---------------------------------------------------------- TeamGrumman-List Digest Archive --- Total Messages Posted Sun 03/18/12: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:31 AM - High CHT on #2 mystery (Mark T. Mueller) 2. 06:19 AM - Re: High CHT on #2 mystery (flyv35b) 3. 11:08 AM - Re: High CHT on #2 mystery (Gary Vogt) 4. 11:08 AM - Re: High CHT on #2 mystery (Gary Vogt) ________________________________ Message 1 _____________________________________ Time: 05:31:15 AM PST US Subject: TeamGrumman-List: High CHT on #2 mystery From: "Mark T. Mueller" Just picked 33R up from annual inspection yesterday, and when flying back to my home 'drome I could not keep my #2 CHT under 400 regardless of power setting, airspeed, or altitude. At 3500' and 2600 RPM in level cruise with an OAT of 72F #2 hit 440!!! This was NOT the case before annual except in extended climb. That cylinder is now running a good 30 - 40 hotter than before annual. The rest of the cylinders are running close to where they were before annual. Oil temp stayed below 190. I asked my IA what had been done, and he said the only thing he had to do was adjust the timing on one mag by a couple degrees and replaced the gasket on that mag. I have a LASAR ignition, and he allegedly used the T-300 tool I provided. The SB388C test was done, and he stated was well within tolerance, and good comps on all cylinders. Prior to annual, the #2 had a much higher EGT than the others, but normal CHT. All four CHTs were within 20+- during normal cruise. Now they are a good 40+ difference between #2 and coolest. Front cyls have always run hotter than rear since my baffling was rebuilt during OH 4 years ago. Now, the obvious answer is my timing is screwed up, but the motor is running more smoothly and stronger than ever (smoother than before annual) and I don't want to give that up. In addition, in my experience owning 33R it is almost NEVER the "obvious" answer... I still have to take a day off work and root around to see if there was any damage to the front baffling when they reassembled the cowling or other simple things (I am really hoping it's something simple). Looking for ideas. It is clearly a thermodynamics problem, but what might be the best way to approach this without sacrificing the best my motor has run in a while? Is it possible that low batteries in the T-300 tool might have caused an error in adjusting timing? What are common baffling issues that might contribute to such a dramatic change in #2 CHT without significantly effecting the other cylinders? Is it possible one cylinder is hypersensitive to timing over all the others? If so, what might this indicate that doesn't show up on an SB388C or other routine engine examination during annual? Thanks in advance, Mark T. Mueller Tiger N1533R ________________________________ Message 2 _____________________________________ Time: 06:19:33 AM PST US From: flyv35b Subject: Re: TeamGrumman-List: High CHT on #2 mystery On 3/18/2012 5:30 AM, Mark T. Mueller wrote: > Just picked 33R up from annual inspection yesterday, and when flying > back to my home 'drome I could not keep my #2 CHT under 400 regardless > of power setting, airspeed, or altitude. At 3500' and 2600 RPM in level > cruise with an OAT of 72F #2 hit 440!!! This was NOT the case before > annual except in extended climb. That cylinder is now running a good 30 > - 40 hotter than before annual. The rest of the cylinders are running > close to where they were before annual. > > Oil temp stayed below 190. > > I asked my IA what had been done, and he said the only thing he had to > do was adjust the timing on one mag by a couple degrees and replaced the > gasket on that mag. I have a LASAR ignition, and he allegedly used the > T-300 tool I provided. > > The SB388C test was done, and he stated was well within tolerance, and > good comps on all cylinders. > > Prior to annual, the #2 had a much higher EGT than the others, but > normal CHT. All four CHTs were within 20+- during normal cruise. Now > they are a good 40+ difference between #2 and coolest. Front cyls have > always run hotter than rear since my baffling was rebuilt during OH 4 > years ago. > > Now, the obvious answer is my timing is screwed up, but the motor is > running more smoothly and stronger than ever (smoother than before > annual) and I don't want to give that up. In addition, in my experience > owning 33R it is almost NEVER the "obvious" answer... > > I still have to take a day off work and root around to see if there was > any damage to the front baffling when they reassembled the cowling or > other simple things (I am really hoping it's something simple). > > Looking for ideas. It is clearly a thermodynamics problem, but what > might be the best way to approach this without sacrificing the best my > motor has run in a while? > > Is it possible that low batteries in the T-300 tool might have caused an > error in adjusting timing? > > What are common baffling issues that might contribute to such a dramatic > change in #2 CHT without significantly effecting the other cylinders? > > Is it possible one cylinder is hypersensitive to timing over all the > others? If so, what might this indicate that doesn't show up on an > SB388C or other routine engine examination during annual? > > Thanks in advance, > > Mark T. Mueller > Tiger N1533R > Is your plane an AG-5B? What kind/brand of CHT/EGT instrumentation? Cliff ________________________________ Message 3 _____________________________________ Time: 11:08:12 AM PST US From: Gary Vogt Subject: Re: TeamGrumman-List: High CHT on #2 mystery I would double check the timing. -If it seems smoother, it's likely the t iming was bumped up enough to make a difference. -It's all a compromise. -EGT vs CHT.