---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Wed 07/13/22: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:42 AM - Re: Re: Low CHT (Richard Goode) 2. 11:19 AM - Re: Low CHT (glipaz) 3. 03:59 PM - Re: Low CHT (Ttail) ________________________________ Message 1 _____________________________________ Time: 12:42:24 AM PST US From: "Richard Goode" Subject: RE: Yak-List: Re: Low CHT These engines are surprisingly "individual" when choosing a suction jet. That is that two engines of seemingly identical specification can require suction jets 0.1 mm or even 0.2 mm apart. But from my experience I would suggest that for an M 14 PF that a 1.3 mm suction jet is probably correct. But I'd also say that a 1.5 mm (larger means leaner since they are compensating jets) is too lean. Then, as I said before, the CHT measuring probe under a sparking plug is an incredibly imprecise way of measuring temperature. But it makes a huge difference if it is really clean as indeed its "seat" onto a cylinder head. Then I would suggest comparing its reading with an accurate external CHT measurement. And, finally, I wouldn't be concerned about fuel flow. I feel too many people have expensive electronic fuel flow measurements and then become obsessed by them. Engine performance and cylinder temperature are, to my mind, the only important factors! RICHARD GOODE AEROBATICS Rhodds Farm, Lyonshall, Hereford, HR5 3LW, UK Tel: +44 (0)1544 340120 Fax: +44 (0)1544 340129 e-mail: richard.goode@russianaeros.com www.russianaeros.com WORLD LEADERS IN SOVIET & CHINESE RADIAL AIRCRAFT ENGINES In partnership with Aerometal Kft, Hungary. -----Original Message----- From: owner-yak-list-server@matronics.com On Behalf Of Ttail Sent: 13 July 2022 03:37 Subject: Yak-List: Re: Low CHT Gil. My engine (M14PF) came with 1.3mm suction jet fitted. This was changed to a 1.5mm suction jet so slightly leaner. No issue controlling CHT's to say 180C. Also picked up a lesser fuel burn at crz power settings. FF reduced by 4L hr. -------- Sean Trestrail ttail[at]internode.on.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=507466#507466 ________________________________ Message 2 _____________________________________ Time: 11:19:27 AM PST US Subject: Yak-List: Re: Low CHT From: "glipaz" Thanks Richard! I will check what size we put in for the suction jet and return. Gil Read this topic online here: http://forums.matronics.com/viewtopic.php?p=507468#507468 ________________________________ Message 3 _____________________________________ Time: 03:59:00 PM PST US Subject: Yak-List: Re: Low CHT From: "Ttail" " I feel too many people have expensive electronic fuel flow measurements and then become obsessed by them. Engine performance and cylinder temperature are, to my mind, the only important factors! '[i] The reduction in FF was an observation not an "obsession". Its also kind of nice to have a second independent fuel qty system. The reason the jet was changed in the first place was consistently low CHT (on all cylinders). After the change CHT is far more manageable.[/i] -------- Sean Trestrail ttail[at]internode.on.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=507469#507469 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message yak-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Yak-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/yak-list Browse Digests http://www.matronics.com/digest/yak-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.