X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-ma04.mx.aol.com ([64.12.206.42] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTP id 5518146 for flyrotary@lancaironline.net; Tue, 01 May 2012 16:21:10 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.206.42; envelope-from=Lehanover@aol.com Received: from mtaomg-mb02.r1000.mx.aol.com (mtaomg-mb02.r1000.mx.aol.com [172.29.41.73]) by imr-ma04.mx.aol.com (8.14.1/8.14.1) with ESMTP id q41KKHF5010707 for ; Tue, 1 May 2012 16:20:18 -0400 Received: from core-moa001a.r1000.mail.aol.com (core-moa001.r1000.mail.aol.com [172.29.233.1]) by mtaomg-mb02.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 06CF2E00008C for ; Tue, 1 May 2012 16:20:18 -0400 (EDT) From: Lehanover@aol.com Message-ID: <35971.703f6ad.3cd19f81@aol.com> Date: Tue, 1 May 2012 16:20:17 -0400 (EDT) Subject: Re: [FlyRotary] Re: It won't run no more To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_35971.703f6ad.3cd19f81_boundary" X-Mailer: AOL 9.6 sub 5004 X-Originating-IP: [173.88.30.23] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20110426; t=1335903618; bh=p8w0g9tQeURMQt/O5vtIOo9Wdc1HSyrHKxC5gk0GGyU=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=aVkZzXDeAAQtxp1NI6GmyHB+GHEqLA8EBmpLSWLjqBZjLEKnbfBmcVXYpw7wQOb58 8X4dp/E5DtTzaF/6+0GYzP+M/qkeXUtHv4zbt1mhH6NgAaMPosuT2o0O01E87esjDM wGsEEV1VPWZjB3q20yRMezCEChxNwAdcFFvkTK2E= X-AOL-SCOLL-SCORE: 0:2:391356608:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d29494fa045821e12 --part1_35971.703f6ad.3cd19f81_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Disable the ignition. Remove the leading plugs(the bottom ones). Prop the throttle wide open. Check again to be sure the ignition is disabled. Have the safety pilot understand to close the throttle instantly should the engine start. Airframe chocked and brakes on. Full up elevator. Screw in a compression gage with the Shrader valve removed. Spin the engine with the starter. Look for 130 to 140 pound of compression on each face. If you get one bad face that means a bad or stuck side seal. Two bad faces means a stuck or bad apex seal. Most rotaries will start and run fine on 100 pounds of compression. The lower the compression the harder the starting. You can also do a leak down check on a rotary. You must have TDC marked for both housings. You must be able to hold the propeller stationary when the 100 PSI air is injected into the chamber. That means a big person with a good grip. With a reduction unit in place the prop will not try to turn a full 180, but will turn about half that way with lots of torque. Then you are comparing the chamber leaks to a .040" hole between the gages. I built my own using a .020" hole and could get ZERO hot leak down on racing engines. The open engines all sound the same to me. I left my hearing on the mighty Forrestal. So maybe you can tell the difference. I don't know. Lynn E. Hanover In a message dated 5/1/2012 1:37:36 P.M. Eastern Daylight Time, echristley@att.net writes: > Pulling the blade through one revolution give me a little more that six solid ker-chunks from the engine with my 3.14 gearbox ratio. Would that indicate a good seal, or with that just be an unreliable first approximation? -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html --part1_35971.703f6ad.3cd19f81_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Disable the ignition. Remove the leading plugs(the bottom ones).
Prop the throttle wide open. Check again to be sure the ignition is=20 disabled. Have the safety pilot understand to close the throttle instantly= =20 should the engine start. Airframe chocked and brakes on. Full up elevator.<= /DIV>
Screw in a compression gage with the Shrader valve removed. Spin the e= ngine=20 with the starter.
Look for 130 to 140 pound of compression on each face. If you get one = bad=20 face that means a bad or stuck side seal. Two bad faces means a stuck or ba= d=20 apex seal. Most rotaries will start and run fine on 100 pounds of=20 compression. The lower the compression the harder the starting. You can als= o do=20 a leak down check on a rotary. You must have TDC marked for both housings. = You=20 must be able to hold the propeller stationary when the 100 PSI air is injec= ted=20 into the chamber.
That means a big person with a good grip. With a reduction unit in pla= ce=20 the prop will not try to turn a full 180, but will turn about half that way= with=20 lots of torque. Then you are comparing the chamber leaks to a .040" hole be= tween=20 the gages. I built my own using a .020" hole and could get ZERO hot leak do= wn on=20 racing engines. 
 
The open engines all sound the same to me. I left my hearing on the mi= ghty=20 Forrestal. So maybe you can tell the difference. I don't know.
 
Lynn E. Hanover
 
 
In a message dated 5/1/2012 1:37:36 P.M. Eastern Daylight Time,=20 echristley@att.net writes:
= > 

Pulling the blade through one revolution = give me=20 a little more that six solid ker-chunks from the engine with my=20 3.14
gearbox ratio.  Would that indicate a good seal, or with tha= t=20 just be an unreliable first approximation?

--
Homepage: = =20 http://www.flyrotary.com/
Archive and UnSub:  =20 http://mail.lancaironline.net:81/lists/flyrotary/List.html
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