REFLECTOR: Fuel Consumption Performance more data

Douglas Holub douglas.holub at gmail.com
Mon Sep 7 20:50:02 CDT 2009


That's pretty sweet. More than 20 mpg at 190 mph is a pretty good trick.

Doug Holub
  ----- Original Message ----- 
  From: Brent Bourgeois 
  To: Velocity Aircraft Owners and Builders list 
  Sent: Monday, September 07, 2009 8:21 PM
  Subject: Re: REFLECTOR: Fuel Consumption Performance more data


        These are the numbers from 9-3-09 for my Std RG  IO-360 200Hp 
        Speed is a 2 way average from the gps.

        9500 ALT
        2580/20.2
        40 deg LOP
        190 MPH
        9 GPH
        55 OAT

        Brent
        N61VB
        New Orleans La


        --- On Fri, 8/28/09, John Tvedte <johnt at comp-sol.com> wrote:


          From: John Tvedte <johnt at comp-sol.com>
          Subject: Re: REFLECTOR: Fuel Consumption Performance
          To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
          Date: Friday, August 28, 2009, 11:29 PM


          Terry,

          I think Scott is saying... as you lean, the first cylinder to peak is the leanest - the last to peak is the richest... if cruising ROP, you lean by the leanest cylinder (first to peak), but if cruising LOP, you lean by the richest cylinder (last to peak) - because you are on the other side of the Red Box.

          www.eaa42.org/misc/gregs_show.ppt

          Note, I do not claim to have any practical experience.

          John

          ________________________________________
          From: reflector-bounces at tvbf.org [reflector-bounces at tvbf.org] On Behalf Of Terry Miles [terrence_miles at hotmail.com]
          Sent: Friday, August 28, 2009 11:31 AM
          To: 'Velocity Aircraft Owners and Builders list'
          Subject: Re: REFLECTOR: Fuel Consumption Performance

          Well I appreciate your patience.  I did read the below articles, and several
          books now on related engine operations and mixture settings and we are in
          full agreement on the concept.  I am not running ROP.  I am running 50
          degrees LOP.  The question between us is which cylinder should be the
          reference cylinder.  My choice in this is that I will use the first cylinder
          to peak.
          Thanks again.
          Terry

          -----Original Message-----
          From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
          Behalf Of Scott Derrick
          Sent: Thursday, August 27, 2009 21:01
          To: Velocity Aircraft Owners and Builders list
          Subject: Re: REFLECTOR: Fuel Consumption Performance

          Terry,

          Below is my reply of a month ago when you indicated you were leaning to 50
          LOP on the first cylinder to peak.  All the rest being richer.  Which as I
          stated a month ago is BAD!

          Maybe I misunderstood and you are now running ROP?  Leaning until the first
          cylinder reaches peak, and then enriching it until it is 50 ROP?
          That would be the old school acceptable  method.  If you decide to read the
          articles below, you will read that  GAMI recommends 75 ROP because 50 ROP
          may be stressful to some engines  at high power settings and low altitude.

          But, since you were running at 10K or above you can run at any mixture
          setting and be fine, as far as detonation is concerned because the engine
          cannot produce more than 75% power at full throttle.

          I once again recommend the articles below by  John Deacon about how to
          safely  operate these big bore aircraft engines.  They are expensive and
          easy harm.

          Scott


          **********************************************************

          Terry,

          running the first cylinder LOP can put some of the richer cylinders right in
          the BAD zone. Thats well... bad!  Thats why you always lean to the last
          cylinder when running LOP.  Thats also why you lean to the first cylinder
          when running ROP, so all the other cylinders are rich of that point.

          you said

          "I was afraid my coolest cyl could be 150 LOP before the last cly peaked and
          that I could burn that exhaust valve."


          Thats exactly backwards. Once a cylinder reaches peak EGT and goes on the
          LOP side it will run cooler and cooler the leaner you run it. The absoluter
          worst mixture is about 25-50 degrees ROP in terms of detonation and the
          timing of peak power pulses.  If your coolest cylinder was running at 150
          degrees leaner than the last cylinder to reach 75 LOP it would probably not
          be firing due to the too lean mixture.

          How to operate your engine is a complex topic.  Here is a great set of
          articles by John Deacon, I consider a must for any recip operator, whether
          you run LOP or ROP.

          part 1
          http://www.avweb.com/news/pelican/182179-1.html
          part 2
          http://www.avweb.com/news/pelican/182176-1.html
          part 3
          http://www.avweb.com/news/pelican/182583-1.html
          part 4
          http://www.avweb.com/news/pelican/183094-1.html


          Here's GAMI's lean test,  a great thing for anybody to do, to see how
          balanced their injectors are.

          http://www.gami.com/gamijectors/leantest.php


          Scott



          >


          _______________________________________________
          To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector

          Visit the gallery!  www.tvbf.org/gallery
          user:pw = tvbf:jamaicangoose
          Check new archives: www.tvbf.org/pipermail
          Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
          _______________________________________________
          To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector

          Visit the gallery!  www.tvbf.org/gallery
          user:pw = tvbf:jamaicangoose
          Check new archives: www.tvbf.org/pipermail
          Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
       




------------------------------------------------------------------------------


  _______________________________________________
  To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector

  Visit the gallery!  www.tvbf.org/gallery
  user:pw = tvbf:jamaicangoose
  Check new archives: www.tvbf.org/pipermail
  Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20090907/fd1f1c6c/attachment-0001.htm>


More information about the Reflector mailing list