pkofman Posted June 30, 2020 Report Share Posted June 30, 2020 So i think iv'e asked this before, but today when flying in some hot humid weather ( 30c + ,yes that is hot in canada ) . The temps on the edm 800 were showing 400f + on two cylinders ( engine running 29/2400 leaned to 1625 @10k) , the balance in the high 300's. For the most part the temps are controllable with a combo of settings, ( cowl flaps, power and fuel ). I understand that the edm uses multi probes and the stock temp gauge is single. But in my case the stock engine cht is generally below 400. So here is the question; (and for reference i typically like to keep cht below 400f) 1. Do you operate by the edm's hottest cylinder and always use that for the most conservative case or reference the stock probe? 2. Do you use the single stock temp cht as a check under any circumstances and/or 3. Does the edm 800 over-read temps? Obviously more information is helpful in order to be precise, but in this case perhaps the edm is simply overly conservative, and im worrying about things just a little too much I am perhaps overly focused on the management of the engine, but that has been my training throughout my flying career It would be nice to know what others are doing to ensure a realistic set of parameters to monitor the engine including what they trust and what is their primary reference. . For those with an edm 800 "type " device what are your personal s.o.p's when it comes to hot humid days.. thoughts. Peter Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 30, 2020 Report Share Posted June 30, 2020 Peter, You have it all covered... 1) We use the ship’s gauge... because our basic ops guides use it to define the process.... 2) An added engine monitor can do this job better... if it were to replace the ship’s old gauge... 3) If you had a JPI900... the sensor would be in the same hole as the Ship’s gauge... 4) Depending on your installer... You need to know what is in the ship’s gauge location... 5) many get a close substitute (Bad)... others get a TC mounted under a spark plug(worse)... 6) It is nice to be able to keep temps under 380°F... I think this is the general rule around MS... 7) It is not a requirement... cooler is better, until it Can’t be achieved... 8) The cost is a higher wear rate of the cylinders... not terribly higher... 9) No, we don’t operate based on one cylinder CHT.... we use all of them... because we want to save them all for a long time down the road.... but, there is always an outlier... how far out? It may be killed so the others can get to the destination faster... 10) Sometimes the CHT is not telling the same story like the other five... literally one of them is mounted in a different location... so the CHT is the same, but what we are reading is different... 11) To improve on this... go primary! JPI or EI will make this discussion much easier... How does that sound? Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Danb Posted June 30, 2020 Report Share Posted June 30, 2020 Sounds good A First off your not focused to much on engine management, temps kill our engine. Also I’d consider keeping your TIT at or below 1600*, I monitor that temp continuously, I’m happy between 1580-1600 My cht’s obviously are higher climbing in hotter weather, my target is 380* sometimes difficult, even though mine are not hot I’m installing new gee bee baffling today hopefully I can run cooler, I’ve looked at my baffling often and replace pieces as they look tired. A little leak can cause definite higher temps, also make sure your cowl does not make the baffling fit poorly. I fly behind an engine monitor which is on all cylinders, Tit, egt oil temp and so on, thereby answering your question re to much engine mgt. Our Bravos are hot running machines so do your best to maintain consistency. The higher you go the thinner the air is losing a good deal of cooling properties Quote Link to comment Share on other sites More sharing options...
Guest Posted June 30, 2020 Report Share Posted June 30, 2020 Hi Peter, If I remember correctly your EDM uses spark plug gasket thermocouples, which will read somewhat higher than the bayonet style. Clarence Quote Link to comment Share on other sites More sharing options...
pkofman Posted June 30, 2020 Author Report Share Posted June 30, 2020 @Danb I think it getting hot in this plane....eh? well in my plane its tough seemingly to climb on a hot without my #2 and #4 cyl creeping up to 400-425 with the ship probe noting quite a bit less than 400 (~375ish). so ill flatten the climb or pop the cowl flaps a bit and that will result in bringing down the temps. if im running in cruise things can creep up when leaned. In my plane I lean to 1625-1640 MAX! on the jpi800,and I will get two cylinders around 400-420 Surprisingly at these temp I would have thought I would be buying oil but I get about 10 hours on a qt. As per @carusoam comment my only problem with only using the ships gauge is that it just so "analog". Maybe Mooney was super smart by providing a basic analogue gauge ( or that's all they had in the day ) in that it gave the airplane allot of latitude on temp range without us fussing over a few degrees, and maybe digital gauges did not exist in "98", but whatever the brilliance of all of this technology available today it certainly can create allot of questions about what's right, wrong and or dangerous. I did have the baffles checked at annual and all were in fitting well and in good shape 1 Quote Link to comment Share on other sites More sharing options...
