EVO Head Torque values

Discussion in 'Engine, Fuel and Exhaust' started by BOBFLHTC, Jul 31, 2010.

  1. BOBFLHTC

    BOBFLHTC Active Member

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    I'm trying to figure out what method to use. I've found several differnet options:

    The Factory service manual uses a Criss cross sequence and 7-9, 15-17 and 24-26 lbs

    Nightrider.com Clymer uses a serial sequence and 7-9, 12-14 lbs and 1/4 turn

    Cylinder Head Bolt Torque Values repeats the Clymer as the factory and also lists a

    Torque wrench method using the Clymer sequence 7-9, 12-15, 22-25 and 38-42 lbs

    I'm tempted to use the Harley service manual I listed first.
    Thanks - Bob
     
  2. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    Personally, I would trust the HD manual...BUT I would check with the HD dealer to make sure there were no revision changes that "corrected" or altered the recommended torque values or sequence just to be sure. That is one of the advantages of keeping track of document updates, because I have seen service manual errors...in my 2004 manual, some that were simply errors and never corrected.
     
  3. Hoople

    Hoople Account Removed

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    At first I was going to say use the HD specs. But then after reading NewHD's recommendation I have to agree with him. Since there are so many listings, there may have been an engineering change to the spec. That is one application of torque where you would not want it to be incorrect.
    I would double check it.
     
  4. BOBFLHTC

    BOBFLHTC Active Member

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    When I talked to the machinist at the dealer who did my valves and honed the cylinders he mentioned the 1/4 turn technique. Nightrider.com and Clymer both refer to it as the factory procedure so it sounds like there may be a update out there since the manual was printer. It sounds like it would be safe to go with that then. I was just wondering how others handled it. Thanks for the quick response - Bob
     
  5. shovelrider

    shovelrider Member

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    Head torque sequence & values are different depending on what brand of head gaskets you are using eg:Genuine,James,Cometic or S&S.Always refer
    to gasket manufacturer specifications & you can't go wrong.:D
     
  6. Breeze3at

    Breeze3at Well-Known Member Contributor

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    Bob; The HD manual for my '92 lists 7 ft. lbs, 12-14 ft. lbs, then 1/4 turn. I have had this bike since '93 and I remember reading many varying torque values through the years. There were aftermarket cylinder studs that used higher values without the 1/4 turn and gasket sets that used different numbers. Unless you are positive of the brand of cylinder studs, I'd not try too high of a torque value. Stock studs are known for stretching, or pulling out. If it was my bike, I'd see if the base gasket/head gskt. mfg. had a value. If not, I'd go with the factory numbers. Make sure your head bolt threads are cleaned and oiled for torque accuracy.
     
  7. BOBFLHTC

    BOBFLHTC Active Member

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    I'm using Harley OEM gaskets so I think that might be another reason to stick with the factory torque values. It looks like the values have changed from my 85 manual to your 92. I used a wire brush on the threads and ran a nut up and down each one. I dipped the screws them in oil too. I was going to swap out the studs but the first one I tried seemed to be in there pretty good and it was my "gut feeling" to leave well enough alone. I still have the stock cam and pistons. I did get a new set of Head bolt screws. When I went to clean the old ones with a brush there was plenty of dirt and metal shavings that came out. The stud threads look good so I think it was the screws wearing out. They must be made of a softer metal. Thanks - Bob
     
  8. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

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    I have always used the factory method of doing the heads with a 1/4 turn to finish and this has given no problems but when i have had the heads off ive always used hd parts
    the various parts of the cylinders and heads are made of different materials which expand and contract to different ammounts and at different rates so staying with hd parts that have all been tested together to expand when heated the correct amount so that the engine is oil tight

    Brian
     
  9. Jack Klarich

    Jack Klarich Expert Member Contributor

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    The 1/4 degree is the most important part, if you dont have a degree wheel just mark the bolt and turn the 1/4 degree dont forget a drop of oil under the head bolt cap this acts like a bearing for the torque , I have replaced tooooo many head gaskets for friends who did not understand the proper torque on these heads and tried to do it all in one sequence, take your time and clean all the mating surfaces and check or replace the case studs:s
     
  10. 86harleybobber

    86harleybobber New Member

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    I just got a brand new HD manual 86-90 and its up to date and it has the 1/4 turn in it I had a older 1 and it dint have it in it so it is better to all ways check the newer HD manual