Tonight's Dumb Idea...

[EHaury at aol.com]

When the suggestion that soft mounting provided more advantages than not was 
proposed, most of us subscribed to the theory that power loss from anything 
less than solid was unacceptable. I set up a test using a fuselage that could be 
equipped with either a hard (cast aluminum) mount or soft (same mount with 
radial Lord mounts and a Lord mounted nose ring). A miniature accelerometer was 
mounted to the inside of the firewall by the lower mount bolt and another to 
the mount at the same location. (Stud for solid, Lord studs for soft.) The 
accelerometers were connected to a dual channel spectrum analyzer to display 
amplitude g's as millivolts on a vertical scale vs. frequency on the horizontal. 
Engine was a piped OS 61 with the MK prop of the time. 

After gathering full throttle data several times, and reversing the 
accelerometers to ensure similar output, the results dramatically told the story. The 
solid mount produced a 600mv amplitude signal and the soft a 6mv signal. A 100 
/ 1 difference. BTW, no measurable difference in engine rpm. Switched to soft 
mounts and never looked back!

Earl
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