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installing roller rockers

Discussion in 'The Hokey Ass Message Board' started by unkamort, May 7, 2011.

  1. unkamort
    Joined: Sep 8, 2006
    Posts: 1,014

    unkamort
    Member

    Howdy! While installing SVO roller rockers on Cleveland style heads I discovered 3 of the intake roller rocker shafts do not seem to fully seat in the pedestals, resulting in the rocker shafts twisting on the mount bolts. My first thought that the threaded bores were machined too shallow. I dug out a set of old Crane semi-rollers for the shims and cured one, the other two got better, but the twist is still there. The shims are .020" thick. Am I gonna' screw up the geometry by adding more shims? Or... its just possible that I'm missing something all-together here. Please advise. (the rockers are 1:73 if that makes a diff)
     
  2. unkamort
    Joined: Sep 8, 2006
    Posts: 1,014

    unkamort
    Member

    bump for the evening crowd ... I don't really want to grind on these bolts. I mean... how close was Fords machining on the mount pads? Crane stuff came with shims... Ford stuff didn't. By raising the center line on the rockers will I loose the same amount of lift?
     
  3. 71buickfreak
    Joined: Sep 26, 2006
    Posts: 609

    71buickfreak
    Member
    from Oklahoma

    SOunds like you need to check your pushrod length. If they are off just a little, things like this happen. You really need a pushrod length checker.
     
  4. unkamort
    Joined: Sep 8, 2006
    Posts: 1,014

    unkamort
    Member

    Ok granted... original push rods. The problem seems to be that the rocker shafts in question are not seating in the pedestals. (I know there is a 'flat' side) The lifters on the intake valve train in question appear to be compressed as normal when compared to all others
     

  5. Mudslinger
    Joined: Aug 3, 2005
    Posts: 1,964

    Mudslinger
    Member

    Are they designed to run with guide rod spacers for the push rods? I had a hell of a time with 302 heads that were cut for the spacers and didnt have them. It threw the whole geometry off.
     
  6. unkamort
    Joined: Sep 8, 2006
    Posts: 1,014

    unkamort
    Member

    guide plates? Not that I'm aware of. Being a splayed valve design makes location of the rocker a pretty big deal, and I have a bit of coin in this engine. I know there are many well educated Ford fans here...and I don't like to make a fuss, but I'd like to keep this up front until I find out if I'm about to light off dynamite.
     
  7. unkamort
    Joined: Sep 8, 2006
    Posts: 1,014

    unkamort
    Member

  8. Judd
    Joined: Feb 26, 2003
    Posts: 1,894

    Judd
    Member

    Flat spot up on the roller where the bolt/stud goes through?
     
  9. Is this the kit that uses the OEM rockers and a roller "pedestal""
     
  10. unkamort
    Joined: Sep 8, 2006
    Posts: 1,014

    unkamort
    Member

    "Flat spot up on the roller where the bolt/stud goes through?" Yes, double/triple checked

    "Is this the kit that uses the OEM rockers and a roller "pedestal"" No, these are full rollers. I had originally bought the Crane set that are semi rollers, using stock stamped steel rockers. Only the shims from the Crane set were used.
     
  11. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,912

    dirty old man
    Member Emeritus

    Pics would help.
     
  12. unkamort
    Joined: Sep 8, 2006
    Posts: 1,014

    unkamort
    Member

    Here ya go! The first 2 show the twist movement of the rocker on the pedestal, the 3rd is the Crane semi roller with shim.
     

    Attached Files:

  13. Is the slop from the roller itself or the pedestal or the head?
    Bolt too long?
     
  14. unkamort
    Joined: Sep 8, 2006
    Posts: 1,014

    unkamort
    Member

    it appears that the rocker is not seated in the pedestal
     
  15. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,912

    dirty old man
    Member Emeritus

    Time to invest in a cheap pair of dial or digital calipers and measure the offending rocker slots in the head and tongues on rocker assy bottom and compare to others.

    Dave
     
  16. If you torqued the bolts properly you shouldn't be able to move the rockers on the pedistals by hand.
     
  17. 71buickfreak
    Joined: Sep 26, 2006
    Posts: 609

    71buickfreak
    Member
    from Oklahoma

    Roller rockers do not always sit square, I have seen this with several 302 Fords recently. If you look at the second pic, the rocker is too far to the right, and the first pics it's too far to the left. Are they getting tight on the stud? Try setting the preload and feel the tension of the nut and the rocker. Take it off and look to see if there are any rub marks. that is a dead giveaway that the pushrods are too short.
     
