X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 29 Jan 2012 17:16:11 -0500 Message-ID: X-Original-Return-Path: Received: from imr-ma06.mx.aol.com ([64.12.78.142] verified) by logan.com (CommuniGate Pro SMTP 5.4.3) with ESMTP id 5367538 for lml@lancaironline.net; Fri, 27 Jan 2012 18:23:46 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.78.142; envelope-from=Sky2high@aol.com Received: from mtaomg-db01.r1000.mx.aol.com (mtaomg-db01.r1000.mx.aol.com [172.29.51.199]) by imr-ma06.mx.aol.com (8.14.1/8.14.1) with ESMTP id q0RNN8mV018432 for ; Fri, 27 Jan 2012 18:23:08 -0500 Received: from core-mtb005a.r1000.mail.aol.com (core-mtb005.r1000.mail.aol.com [172.29.234.209]) by mtaomg-db01.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 112B8E000081 for ; Fri, 27 Jan 2012 18:23:08 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: <2aca8.5892f563.3c548bdb@aol.com> X-Original-Date: Fri, 27 Jan 2012 18:23:08 -0500 (EST) Subject: Re: [LML] Re: Steam Gauge Backup X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_2aca8.5892f563.3c548bdb_boundary" X-Mailer: AOL 9.6 sub 168 X-Originating-IP: [67.175.156.123] x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:414707072:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d33c74f2331dc3867 --part1_2aca8.5892f563.3c548bdb_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Paul, Good point. Everyone turns their prop backwards when..... Cleaning bugs off the spinner Checking mag timing Compression checks Posing the prop to look pretty on the ramp etc.... Grayhawk In a message dated 1/27/2012 12:42:48 P.M. Central Standard Time, paul@tbm700.com writes: In a past life I went through a lot of dry pumps on the twin Cessna. We did a lot of testing and found some easy ways to extend life. To test, we turned a pump with a motor in the shop to see the temperatures. The pump without airflow will get VERY hot and needs external airflow. Once we ducted airflow with those addon plastic housings, life was extended on the airframe. Also, we disassembled worn pumps and found the carbon blades worn at the edges and getting thin. Turning the pump backwards broke some of those blades. This means that if you have someone turning your prop backwards on a worn pump, it might lead to premature failure. I tried to prevent anyone from moving the prop backwards and you can't imagine how often that happens. Hope that helps. I'm certain the cooling and lubrication from a wet system is part of the reason they last so much longer. Cooling is probably the prime requirement in a dry pump. Paul Spruce Creek On 2012-01-23, at 7:50 AM, Charles Brown wrote: My experience with two wet vac pumps on a C-310 is that they never failed. But they're rather large and heavy? as I recall. On Jan 20, 2012, at 1:36 PM, thomas williams wrote: a wet vacuum pump is VERY reliable compared to the dry pumps. = --part1_2aca8.5892f563.3c548bdb_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Paul,

Good point. Everyone turns their prop backwards when.....

Cleaning bugs off the spinner

Checking mag timing

Compression checks

Posing the prop to look pretty on the ramp

etc....

Grayhawk

In a message dated 1/27/2012 12:42:48 P.M. Central Standard Time,=20 paul@tbm700.com writes:

= In a=20 past life I went through a lot of dry pumps on the twin Cessna. We = did a=20 lot of testing and found some easy ways to extend life. To test, w= e=20 turned a pump with a motor in the shop to see the temperatures. The= pump=20 without airflow will get VERY hot and needs external airflow. Once = we=20 ducted airflow with those addon plastic housings, life was extended on th= e=20 airframe. Also, we disassembled worn pumps and found the carbon bla= des=20 worn at the edges and getting thin. Turning the pump backwards brok= e=20 some of those blades. This means that if you have someone turning y= our=20 prop backwards on a worn pump, it might lead to premature failure. = I=20 tried to prevent anyone from moving the prop backwards and you can't imag= ine=20 how often that happens. Hope that helps.=20

I'm certain the cooling and lubrication from a wet system is part of= the=20 reason they last so much longer. Cooling is probably the prime=20 requirement in a dry pump.

Paul

Spruce Creek

On 2012-01-23, at 7:50 AM, Charles Brown wrote:

My experience with two wet vac pumps on a C-310 is that they never= =20 failed. But they're rather large and heavy? as I recall.

On Jan 20, 2012, at 1:36 PM, thomas williams wrote:

a wet vacuum pump is VERY reliable compared to the dry pumps= .=20

=3D= --part1_2aca8.5892f563.3c548bdb_boundary--