IO-390 Case Bolts and Studs
Don,
The basic values are:
1/2" thru-studs: 600 in.-lbs
3/8" nuts: 300 in.-lbs
1/4" nuts and capscrews: 96-108 in.-lbs
1/4" shear nuts: 55-60 in.-lbs
There's a specific sequence for torquing case bolts and studs in Section 8 of the IO-390 Lycoming Operation Reference Manual; this is a small ring binder that is sent with with engine.
Send me an email and I will scan the pages for you.
Best,
Mike
