magneto hold-down bolt torque?

[Bevan]

I had to remove a mag to get at a oil hose fitting. Does anyone have a quick reference for the torque spec for the bolts that hold down the magneto? Looks like 5/16 course thread so I'm thinking 160 in lb max but this seems much less tight than they were.

Bevan

[TSwezey]

Originally Posted by Bevan

I had to remove a mag to get at a oil hose fitting. Does anyone have a quick reference for the torque spec for the bolts that hold down the magneto? Looks like 5/16 course thread so I'm thinking 160 in lb max but this seems much less tight than they were.

Bevan

Maybe the last person didn't torque them correctly.

[LettersFromFlyoverCountry]

[quote=Bevan;656516]I had to remove a mag to get at a oil hose fitting. Does anyone have a quick reference for the torque spec for the bolts that hold down the magneto? Looks like 5/16 course thread so I'm thinking 160 in lb max but this seems much less tight than they were.

Bevan[/QUOT

What kind of mag? I looked at this this morning. Bendix was listed as 170-320. Slick was listed at something like 130.

[DanBaier]

204 inch pounds (per Lycoming Table of Limits - page 1-37) - be sure to use a new star washer

Dan

[Bevan]

They are actually P-mags on a Lyc 0-360. The hold down bolts are actually studs embeded in the case. All we are doing is putting nuts on the studs and torquing. I don't know what the original mag type was.

My torque chart for 5/16 coarse bolt is 160 in lb for max. But surely there is a lyc spec for this torque and perhaps it is different. Anyone have a lyc overhaul manual handy and could look it up?

Bevan

[Bevan]

Thanks Dan.

Bevan

[az_gila]

This might help for those generic torques for the coarse thread screws on your Lycoming -

NOTE - unlike airframe torques which are quoted dry, these are for lubricated nuts.