Parker_Woodruff Posted March 9, 2020 Report Share Posted March 9, 2020 1 hour ago, kortopates said: elevated EGTs from high resistance plugs in need of replacement. That’s what I’m thinking Quote Link to comment Share on other sites More sharing options...
carusoam Posted March 10, 2020 Report Share Posted March 10, 2020 Congrats on your first post Mikosch! You picked an excellent technical topic. +1 on sharing your engine data using the Savvy.com site... when shared, everyone gets to see your data, without any confusion... or missing details... +1 on making sure your TIT TC is in good condition... many have met the end of the line... erosion is tough on them... they are in the most harsh environment... LOP climbs are an interesting topic... I had discussed them for my NA IO550... but couldn’t find anyone willing to go this route other than to try it out... Our time in the climb at such high power setting is not very many minutes... and the risk of detonation under high power doesn’t have enough reward... For full power climb, 200-300°F ROP in the NA IO550 is usual... to avoid the red box... lots of excess fuel being used for this. Going LOP will require a lot of excess air being used for this.... unfortunately, being NA... I am missing the excess air part or the high power part... Looking forward to you making headway with your quest. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Mikosch Posted March 10, 2020 Author Report Share Posted March 10, 2020 1 hour ago, carusoam said: +1 on sharing your engine data using the Savvy.com site... when shared, everyone gets to see your data, without any confusion... or missing details... +1 on making sure your TIT TC is in good condition... many have met the end of the line... erosion is tough on them... they are in the most harsh environment... I will down and upload the data the next time I am at the airport. The probe from the JPI are only about 50h old so they should still be accurate, though the previous owner didn’t connect the RMP, MP, TIT and OAT for reasons I don’t understand . We are going to take care of that at the next 50h inspection. Currently I am using a digital Electronic International TIT. That said the TIT reads usually 20 degrees hotter than my hottest EGT. Does that make sense? I would of thought that TIT should be cooler than EGT because the probe ist further “down stream”... Until now I mostly flew M20J an never experimented with lop climbs because it didn’t have a very good climb rate at 110kt. Now in my new K things are very different. At full power I consistently see 1000 ft\min at 110-120kt and with my 85% lop setting I saw about 700 ft/min at the same speed... 1 hour ago, carusoam said: LOP climbs are an interesting topic... I had discussed them for my NA IO550... but couldn’t find anyone willing to go this route other than to try it out... Our time in the climb at such high power setting is not very many minutes... and the risk of detonation under high power doesn’t have enough reward... For full power climb, 200-300°F ROP in the NA IO550 is usual... to avoid the red box... lots of excess fuel being used for this. Going LOP will require a lot of excess air being used for this.... unfortunately, being NA... I am missing the excess air part or the high power part Quote Link to comment Share on other sites More sharing options...
tmo Posted March 10, 2020 Report Share Posted March 10, 2020 3 hours ago, Mikosch said: TIT reads usually 20 degrees hotter than my hottest EGT. Does that make sense? I would of thought that TIT should be cooler than EGT because the probe ist further “down stream”. It does make sense if you consider that the EGT probe has 1 cycle of temperature (exhaust) and 3 cycles of relative rest (intake, compression, power) while the TIT probe is constantly warmed by all six cylinders. So yes, the TIT is both more stable and usually warmer than the individual EGTs would imply on their own. IOW, EGT is not a valid proxy for TIT. 1 Quote Link to comment Share on other sites More sharing options...
Fry Posted March 10, 2020 Report Share Posted March 10, 2020 (edited) Hi Mikosch, congrats on your 252. I believe we've met in Allendorf looking at D-ELGA, correct? Meanwhile, I have purchased an M20J 201. And I am also VERY happy with it. Put an Avidyne IFD540 and Audio panel GMA345 in it. A good engine analyzer (JPI EDM 800 primary) is also there. I usually fly 155 KTAS using 9.4gph LOP. And at this time of the year, around 300°F CHT :-) of course, no turbo, so more limited in altitude, but pretty nice up to about 10k-12k ft. Finewire spark plugs are the secret I believe (the former owner put them in). BR Edited March 10, 2020 by Fry Quote Link to comment Share on other sites More sharing options...
