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roller block

This is a discussion on roller block within the Performance forums, part of the General Discussion category; this might be a dumb question but what is a roller block? does this apply to the camshaft or what? ...

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    roller block


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    this might be a dumb question but what is a roller block? does this apply to the camshaft or what? if it is the camshaft whats the difference between a regular cam vs. a roller one? sorry just tryin to learn all i can. thanks

  2. #2
    Registered User fastfew's Avatar
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    Re: roller block

    a roller block is usually 96 and up block with a roller cam and lifters ...

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    Re: roller block

    87+ camaro/firebird/Vette 305 and 350's and 265 L99's and 1996+ truck engines are all rolelr cammed engines.

    TBI truck engines are hit and miss, Ive seen them rolelr and non roller.

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    Re: roller block

    its easy to tell the difference in the cams, a flat tappet has skinny more pointed lobes and a roller has wider more rounded tips of the lobes, for the roller in the lifter to transition around the tip and back down the other side of the cam.. you can buy what they call a "retro-fit" hydraulic roller cam to fit in place of a factory flat tappet cam, thats what i did for the 383 i'm building.. hope this helps!
    Last edited by 91fullsize; 12-26-2009 at 05:10 PM.

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    Cars & Guitars 04SilveradoMykk's Avatar
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    Re: roller block

    A roller block simply means the block has two qualitys.

    The top of the block, in the lifter valley, has 3 pedestols that are drilled & tapped. The lifter retainer cage bolts down to the block here:





    And the front of the block, where the camshaft is, is also drilled & tapped to accept a camshaft retaining plate.



    When someone says they did a roller cam retrofit, it means they use a roller camshaft, a special kind of lifter with link bars:


    And a "Cam Button" that sits in front of the camshaft between the cam & timing cover to prevent the cam from walking forward.




    The difference between "Flat Tappet" and "Roller" cams is referring to the lifter style. A flat tappet is literally flat, as the name implies. It makes direct contact to the cam and slides on the cam lobe. The roller cam lifter, has a small wheel on the end that makes contact with the cam and rolls over the cam lobe. They are not interchangeable.



    There are several manufacturing differences, the benefit to the roller cam, aside from reduced friction, drag & heat is that roller cams can have more radical lobe profiles compared to flat tappet cams. Flat tappet cams have the lobes ground at an angle pointing towards the front of the block. As the cam spins and pushes up & down on the lifters the downward force on the cam from the pressure of the rest of the valvetrain is pushing the cam towards the back of the block and preventing cam walk.

    Roller cams do not have this angle ground into the lobes, so without the cam retainer plate (or cam button) the roller cam would want to keep rolling right out the front of the engine. We're only talking about a 'walk' movment of several thousandths of an inch, but that's enough to wreak havoc on cam timing events, as well as ignition timing.

    Roller lifters are re-usable when installing a new cam, wich is good cause their pricey. Flat tappet lifters need to get replaced when installing a cam, they are only re-usable if you install them on the same cam that was previously used and on the same lobe. Flat tappets wear or seat against the cam their mated to.

    Cheers ~Mykk
    Last edited by 04SilveradoMykk; 12-26-2009 at 09:48 PM.

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    Re: roller block

    ^ what Mykk said
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    Re: roller block

    Quote Originally Posted by 04SilveradoMykk View Post
    A roller block simply means the block has two qualitys.

    The top of the block, in the lifter valley, has 3 pedestols that are drilled & tapped. The lifter retainer cage bolts down to the block here:





    And the front of the block, where the camshaft is, is also drilled & tapped to accept a camshaft retaining plate.



    When someone says they did a roller cam retrofit, it means they use a roller camshaft, a special kind of lifter with link bars:


    And a "Cam Button" that sits in front of the camshaft between the cam & timing cover to prevent the cam from walking forward.




    The difference between "Flat Tappet" and "Roller" cams is referring to the lifter style. A flat tappet is literally flat, as the name implies. It makes direct contact to the cam and slides on the cam lobe. The roller cam lifter, has a small wheel on the end that makes contact with the cam and rolls over the cam lobe. They are not interchangeable.



    There are several manufacturing differences, the benefit to the roller cam, aside from reduced friction, drag & heat is that roller cams can have more radical lobe profiles compared to flat tappet cams. Flat tappet cams have the lobes ground at an angle pointing towards the front of the block. As the cam spins and pushes up & down on the lifters the downward force on the cam from the pressure of the rest of the valvetrain is pushing the cam towards the back of the block and preventing cam walk.

    Roller cams do not have this angle ground into the lobes, so without the cam retainer plate (or cam button) the roller cam would want to keep rolling right out the front of the engine. We're only talking about a 'walk' movment of several thousandths of an inch, but that's enough to wreak havoc on cam timing events, as well as ignition timing.

    Roller lifters are re-usable when installing a new cam, wich is good cause their pricey. Flat tappet lifters need to get replaced when installing a cam, they are only re-usable if you install them on the same cam that was previously used and on the same lobe. Flat tappets wear or seat against the cam their mated to.

    Cheers ~Mykk
    nice explanation!! i wish i had a roller block im going to have to get a retrofit myself

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