Verner Engine Mount on LE Treehugger

[Tom H]

Chuck in Indiana asked about the Verner engine mounts on Treehugger.

The first mount I built included "angle iron" sections bolted to the Verner mounting ears, then attached to a Lord isolator, which was attached to the mount tubing which had a "donut" looking affair on the end.  This mount was used for a while, but we found cracks in the "angle irons" attached on the engine.  The "donut" encapsulated the rubbers too much, and diminished the isolation, reducing the squish of the rubber, and may have resulted in metal to metal contact which broke the "angle irons".  I have attached a few pics showing the overall installation, the gray mount and one of the failed "angle irons".  Note, the original mount pics are called "old", the new mount pics are a number starting with "P".

The 2nd, and current mount was built using attachments at the engine which spread out to allow several bolt attachments to the engine, which did not rely on only the mounting ears, and also eliminated any rotation of the mount on the engine ears.  The Lord mounts attach between these and the thick tabs on the end of the mount tubing.

Our theory and experience suggest that the largest vibration is rotation about the crank shaft axis.  We oriented each of the Lord isolators so that the isolator bolts are tangent to a circle about the crank axis.  This allows the engine to move against the rubbers a fair amount so that contact is never made between the engine attachment and the mount tubing thick tab.  This mount has proven to be fairly effective and strong.

I have attached pics of the current mount which include the top-left engine attach, a right side view and a view of the bottom mount (the part that attaches to the engine is one piece and includes both the left and right bottom Lord isolators).

Les and I traded ideas back and forth on engine mounts, and I believe we ended up with similar configurations.  He tested several different durometers of the Lord mounts.  We used what we had, and I don't know which it is.

As many of Les' videos show, the engine does not shake too badly at low idle, shakes a bunch at a fast idle, but smooths out at higher rpms.

Hope this helps.

[leshoman]

I had problem with mounts on the 3V at first but went to a modified mount similar to Toms and have over 100 hours on mount with no problems.
When i built LE SR 7-1/2 tried a mount concept similar to what is being used on the 5V but it did no work, went to mount like on ORV and i have over 10 hours on it with no problems.

[Chuck in Indiana]

Thanks, gentlemen..food for thought.

[Brock]

Reviving an old thread for a quick question.

What diameter and thickness of tubing have folks been succeeding with on the Verner engine mount? 

[Tom H]

On the Treehugger mount as seen in the photos above, we used a combination of 1/2" and 5/8" od 4130 tubing.  Thickness was either 0.035" or 0.049", maybe a combination of both - can't remember.

[jack264]

Did you design your own mount? And also where did you get your oil tank

[Tom H]

Jack, been a while since I designed/built the mount for the Verner 3VW.  Here is the general procedure:
- level the airplane
- securely support the engine at the location/orientation desired
- the brackets on the engine are made to pick up several bolts on the engine for attachment.  Using only a single bolt through the mounting "ears" on the engine to secure the mount bracket (as used with the broken mount shown) caused some twisting of the mount vs. the engine.  So, our mounts on the engine were developed to be attached with the engine mounting ears and several engine assembly bolts.  This type of mount can not twist relative to the engine.  Attached is a picture of the bottom mount during early fabrication.  The bottom mount picks up both the left and right Lord isolators, but the left and right top mounts are separate from each other.  Also, in the picture - note that there is a steel sleeve (tube) that the bolt goes through the inside of the rubber Lord isolators.  It is of a length that, when the bolt/nut is tightened against it, the Lord rubbers are slightly compressed.
- make the Lord mounts assembly
- make 5/8" tube from Lord mount to firewall attach (not sure, but probably 0.049 wall)
- connect the 5/8 tubes near the engine to each other with 1/2 tubing (again, probably 0.049 wall)
- put in 1/2 diagonal tubes, which result in a triangular structure.
- as can be seen in several of Les's videos, the only movement is through the Lord mounts, which isolate the engine shaking from the airframe

The oil tank was made from a kit purchased by one of our guys.  I believe it was meant for motorcycles, and it is heavier than needed.  I added the hose fittings, drain and fill tube as required.  For someone with aluminum welding capability, a simpler, lighter tank could be made.

Hope some of this makes sense and is of some help.