New engine mount spacers location?

[Mcstealth]

Question please. I did not take off the engine mounts off so I don't know where the spacers were before disassembly. There are two on this 160hp Lycoming. If you were putting néw mounts on, where would you put the spacers?

Glasair1 160hp retract. 

I have all the build books so I will start reading tomorrow. 

[N201MKTurbo]

That's how I would do it. 

One thing to be aware of, is to be sure the nut isn't bottoming out on the threads. There is a spacer inside the mount. That spacer needs to be tight to both ends before you run out of threads. With the Mooney installation, you need 7/16 of washers total to keep this from happening. The big washer is 1/8 inch thick and the little washers are 1/16 inch thick each. With two big washers, you need 3 little washers, with one big washer, you need 5 little washers somewhere. The mount in the picture doesn't look compressed enough.

[Mcstealth]

47 minutes ago, N201MKTurbo said:

That's how I would do it. 

One thing to be aware of, is to be sure the nut isn't bottoming out on the threads. There is a spacer inside the mount. That spacer needs to be tight to both ends before you run out of threads. With the Mooney installation, you need 7/16 of washers total to keep this from happening. The big washer is 1/8 inch thick and the little washers are 1/16 inch thick each. With two big washers, you need 3 little washers, with one big washer, you need 5 little washers somewhere. The mount in the picture doesn't look compressed enough.

One mechanic recommend that the big spacer in the picture be on the firewall side, explaining that the torque force and weight should be applied to the firewall side of that mount. That the washer on the  engine side is not using the spacer correctly. He also told me as you explained about the nut bottoming out. 

Thank you. 

David. 

[N201MKTurbo]

39 minutes ago, Mcstealth said:

One mechanic recommend that the big spacer in the picture be on the firewall side, explaining that the torque force and weight should be applied to the firewall side of that mount. That the washer on the  engine side is not using the spacer correctly. He also told me as you explained about the nut bottoming out. 

Thank you. 

David. 

That logic would make sense if the mounts weren't so sturdy. The metal in the ends of the mounts are beefy enough. they don't need the washer for strength.

If it was true, the spacers should be on the back on the top and the front on the bottoms. I just put them where they fit the best and move them around to get the prop in the right place in the cowl.

[Mcstealth]

37 minutes ago, N201MKTurbo said:

That logic would make sense if the mounts weren't so sturdy. The metal in the ends of the mounts are beefy enough. they don't need the washer for strength.

If it was true, the spacers should be on the back on the top and the front on the bottoms. I just put them where they fit the best and move them around to get the prop in the right place in the cowl.

I should wait for the prop to get back from overhaul before I claim the spacers are set??

[EricJ]

41 minutes ago, Mcstealth said:

I should wait for the prop to get back from overhaul before I claim the spacers are set??

You don't need the prop, you can put the backplate and spinner on the flange and see where it lines up with the cowl.

[RoundTwo]

The thick washers go on the “loaded” side of the mount. That means under the bolt head on the uppers and between the mount and case on the lowers.

[Mcstealth]

Here is how the engine is lining up..it seems I'm a little left, and low. 

[M20F]

The spacers are to address sagging, there was a really good article Maxwell wrote about Mooney’s that I can’t find.  Maybe you need 10 spacers, maybe you need none, somebody will come along with the actual math as to how you figure it out. 

[EricJ]

Put the spinner backplate on the flange and it should be pretty evident whether you need to make adjustments or not.

 

[Mcstealth]

1 hour ago, EricJ said:

Put the spinner backplate on the flange and it should be pretty evident whether you need to make adjustments or not.

 

Copy. Thank you. 

[Fly Boomer]

3 hours ago, Mcstealth said:

Copy. Thank you. 

Not sure how useful this document is, but you are welcome to it:

Don Maxwell - Aligning Your Engine Using Shims.pdf