Wings Forum

KevinC · Posted: Sat Mar 29, 2008 6:19 pm Post subject: Lord mounts

What is the correct and best way to install the Lord mounts in the engine mount brackets? It appears to be a tight fit - proper way to facilitate the install? What type/size bolts are used there and to mount the brackets to the engine (Rotax)?

Looks like my firewall forward might be missing a few things...

thanks!

k

scubarider2 · Joined: 28 Jan 2008 Posts: 142 Location: Cleveland, GA

Kevin, the best I remember is that I installed the motor mount bolts to the aluminum brackets, then put on the lord mounts and bolts. Then lifted the engine into place. It was really hard to get to all the bolts. Everything was in the way. :?
I got all the bolts from Just.
Dennis

alan · Joined: 04 Feb 2005 Posts: 89 Location: Baytown, TX

There has also been problems with the soft mounts supplied with the kit. It is my opinion that the supplied mounts are a hold over from earlier kits with the 80hp engine. You can order the hardest (green) mounts from LEAF, p/n H6143, or Lockwood, p/n 22002-13.

The parts supplied are the medium (yellow) mounts and they WILL deteriorate over the first 50 to 100 hours, requiring replacement.

The jury is still out as to if the green mounts are the way to go. There are some much larger mounts availabe, but they will require replacing the two aluminum angles.

One thing you might do to help is to lubricate the mounts upon install to allow them to properly seat. Someone somewhere said to use silicone grease so as not to harm the rubber.

Alan

scubarider2 · Joined: 28 Jan 2008 Posts: 142 Location: Cleveland, GA

Alan, You have me worried now. I have the yellow mounts with the rotax 912uls. I have 25 hours on it with no visible problem with them. You are saying they will give out within the next 75 hrs of flight? What will this look like? Has this happend to others? The weight difference is only 10 pounds or so. Is it the torque movement that causes it?
*sigh*
Dennis

alan · Joined: 04 Feb 2005 Posts: 89 Location: Baytown, TX

Dennis,

I was alerted to this by a fellow Texan who bought a ready built SLA by Just. The mounts just disintegrate starting with the port front mount.

I checked mine after the first flight with the new mounts (unfortunately I replaced in kind) and found that the new port front mount, with just 2 hours flight time, was vastly more compressed than any of the others. Jim has been replacing his as they dissolve, and has replaced all of them one at a time, but I replaced all of mine at once even though only 3 were damaged.

What they look like is the bottom part of the mount cuts around the bushing and then starts to shed rubber until most of the rubber is gone. My top parts were all OK as they carry no load.

My idea about these mounts being intended for the 80hp 912 is the 100hp 912S applies quite a bit more torque to the mounts and also has more vibration, especially at low RPM, because of the higher compression ratio.

I called Just about this several months ago and talked to Tim. He said the only problem they were aware of was with the afore mentioned (other) Texas Highlander, Jim's. He said to lube the mount as it is installed and that has taken care of Jim's problem.

Jim says otherwise. Jim has replaced his yellow mounts with the green and is waiting to see if the problem persists. My second set of yellow is still OK and I am also waiting for Jim to let me know how it works out.

I will post the results.

Alan

scubarider2 · Joined: 28 Jan 2008 Posts: 142 Location: Cleveland, GA

Thanks Alan. I will keep a close eye on them. What do you mean by lubing the mount? Inside? Outside?
Dennis

alan · Joined: 04 Feb 2005 Posts: 89 Location: Baytown, TX

Just back from S&F...

Lube the rubber part as it goes into the aluminum ell.

Alan

KevinC · Posted: Mon Apr 14, 2008 8:06 pm Post subject: Lube the mount

What should be used to lube the mount?

k

stede52 · Joined: 06 Sep 2007 Posts: 158 Location: Carnation, WA

Never heard of that stuff, were do you get it?

Steve

alan · Joined: 04 Feb 2005 Posts: 89 Location: Baytown, TX

I used general purpose bearing grease. Someone mentioned somewhere to use silicone grease so as not to degrade the rubber.

Alan

scubarider2 · Joined: 28 Jan 2008 Posts: 142 Location: Cleveland, GA

I don't believe lubing the mounts will do anything to increase the stability. All that will do is preserve them from stiffness, deterioration and UV damage. All of which has nothing to do with the actual strength needed for the 912uls. I believe that it was a Just Aircraft mistake ordering the wrong mounts for the 912s to begin with. I am upset about this because I am seeing the problem with the front crushing in due to weight and torque. I also have noticed now my left exhaust pipe is starting to hit the engine mount. This will cause the pipe to break in time I am sure. This is directly due to the mount giving way. Troy says it is not that hard of job to replace the mounts. With mine it WILL be. My water hoses are all in the way. He said to just cut the bolts. Well, you gotta put the new ones in don't you? You can't cut them to get it done right. Ordering the whole firewall forward "kit" was a chore to begin with. I dealt with Tim at the time. Had to reorder and actually "go" to Wahalla to get the engine mounting bolts. He ran to Ace Hardware to get them after I arrived :?
I am now looking at some major work to make this right. All with 40 hours on the plane.
My advice to all is to make sure you have the "right" materials to begin with. I would take a look at the list for firewall forward and compare the materials with CPS or Lockwood and maybe even call them for advice for the 912s. There are NO directions/manuals on setting things up front correctly. I would definetly use this forum for advice and pictures. I would also recommend the rotax install DVD.
It is me again bellyaching... :(
Dennis

Dave Krall CFII SEL SES · Joined: 14 Mar 2007 Posts: 274 Location: Seattle WA

Dennis, do they sell AN grade aircraft bolts at Ace Hardware?
Bolts that will bend a lot before they break on an engine mount are best, right?

scubarider2 · Joined: 28 Jan 2008 Posts: 142 Location: Cleveland, GA

Dave, Ace Hardware has a whole section just for aircraft. All colors :?
I like those bending bolts.... :shock:
Dennis

scubarider2 · Joined: 28 Jan 2008 Posts: 142 Location: Cleveland, GA

Alan, Thanks for all the info. I went to the Lockwood catalog and found several lord mounts. I went ahead and ordered the ones you suggestioned that said it was for the 912. There were others there like the "blue" hardest ones. Those will not fit?
Thanks,
Dennis

stede52 · Joined: 06 Sep 2007 Posts: 158 Location: Carnation, WA

the Part number JA gave me for the new motor mount was 13-03803 (BARRY ENGINE MOUNT-HARD) which I bought from Aircraft Spruce and they had a green strip on it.

Steve