pkofman Posted June 30, 2020 Author Report Share Posted June 30, 2020 4 minutes ago, M20Doc said: Hi Peter, If I remember correctly your EDM uses spark plug gasket thermocouples, which will read somewhat higher than the bayonet style. Clarence Hi Clarence... #2 and and I think #4 run consistently hotter than the other cylinders. Typically around 420-430f when the others are under 400. At the same time the ship probe would be about 374 -380... Which one would you suggest to use for leaning . . Im not leaning over 1650 EVER ( yielding around 75% power at 29/2400)!, So do you recommend that 420-430 might be a high representation of what is really going on when the ship probe is below 400 ? The tough thing about this that those cylinders may be running a bit hot, but they may also be reading hotter than they actually are because of the probe type. It's hard to know actually, and perhaps i'm over thinking this. Perhaps running with two cylinders below 430f ( redline incredibly 500f) is just fine and wont break the engine, and therefore this is a ridiculous post on my part. Im simply trying to understand what i'm looking at so that I can make informed decisions on the fly ( no pun intended!) The easy solution is drop the t.i. t in the summer to 1575 to 1600 and everything will be much cooler but not really efficient Quote Link to comment Share on other sites More sharing options...
mike_elliott Posted June 30, 2020 Report Share Posted June 30, 2020 16 minutes ago, M20Doc said: Hi Peter, If I remember correctly your EDM uses spark plug gasket thermocouples, which will read somewhat higher than the bayonet style. Clarence There was a 50 Deg F difference when I switched my spark plug thermocouple to a piggyback style for the #3 cylinder that accommodates the ships thermocouple on an IO360. Having all 6 CHT thermocouples on the spark plugs plus the ships gauge being in the head would tend to have the JPI reading higher, if that is what Clarence is saying. If it is just the one cylinder where you have CHT redundancy, expect the EDM to be about 30-50 higher because of the spark plug thermocouple. The Bravo I had came with a piggyback and I quit paying attention to the ships gauge unless alarmed. Your baffling might need a good peak at to make sure all is in order, 1 Quote Link to comment Share on other sites More sharing options...
pkofman Posted June 30, 2020 Author Report Share Posted June 30, 2020 Clarence @M20Doc what do you think about @mike_elliott suggestion . Is this something we can clear up with an easy change or modification.. I probably need an oil change, and I always need a reason to fly to CYKF... thoughts? Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 30, 2020 Report Share Posted June 30, 2020 PK... there are three possibilities of where thermocouples get placed, in all Mooneys... 1) Each cylinder has one TC well... 2) Nobody has built a bayonet with two TCs to fit in the well... (Sort of)... or made a second well... (I think) 3) The ship’s gauge, with all the red lines associated with it, is supposed to reside in the well... CHT varies all over the surface of the head... It gets hotter closer to the exhaust. We use the standard place, and make decisions based on it... 4) When the JPI gets added... it is not FAA compliant to have the non-primary sensor live in the primary position... 5) Knowing this... JPI and others built a sensor that goes under the spark plug... (dumb idea, but it sort of works-ish) expect a 50°F variation. A quick solution that comes from old cylinders that didn’t have a TC well in them... 6) Discriminating users of the JPI gauge catch on after a while... after fighting CHTs that don’t make A lot of sense... 7) MSer users of the JPI demand the next best thing... a thermocouple that is known as the piggy-back... that goes under the TC’s well... 8) The piggy back, is now in the same area as the ship’s gauge, just not deep in the well... expect a 25°F variation... 9) When you no longer use the ship’s gauge because of its poor display of data... this is where people decide to connect the TC that is in the well to the JPI.... All six TCs will be reading similar data unless something is not cooling properly... 10) My 94 ship is the same... JPI was added by the first owner... a piggy back is used under the ship’s gauge... I do mental math to recognize the hot CHT isn’t a real number until it gets adjusted properly... 11) Mooney took a very slow approach to using digital data... many of my instruments are digital with analog displays... literally dumbing down my data for me... 12) When using EGTs... a similar thing occurs... know where your TIT data is coming from... in the NA IO550s the ship’s EGT gauge is sitting in the exhaust after three streams come together... 13) The JPI is an averaging machine... the average temperature of three exhaust streams is actually much higher than any one EGT.... 14) The TIT for the Bravo is most likely mounted on the inlet of the turbine... where six streams / pulses of exhaust are going by... 15) so... further downstream, the TIT is reading much hotter Than any of the single EGTs... it turns out the single EGTs are sitting ‘cold’ for a long period of time between exhaust pulses coming by... Mooney clients have become more technically savvy over the years... They have always wanted to protect their investment.... (now they can) The first signs of LOP and digital data gathering probably arrived with the ‘94 models... They didn’t go mainstream putting data gathering on every Mooney until the G1000 systems were standard... some of the gathered data, didn’t get saved. Getting data out of some G1000 systems is still a drag... Know where all your sensors are located... it makes life a lot easier when you are wondering... why is that doing this? Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Guest Posted July 1, 2020 Report Share Posted July 1, 2020 13 hours ago, pkofman said: Clarence @M20Doc what do you think about @mike_elliott suggestion . Is this something we can clear up with an easy change or modification.. I probably need an oil change, and I always need a reason to fly to CYKF... thoughts? If I’m not mistaken, the factory CHT hole is occupied by your Tanis heaters, other than the cylinder with the factory CHT probe. There are a few ways to get more accurate CHT readings. Move the Tanis heaters to new bolt style in the intake flange, then install JPI bayonet thermocouples, or install combined Tanis heater/CHT thermocouples, or install JPI ring type thermocouples under the Tanis heater. Clarence Quote Link to comment Share on other sites More sharing options...
