ACRO E-mail Archive Thread: [Acro] rpm surge on IO-360?
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Thread: [Acro] rpm surge on IO-360?
Message: [Acro] rpm surge on IO-360?
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From: Jamie Monberg <jmonberg at attbi.com>
Date: Mon, 12 Aug 2002 06:49:35 UTC
I've got a persistent problem with engine surging on my Eagle2 (AEIO-360-A1D w/hartzell constant speed) The problem manifests itself almost immediately after I reduce power from takeoff. The rpm will surge +-100rpm with a period of maybe 2 seconds from low to high. The surge will reduce in amplitude over the next 4-5 cycles and then settle down to a consistent rpm. After a few minutes the "wobble" will re-appear. I notice slight oil pressure fluctuation during (not preceding) the surging behavior that is consistent with what might happen were one to quickly change the pitch of the prop. Engine temp does not seem to be a factor. The problem seems worse when the crankcase is filled closer to eight quarts than when it is filled closer to 6 quarts. The problem also seems to be slightly less extreme when I increase the pitch of the prop for a really low cruise setting (i.e. 20 square) Oil consumption has not changed -- there is about 630 hrs on the engine and prop. My mechanic seems a little mystified and recommends a governor and prop rebuild. Just in the spirit of better understanding the problem I thought I would put this to the list. For all I know it is entirely typical for what happens when a governor starts going south. Thanks in advance for any help! jamie