Matronics Email Lists :: View topic - LycomingEngines-List Digest: 0 Msgs

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

LycomingEngines-List Digest: 0 Msgs - 05/11/08

Matronics Email Lists Forum Index -> LycomingEngines-List

View previous topic :: View next topic

Author Message

bobair8(at)msn.com
Guest

Posted: Mon May 12, 2008 6:53 pm Post subject: LycomingEngines-List Digest: 0 Msgs - 05/11/08

<?xml:namespace prefix="v" /><?xml:namespace prefix="o" /><![endif]-->  I have a topped O-360-A1A (180 HP) in an experimental amateur-built that is  ready for its first flight.  The prop is fixed pitch and I don't have a  manifold pressure gauge in the panel.  I want to prepare a simple table of  RPM at various pressure altitudes to yield 65% (117 HP) and 75% (135 HP) power  so that I can set the power appropriately for the first few hours on the engine  to set the rings properly.  

  

 I have the Lycoming Operator's Manual (Publication No. 60297-12, Revision  -6/7th Edition).  I'm trying to decipher Figure 3-17, Sea Level and  Altitude Performance on Page 3-33.  By my reading it seems like I can  generate 75% power at less than 2000 RPM up to a pressure altitude of about 3000  feet and pull 65% power at 2000 RPM at 7500 feet pressure altitude.  That  RPM seems way too low to generate those power levels.  

  

 Do any of you have the right power settings for an O-360 180 HP fixed  pitch set-up?  The prop is a Sensenich 74" diameter and the pitch  is 65" if I recall correctly (the pitch between climb and  cruise).  

  

 Or can someone tell me how to properly interpret the table?  My  inclination is to run it at 2700 RPM for take-off and then reduce it to 2500 RPM  from then on out and then vary the RPM +/- 100 RPM every half hour or so.   I'll be operating at pressure altitudes of between sea level and 5000  feet.

  

 Bob



   [quote][b]

- The Matronics LycomingEngines-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?LycomingEngines-List

douglas.dodson(at)pobox.c
Guest

Posted: Tue May 13, 2008 6:22 am Post subject: LycomingEngines-List Digest: 0 Msgs - 05/11/08

With a fixed pitch propeller, setting the throttle to 2000 RPM will result in a manifold pressure much less than atmospheric pressure.  I don’t think those charts can be used without knowing the manifold pressure.  

       

Douglas L. Dodson, Jr.

 Glasair II-S FT

 Flight Test Engineer, CFI-A/S&ME,I,G   

  

  

--

- The Matronics LycomingEngines-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?LycomingEngines-List

Display posts from previous:

	Matronics Email Lists Forum Index -> LycomingEngines-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum