Head bolt torque

[stevesmustang]

I am sorry if it is posted somewhere on the board and i didnt see it, i had to chase down my cherry picker to yank the motor out to change the pass side cassette and the cam tools just came in the mail, i am very happy with the kit. Anyways on the 4.0 SOHC heads whats the torque? My manual says this torque to 26 foot pounds, then second rotate 90 degrees then third rotate another 90 degrees. My 90 degrees maybe different from other peoples 90 along with everyone is different. Do you know the total torque so i can skip the 90 degree stuff? Its has the torque pattern.Thanks Steve

 

[TheJackal]

The factory manual says the same thing... torque to 26 ft-lb, then 90°, then 90° again, following the torque pattern each time.

I'm guessing they do this because they don't want the bolts to be tightened all the way to their final torque all at once. Perhaps this would put to much stress on the bolts, threads or the head itself?

 

[Dilbert5]

I would recomend following the factory recomended procedure as close as possible. It may be a hassle, but in the long run it will probably be better. Headbolts, rod bolts, and main bearing bolts are all critical for long engine life.

 

[stevesmustang]

thanks

thankyou, i just figured maybe someone did a check on what the total torque was after following the manual directions. What i mean is after you torque to the first poundage, then your 2-90 degree things if someone checked with a torque wrench what it came out to be total. I just dont want to under tighten or over tighten them. Also it looked like the factory head gaskets had RTV on them, do i put it on both sides of the gaskets or does it not need any? I know my motor in my mustang and other motors i built, you just clean the surface, put new gaskets on and bolt the heads down and you are good to go. Thanks

 

[Dilbert5]

I'm a little surprised that they would put rtv on a head gasket. I allways believed that they go on with no sealant. Did you remember to run a tap thru all the head bolt threads to clean them up?

 

[stevesmustang]

ya ran a tap in the bolt holes

Yep ran a tap in all the holes, got to wire brush the deck on the block still.

I'm a little surprised that they would put rtv on a head gasket. I allways believed that they go on with no sealant. Did you remember to run a tap thru all the head bolt threads to clean them up?

 

[J.A.F.E.]

These are torque to yield bolts and normally must be replaced instead of reused. Rather than using absolute torque the bolts are stretched a predetermined amount by the 90*/90* pattern. I guess the engineers consider this more consistant tightening than just simple torque measurements.

There is an angle guage to allow you to measure degrees of rotation. Autozone, Pep Boys & etc all have them for less than $20. Or you could buy the Snap-on one for $80:

http://buy1.snapon.com/catalog/item...0&group_ID=980&store=snapon-store&dir=catalog

 

[stevesmustang]

I think my pinion angle gauge will work

Wow they have tool for everything. I wonder if my pinion angle tool will work, its got degree setups just like the tool you posted. Thanks man

 

[Maniak]

You don't "have" to use a degree gauge like that.. 90 Degrees is 1/4 turn..

The 1st Gen X's say 85 degrees for final torque, which is just a hair under a quarter turn.. I just turn it just under 1/4 turn.

For you 90.. just turn it 1/4 turn.. It not like its some odd ball number like 65 degrees

~Mark