Exhaust manifold mounting studs and another question.

[oemor722]

Greetings-

Currently restoring a 2002 K1200RS. I am currious... Are there torque specs for the manifold mounting studs that screw into the head? The nuts were so rusted that I had to remove the studs to get the nuts off. I found that the torque specs on the nuts nuts are 22 NM. What about the studs? Guy at dealer told me just to use some blue locktight and bottom them out and when I tourque the nuts the studs will set themselves. Does this sound right? Also... Is there any meaning to the "O" and the "E" stamped on each end of the stud?

Now to my stupid question...

Becasue I wasn't paying attention when I changed the final drive fluid... I torqued the bolts to 23lbs rather than 17lbs. 23 is the NM number. It was about a 1/4 more on each of the nuts. How big a deal is this? Did I totally screw (pun intended) things up?

Thanks-

 

[pglaves]

Greetings-

Currently restoring a 2002 K1200RS. I am currious... Are there torque specs for the manifold mounting studs that screw into the head? The nuts were so rusted that I had to remove the studs to get the nuts off. I found that the torque specs on the nuts nuts are 22 NM. What about the studs? Guy at dealer told me just to use some blue locktight and bottom them out and when I tourque the nuts the studs will set themselves. Does this sound right? Also... Is there any meaning to the "O" and the "E" stamped on each end of the stud?

Now to my stupid question...

Becasue I wasn't paying attention when I changed the final drive fluid... I torqued the bolts to 23lbs rather than 17lbs. 23 is the NM number. It was about a 1/4 more on each of the nuts. How big a deal is this? Did I totally screw (pun intended) things up?

Thanks-

There really isn't a torque spec to bottom the studs in the head. They are in and of themselves not exerting any clamping force. Assuming clean threads I would just screw them in until they bottom and then out say 1/2 turn. This is so any expansion from heating doesn't wedge the stud against the bottom and stress the threads. A little blue loctite will indeed then keep the studs from bottoming when you install the headers and the nuts. It is the installation of the nuts that will then apply the necessary clamping force when torqued to specifications.

As for the final drive - if you didn't feel anything strip you probably escaped damage. Don't mess with it until you need to.

 

[dieselyoda]

The rule of thumb, assuming clean threads, is to torque the studs to the same as the nut, with RED Loctite. The assumption is that the stud will actually seat in the bore of the boss of the female and the shoulder of the stud will seat in it.

Just a rule of thumb...............................

Beyond that, you must make sure that the bore of the female is absolutely clean.

When over torquing something, two things usually happen. Stuff breaks or stuff strips. I wouldn't get too worried about the over torque but when you take it apart, make sure you didn't flatten the threads.

 

[oemor722]

Thanks!!

 

[72r60/7]

On some models of the brick engines the projection of those studs is more important than bottoming and backing off some. The projection should be,obviously, to accommodate the length of the pipe and gaskets and nut and washers if used for fastening. You might want to keep that in mind before using red loctite.
And also check for old gaskets should they not have been removed upon disassembly.

Charlie

 

[58058D]

Indeed, if the prior gaskets did not fall out or come off the end of the header pipe, get in there and carefully dig them out of the exhaust manifold opening.....both studs and nuts on mine were so old and corroded I just planned on replacing both when I replaced my O2 sensor a couple years ago. Several of the studs were easily removed with no tools, a couple came out with the nuts...I followed the advice Paul noted above for install and all went smoothly and have done their job. The new style looks different, but is easy to work with.

 

[oemor722]

Do the gasket rings have to be replaced? What should I use to get them out?

 

[58058D]

Absolutely, they are one time crush rings. I think I used a small screw driver, being careful not to gouge the engine metal, but the rings are really pretty soft. The few that stayed on the engine were really easy to pry out. And, there are only four.....one for each exhaust port.