First torque on assembly. multiple stages, the more the better so the head clamps down evenly, 15/30/45/60 and then finally 69 lb/ft. This is going thru all the bolts /nut one at a time in torque sequence to each value, then stepping up the wrench to the next value, and repeating... it takes a little while, but certainly pays dividends by only having to do the head overhaul / gasket replacement once.
First re-torque after one heat cycle... run car, fan cycles on / off maybe three times, shut her down. Let it completely cool, overnight is best, retorque in the morning when the ambient temp is coolest.
Second re-torque, I usually do after maybe 100 miles (160km) so in your case this would be after maybe ten heat cycles... again completely stone cold.
For retorques...In torque sequence, one bolt/nut at a time, loosen the bolt/nut around 1/4 to 1/2 a turn with a breaker bar, retighten back the same amount... I use a paint marker on the bolt nut to get it back to pretty close to its original position... Then swap the breaker bar for the torque wrench and using steady slow and even pressure on the torque wrench, take it straight up to the final torque value (9.5kg/m)
Make sure bolt holes and threads are clean. Oil and drain bolt threads. apply a small dab of antisieze compound under the nut/bolt head between it and the thick flat washer, this reduces the friction involved to a minimum and helps achieve the maximum clamping force without taking the fastener into the 'plastic (deformation stage) and keeping things in the 'elastic' range where the fastener will return to it's original dimensions when load is released.
follow these steps and you will have success. (Bernice has more or less said exactly the same thing in this and other threads)
added thought... it also pays to check the manifold to head stud/nuts at the re-torque stages... and also the exhaut flange nuts (if your running a twin front pipe) as these will also come down another 1/8 of a turn usually. after 100 miles I usually check the cambox bolt tension too, and run a feeler gauge thru the gaps to confirm the lash hasn't altered beyond spec.
SteveC
