I like the Dave Brown glass filled nylon mounts. I used one for quite some time on my 89" WS Dynaflite PT-19 W/an FA-150. They are light, exceedingly strong for the application & they tend to dampen the transmission of vibration to the airframe. I will be going to greater lengths in that last respect by using rubber "well nuts" in lieu of "T" nuts in the firewall.

More on that in the next post.

I started out by clamping the mount in the drill press vise to determine the 6" recommended distance form the firewall to the prop hub. (sorry for the out of focus shot, I didn't have the camera set for close-up)




After establishing the distance, I checked to assure that the engine was square to the base of the mount.




Using a transfer punch through the engine base, I marked the location of the hole on one beam only, then drilled the mount W/a #30 bit & tapped the holes for 8-32 screws.




After tightening the screws, I checked for alignment again.




With the screws tightened down I used the transfer punch on the other mount beam.




I then repeated the drill & tap operation on the remaining mount beam.




I'm headed to the local HDWE store to get 2 more 8-32 socket head screws. This afternoon I will go about laying out the hole locations on the firewall & go into further detail on the vibration dampening methods I use. The FA-180, while not as bad of a vibrator as a big gas single, it still shakes quite a bit. I have heard of firewall failures W/this bird when the firewall was punished W/a lot of high stress hovering & such W/an FA-180. Since this engine will be producing as much as 1HP more than a stock glow ignition FA-180, I think some added reduction in airframe stress is in order. This is a lightly constructed bird & I don't want to add more weight via heavy reinforcement

Better to reduce airframe stress in the 1st place than add weight by over building to withstand the strain.

Stay tuned.