cylinder studs.

[Bigleo]

I am currently installing some new crankcase studs (the ones for the cylinder and head) into my xs1100 crankcase. Does
anyone know what the torque spec is for installing the stud into the crankcase? Also the machine shop that did the valve job on the head removed the camshaft cap studs. Does anyone know the torque specs for re installing these studs back into the head? Any information would be great
thanks
Leo

[Ken Talbot]

I've never seen a torque spec for inserting the studs, probably because most people would never mess around with removing them. The torque spec comes into play when installing the nuts. What I would do, is give them a dab of medium strength loctite, then spin them in until they are lightly seated.

[TopCatGr58]

Hey Leo,

Well, I've been searching the shop manuals, and I can't find any values for the STUDS, just the actual nuts for them.

The cam cap nuts are 7.2 ft/lbs. The head nuts that attach to the studs are ~25 ft/lbs in 2 steps.

The head as well as the crankcase are aluminum, where as the studs are steel, so they can strip out the holes if tightened too much. However, the torque is applied to the nuts that are put ON the studs. I would think that making sure the stud hole threads are clean as well as the studs, and then apply locktite, and then screw them in till the easily seat or bottom out or run out of thread, but I don't think they require much torque. The nuts securing to them will be doing all of the turning when tightening/torquing down the parts that are held by them, the studs shouldn't be turning!

Perhaps some REAL mechanics like Prom, DiverRay, Gnepig will chime in with their words of wisdom!
T.C.

[Bigleo]

Thanks Ken and TC for your responses. Yeah, I understand that most people would not want to fool around with these studs. But the front ones were pretty corroded, and I happened to find some new ones, so I took the old ones out. My concern is that if I put them in too tight, there is the stripping issue with the aluminum. And if too loose, that the stud might back out instead of the acorn nut loosening first, if I have to remove the head in the future. I've looked everywhere and can't find any info on the torque required. I would imagine any Japanese bike with 10mm cylinder studs would be pretty close, if anyone has other bike info.
Leo

[mro]

a 3/8" grade 8 bolt with oil...general torque is around 45 foot pounds. (steel into steel)

ones I changed in an 79H XS did not torque
but bet was at least 25 foot pounds.
that was a couple years ago and have not got any complaints.


mro
BTW, no locktight, gust cleaned em on a wire wheel, couple drops of oil and installed em. I do torque everything...even a valve cover if I have a spec for it. Other wise just do what "feels" right.

[TADracer]

Not to be contrary with anyone but I think some non-permmanant Locktite type threadlocker is called for here and then tighten the studs to 25 +/- lbs/ft onto the case. Just my thought.

I think this only because it would be a pain if you have to remove the head and the acorn nut is tighter to the stud than the stud is into the case. Then the stud will want to come out with the acorn nut instead of staying in the case...right?

[mro]

Not to be contrary

Was not saying what I've done was the "right" way...just what I did at the time. Little lock tight wouldn't hurt, then again did not notice any on the threads when I took em out. Was a PITA getting the cylinders off that one, had engine sitting on the bench.
Will not try that again...then again will have to one more time as I have a low mileage engine bolted to the engine stand. One year closer to getting that project started


mro

[Bigleo]

cylinder studs

After much research, the APE website recommends 12ft/lbs of torque with oiled threads for 10mm cylinder studs.