The Cessna 120-140 Association Forum

Changing out the bolts that hold the engine mount to the fire wall. Somewhere back in the last
Century, shorter bolts were used rather than NAS 145-15.

30 foot lbs sticks in my head for the torque but I cannot seem to find the publication that has that info. Does someone know where I can find it so I can hit my self in the head “ I could have had a V8”, afterwards?

Thanks much

I guess I’m going to answer my own question to a degree. Since it’s a 5/16 bolt, it must be around 20 ft lbs. But still can’t find the publication.

Thanks

Advisory Circular 43.13-1B, chapter 7

5963 wrote: ↑Wed May 09, 2018 6:00 pm Advisory Circular 43.13-1B, chapter 7

Correct. Since the NAS145 bolts have a higher strength than AN5 bolts, the nut is the limiting factor. If you're using MS20365 nuts the upper limit is 225 inch-lbs (18.75 ft-lbs). I think 140 in-lb (the max for AN5 bolts) would do just fine.

Thank you for the info!