pkofman Posted July 2, 2020 Author Report Share Posted July 2, 2020 On 6/30/2020 at 9:11 PM, M20Doc said: If I’m not mistaken, the factory CHT hole is occupied by your Tanis heaters, other than the cylinder with the factory CHT probe. There are a few ways to get more accurate CHT readings. Move the Tanis heaters to new bolt style in the intake flange, then install JPI bayonet thermocouples, or install combined Tanis heater/CHT thermocouples, or install JPI ring type thermocouples under the Tanis heater. Clarence @carusoam @mike_elliott @M20Doc thank you for all of this advice.. as usual nothing is exactly simple. I think I will continue through the summer and keep doing what im doing. Run the t.i.t a bit cooler and dont let anything go over 425-430 on the jpi and monitor the ship gauge as a back up. if that thing goes over 400 then the jpi will sow way about the limits im suggesting here..... if I can maintain those numbers I think ill be ok . Then at annual ( October /November ) the doctor will have a look!!. Quote Link to comment Share on other sites More sharing options...
Bravoman Posted July 2, 2020 Report Share Posted July 2, 2020 FWIW I think 425-430 is way too high, even if you think it is somewhat erroneous. Even factoring in a margin of error if your cruise setting is in the neighborhood of 29/24 and you keep your TITs in the 1550 range your hottest cylinders should be in the 380s with cowl flaps closed. For me this yields a fuel flow of 18-19 gph. I was not getting these numbers on my old engine before the factory reman that I have now on which I also have the Gee Bee baffling. 2 Quote Link to comment Share on other sites More sharing options...
LANCECASPER Posted July 3, 2020 Report Share Posted July 3, 2020 On 6/30/2020 at 6:18 AM, pkofman said: so ill flatten the climb or pop the cowl flaps a bit and that will result in bringing down the temps. You definitely need to keep cowl flaps completely open in the climb 2 Quote Link to comment Share on other sites More sharing options...
PT20J Posted July 4, 2020 Report Share Posted July 4, 2020 On 6/30/2020 at 4:10 AM, M20Doc said: Hi Peter, If I remember correctly your EDM uses spark plug gasket thermocouples, which will read somewhat higher than the bayonet style. Clarence This is a great point. When I purchased my J with a little ole' Lycoming IO-360-A3B6D, the EDM 700 spark plug thermocouple for cyl 3 had been put on cyl 1 apparently by mistake. So, I had two thermocouples on the same cylinder that allowed direct comparison. The spark plug thermocouple consistently read 40 deg C higher than the bayonet thermocouple. When I replaced the engine, I got a new thermocouple for cyl 3 that mounts under the factory thermocouple and I now get readings consistent with the factory gauge and the other cylinders. The spark plug thermocouple was accurate. The temperature is higher at the spark plug boss than at the bayonet thermocouple location. So, cylinder head temperature depends on where you measure it. I think we stress out way too much over CHTs. I remember when everyone was stressed about shock cooling. Don't reduce MP more than 1" per fortnight or whatever. Now, the generation that doesn't remember that stresses over the dreaded RED BOX. Don't do this, don't do that, you'll destroy your engine. I get it. These things are expensive and we don't want harm them. But, I think Mike Busch has it right. Understand how these things work. Develop some conservative SOPs that minimize workload and have fun flying. Now if you want to do something more radical like cruise at 80% power deeply LOP, then you need to be more circumspect. Skip Quote Link to comment Share on other sites More sharing options...
