Gas Engine Mounting tips
 

I seem to have sparked a hot topic among some club members...... Some think I am crazy for wanting to hard mount my Brison 3.2 to the firewall with aluminum standoffs.......... They seem to think that the rubber Isolation gas mount is needed.......
I need to better understand this subject..... I figured a poll would work well if only members that are knowledgeable in this area voted I would appreciate it......
Thanks in advance...................
Feel free to educate me..... I want to mount it safely!!!!!

Gas Engine Mounting tips
 

The aluminum stand offs are fine to use. I use 1"X red oak for all my stand offs. Cheap and strong!


Doug

Gas Engine Mounting tips
 

Just of note, Bisson Mufflers will void your warranty if you soft mount your engine. My Brison 3.2 is hard mounted with dowel standoffs on my Extra and is doing great.

Gas Engine Mounting tips
 

Take it from somebody who has soft mounted many pattern engines and now flies big gassers too. You do not want to soft mount that engine...you will hate it. The engine will flop up and down during rolls (unless you have a complicated nose ring installation) and start working on your muffler system and carb block. It will void the warranty on just about every muffler system made including (especially) pipes, and unless it is a hyde mount will probably amplify the vibration not eliminate it. Soft mounts are complicated, and the muffler systems require constant maintenance. I bet I went through 3 headers a year on my pattern airplanes until they came out with a solid wrap around style, and even broke one of those. In a soft mount system, something has to give. I wasted I don't know how many hours of flying time trying to get the muffler system to match the frequency of movement of the engine. I got it pretty close, but it still was never just right. On a pattern airplane they are pretty much required, but on a big gasser they will be nothing but trouble. The Hyde mount is the only one I know that will work right, but you will have to have a complicated nose ring setup, and the mufflers, or headers and pipes, and carb block will take a beating. I've flown my DA 100 hard mounted with wood standoffs I made from cutting disks out of 1/4'' ply and stacking them up, then glueing and tapering them down some, and the airframe is like brand new. This airframe has a year and a half on it, and has been flown ALOT in practice and IMAC meets. I can see no advantage at all to using a soft mount on a gasser. In case noise may be a concern, this plane also tests well below 90 db in competition, and there ain't no cheat switch on this one! hehe :)

Gas Engine Mounting tips
 

Looks like hard mounting is winning ;)
Can't believe there are only 14 gas engine users though :(

Gas Engine Mounting tips
 

I hard mount all my stuff. I thought about doing the soft mount when I first went to gassers but when I asked the experts at our field they all nodded in favor of the hard mount. The airframe it self does most of the buffering of the vibration. There are of course certain throttle settings that really shake the plane really good but it's usually at a speed you don't spend much time at anyway. No problem yet with any of my hard mounted gassers.