How tight to torque head bolts?

Discussion in 'Mechanic and Repair' started by karlInSanDiego, May 12, 2003.

  1. karlInSanDiego

    karlInSanDiego LawnSite Member
    Posts: 10

    Working on a Briggs 16hp opposed twin (F valves). Anyone happen to know how tight(ft/lbs or in/lbs) to torque the head bolts and if the tighting pattern is crucial (like it is on a car) I'm assuming that it's ok to reuse the bolts.

    Also, I plan to do a compression test when I get it back together. Anyone want to venture a guess as to what kind of compression (in psi) that I could expect out of one of these engines if it's healthy. I know that the important part is that both cylinders are similar in compression, but I don't know if 150 lbs. is what I should be hoping for, or something much less.

    Thanks,
    Karl
     
  2. mmathys

    mmathys LawnSite Member
    Posts: 13

    Hi Karl

    I don't know the specs for that particular engine but the general specs for 3/8 bolts is usually 35 ft lbs and for 5/16 it is approx 22 ft lbs.

    As for order it is important to draw it down evenly. Without a torque pattern diagram I would torque one and then go to the opposite bolt and then keep working around. Sometimes it is a good idea to go to about 1/2 the final torque and then crank it up all the way.

    If you can find the actual spec it would be better but if you can't then this general info should be OK.

    Good luck

    Mark
     
  3. Heres bolt patterns

    briggs bolt pattern.jpg
     
  4. and torque

    briggs torque.jpg
     
  5. karlInSanDiego

    karlInSanDiego LawnSite Member
    Posts: 10

    Your help is much appreciated. Thank you very much!:D
     

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