Message-ID: <002101c1bc6b$e490c520$0201a8c0@net.Bellsouth.net>
From: "DOUGLAS W JOHNSON" <LANCAIR1@bellsouth.net>
To: "lancair list" <lancair.list@olsusa.com>
Subject: LIV-P Prop/Engine Combos related to early fatigue?
Date: Sat, 23 Feb 2002 08:13:31 -0500
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I have been told by an aerospace engineer that with our big Continental
engines which historically have not been perfectly internally balanced, that
the use a heavier Hartzell prop may provide longer engine life than lighter
composite props because it acts as a dampening flywheel for many of the
internal vibrations in the engine.  The lighter props allow more "shake,
rattle, and roll" inside our engines, potentially leading to early failures
in many components/accessories.

When I bring up that most aerobatic performers use the lighter props for
fast response, he points out that using the prop in that environment is
different, because those engines are usually torn down and reworked or
replaced every year anyway, so the early failures of components don't have a
chance to show up in that short a time frame.

Any knowledgeable comments on this?  Has anyone kept a tally of Continental
engine problem frequency based upon the prop they flew behind?
Douglas W. Johnson MD, FACR
N654DM  555 flight hours and ticking (TSIO550 + Hartzell)
Jacksonville, FL
(904) 642-6016
Lancair1@bellsouth.net


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