---------------------------------------------------------- Engines-List Digest Archive --- Total Messages Posted Sat 05/16/09: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:20 AM - Re: Engines-List Digest: 1 Msgs - 05/15/09 (Stu Brown) 2. 09:32 AM - Re: Re: Engines-List Digest: 1 Msgs - 05/15/09 (Ken) ________________________________ Message 1 _____________________________________ Time: 09:20:39 AM PST US From: Stu Brown Subject: Engines-List: Re: Engines-List Digest: 1 Msgs - 05/15/09 Drawing a comparison between an automobile and aircraft engines based upon compression can get you into trouble. Temperatures vary greatly in the AC engine and the ignition timing is fixed. Automobile engines use a timing curve based upon rpm, load, temp. etc. Ain't technology great? Stu Brown Engines-List Digest Server wrote: > * > > ================================================= > Online Versions of Today's List Digest Archive > ================================================= > > Today's complete Engines-List Digest can also be found in either of the > two Web Links listed below. The .html file includes the Digest formatted > in HTML for viewing with a web browser and features Hyperlinked Indexes > and Message Navigation. The .txt file includes the plain ASCII version > of the Engines-List Digest and can be viewed with a generic text editor > such as Notepad or with a web browser. > > HTML Version: > > http://www.matronics.com/digest/digestview.php?Style=82701&View=html&Chapter 09-05-15&Archive=Engines > > Text Version: > > http://www.matronics.com/digest/digestview.php?Style=82701&View=txt&Chapter 09-05-15&Archive=Engines > > > =============================================== > EMail Version of Today's List Digest Archive > =============================================== > > > ---------------------------------------------------------- > Engines-List Digest Archive > --- > Total Messages Posted Fri 05/15/09: 1 > ---------------------------------------------------------- > > > Today's Message Index: > ---------------------- > > 1. 06:58 AM - Re: Auto Engine - compression ratio vs. octane (Noel) > > > > ________________________________ Message 1 _____________________________________ > > > Time: 06:58:01 AM PST US > From: "Noel" > Subject: RE: Engines-List: Auto Engine - compression ratio vs. octane > > > I had a friend who regularly ran his 426 Hemi Charger on high octane Avgas > before the advent of 100 LL. > > Noel > > -----Original Message----- > From: owner-engines-list-server@matronics.com > [mailto:owner-engines-list-server@matronics.com] On Behalf Of DEAN > PSIROPOULOS > Sent: 15 May 2009 01:14 AM > Subject: RE: Engines-List: Auto Engine - compression ratio vs. octane > > > > > The big automotive engines of the 1960s took compression ratios to their > ultimate state of the art with premium leaded auto gas. Ratios from 10.5 to > 11.5 to 1 were common place with 100 octane auto fuel. Since the unleaded > mandate, computer analysis has advanced the state of the art in combustion > chamber technology so that 9.5 to 1 ratios are possible on regular unleaded > fuel (87 octane) without detonation. If you use computerized engine control > with knock sensing you could probably go even higher. And with avgas being > the equivalent of somewhere around 110 octane autofuel, the sky should be > the limit (not quite but it would be an interesting exercise to see how high > one could go using a modern auto engine with avgas). > > Dean Psiropoulos > RV-6A N197DM > Struggling with erratic idle on 0-360 > > > > > > > > > > ________________________________ Message 2 _____________________________________ Time: 09:32:17 AM PST US From: Ken Subject: Re: Engines-List: Re: Engines-List Digest: 1 Msgs - 05/15/09 And also a huge difference in volumetric efficiency. Ken Stu Brown wrote: > > > > Drawing a comparison between an automobile and aircraft engines based > upon compression can get you into trouble. Temperatures vary greatly in > the AC engine and the ignition timing is fixed. Automobile engines use a > timing curve based upon rpm, load, temp. etc. Ain't technology great? > > Stu Brown > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message engines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Engines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/engines-list Browse Digests http://www.matronics.com/digest/engines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.