-=0A=0A=0A=0A________________________________=0A From: Mark T. Mueller =0ATo: teamgrumman-list@matronics.c om =0ASent: Sunday, March 18, 2012 5:30 AM=0ASubject: TeamGrumman-List: Hig h CHT on #2 mystery=0A =0A=0AJust picked 33R up from annual inspection yest erday, and when flying back to my home 'drome I could not keep my #2 CHT un der 400 regardless of power setting, airspeed, or altitude. -At 3500' and 2600 RPM in level cruise with an OAT of 72F #2 hit 440!!! -This was NOT the case before annual except in extended climb. -That cylinder is now ru nning a good 30 - 40 hotter than before annual. -The rest of the cylinder s are running close to where they were before annual.=0A=0AOil temp stayed below 190.=0A=0A=0AI asked my IA what had been done, and he said the only t hing he had to do was adjust the timing on one mag by a couple degrees and replaced the gasket on that mag. -I have a LASAR ignition, and he alleged ly used the T-300 tool I provided.=0A=0AThe SB388C test was done, and he st ated was well within tolerance, and good comps on all cylinders.=0A=0APrior to annual, the #2 had a much higher EGT than the others, but normal CHT. -All four CHTs were within 20+- during normal cruise. -Now they are a g ood 40+ difference between #2 and coolest. -Front cyls have always run ho tter than rear since my baffling was rebuilt during OH 4 years ago.=0A=0ANo w, the obvious answer is my timing is screwed up, but the motor is running more smoothly and stronger than ever (smoother than before annual) and I do n't want to give that up. -In addition, in my experience owning 33R it is almost NEVER the "obvious" answer...=0A=0AI still have to take a day off w ork and root around to see if there was any damage to the front baffling wh en they reassembled the cowling or other simple things (I am really hoping it's something simple).=0A=0ALooking for ideas. -It is clearly a thermody namics problem, but what might be the best way to approach this without sac rificing the best my motor has run in a while?=0A=0AIs it possible that low batteries in the T-300 tool might have caused an error in adjusting timing ?=0A=0AWhat are common baffling issues that might contribute to such a dram atic change in #2 CHT without significantly effecting the other cylinders? =0A=0AIs it possible one cylinder is hypersensitive to timing over all the others? -If so, what might this indicate that doesn't show up on an SB388 C or other routine engine examination during annual?=0A=0AThanks in advance ======== ________________________________ Message 4 _____________________________________ Time: 11:08:44 AM PST US From: Gary Vogt Subject: Re: TeamGrumman-List: High CHT on #2 mystery my guess, Cheetah with JPI=0A=0A=0A________________________________=0A From : flyv35b =0ATo: teamgrumman-list@matronics.com =0A Sent: Sunday, March 18, 2012 6:19 AM=0ASubject: Re: TeamGrumman-List: High yv35b@minetfiber.com>=0A=0AOn 3/18/2012 5:30 AM, Mark T. Mueller wrote:=0A> Just picked 33R up from annual inspection yesterday, and when flying=0A> b ack to my home 'drome I could not keep my #2 CHT under 400 regardless=0A> o f power setting, airspeed, or altitude.- At 3500' and 2600 RPM in level =0A> cruise with an OAT of 72F #2 hit 440!!!- This was NOT the case befor e=0A> annual except in extended climb.- That cylinder is now running a go od 30=0A> - 40 hotter than before annual.- The rest of the cylinders are running=0A> close to where they were before annual.=0A>=0A> Oil temp stayed below 190.=0A>=0A> I asked my IA what had been done, and he said the only thing he had to=0A> do was adjust the timing on one mag by a couple degrees and replaced the=0A> gasket on that mag.- I have a LASAR ignition, and h e allegedly used the=0A> T-300 tool I provided.=0A>=0A> The SB388C test was done, and he stated was well within tolerance, and=0A> good comps on all c ylinders.=0A>=0A> Prior to annual, the #2 had a much higher EGT than the ot hers, but=0A> normal CHT.- All four CHTs were within 20+- during normal c ruise.- Now=0A> they are a good 40+ difference between #2 and coolest.- Front cyls have=0A> always run hotter than rear since my baffling was rebu ilt during OH 4=0A> years ago.=0A>=0A> Now, the obvious answer is my timing is screwed up, but the motor is=0A> running more smoothly and stronger tha n ever (smoother than before=0A> annual) and I don't want to give that up. - In addition, in my experience=0A> owning 33R it is almost NEVER the "ob vious" answer...=0A>=0A> I still have to take a day off work and root aroun d to see if there was=0A> any damage to the front baffling when they reasse mbled the cowling or=0A> other simple things (I am really hoping it's somet hing simple).=0A>=0A> Looking for ideas.- It is clearly a thermodynamics problem, but what=0A> might be the best way to approach this without sacrif icing the best my=0A> motor has run in a while?=0A>=0A> Is it possible that low batteries in the T-300 tool might have caused an=0A> error in adjustin g timing?=0A>=0A> What are common baffling issues that might contribute to such a dramatic=0A> change in #2 CHT without significantly effecting the ot her cylinders?=0A>=0A> Is it possible one cylinder is hypersensitive to tim ing over all the=0A> others?- If so, what might this indicate that doesn' t show up on an=0A> SB388C or other routine engine examination during annua l?=0A>=0A> Thanks in advance,=0A>=0A> Mark T. Mueller=0A> Tiger N1533R=0A> =0AIs your plane an AG-5B?- What kind/brand of CHT/EGT instrumentation? ====================== ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message teamgrumman-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/TeamGrumman-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/teamgrumman-list Browse Digests http://www.matronics.com/digest/teamgrumman-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.