Return-Path: Received: from web41503.mail.yahoo.com ([66.218.93.86] verified) by logan.com (CommuniGate Pro SMTP 4.2.2) with SMTP id 422034 for flyrotary@lancaironline.net; Mon, 20 Sep 2004 01:32:32 -0400 Received-SPF: none receiver=logan.com; client-ip=66.218.93.86; envelope-from=tomtugan@yahoo.com Message-ID: <20040920053201.12599.qmail@web41503.mail.yahoo.com> Received: from [63.225.104.191] by web41503.mail.yahoo.com via HTTP; Sun, 19 Sep 2004 22:32:01 PDT Date: Sun, 19 Sep 2004 22:32:01 -0700 (PDT) From: Tom Subject: Re: [FlyRotary] Oil temperature limits To: Rotary motors in aircraft In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii --- Lehanover@aol.com wrote: The primary object of cooling the oil is to prevent the movement of the bearing overlay. The soft shiny stuff that turns up in the filter when things go wrong. Lynn E. Hanover > Hi guys, I mostly lurk until I have anything meaningful to add. So much good detail in these posts. I'm not an engine guy but it surprised me to hear that engine metals have problems with oil temps which aren't even at 300 degrees. It occurred to me today that another real basis for oil temperature limits should probably be the breakdown of the engine oil. I googled on this topic 'auto oil breakdown temp' to find discussion on oil temp limits before breakdown. Many good links to discussion such as this... http://faq.f650.com/FAQs/AftermarketInstrumentationFAQ.htm "Max. Temperature: The gauge is redlined at 240F, which sounds about right to me, for synthetic oil. Dino oil is best kept below 230F. The best temperature is around 190 to 200F. You want the oil hot enough to cook out any water vapour that builds up in the crankcase and oil when the engine cools down at night, but not too hot that the oil will start to "breakdown". Richard #230 You also need to be concerned about engine blow-by and condensation creating acids in the oil that will attack the bearing materials. Even synthetic oil will not keep this stuff at bay for too long, under short-haul riding conditions. Seeing that my bike's oil will be anywhere from 170 to 245 at full temp, depending on the weather and conditions, I'm not sure I agree the cooling system is all that great. running at a good clip in warm weather will usually get the temp up to 220-225. today, in cool weather, it barely reached 190. but I've hit 245, and my coolant's always been at the right mix and level. Mark #403 One of the most interesting thing's I've noted is that I can run forever below 6K with just about any load on any terrain and my temp hovers close to 200°. The second I go above that, temp starts to climb. Sometimes in the summer with a full load up to 250° That's another reason I use Synth. The observations I noted occur regardless of ambient temperature. They just happen quicker. If I ride close to red line on a 50° day, it still gets up to 240°-250° eventually. David#476.".... Tom/Denver I just moved up from Birmingham last month and so have been following the southern storms with interest. Paul, It was I who sat in Dan's Cozy at SERFI last year and left my cell phone in it. __________________________________ Do you Yahoo!? Yahoo! Mail - 50x more storage than other providers! http://promotions.yahoo.com/new_mail