Head Bolt Torque.
#1
11-20-2014, 03:45 PM
Head Bolt Torque.
Hi, everyone new to this forum. I have a 2008 Accent 1.6L which i got for cheap from a friend. He told me it overheated a couple of times within the past year the last time was about a week ago. Which he could not start after it happened So, instead of getting it repaired he sold it to me. I figured it was head gasket/ warped head. I got it home and tore into it and sure enough the gasket was blown between #1&2 cylinders. Got all the parts to put back together and had the head checked/resurfaced, everything O.K. The question i have is the torque spec on head bolts. What i have found says 22 ft-lbs+90 degrees ,loosen all bolts, then 22 ft-lbs+90 degrees. Is it 22 ft-lbs all the way
around then the 90 degrees all the way around, loosen all bolts, then 22 ft-lbs all the way around then the 90 all the way around or is it 22+90 on #1 22+90 #2 etc. loosen all, repeat. I hope this not confusing. Thanks for any and all replies..
around then the 90 degrees all the way around, loosen all bolts, then 22 ft-lbs all the way around then the 90 all the way around or is it 22+90 on #1 22+90 #2 etc. loosen all, repeat. I hope this not confusing. Thanks for any and all replies..
#2
11-20-2014, 08:25 PM
Bolt Torque Intent
Assuming you have the sequence of applying torque, the reason
you make several passes to achieve final torque is so you compress
the gasket evenly and then loosen it in reverse order. Then you
apply a final torque after you work your way around a second time.
They do this to get the gasket compressed before applying the final
torque. In older models they used to torque the bolts, run the motor
to get it hot and all components expanded, then when the engine cools
down, apply final torque on the bolts.
What they want you to do is torque each of the ten bolts to the same
value in the sequence they show you. Say you torque each to 5 ft lbs,
then start at 1 again and torque to 10 ft lbs, go all the way through 10
and then torque them all to 15 ft lbs, then 1 through 10 to 22 lbs. Once
you get to 22 lbs, apply a final "Quarter Turn" on the bolt heads, 1
through 10. That completes the first torque. Loosen them all in the
reverse sequence in steps that relieves the bolt torque on each.
Once you have relieved the torque, start the torquing sequence again
in increments that get you to the final 22 ft lbs of torque. Your final
90 degree torque on each bolt will conclude the bolt torque job.
You must work the torque in steps and in the sequence shown to get
even clamp forces holding the head in place. This method is done for the
sole purpose of minimizing warping of the head due to uneven forces
holding the head in place. The first torque application is done to
pre-compress the gasket so it won't require retorque after it heats up
after being run. Hope this isn't too windy and makes clear what they
want you to do. Good luck.
Paul
you make several passes to achieve final torque is so you compress
the gasket evenly and then loosen it in reverse order. Then you
apply a final torque after you work your way around a second time.
They do this to get the gasket compressed before applying the final
torque. In older models they used to torque the bolts, run the motor
to get it hot and all components expanded, then when the engine cools
down, apply final torque on the bolts.
What they want you to do is torque each of the ten bolts to the same
value in the sequence they show you. Say you torque each to 5 ft lbs,
then start at 1 again and torque to 10 ft lbs, go all the way through 10
and then torque them all to 15 ft lbs, then 1 through 10 to 22 lbs. Once
you get to 22 lbs, apply a final "Quarter Turn" on the bolt heads, 1
through 10. That completes the first torque. Loosen them all in the
reverse sequence in steps that relieves the bolt torque on each.
Once you have relieved the torque, start the torquing sequence again
in increments that get you to the final 22 ft lbs of torque. Your final
90 degree torque on each bolt will conclude the bolt torque job.
You must work the torque in steps and in the sequence shown to get
even clamp forces holding the head in place. This method is done for the
sole purpose of minimizing warping of the head due to uneven forces
holding the head in place. The first torque application is done to
pre-compress the gasket so it won't require retorque after it heats up
after being run. Hope this isn't too windy and makes clear what they
want you to do. Good luck.
Paul
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