[Rog246]

One of the things I find a bit strange with US engine building is why exhaust bolts come loose A LOT.
Have spent way more years than I care to remember working on HP Jap engines and for the life of I can not remember or re-call this being ever an issue.
My observation being that ALL the engines that I've worked on were all internally balanced, and don't suffer from the harmonic vibes that externally balanced engines seem to. Maybe I'm missing something but I don't think so.
Maybe someone can shed some light on this.
Either way whenever I work with aluminium parts and steel bolts nuts and studs my NeverSieze is right there beside me.
An alternative is to use Monel metal nuts on the exhaust manifold-as the aircraft industry has done since before WW2 -they rarely seize and don't vibrate off either!

Rog