Mikosch Posted March 10, 2020 Author Report Share Posted March 10, 2020 27 minutes ago, Fry said: Hi Mikosch, congrats on your 252. I believe we've met in Allendorf looking at D-ELGA, correct? Meanwhile, I have purchased an M20J 201. And I am also VERY happy with it. Put an Avidyne IFD540 and Audio panel GMA345 in it. A good engine analyzer (JPI EDM 800 primary) is also there. I usually fly 155 KTAS using 9.4gph LOP. And at this time of the year, around 300°F CHT :-) of course, no turbo, so more limited in altitude, but pretty nice up to about 10k-12k ft. Finewire spark plugs are the secret I believe (the former owner put them in). BR Jup, that was me good to hear that you also found a nice Mooney fitting your needs! Nice Performance, D-ELGA was not quite as fast due to the TKS system. I thought about installing finewire plugs but I am not sure I would benefit that much because I have no trouble operating at 80 degrees LOP... Quote Link to comment Share on other sites More sharing options...
carusoam Posted March 10, 2020 Report Share Posted March 10, 2020 +1 EGT vs. TIT readings... they are averages over time... with strong peaks coming through in waves... EGTs experience one pulse/peak for every Two engine revolutionS... A six cylinder engine will send six peaks/waves of heat in the same period of time... So... a thermocouple sitting in the exhaust stream of one cylinder sees a lot of rest time compared to a thermocouple sitting in the confluence of six exhaust streams... Amazing how stable the EGT readings are considering the exhaust stroke is only 1/4 of the overall time available... Another thing to consider... in a normally aspirated engine the exhaust temps drop rather quickly down the exhaust pipe, due to pressure dropping allowed by the open ended exhaust pipe... In a TC’d engine there is no open ended exhaust pipe... there is a turbo causing a significant amount of back pressure... this limits the adiabatic cooling that occurs with the limited pressure drop... Somebody should write a book... thermodynamics for aviators... PP thoughts only, not a thermo guy... Best regards, -a- 2 Quote Link to comment Share on other sites More sharing options...
kortopates Posted March 10, 2020 Report Share Posted March 10, 2020 13 hours ago, Mikosch said: Currently I am using a digital Electronic International TIT. You're not using a EI TIT probe connected to your JPI analyser are you? If so, these are not compatible. I think they both use K type thermocouples but EI used ungrounded probes and JPI uses grounded probes making them incompatible. Hopefully you are referring to a separate EI indicator for the EI TIT probe. Anthony explained why TIT is hotter than your EGTs (except at idle power). Its also very common with these engines to see TIT a full 100F higher than your warmest EGT. But it varies and can only be as little as 20F higher at lower LOP power settings but it seems higher power settings result in the biggest difference. 2 Quote Link to comment Share on other sites More sharing options...
Mikosch Posted March 10, 2020 Author Report Share Posted March 10, 2020 24 minutes ago, kortopates said: You're not using a EI TIT probe connected to your JPI analyser are you? If so, these are not compatible. I think they both use K type thermocouples but EI used ungrounded probes and JPI uses grounded probes making them incompatible. Hopefully you are referring to a separate EI indicator for the EI TIT probe Yes it is a separate EI indicator for a EI probe with a 1 degree accuracy. I contacted the APS guys and they told me that they generally don’t recommend 36” due to a smaller detonation margin, however due to the intercooler I could use that power setting with a watchful eye on the CHT. I also asked him how ICP would compare between full power, full rich and 85% 80 degrees LOP and he said the ICP should be roughly in the same ballpark. Quote Link to comment Share on other sites More sharing options...
