---------------------------------------------------------- LycomingEngines-List Digest Archive --- Total Messages Posted Wed 11/25/09: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:02 PM - Re: CHT update (Thomas G Koelzer) 2. 06:16 PM - Re: CHT update (Ralph E. Capen) 3. 07:17 PM - Re: CHT update (Thomas G Koelzer) ________________________________ Message 1 _____________________________________ Time: 06:02:35 PM PST US Subject: Re: LycomingEngines-List: CHT update From: Thomas G Koelzer Are you absolutely convinced the right side is running hotter than the left? Is there instrumentation error and can you confirm accuracy via another method or by swapping sensors? Do you have EGT numbers to confirm the cylinders are at the proper mixture but the cooling is inadequate? Just some food for thought. Tom Do not archive On Nov 23, 2009, at 5:22 PM, Ralph E. Capen wrote: > As many of you may know, I have been obsessing a bit about my CHT's...to get them consistent. > > Here's the setup: > IO360B1F6 > 9.2:1 pistons > AFP Fuel Injection > LASAR Ignition with CHT sender relocated to allow for testing > Vetterman Dual Crossover Heater/Mufflers > SamJames cowl and plenum > Advanced Flight Systems 3400 Engine Monitor > > Oil Cooler mounted behind #4 cylinder > Air for both Heater/Mufflers behind #3 cylinder > > For constant power setting, here's the consistency that I have achieved: > #1 and #3 cylinders run within three degrees (avg) of each other > #2 and #4 cylinders run within three degrees (avg) of each other > The #1/#3 cylinders run 8.5 degrees hotter (avg) than the #2/#4 cylinders > > With the members of the sets of cylinders running this close each other, I'm thinking that I have the balance (front to rear) for each side pretty well matched. > > I'm trying to wrap my head around what could be causing the right side to run hotter than the left. Here's some of what I'm thinking...: With this plenum set-up, I'm thinking that the pressure/volume should equalize from left to right. This would leave me with not much to change to cause more cooling air to go from the left to the right - meaning that I probably have to live with the differences. Alternatively, maybe it's not really hotter...the two sets of CHT wires for the left side (both equal length) are about three feet longer than the ones for the right side (again, both equal length). Could the difference in the lengths of the wires account for the reported temperature difference? > > I'm pretty close to thinking that this is as good as it gets...but I would really like to know why... > > Thanks, > Ralph > > > > > ________________________________ Message 2 _____________________________________ Time: 06:16:10 PM PST US From: "Ralph E. Capen" Subject: Re: LycomingEngines-List: CHT update Tom, Thanks for your input... I have calibrated the sensors with boiling water and candy thermometer - and swapped the sensors enough to know that the sensors are consistent and accurate. The EGT numbers show a good mixture distribution - but I haven't balanced the injectors yet. That may change things when the balancing act is accomplished - we'll see. Some of the other postings provided info on a couple of other places to look in the cooling system - just in case. Most of the other postings told me to go have a coke and a smile - and fly-on. I'm planning to fly for a while - balance my injectors and see what happens. Ralph ----- Original Message ----- From: "Thomas G Koelzer" Sent: Wednesday, November 25, 2009 9:01 PM Subject: Re: LycomingEngines-List: CHT update > > > Are you absolutely convinced the right side is running hotter than the > left? Is there instrumentation error and can you confirm accuracy via > another method or by swapping sensors? Do you have EGT numbers to confirm > the cylinders are at the proper mixture but the cooling is inadequate? > > Just some food for thought. > > Tom > > Do not archive > > On Nov 23, 2009, at 5:22 PM, Ralph E. Capen wrote: > >> As many of you may know, I have been obsessing a bit about my CHT's...to >> get them consistent. >> >> Here's the setup: >> IO360B1F6 >> 9.2:1 pistons >> AFP Fuel Injection >> LASAR Ignition with CHT sender relocated to allow for testing >> Vetterman Dual Crossover Heater/Mufflers >> SamJames cowl and plenum >> Advanced Flight Systems 3400 Engine Monitor >> >> Oil Cooler mounted behind #4 cylinder >> Air for both Heater/Mufflers behind #3 cylinder >> >> For constant power setting, here's the consistency that I have achieved: >> #1 and #3 cylinders run within three degrees (avg) of each other >> #2 and #4 cylinders run within three degrees (avg) of each other >> The #1/#3 cylinders run 8.5 degrees hotter (avg) than the #2/#4 cylinders >> >> With the members of the sets of cylinders running this close each