  18. 71buickfreak
    Joined: Sep 26, 2006
    Posts: 609

    71buickfreak
    Member
    from Oklahoma

    Here is a pic of a recent Ford 347 I built. note the rocker arms have a slight angle over the springs. This is normal. You want the roller as close to centered over the valve tip, but it may be at a slight angle
     

    Attached Files:

  19. 71, I have the engine builders secret for you, the answer is in the Isky catalog. I have built many high end SBF's, Isky makes 2 piece adjustable guide plates. Center the rocker over each tip of the valve stems, and then tighten down your rocker arm studs. You can then mark/scribe or put a small tack on the two pieces, and if your sure you have them correct, remove and TIG or MIG them permanantly. It makes for a very professional job, and with the correct length pushrods, you will have perfect geometry, and a few extra numbers on the dyno sheet too. TR
     
  20. 71buickfreak
    Joined: Sep 26, 2006
    Posts: 609

    71buickfreak
    Member
    from Oklahoma

    TR- That sounds pretty neat. In my situation, it is the guideplates that do it. I have tried to adjust them, but they self-center when torqued.
     
  21. BERNIES WELDING
    Joined: Mar 31, 2011
    Posts: 216

    BERNIES WELDING
    Member

    have you considered guide plates and also check your assembled height, also are the studs original press in or have they been changed to screw in studs and check the stud bosses for cracking .
     
  22. unkamort
    Joined: Sep 8, 2006
    Posts: 1,014

    unkamort
    Member

    A little update here, since the 400 thread popped up again... Turns out the stock push rods are too long for the roller rocker install. By adding a total of .060" shims under the pedestal I have travel in the lifter. Am I correct in thinking that a .060" shorter push rod would bring me where I need to be? This leads to a second question... I don't have any thing that big with the degree of accuracy to measure the stock push rods. That spec is not on my AERA sheet. Anyone know where that info might be available?
    AND Thanks to all the SBF guys that responded with advice about guide plates. Nothin' but love for ya...(except my DD front cover is leaking) but this is a different beast.
     
  23. johnnie
    Joined: Jan 7, 2009
    Posts: 493

    johnnie
    Member
    from indiana

    I am guessing you have a 400? Yeah, guide plates are not needed with the pedestal mounted rockers unless they are machined flat.
     
  24. unkamort
    Joined: Sep 8, 2006
    Posts: 1,014

    unkamort
    Member

    Yes its a 400. These are not anything special... just stock 2V Cleveland heads. I'm just trying to take advantage of the lift spec on this cam without bending the valves on the first crank. One things for certain...If there is anywhere on the planet that my questions can be answered it would be here. Please spare me the boat anchor comments, the argument is well documented here. I built it, I'm runnin' it.
     
  25. Judd
    Joined: Feb 26, 2003
    Posts: 1,894

    Judd
    Member

    Comp Cams makes adj push rod with markings to measure length. My local shop measured my old push rods and ordered one about the length I needed then I set my rollers to run over the valve stem correctly and he ordered a set of push rods from the tools reading. Seems like I need a different length push rods every time I change the spark plugs on my Comet LOL?




     
  26. unkamort
    Joined: Sep 8, 2006
    Posts: 1,014

    unkamort
    Member

    Thanks for that. It's the spec I'm looking for. If I'm correct in my thinking, and a std .060" unit is available I'm good. I had thoughts of pulling the ball out of the tubes and taking the .060 off there on a Souix machine. Budget is a large concern here.
     
  27. RichFox
    Joined: Dec 3, 2006
    Posts: 10,020

    RichFox
    Member Emeritus

    My experience with mounting roller rockers on a Ford head that came with bolt down stock rockers is that the pedestals need to be machined to accept the studs. Maybe these are some rockers I have not seen. But ones that I have seen require a trip to the machine shop. Check with your machinist or supplier of the rockers.
     
  28. johnnie
    Joined: Jan 7, 2009
    Posts: 493

    johnnie
    Member
    from indiana

    No machining needed for these rockers. Yup. There are, usually, +/- .030 and .060 from the stock sizes. Ford Racing site used to have directions for installing these type rockers. They give the "amount of turns past contact" figure for correct, or good enough use.
     
  29. RichFox
    Joined: Dec 3, 2006
    Posts: 10,020

    RichFox
    Member Emeritus

    I at one time made an adjustable, measuring, push rod out of a stock push rod cut in half with a nut and some screw threads brazed to it at the split. It was a tubular push rod. Then using soft springs I adjusted it until the rocker tracked correctly. Snugged it down and mailed it to the push rod Manufacture. Let him do the measuring. You guys and your hydraulic lifters always catch me off guard.
     
  30. +1
    I cut a pushrod, tapped it 1/4 x 20 and used a piece of 1/4 x 20 all-thread.
     

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