carusoam Posted March 10, 2020 Report Share Posted March 10, 2020 The importance of the accuracy of the TIT probe.... 1) it is being used for the safety of the Turbo engine’s hardware... 2) 1650°F is often used as a do not exceed number... 3) Some people select a lower number to operate at... 4) Exceeding this number over time erodes the turbo blade tips on the hot side.... 5) TIT is not a step function... the hotter the parts are, the softer they get... similar to cylinders and CHTs... 6) Also important is the health of the first sections of exhaust tubes between the engine and turbo... they have a tendency to get thinner over time... an erosion challenge... 7) the exhaust tubes will also suffer the higher average temps as there is a three into one pipe on each side of the engine... 8) Broken exhaust tubes on a turbo have a high risk of causing fires... the small holes act like a blow torch as they open up... PP thoughts on safety issues of turbo exhaust systems... not a mechanic or CFI... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
jlunseth Posted March 11, 2020 Report Share Posted March 11, 2020 On 3/10/2020 at 3:21 PM, Mikosch said: Yes it is a separate EI indicator for a EI probe with a 1 degree accuracy. I contacted the APS guys and they told me that they generally don’t recommend 36” due to a smaller detonation margin, however due to the intercooler I could use that power setting with a watchful eye on the CHT. I also asked him how ICP would compare between full power, full rich and 85% 80 degrees LOP and he said the ICP should be roughly in the same ballpark. I am glad you got ahold of the APS guys, that was the right thing to do. There are still a couple of things that are dissonant about your power setting that I thought I should mention. First, though, let me say that it looks like you are truly lean of peak by a good margin and if the APS guys say your ICP is ok then I certainly won't say otherwise. The two things I noticed were (1) temps and (2) your true air speed. On your TAS, in my 231 at 34", 2450 RPM's and 11.1 GPH I would not be at 155 kts. at 8,000 but would be very close, around 152-153 kts. Of course, that can vary some with OAT and my plane is slower in cold OATs than warm. That 152-153 is the speed I would get in the summer and you are doing it in slightly cooler weather, around 50 dF. But still, there is very little difference in my TAS at 71% and yours at 84% HP. The HP to speed ratio is a hard master, speed varies proportionally to the cube of HP, so maybe three kts. faster than my setting is about right. Maybe our two aircraft are different in the speeds they are able to make just because of profile or configuration. But I have not ever thought of mine as particularly fast for a K. But the point is, you will be running the engine quite a bit harder than I do to get just a few, as in single digits, more knots. Then on temps, I completely agree with the APS guys to watch the CHTs and also the TIT. I can run pretty much anywhere I want in the winter where I live, and sometimes I will run very close to peak just because I really need more heat in the engine to keep the CHTs and oil temp in operating range. But I have noticed that temps like to creep up pretty quickly in the summer when the temps are in the 80's and 90's, and having taken off from Phoenix at 3,000 feet with the temps in the 113 range, the CHTs and TIT can get pretty hot pretty fast. You can help it, especially if you have electric cowl flaps just be opening those a little. Also, your engine is set up better than mine to keep things cool, hope it works out for you. That's about it. Best of luck and it sounds like you have a great aircraft. 1 Quote Link to comment Share on other sites More sharing options...
Mikosch Posted March 13, 2020 Author Report Share Posted March 13, 2020 On 3/11/2020 at 11:55 PM, jlunseth said: I am glad you got ahold of the APS guys, that was the right thing to do. There are still a couple of things that are dissonant about your power setting that I thought I should mention. First, though, let me say that it looks like you are truly lean of peak by a good margin and if the APS guys say your ICP is ok then I certainly won't say otherwise. The two things I noticed were (1) temps and (2) your true air speed. On your TAS, in my 231 at 34", 2450 RPM's and 11.1 GPH I would not be at 155 kts. at 8,000 but would be very close, around 152-153 kts. Of course, that can vary some with OAT and my plane is slower in cold OATs than warm. That 152-153 is the speed I would get in the summer and you are doing it in slightly cooler weather, around 50 dF. But still, there is very little difference in my TAS at 71% and yours at 84% HP. The HP to speed ratio is a hard master, speed varies proportionally to the cube of HP, so maybe three kts. faster than my setting is about right. Maybe our two aircraft are different in the speeds they are able to make just because of profile or configuration. But I have not ever thought of mine as particularly fast for a K. But the point is, you will be running the engine quite a bit harder than I do to get just a few, as in single digits, more knots. My airspeed was 155 IAS in 8000 ft. That equals to about 180TAS wich I think is about average for a 252 or? Quote Link to comment Share on other sites More sharing options...
jlunseth Posted March 13, 2020 Report Share Posted March 13, 2020 That’s pretty good, more what I would have expected. Quote Link to comment Share on other sites More sharing options...
Mikosch Posted April 4, 2020 Author Report Share Posted April 4, 2020 (edited) On 3/9/2020 at 5:43 PM, gsxrpilot said: I'm willing to give these power settings next time I'm in the airplane. I have tried 31" 2450 10gph which were the power settings Brian Lloyd uses in his 231 LB engine, when flying around the world LOP. Those settings gave me nearly 100° LOP. So 13 gph at 36" seems reasonable to me to be LOP as well. Here is the link to the test flight I did. At 12:48 I did the big mixture Pull back to about 13GPH and at 25:52 I tried the same powerseeting again in cruise the the cowlflaps fully closed to get a feeling how hot the CHT would get at that power setting. Edited April 4, 2020 by Mikosch Quote Link to comment Share on other sites More sharing options...
gsxrpilot Posted April 4, 2020 Report Share Posted April 4, 2020 4 hours ago, Mikosch said: Here is the link to the test flight I did. https://apps.savvyaviation.com/my-flights/22200/579417cb-4f4f-4588-b161-0793dc3a7b3a At 12:48 I did the big mixture Pull back to about 13GPH and at 25:52 I tried the same powerseeting again in cruise the the cowlflaps fully closed to get a feeling how hot the CHT would get at that power setting. That link is for all your flights. Which individual flight should we look at? Quote Link to comment Share on other sites More sharing options...
