We over torqued the nuts for my Ducati 900 SS Cylinder Head, do I need to replace...

N

N.Serdar

New member
...the studs? The Haynes manual sold in the US still had Nm (Newton Meters) for the torque specs, and the torque wrench was Nm with M. Kgs. and apparently the book was M. g? Anyway, after I looked up a conversion, we realized we had tightened almost by double. We backed up the nuts and tightened them to the specs, but there is anywhere from 1/2 thread to 1 thread extra showing versus the other head. So we probably stretched the studs and I just want to know am I okay or do I need to replace the studs?
No head gasket... Metal to metal on Ducati Heads. (Same metal type expands and contracts at same rate)
 
You might get away with it, but to be honest, from what you describe, you might play safe. The studs might not have stretched, more likely is you have stripped the tread in the block...oooh.
 
If it was mine personally I would have replaced the studs the first time I replaced the heads. Anytime you torque something one time it stretches, even if a minute bit you still won't be able to get everything perfect as it should be. So Yes I would say go with new studs, and nuts.
 
I'd be more concerned with replacing the head gasket. Once you over tightened the heads you flattened the gasket too far and it will not seal properly now that it has been over torqued. If the studs have a raised surface around them from being over torqued you may have problems down the road. If the area that the studs fasten into at the crankcase are flat, they did not start to pull out. Just make sure when you re-torque the head with the new head gasket that the final torque is met without it feeling like things are stretching and taking forever to reach the torque setting.
 
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