View Full Version : PA-11 with a O-200 Engine mount bushing/shiming?

Dan M
10-23-2020, 10:07 AM
In a couple of the other treads I read references to shims or bushings under the bottom engine mount bolts on a PA-11 with a O-200. I would assume they are going between the engine mounts and the firewall to change the thrust angle.

I have a few questions.
#1 How much shim are folks installing?

#2 What performance changes are you seeing?

#3 Any changes to the cowling needed as the engine is shifted up a degree or two?

I would rather learn off of someone else's experience rather then trying to get my own degree from the "school of hard knocks".

Thank you
Dan M

Dan Gervae
10-23-2020, 03:29 PM
I put a J3 mount on mine which has the zero thrust. I have not flown it yet, so I can only tell you I had to add to my bottom cowl piece to account for the new angle

Jerry Burr
10-23-2020, 04:44 PM
Engine C/L 2.15 down from Fuse C/L. Jerry

10-23-2020, 06:04 PM
Engine C/L 2.15 down from Fuse C/L. Jerry

At prop flange? So.....shim is what percentage of that?


10-23-2020, 06:28 PM
Engine C/L 2.15 down from Fuse C/L. Jerry

jerry are you meaning have the engine centerline down 2 inches from the frame centerline, with the engine not tilted up or down from that. glenn thats going to take a little figuring, but i believe the pall engine mount is pointed 4 degrees down. so dan m how far is it from the front of your engine mount to the front of the crankshaft? thinking 3/16 but dont remember how i came up with that.

Jerry Burr
10-23-2020, 08:03 PM
I'm sorry, my mistake. That's 2.15 degrees down. Tempdoug is correct. The -11 is 4deg. plus or minus down. Cut that in half. And use the lord to conical adapters on the engine or it will promptly be back down. 0 deg. if you want speed. 4 down if you want takeoff. Cut it in half to get some of both. If your -11 has flaps 0deg will help the takeoff and kill your landing. I have 3 motor mounts in the attic used to confirm the above. Jerry PM me with your mail and I will send specs.