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Engine mount to Firewall torque values

rgaynor

Active Member
Hi everyone

Sorry if this has been asked and answered, I searched and couldn’t find it. Section 5 gives torque values for an AN6 with std nut of up to 190 inch-lbs. nothing for with a locking nut. Anyone know where I can find the final torque values for those four AN6’s?

Thanks in advance.

Rob
 
The common method is to torque to the minimum value, 160 inch pounds I think. If none of the slots align, keep tightening until one lines up and you can install the pin. You should get there before you hit 190.
Cheers DaveH
 
Hi Dave

Thanks but wrong bolts I think. The engine mounts don’t have cotter pins. They have locking nuts.

Rob
 
I *think* I heard that Vans has changed to locknuts at this location.(??) If so, use a ‘bending beam’ (not click) type torque wrench to determine how much torque it takes to keep the nut smoothly turning with its locking feature fully engaged on the threads. Add this number to the torque you desire, set the sum on your wrench.
If you meant a castellated nut plus cotter pin, see previous post.
Edit. I see you did mean locknuts. This is a fairly recent change, expect confusion. You should have been determining the running torque of every locknut used on the build, and adding it to the desired bolt torque when torquing.
 
Last edited:
Yes.. the RV-12 switched from castellated nuts to locknuts sometime after 2020. The method described earlier for castellated nuts is correct. The locknuts are convenient for torquing purposes.. but, I still like looking inside the cowl and actually seeing the cotter pins.
 
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