School me on valvetrains!

Discussion in '94-95 5.0 - Specific' started by duh09, Jul 1, 2014.

  1. duh09

    duh09 Legend

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    So as some of you may or may not know, I recently picked up a 94 GT that has recently had a topend done on it and the previous owner could never get it to run right so I scooped it up for a steal. Fixed some vacuum leaks, and got the car running and I drove it for a hundred or so miles just to get a feel for what the car was doing. Now I've pulled it apart and I think a lot of my issues with the car feeling sluggish and down on power is due to the valvetrain and I'm hoping someone can help me and walk me through this.


    For starters, my car is a 94 GT. It is running a E303 cam, and a set of ProComp heads with cheap 1.6 stud-mount roller rockers and I believe the factory non-hardened pushrods. The shortblock that is currently in it is believed to be out of a Fox-body due to the dipstick but not 100% where it came from but it is NOT the factory motor. I will be putting a GT40 intake on this car along with a set of 24# injectors in it before I get a tune. This car will be daily driven and probably weekly beaten at various events.

    Here is the link to the exact heads the PO bought:
    http://www.ebay.com/itm/230838702849
    And after seeing what's on the car, I believe he also bought these to finish it off:
    Roller Rockers- http://www.ebay.com/itm/230897045318
    Guide Plates- http://www.ebay.com/itm/230838635541
    Studs- http://www.ebay.com/itm/230838697193

    My pushrods have a lot of wear on them from scraping the sides of the guide plates. They seem to be fairly centered but the rockers have a good bit of side-to-side movement and you can actually rotate them around the stud enough by hand, side to side, to where the pushrod will make contact with either side of the guide plates with the valves closed.

    I've been doing a little bit of searching but I'm a bit confused. This contact is bothering me but is it something that happens with roller rockers? A lot of the how-to's and what not I've looked at mention using hardened pushrods and sort of mention the possibility of metal-to-metal contact with the guide plates as the reason behind the hardened pushrods. Would a properly adjusted valve train have this contact or is that due to mine being out of whack? Do pedestal mounted rollers have this same movement?

    I'm planning on pulling the heads off soon to have checked out (I believe a lot of my oil burning issues are due to valve stem seals) and I'm considering pulling the trigger on a new LMR shortblock to insure that I don't put an unknown motor back together with worn rings/bottom end issues. I plan to reuse as many parts as I can because I don't have much to put into this build and I don't want to waste money that isn't required but I want this car to be right and reliable the first time around. Would a different set of rockers be money well spent or would this cheaper set do the trick? I know there's a lot of negative information out on the web about the ProComp heads but unless the machine shop finds major issues with them, I will probably continue to run them unless I happen upon a great deal for some Trickflow or AFR's. I know they're a little big but I'm trying my best to work with what I've got.

    Charging my phone back up right now and will have pics and a video showing the movement up in just a few minutes.

    Thanks for the help guys
     
  2. rz5.0

    rz5.0 Legend

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    You should have harden push rods. .. make sure they are the right size. . If you can sell the heads pick up something a lil better. .
     
  3. duh09

    duh09 Legend

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    [​IMG]
    [​IMG]
     
  4. rz5.0

    rz5.0 Legend

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    :(
     
  5. duh09

    duh09 Legend

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    Will hardened pushrods prevent that damage or is that something I shouldn't be experiencing at all?

    I've got a rough idea on finding the length, but is the width of the pushrod something else that should be in consideration? I feel like there would still be enough play side-to-side to make contact as it sits now, but again, I'm a engine building n00b.
     
  6. rz5.0

    rz5.0 Legend

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    Yes harden pushrods will keep that from happening and are required..
     
  7. rz5.0

    rz5.0 Legend

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    Width should be the same. .
     
  8. Musturd

    Musturd Legend

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    Just grab a adjustable push rod to get your length