other, >> I'm thinking that I have the balance (front to rear) for each side pretty >> well matched. >> >> I'm trying to wrap my head around what could be causing the right side to >> run hotter than the left. Here's some of what I'm thinking...: With this >> plenum set-up, I'm thinking that the pressure/volume should equalize from >> left to right. This would leave me with not much to change to cause more >> cooling air to go from the left to the right - meaning that I probably >> have to live with the differences. Alternatively, maybe it's not really >> hotter...the two sets of CHT wires for the left side (both equal length) >> are about three feet longer than the ones for the right side (again, both >> equal length). Could the difference in the lengths of the wires account >> for the reported temperature difference? >> >> I'm pretty close to thinking that this is as good as it gets...but I >> would really like to know why... >> >> Thanks, >> Ralph >> >> >> >> >> > > > ________________________________ Message 3 _____________________________________ Time: 07:17:35 PM PST US Subject: Re: LycomingEngines-List: CHT update From: Thomas G Koelzer Sounds like you have it covered. Cokes and smiles are fine but I always enjoy the challenge of unanswered questions. It's what makes man so great and why we have achieved such heights. Tom do not archive On Nov 25, 2009, at 8:17 PM, Ralph E. Capen wrote: > > Tom, > > Thanks for your input... > > I have calibrated the sensors with boiling water and candy thermometer - and swapped the sensors enough to know that the sensors are consistent and accurate. > > The EGT numbers show a good mixture distribution - but I haven't balanced the injectors yet. That may change things when the balancing act is accomplished - we'll see. > > Some of the other postings provided info on a couple of other places to look in the cooling system - just in case. > Most of the other postings told me to go have a coke and a smile - and fly-on. > > I'm planning to fly for a while - balance my injectors and see what happens. > > Ralph > ----- Original Message ----- From: "Thomas G Koelzer" > To: > Sent: Wednesday, November 25, 2009 9:01 PM > Subject: Re: LycomingEngines-List: CHT update > > >> >> Are you absolutely convinced the right side is running hotter than the left? Is there instrumentation error and can you confirm accuracy via another method or by swapping sensors? Do you have EGT numbers to confirm the cylinders are at the proper mixture but the cooling is inadequate? >> >> Just some food for thought. >> >> Tom >> >> Do not archive >> >> On Nov 23, 2009, at 5:22 PM, Ralph E. Capen wrote: >> >>> As many of you may know, I have been obsessing a bit about my CHT's...to get them consistent. >>> >>> Here's the setup: >>> IO360B1F6 >>> 9.2:1 pistons >>> AFP Fuel Injection >>> LASAR Ignition with CHT sender relocated to allow for testing >>> Vetterman Dual Crossover Heater/Mufflers >>> SamJames cowl and plenum >>> Advanced Flight Systems 3400 Engine Monitor >>> >>> Oil Cooler mounted behind #4 cylinder >>> Air for both Heater/Mufflers behind #3 cylinder >>> >>> For constant power setting, here's the consistency that I have achieved: >>> #1 and #3 cylinders run within three degrees (avg) of each other >>> #2 and #4 cylinders run within three degrees (avg) of each other >>> The #1/#3 cylinders run 8.5 degrees hotter (avg) than the #2/#4 cylinders >>> >>> With the members of the sets of cylinders running this close each other, I'm thinking that I have the balance (front to rear) for each side pretty well matched. >>> >>> I'm trying to wrap my head around what could be causing the right side to run hotter than the left. Here's some of what I'm thinking...: With this plenum set-up, I'm thinking that the pressure/volume should equalize from left to right. This would leave me with not much to change to cause more cooling air to go from the left to the right - meaning that I probably have to live with the differences. Alternatively, maybe it's not really hotter...the two sets of CHT wires for the left side (both equal length) are about three feet longer than the ones for the right side (again, both equal length). Could the difference in the lengths of the wires account for the reported temperature difference? >>> >>> I'm pretty close to thinking that this is as good as it gets...but I would really like to know why... >>> >>> Thanks, >>> Ralph >>> >>> >>> >>> >>> >> >> >> >> >> > > > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message lycomingengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/LycomingEngines-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/lycomingengines-list Browse Digests http://www.matronics.com/digest/lycomingengines-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.