Im confused after looking at the torque specs for a d16y8 head. If step 3 is to torque all the bolts to 49 ft/lbs, how can step 4 be to torque only bolts 1 and 2 to 49ft/lb?

Cylinder Head Bolts for D16Y8
step 1(bolts 1-10)....15ft lbs
step 2(bolts 1-10)....36ft lbs
step 3(bolts 1-10)....49ft lbs
step 4(bolts 1 & 2)....49ft lbs

 

You go back and check that 1 and 2 are still at 49 ft lb. Really you could go back over all 10 and make sure they are still 49 ft lb. In other words, they should not turn further when you apply 49 ft lb of torque.

As you tighten the bolts, the head can move down and reduce stress on some of the previously tightened bolts. Thus the need to go back and retorque in several steps.

 

oh, ok thanks.