X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-da04.mx.aol.com ([205.188.105.146] verified) by logan.com (CommuniGate Pro SMTP 5.4.6) with ESMTP id 5623372 for flyrotary@lancaironline.net; Sun, 24 Jun 2012 11:20:00 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.105.146; envelope-from=Lehanover@aol.com Received: from mtaomg-mb04.r1000.mx.aol.com (mtaomg-mb04.r1000.mx.aol.com [172.29.41.75]) by imr-da04.mx.aol.com (8.14.1/8.14.1) with ESMTP id q5OFJNTh017999 for ; Sun, 24 Jun 2012 11:19:23 -0400 Received: from core-moe003c.r1000.mail.aol.com (core-moe003.r1000.mail.aol.com [172.29.188.73]) by mtaomg-mb04.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id B3C49E000082 for ; Sun, 24 Jun 2012 11:19:22 -0400 (EDT) From: Lehanover@aol.com Message-ID: <7e2c.52ab578b.3d1889f9@aol.com> Date: Sun, 24 Jun 2012 11:19:21 -0400 (EDT) Subject: Iron Man/loss of fuel pressure/oil pressure To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_7e2c.52ab578b.3d1889f9_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=1340551163; bh=4vPj6k5PgwUeDOuvK6EXttPJDC+tiQ1OkhBuOkhXEQE=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=v1jTphPIBVkiyuQjZ5etalx9Rd75xsfjEcyQ/9yJIDoRMUps1bnBaQajkufur6xXD L4D4FEQUbMjRzBpxNLwaqQfRgl1dgmHGZ3VeQYHfEj330OeaqDDhrk7IVLv0w9drdr qHdPmaDovonN5nD8ug+f44UiN2pF4wMDUI6jLvuA= X-AOL-SCOLL-SCORE: 0:2:376899072:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d294b4fe72ffa42a0 --part1_7e2c.52ab578b.3d1889f9_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit It sounds as though a fuel leak developed that could be overcome by both pumps running but not with one pump running. The best news is that you are here to tell the tale. I doubt that there was an oil system problem until the last restart. The rotary can rev up so fast that it is possible to have oil pressure much higher than the relief valve cracking pressure elsewhere in the system. Plus there is a bit of hysteresis in the relief valve (all relief valves). This where the valve will hold one pressure when open and flowing, but requires a bit more pressure to unseat (crack). The rotary oil pressure is controlled by a valve at the end of the system, rather than at the pump as in most engines. So all of the system is at a slightly higher pressure than the cracking pressure all of the time. If you have the stock relief valve in the front cover, it is set at 144 pounds and is there to protect the oil cooler in cold starts. Not a factor here. The engine being turned by the gear box and the reduction ratio gives the engine a head start on an over rev (A very rapid acceleration)before the RPM is again controlled by the load. Baring a fire as a result of the loss of oil, the engine can run quite a while with no oil pressure at all. Big bearings lightly loaded. My driver has demonstrated that several times. Just speculation on my part. Remember the FAA motto. We're not happy until you're not happy. Lynn E. Hanover --part1_7e2c.52ab578b.3d1889f9_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

=20

It sounds as though a fuel leak developed that could be overcome by bo= th=20 pumps running but not with one pump running.

The best news is that you are here to tell the tale.

I doubt that there was an oil system problem until the last restart.

The rotary can rev up so fast that it is possible to have oil pressure= much=20 higher than the relief valve cracking pressure elsewhere in the system. Plu= s=20 there is a bit of hysteresis in the relief valve (all relief valves). This = where=20 the valve will hold one pressure when open and flowing, but requires a bit = more=20 pressure to unseat (crack).

The rotary oil pressure is controlled by a valve at the end of the sys= tem,=20 rather than at the pump as in most engines. So all of the sy= stem=20 is at a slightly higher pressure than the cracking pressure all of the time= . If=20 you have the stock relief valve in the front cover, it is set at 144 pounds= and=20 is there to protect the oil cooler in cold starts. Not a factor=20 here.

The engine being turned by the gear box and the reduction ratio gives = the=20 engine a head start on an over rev (A very rapid acceleration)before the RP= M is=20 again controlled by the load.

Baring a fire as a result of the loss of oil, the engine can run quite= a=20 while with no oil pressure at all. Big bearings lightly loaded. My driver h= as=20 demonstrated that several times.

Just speculation on my part.

Remember the FAA motto.

We're not happy until you're not happy.

Lynn E. Hanover

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