600 Mile Runin Check - Head Torque Procedures

[Mcrider]

Help - I have a question on the proper procedure to tighening the cylinder head fasteners. The manual says to slacken and retighten cylinder-head nuts in correct sequence. Not a problem I can do that. what I don't understand is the torque procedures that are given for the bolts. The manual says the closing torque is 20 Nm and final torque, 180 degrees. Does anybody know what that means?

 

Thanks

[YesMan]

There was a video link posted in AdvRider that explained it pretty well. (I think in GSpot).

[Fergie]

Losen nut, torque to 20Nm, then tighten nut an additional 1/2 turn. Germans used this procedure alot.

[Mcrider]

Thanks Wayne,

 

That was a big help and will save me a bunch of money. Is this a great forum or what?

 

This torque procedure was a new one for me and I had suspected that's what they meant but I've never heard of doing it like that before.

[Fergie]

The reason you have to torque a fastner to keep it tight is that the fastner has to strech to stay tight. A given torque depends on the fastner size, thread pitch, lube and grade of material. Some manufactures use a small torque value to just seat componets then an amount of turn in degrees as a final torque.