X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [64.12.137.3] (HELO imo-m22.mail.aol.com) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2340299 for flyrotary@lancaironline.net; Wed, 19 Sep 2007 15:41:01 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.3; envelope-from=WRJJRS@aol.com Received: from WRJJRS@aol.com by imo-m22.mx.aol.com (mail_out_v38_r9.2.) id q.bdb.1c1183fb (37034) for ; Wed, 19 Sep 2007 15:39:50 -0400 (EDT) Received: from webmail-md10 (webmail-md10.webmail.aol.com [64.12.170.148]) by cia-db02.mx.aol.com (v119.9) with ESMTP id MAILCIADB024-90aa46f17b05108; Wed, 19 Sep 2007 15:39:49 -0400 References: To: flyrotary@lancaironline.net Subject: Re: [FlyRotary] TDC Date: Wed, 19 Sep 2007 15:39:49 -0400 In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: wrjjrs@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8C9C90BF9B8DECA_BA8_5E93_webmail-md10.sysops.aol.com" X-Mailer: AOL WebMail 30583 Received: from 65.161.241.3 by webmail-md10.sysops.aol.com (64.12.170.148) with HTTP (WebMailUI); Wed, 19 Sep 2007 15:39:49 -0400 Message-Id: <8C9C90BF9B8DECA-BA8-2EB5@webmail-md10.sysops.aol.com> X-AOL-IP: 64.12.170.148 X-Spam-Flag: NO ----------MB_8C9C90BF9B8DECA_BA8_5E93_webmail-md10.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Not unless you fill the engine with oil. The syringe "sticktion" will allow=20= considerable compression. Oil=C2=A0or other to fill the combustion chamber w= ould be fairly accurate. A solid block moving in both directions is by far t= he most accurate. Bill Jepson -----Original Message----- From: bmears9413@aol.com To: Rotary motors in aircraft Sent: Wed, 19 Sep 2007 11:56 am Subject: [FlyRotary] TDC Changing the subject a bit, I want to make sure i have my motor on TDC to se= t my timing marks on the flywheel. This is my plan, tell me what you think.=20= I'm building a fitting to screw in the spark plug hole, and running a vacuum= line to a small suringe (like a insulin suringe). I can eyeball the rotor l= ocation close to TDC, the install this contraption and rotate the motor so t= he suringe moves out to the end and starts back in. then back the motor up a= gain till the suringe tops out. I figure that outa be and accurate TDC. Whad= da ya think??? Bob Mears Supermarine Spitfire -----Original Message----- From: Ed Anderson To: Rotary motors in aircraft Sent: Wed, 19 Sep 2007 1:16 pm Subject: [FlyRotary] Re: Strange Ignition?=20 I do not believe that is a significant factor, either, Al.=C2=A0 After all,=20= we're suppose to do our ignition checks on the ground before take off {:>).= =C2=A0 My understanding is that best power on the 13B has ignition timing be= tween 25-28 deg BTDC, so not surprising that the 20B would fall in that rang= e also.=C2=A0 Sounds reasonable to me. =C2=A0 Ed =C2=A0 =C2=A0 ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Wednesday, September 19, 2007 3:08 PM Subject: [FlyRotary] Re: Strange Ignition?=20 I wondered if perhaps one issue was that I was doing the ignition check stat= ic, on the ground; where the combination of RPM and MAP would be different t= han in the air.=C2=A0 But on checking with Tracy=E2=80=99s spreadsheet on th= e timing settings, over a fairly broad range above about 4900 the timing is=20= (should be) in the range of 26 to 28 degrees BTDC. =C2=A0 Al Email and AIM finally together. You've gotta check out free AOL Mail! ________________________________________________________________________ Email and AIM finally together. You've gotta check out free AOL Mail! - http= ://mail.aol.com ----------MB_8C9C90BF9B8DECA_BA8_5E93_webmail-md10.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="utf-8"
Not unless you fill the engine with oil. The syringe "sticktion" will a= llow considerable compression. Oil or other to fill the combustion cham= ber would be fairly accurate. A solid block moving in both directions is by=20= far the most accurate.
Bill Jepson


-----Original Message-----
From: bmears9413@aol.com
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Wed, 19 Sep 2007 11:56 am
Subject: [FlyRotary] TDC

Changing th= e subject a bit, I want to make sure i have my motor on TDC to set my timing= marks on the flywheel. This is my plan, tell me what you think. I'm buildin= g a fitting to screw in the spark plug hole, and running a vacuum line to a=20= small suringe (like a insulin suringe). I can eyeball the rotor location clo= se to TDC, the install this contraption and rotate the motor so the suringe=20= moves out to the end and starts back in. then back the motor up again till t= he suringe tops out. I figure that outa be and accurate TDC. Whadda ya think= ???

Bob Mears
Supermarine Spitfire


-----Original Message-----
From: Ed Anderson <eanderson= @carolina.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Wed, 19 Sep 2007 1:16 pm
Subject: [FlyRotary] Re: Strange Ignition?

I do not believe that is a significant factor, eithe= r, Al.  After all, we're suppose to do our ignition checks on the groun= d before take off {:>).  My understanding is that best power on the=20= 13B has ignition timing between 25-28 deg BTDC, so not surprising that the 2= 0B would fall in that range also.  Sounds reasonable to me.
 
Ed
 
 
----- Original Message -----
F= rom: Al= Gietzen
Sent: Wednesday, September 19, 2007 3= :08 PM
Subject: [FlyRotary] Re: Strange Igni= tion?

I wondered if perhaps one issue was that I was doing the ignition=20= check static, on the ground; where the combination of RPM and MAP would be d= ifferent than in the air.  But on checking with Tracy = ;
Al
Email and AIM finally together. You've gotta check out free AOL Mail!
----------MB_8C9C90BF9B8DECA_BA8_5E93_webmail-md10.sysops.aol.com--