X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from wr-out-0506.google.com ([64.233.184.231] verified) by logan.com (CommuniGate Pro SMTP 5.2c1) with ESMTP id 2466889 for flyrotary@lancaironline.net; Sun, 11 Nov 2007 20:38:25 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.233.184.231; envelope-from=msteitle@gmail.com Received: by wr-out-0506.google.com with SMTP id 76so536447wra for ; Sun, 11 Nov 2007 17:37:49 -0800 (PST) Received: by 10.70.54.1 with SMTP id c1mr2092642wxa.1194825658064; Sun, 11 Nov 2007 16:00:58 -0800 (PST) Received: by 10.90.34.19 with HTTP; Sun, 11 Nov 2007 16:00:58 -0800 (PST) Message-ID: <5cf132c0711111600h66722fb1x178c0674452b2115@mail.gmail.com> Date: Sun, 11 Nov 2007 18:00:58 -0600 From: "Mark Steitle" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Dimensions of my oil/water heat exchanger In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: Doug, As we all know, there's no free lunch. What I have discovered is that if you go with the oil/water exchanger, you must have enough excess radiator capacity to handle the extra btu's from the oil. I have tried different configurations and what I have now seems to work best (for me). Keep in mind that my oil temps were in the 230-240* on shallow climbs. They would come down when I leveled off, but not as much as I would have liked. However, water temps were always well within limits, bordering on too cold. Through the use of the oil/water exchanger, I was able to shift some of the heat load to the water. A side benefit of this system is that the oil and water now track within 5* of each other. My latest configuration is to run the oil from the engine into the oil/air exchanger first, then into the oil/water exchanger, and finally into the engine. This way I'm dumping the most heat directly into the air. The remaining heat is transferred into the water. I flew today and the oil and water temps barely went over 200 in a pretty aggressive sustained climb, and both came down into the 170-175* range during my economy cruise settings (1700 prop rpm, 5100 engine rpm, full throttle). (Yes, I have a constant speed prop.) This is on the low side of my targeted temps. So, I'll probably leave it like it is and concentrate on some of the other issues. Mark S. On Nov 11, 2007 8:17 AM, wrote: > > > Mark: > > Did yours come with AN fittings all around or just on the oil hookups? I > have seen a couple with tubing connections for water and AN for the oil. I > think I will start looking for one and install right from the start since I > think I should have some excess radiator capacity with the Griffin and a > goal of only producing 160-170 hp... > > Doug Lomheim > RV-9A, OK City, OK FWF > > > > > ________________________________ > See what's new at AOL.com and Make AOL Your Homepage.