Turning crank with jug off

[lr172]

Originally Posted by Ironflight

Just so you know, using washers on the bolts is considered a no-no by Lycoming because if they spin they can scratch the mating surface for the cylinder. That why they have the torque plates. Alternatively, you can make a steel strap with holes that pick up two bolts at once - that can’t spin.

Paul

I understand the concern. However, when I overhauled my engines, I used washers. I needed a stack of about 8 or so washers per stud to keep the nut on the threaded portion of the stud (narrow deck). Almost no chance of the bottom washer spinning and galling the deck surface.

Larry

[mahlon_r]

Personally, I would not worry about bearing damage from turning the crank with no torque on the thru studs. I would worry about bearing damage from increased crush on them from a fretted case getting retorqued and producing more crush on the bearing clearance because you are taking up the space from the case fretting. You can check the running clearance by torqueing up the thru stud you loosened taking the cylinder off and making sure the engine isn't tighter than with them un torqued. If the engine gets significantly tighter when the thru stud is torqued up, you have more issues that just a cylinder replacement!
With the history of these engines fretting crankcases, I made it SOP to do a running clearance check, as described, every time I un-torqued a cylinder or cylinders.
Good Luck,
Mahlon