Torque on rod bolts

Discussion in 'PSI Superchargers Tech Questions' started by alkyholic, Apr 21, 2004.

  1. alkyholic

    alkyholic Jr. Dragster

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    Hello everyone, I'm new to the alky funny car ranks and will be testing, driving the car for the first time in a couple of weeks at Norwalk and my question is...

    When I bought the motor I was give maintenance sheets and it says to torque the rod bolts to 93lbs in ONE TURN. Does this mean that once you start, you cannot stop until you reach 93. This is no problem when the motor is out on a stand but I have some trouble doing this with the motor in the car on the stands.

    Any help would be greatly appreciated.
    Thanks,
     
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  2. Mike Canter

    Mike Canter Top Dragster
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    Different rod makers have different theories. Miller rods and GRP are close to the same procedures and Brooks is totally different. When GRP or Miller want torque on the rods they want it in one single pull so you really get to the ft lbs you want. The problem is if you sneak up on the torque you can hear the rod bolt popping. It is possible to stop before one of these pops so you get a false torque reading. GRP and Miller want you to bring the rods bolts down so that you know the cap is seated correctly and aligned. I usually use hand tighten with a ratchet to make sure this happens (I would guess around 20 ft lbs) then use the torque wrench for one smooth continous final full single pull to the specified torque. You have to have the torque wrench lined up right to do this or you will end up stopping in the middle of the swing.
     
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  3. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    disclaimer up front, this is just what we do on our car... we use grp rods and torco assembly lube.

    i run the rod bolts up with a cordless impact, a little on each side until both are tight with the gun. i then pick up the torque wrench and give each side one good pull then go back and slowly pull to 90 lbs. if you pull too quick and hard, its hard to get the exact desired torque. this is the way i was taught working under tom conway on shelly howard's car.

    note i always lube my rod bolts with assembly lube (torco). different assembly lubes will effect rod bolt stretch, with is the ultimate goal you are looking for; the torque is just the mfg's suggested attempt to achieve that. brian scollon of grp noted differences between different lubes such as royal purple, regular oil, torco among others.

    go with what the mfg suggests in the end. i'm just conferring along our particular procedure.
     
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  4. James2

    James2 Member

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    The GRP instructions specify motor oil to lube the bolts. Am I supposed to lube the entire bolt, including the threads? or just the head?

    Anyone have an idea about GRP rod life in a fuel car?
     
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  5. M Tigges

    M Tigges TAFC

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    Good Luck ,Adam
    Mark
     
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  6. Mike Canter

    Mike Canter Top Dragster
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    Lube the entire thread and under the head of the bolt
     
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  7. alkyholic

    alkyholic Jr. Dragster

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    Thanks for the info guys. Great site Will, it's good to know there is somewhere to get answers to questions from experienced racers.
     
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  8. alkyholic

    alkyholic Jr. Dragster

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    Hey Mark, if you remember it was talking to you and your dad that got me into this mess in the first place! Can you believe after all this time I think I'm finally going to have a chance to drive this thing in a few weeks!
     
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