CHOP CULT HOME
Email Password
Search
  1. #1
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    May 2019
    Posts
    672

    Default Pushrod Diameter Question?

    EVO oiling for the Shovel has kind of fascinated me. I picked up some EVO lifter blocks and some rockers and mocked the old heads with some light springs..

    Everything looks pretty good. As JB said, the rockers are too long. I think I can end mill those things off. (I now understand why some people are using a stepped spacer.)

    Putting some black marker on the rocker and valve stem area reveals they line up very well, actually. Have to grind in the boxes a little, but everything looks pretty good except for the pushrods. They get close to the covers and may rub at the top, where the rods enter the rocker box.

    All I have to test with are the 7/16th rods that came out of it..

    Does anyone know of a quick install/collapsible style 3/8" pushrod that will work in this application?

    I'm pretty sure everything would work just fine with a set of smaller pushrods.

    ??

  2. #2
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Dec 2017
    Posts
    2,560

    Default

    Not sure what you are doing there, but I see these with 3/8":

    Hurricane Chrome Moly Pushrods

    NRHS is proud to offer our own line of super strong pushrods. We looked at all the features we wanted in a pushrod and incorporated them into this product. We started with high strength heat treated seamless 4140 chrome moly tubing, for outstanding rigidity under even the most demanding conditions. “Mae West” ends accommodate high lift cams without concern for the end coming out of the rocker arm seat.
    Twin Cam and Evo Big Twin sets include different lengths for intake and exhaust to maximize the amount of thread engagement and make the assembly stronger.

    Available in ultra stiff .065 straight 3/8” wall design, or a tapered design for the ultimate strength to weight ratio without the rub problems common with 7/16” pushrods. Tapered style are also available sized for fast installation (fast install available for Big Twin & TC88 only).

    Available for standard applications or specify custom working length, wall thickness, and whether or not you need oil holes. Custom fixed length (non-adjustable) pushrods also available.

    https://www.nrhsperformance.com/partsvalvetrain.shtml

    oh, check their Tech Tips on that page too.

  3. #3
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    May 2019
    Posts
    672

    Default

    Cool.. Thanks.

    I notice they mention 7/16" rubbing issues also.

  4. #4

    Join Date
    Dec 2018
    Posts
    1,713

    Default

    S&S offer a set of adjustable pushrods that have a wide range of adjustment, something like 9 1/2 to 11 1/4. I think they are 3/8 diameter.

    Jim

  5. #5
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2010
    Posts
    12,398

    Default

    Jim's, at one time, made pushrods from Titanium, he called them "Signature Series"

    No longer available, but there are some NOS still around ...

    (Got a set in my Buell, their light as a feather)
    Last edited by Dragstews; 12-30-2019 at 2:10 AM.

  6. #6
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    May 2019
    Posts
    672

    Default

    Thanks everyone..

    I can't readily identify them on the S&S or Jim's website.

    Guess I'll give them a call and see.

    Andrews has some "quick install" rods too for EVO, but no specs beyond chromoly or aluminum? So, I dunno how small they go or the size.

    You'd think this stuff would be important enough to list up front. Maybe they think everybody already knows this stuff so they don't bother?

  7. #7
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    May 2019
    Posts
    672

    Default

    PS: Of possible interest..

    I've been pestering a well known builder with my stupid noobie questions (New people are so annoying) and he does this mod differently.

    He says, he uses EVO blocks and Shovel rockers, blocks the oil passage and retains the Shovel oil lines. It was an e-communication so I didn't have a chance to ask him for specifics or part numbers.. Yet.. But I get the impression he is blocking the oil hole which passes through the Shovel rocker, so the lifters pump up the rods and lube the pivots, then the lines take care of the rest.
    Last edited by confab; 12-30-2019 at 10:53 AM.

  8. #8
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2010
    Posts
    12,398

    Default

    Quote Originally Posted by confab View Post
    But I get the impression he is blocking the oil hole which passes through the Shovel rocker,
    What oil hole ... ??

    If your after oil up the pushrod top end oiling, stock Shovel rockers arms won't get you there ..
    Both Jim's & S&S makes Shovel arms that are drilled for up the pushrod oiling ....

    The Evo arms is a good way to get that oil path, but is a bit of work to make fit in the Shovel rocker box..
    Shoot for the difference in the arm ratio at the valve lift, dang if I wouldn't just pick a cam that had more lift .. !

