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<DIV><STRONG><FONT face="MS Sans Serif"
color=#008080>Earl...</FONT></STRONG></DIV>
<DIV><STRONG><FONT face="MS Sans Serif" color=#008080> Not to
disagree with your findings but could you shed some light on why we often gained
rpm when solid mounting our engines to good maple mounts compared to some of the
fiber man made mounts of that same era? </FONT></STRONG></DIV>
<DIV><STRONG><FONT face="MS Sans Serif" color=#008080> As I
remember there was much discussion that went around why soft mounting wouldn't
work and it was felt the trade off in lost rpm was worth it for the savings on
airframe and equipment. Course about that time gobs more power was becoming
available to those that were sponsored or could afford dumping their engines for
the new crop.</FONT></STRONG></DIV>
<DIV><STRONG><FONT face="MS Sans Serif"
color=#008080> </FONT></STRONG></DIV>
<DIV><STRONG><FONT face="MS Sans Serif"
color=#008080>
del
<BR>
NSRCA - 473</FONT></STRONG></DIV>
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style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #008080 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=EHaury@aol.com href="mailto:EHaury@aol.com">EHaury@aol.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, February 19, 2004 7:50
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Tonight's Dumb Idea...</DIV>
<DIV><BR></DIV>
<DIV>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. </DIV>
<DIV> </DIV>
<DIV>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!</DIV>
<DIV> </DIV>
<DIV>Earl</DIV></BLOCKQUOTE></BODY></HTML>