $175 shipped to my door.

  8. #8
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    The only way the ratio on a rocker, any rocker, regardless of construction or ratio, will not change during its range of motion is if its length is infinite.

  9. #9
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    This is directly form the Ford Performance Handbook page 221. Here they are talking about a 5.0 rocker.

    "The rocker arm ratio on a non GT-40 engine varies mechanically, due to the design of the sled-type OE fulcrums. At the point of maximum lift, the (sled type) rocker ratio is effectively 1.59:1. This number is commonly rounded off to 1.60:1. At points of less than maximum lift, the sled fulcrums and the slotted rockers cycle the effective rocker ratio between 1.53:1 and 1.60:1. Minor production variations and some flex under load also affect the stock steel stamping's effective ratios. Unlike sled fulcrumed rocker arms, a true roller type (used in the 1993 Cobra GT-40 engine) operates with a constant ratio to provide a definite performance benefit in many applications."

  10. #10
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    That's very interesting. It's also wrong.

  11. #11
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    How so? Some explanation of your reasoning might help

  12. #12
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    Thumbs up

    Anytime you can eliminate metal to metal your gonna get more power. I bet putting on roller rockers you'll get 2-5hp in stock trim!

  13. #13
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    In the N/A Mustang forums, that is what most found at the dyno was about 3-5 hp with the 1.73 rollers. The 1.8's cam in at a bit more showing about 7- 10 hp.

  14. #14
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    Quote Originally Posted by stempak View Post
    Anytime you can eliminate metal to metal your gonna get more power. I bet putting on roller rockers you'll get 2-5hp in stock trim!
    There are many things you can do to increase performance. I just don't think spending $175 for rockers plus whatever it cost for pushrods and gaskets, plus about 4 hours labor minimum under the hood is worth a measly 3 HP.

    For example you could get 15 HP from a 5% jackshaft pulley that takes about 20 minutes to install. You could get another 15 from a set of underdrives...another 2 from removing the air silencer.

    David
    1991 SC AOD 4.2..2.3 Whipple..........10.910 @ 125.61
    2016 SRT Challenger Hellcat.............10.597 @ 135.78

    My Garage

  15. #15
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    Lightbulb

    that also! there's alot of hidden hp in these cars!

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