X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from exhub003-1.exch003intermedia.net ([207.5.74.28] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with ESMTPS id 4987313 for flyrotary@lancaironline.net; Wed, 18 May 2011 08:17:00 -0400 Received-SPF: none receiver=logan.com; client-ip=207.5.74.28; envelope-from=jwhaley@datacast.com Received: from EXVMBX003-5.exch003intermedia.net ([207.5.74.45]) by exhub003-1.exch003intermedia.net ([207.5.74.28]) with mapi; Wed, 18 May 2011 05:16:24 -0700 From: Jeff Whaley To: "flyrotary@lancaironline.net" Date: Wed, 18 May 2011 05:17:32 -0700 Subject: RE: Engine Tuning Thread-Topic: Engine Tuning Thread-Index: AcwVQq0Bb4xm+Mr2TJ2DulzOsBm5gQADxthgAADFRKA= Message-ID: References: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Hello Brian: Don't know what happened to that last post; it was a jumbled mess. I don't = subscribe to the feed so I have to cut and paste. Anyway the first attachment was obviously your MAP and the second attachmen= t includes Ed's MAP in light blue (hope you don't mind Ed) and mine is the = one in purple for comparison ... hope these graphs are useful. Jeff From: bktrub@aol.com Subject: Re: [FlyRotary] Your Fuel Map: [FlyRotary] Re: Engine Tuning Date: Wed, 18 May 2011 00:02:01 -0400 To: flyrotary@lancaironline.net Ok, that is interesting. I forgot to mention that I am running 28 lb primar= ies and 40 lb secondaries. Looks like I will be doing some more setting of = the tables and experimentation. I do have an O2 sensor and monitor, so I'll be looking at that also. Brian Trubee -----Original Message----- From: Ed Anderson To: Rotary motors in aircraft Sent: Tue, May 17, 2011 8:28 pm Subject: [FlyRotary] Your Fuel Map: [FlyRotary] Re: Engine Tuning Hi Brian, I have my fuel MAP values and comments (in blue) buried in your spread shee= t. IF I had to make a stab at this point and quick look, I would say you a= re probably running excessively rich at your higher map values > bin pointe= r 75 < bin pointer 103. See my notes. I took my MAP values (turbo block s= treet ported - good intake - no turbo) and converted them to your reference= - that column is in blue is my value for direct comparison with yours. So= me places we different but it probably doesn't really matter - in other are= as where we differ, you are running considerably richer than my engine. I have the 2.84:1 gear box swinging a 74x88 prop and consistently get 6000 = rpm static on a normal day and can get up to 6200 on a colder day. My fuel= flow will range from 16.5-18 GPH on take off and has hit 20 GPH on a cold = day. I use a 91 Turbo block street ported sans turbocharger. I have a fair= ly decent intake system (about the sixth version - so I did quite a bit of = experimentation to get it right and I think it's a pretty descent intake) Do you have an air/fuel ratio indicator? If so I suggest you run your engi= ne at some of those bin numbers and record what it is telling you (lean, Me= dium Rich, etc). While at higher Manifold pressure you do want an air/fuel= ratio running closer to 12.5:1, I suspect your air/fuel ratio may be even = richer than that. Now all of these comments apply to bin/manifold pressure= s in the non-boosted range < bin 103 or so. Take a look at my notes - it is possible your problem could be too rich. T= oo much fuel in your mufflers getting ignited can certainly produce a loud = bang. Perhaps ignition could also cause it, but right now it appears to me= you are simply way too rich between bins 75-103. If you have an air/fuel = ratio indicator, I would try reducing the mixture in those areas. Hope this helps Ed __________ Information from ESET NOD32 Antivirus, version of virus signatur= e database 6131 (20110518) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com This message, and the documents attached hereto, is intended only for the a= ddressee and may contain privileged or confidential information. Any unauth= orized disclosure is strictly prohibited. If you have received this message= in error, please notify us immediately so that we may correct our internal= records. Please then delete the original message. Thank you.