  9. #9

    Join Date
    Dec 2018
    Posts
    1,713

    Default

    Quote Originally Posted by confab View Post
    PS: Of possible interest..

    I've been pestering a well known builder with my stupid noobie questions (New people are so annoying) and he does this mod differently.

    He says, he uses EVO blocks and Shovel rockers, blocks the oil passage and retains the Shovel oil lines. It was an e-communication so I didn't have a chance to ask him for specifics or part numbers.. Yet.. But I get the impression he is blocking the oil hole which passes through the Shovel rocker, so the lifters pump up the rods and lube the pivots, then the lines take care of the rest.
    It has been mentioned many times, that you can swap in the evo cam, tappets, and tappet blocks, and keep the shovel rocker arms. If that is done, the shovel top end oil lines must be retained. You don't have to plug anything on the shovel rocker arms, and there is no good method of doing so. The evo tappets will meter oil up the pushrod (there's a piddle valve in the top of the tappet), but the shovel rocker arms need oil from the stock oil lines.

    Also realize that with the shovel rocker arms, the evo cam will not lift the valves the listed distance, because of the different rocker arm ratio (1.43:1 vs. 1.63:1).

    Jim

  10. #10
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    May 2019
    Posts
    672

    Default

    Quote Originally Posted by Dragstews View Post
    What oil hole ... ??
    I asked why use the lines with the EVO setup, and he said he had shovel rockers and "blocked the oil hole"

    So, I assume it is the one in the rocker?

  11. #11
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    May 2019
    Posts
    672

    Default

    Quote Originally Posted by JBinNC View Post
    It has been mentioned many times, that you can swap in the evo cam, tappets, and tappet blocks, and keep the shovel rocker arms. If that is done, the shovel top end oil lines must be retained. You don't have to plug anything on the shovel rocker arms, and there is no good method of doing so. The evo tappets will meter oil up the pushrod (there's a piddle valve in the top of the tappet), but the shovel rocker arms need oil from the stock oil lines.

    Also realize that with the shovel rocker arms, the evo cam will not lift the valves the listed distance, because of the different rocker arm ratio (1.43:1 vs. 1.63:1).

    Jim
    Good info.. I have no idea why he would block anything.

    But that is what he said?

  12. #12

    Join Date
    Dec 2018
    Posts
    1,713

    Default

    FYI:
    The S&S pushrods I mentioned, with the wide range of adjustment, are #930-0052. They are good for Frankenmotors like you are contemplating.

    Jim

  13. #13
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    May 2019
    Posts
    672

    Default

    COOL!!! Thank you very much.

  14. #14

    Join Date
    Dec 2018
    Posts
    1,713

    Default

    Quote Originally Posted by confab View Post
    I asked why use the lines with the EVO setup, and he said he had shovel rockers and "blocked the oil hole"

    So, I assume it is the one in the rocker?
    I would block the oil hole in the pushrod, specifically the pushrod adjustment screw/end. That would keep excess oil out of the rocker boxes and pushrod tubes.

    Jim

  15. #15
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2010
    Posts
    12,398

    Default

    It's already blocked by the arm not being drilled ...
    Oil comes to a dead stop at the ball & socket ...

  16. #16

    Join Date
    Dec 2018
    Posts
    1,713

    Default

    Quote Originally Posted by Dragstews View Post
    It's already blocked by the arm not being drilled ...
    Oil comes to a dead stop at the ball & socket ...
    Nope. Shovel rocker arm socket has a hole, through which drip oil lubes the top of the pushrod. If used with evo tappets and pushrods with the through hole, extra oil is getting to the rocker arm from the tappets.

    Jim

  17. #17
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2010
    Posts
    12,398

    Default

    Weld it up ...
    It no longer needs splashed oil to lube the ball & socket ...

  18. #18
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    May 2019
    Posts
    672

    Default

    Whoops.. I told you wrong.

    Verbatim:
    i plugged the oil holes in the pushrods. they make two styles of the pushrods but i know how to make things work myself.
    when you have no oil pressure that would be a good sigh you over did it. unless you have the s&s rockers with the correct oil holes in them the pushrods don't work because it just dumps the oil into the rockerbox with the oem arms. just look at how your parts are made and you can figure out what to do.
    I thought he meant the pushrod hole, but he said the rods themselves.
    Last edited by confab; 12-30-2019 at 5:53 PM.

Share This



Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Log in

Log in