X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [67.8.179.94] (account marv@lancaironline.net) by logan.com (CommuniGate Pro WebUser 5.0.9) with HTTP id 1081880 for lml@lancaironline.net; Wed, 26 Apr 2006 13:00:07 -0400 From: "Marvin Kaye" Subject: Re: [LML] FW: Compression, boost, and detonation To: lml X-Mailer: CommuniGate Pro WebUser v5.0.9 Date: Wed, 26 Apr 2006 13:00:07 -0400 Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format="flowed" Content-Transfer-Encoding: 8bit Posted for "richard titsworth" : Frederick, Interesting story and good comment. At the APS seminar George can show what detonation "looks" like on his dyno with combustion pressure tracking. It is different from auto-ignition (pre-ignition). The two are related in cause. However, detonation is the "un-natural" combustion process following the spark event. Whereas, auto-ignition is premature combustion initiated by temp/pressure (dieseling), rather than the spark. When you consider that the spark is typically advanced approx 20'ish degrees from TDC, both phenomenon can become intertwined conceptually. During the course, they cover the concepts you discuss in detail, along with real world examples, hard facts/data and hands-on exercises. Being an auto engineer with commercial/multi/inst rating, I though I knew ~ 80% of what there was to know. I had also previously read many of their LOP articles. I still got a lot out of it. Well worth the $ and time. More info available at http://www.advancedpilot.com/. Some of John's Deakins articles can be found at http://www.avweb.com/news/columns/182146-1.html. Look for #63 - #66. In the turbo LOP world, I "want" high MP, and the most power (read Fuel Flow) that temp and hence detonation will allow (while remaining LOP). So, power reductions and ROP enrichment are "undesirable". I can't change the bore size. So, I'm assuming that heat is really my performance/efficiency enemy! Get rid of the heat ==> delay the detonation ==> run WOT and add some more fuel (and/or better yet increase the compression). Thus, less heat = opportunity for more fuel = more power (when LOP). Now, how "best" to fight heat (assuming liquid is out of the question)??? More cocktails required on that issue. Very open to suggestions, I'll get the bar tab ;-)