Mikosch Posted April 4, 2020 Author Report Share Posted April 4, 2020 34 minutes ago, gsxrpilot said: That link is for all your flights. Which individual flight should we look at? Sorry my mistake. This should be the correct one ( date: 2020-03-08) https://apps.savvyaviation.com/flights/3806889/658e2298-7384-451c-ad27-58c73c849deb Quote Link to comment Share on other sites More sharing options...
MICKEY Posted April 4, 2020 Report Share Posted April 4, 2020 48 minutes ago, Mikosch said: Sorry my mistake. This should be the correct one ( date: 2020-03-08) https://apps.savvyaviation.com/flights/3806889/658e2298-7384-451c-ad27-58c73c849deb Not a turbo guy, but looking into getting one. I had an F and was very specific with that engine. Here is what I saw. I looked at your data from 03/08/2020. 1 thing I noticed was that there is EGT/CHT/TIT. There is no MAP (manifold pressure) noted on the graph. Regarding your Peak/LOP/ROP operations. At 19:12 you were leaning at cruise at 7500ft, and noted while leaning to have EGT peak at 10.1gph. Spread was 0.2 gph. You leaned at that time about 20:14 to 8.4gph which is about 50-60 deg LOP. And 55% power with a 13.7 hp/(gph) factor = 54.8% power. <- This is LOP ops. You went to 13.2 gph at 25:52 and EGT was minimally increased to 20 deg increase from peak and stabilized to 12.7gph. There was no appreciable change in EGT/CHT as far as I could see. Which is difficult see. I can't comment on this short setting, except that it likely was ROP, though MAP is not available in the data. You then went down to ~55% for the duration of your flight. Eric Quote Link to comment Share on other sites More sharing options...
Mikosch Posted April 4, 2020 Author Report Share Posted April 4, 2020 It doesn’t show MAP because the option is not installed at this time. I am going to add MAP and TIT to the JPI this summer while my airplane is in the shop getting the “encore” upgrade. Yes 55% sound about right. That ist the power Setting I usually use when I am just doing a local flight. 25”, 2200rpm and 8,5GPH Quote Link to comment Share on other sites More sharing options...
carusoam Posted April 4, 2020 Report Share Posted April 4, 2020 Miko @Mikosch, The latest link you provided... indicates it’s not publicly viewable... There is a share button at Savvy that allows sharing... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Mikosch Posted April 4, 2020 Author Report Share Posted April 4, 2020 1 hour ago, carusoam said: Miko @Mikosch, The latest link you provided... indicates it’s not publicly viewable... There is a share button at Savvy that allows sharing... Best regards, -a- I enabled public sharing now. Can you view it now? If not the link with all the flights should work. Date of flight was 03/08/2020 Quote Link to comment Share on other sites More sharing options...
carusoam Posted April 4, 2020 Report Share Posted April 4, 2020 13 minutes ago, Mikosch said: I enabled public sharing now. Can you view it now? If not the link with all the flights should work. Date of flight was 03/08/2020 Sharing my screen... -a- Quote Link to comment Share on other sites More sharing options...
gsxrpilot Posted April 4, 2020 Report Share Posted April 4, 2020 Just go to this link and select the flight on 3/8/2020. https://apps.savvyaviation.com/my-flights/22200/579417cb-4f4f-4588-b161-0793dc3a7b3a 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted April 4, 2020 Report Share Posted April 4, 2020 Thank you Paul... Proof that even I can get it to work... But, go to the savvy site to click on the various data you can’t get from a single pic... -a- Quote Link to comment Share on other sites More sharing options...
carusoam Posted April 4, 2020 Report Share Posted April 4, 2020 EGTs are all looking close together... TIT seems to be missing... FF vs GSpd as mentioned... -a- Quote Link to comment Share on other sites More sharing options...
carusoam Posted April 4, 2020 Report Share Posted April 4, 2020 good reasons for going LOP... 1) lower CHTs... #2 appears to be a bit colder than the rest... 2) Good fuel economy... high conversion rate of fuel to distance covered... about 18.3 mpg (statute miles) 3) Compared to driving... 18mpg at 157mph... is pretty good. Quote Link to comment Share on other sites More sharing options...
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