pkofman Posted July 6, 2020 Author Report Share Posted July 6, 2020 (edited) On 7/3/2020 at 8:31 PM, PT20J said: This is a great point. When I purchased my J with a little ole' Lycoming IO-360-A3B6D, the EDM 700 spark plug thermocouple for cyl 3 had been put on cyl 1 apparently by mistake. So, I had two thermocouples on the same cylinder that allowed direct comparison. The spark plug thermocouple consistently read 40 deg C higher than the bayonet thermocouple. When I replaced the engine, I got a new thermocouple for cyl 3 that mounts under the factory thermocouple and I now get readings consistent with the factory gauge and the other cylinders. The spark plug thermocouple was accurate. The temperature is higher at the spark plug boss than at the bayonet thermocouple location. So, cylinder head temperature depends on where you measure it. I think we stress out way too much over CHTs. I remember when everyone was stressed about shock cooling. Don't reduce MP more than 1" per fortnight or whatever. Now, the generation that doesn't remember that stresses over the dreaded RED BOX. Don't do this, don't do that, you'll destroy your engine. I get it. These things are expensive and we don't want harm them. But, I think Mike Busch has it right. Understand how these things work. Develop some conservative SOPs that minimize workload and have fun flying. Now if you want to do something more radical like cruise at 80% power deeply LOP, then you need to be more circumspect. Skip Edited July 6, 2020 by pkofman need to change content Quote Link to comment Share on other sites More sharing options...
LANCECASPER Posted July 6, 2020 Report Share Posted July 6, 2020 2 hours ago, pkofman said: . . . I consider listening to all fellow mooney experiences as fodder from my safety, the upkeep and relevant maintenance of the aircraft and the health and safety practices of my fellow colleagues here . I would listen to your POH first and then fellow Mooney pilots. Quote Link to comment Share on other sites More sharing options...
pkofman Posted July 6, 2020 Author Report Share Posted July 6, 2020 7 hours ago, LANCECASPER said: I would listen to your POH first and then fellow Mooney pilots. AGREED !, 100 percent! Quote Link to comment Share on other sites More sharing options...
irishpilot Posted July 16, 2020 Report Share Posted July 16, 2020 On 7/2/2020 at 9:47 AM, Bravoman said: FWIW I think 425-430 is way too high, even if you think it is somewhat erroneous. Even factoring in a margin of error if your cruise setting is in the neighborhood of 29/24 and you keep your TITs in the 1550 range your hottest cylinders should be in the 380s with cowl flaps closed. For me this yields a fuel flow of 18-19 gph. I was not getting these numbers on my old engine before the factory reman that I have now on which I also have the Gee Bee baffling. I agree. I fly cowls full open until after I get leaned out, then shut. I climb full power until I have glide back to the field, then cruise climb 34"/2400 all the way til level off. If in the FLs and a hot day, I keep the cowls cracked. Cruise at 29"/2400 and see what @Bravoman sees. I also adhere to 1550 TIT. On 7/6/2020 at 6:07 AM, pkofman said: AGREED !, 100 percent! If you followed the Bravo POH, we'd be leaning to peak TIT and flying a max CHT of 500 degrees. That's too hot for me. There's lots of good threads about this. However, to each his/her own. Speed is all about $$...how fast do you wanna go? 1 Quote Link to comment Share on other sites More sharing options...
LANCECASPER Posted July 16, 2020 Report Share Posted July 16, 2020 4 hours ago, irishpilot said: If you followed the Bravo POH, we'd be leaning to peak TIT and flying a max CHT of 500 degrees. That's too hot for me. There's lots of good threads about this. However, to each his/her own. Speed is all about $$...how fast do you wanna go? I agree completely with one more thing to think about. What has killed people in the Bravo is a failure of the exhaust components, specifically the clamps and the tailpipe transition and then the fire coming into the cabin. Regularly inspecting the exhaust system and keeping TIT at 1600 or less seems to make sense. A gallon or two an hour extra to keep things cool is pretty small in the grand scheme of flying expenses. 3 Quote Link to comment Share on other sites More sharing options...
slowflyin Posted July 16, 2020 Report Share Posted July 16, 2020 On 7/11/2020 at 8:36 AM, GEE-BEE said: Pic of baffle seals please My Bravo ran warm after purchase. Immediately replaced the baffling with great results. Hottest jug runs no more than 370 in cruise and 400 is my max in climb on only the hottest days with the most aggressive climbs. 1 Quote Link to comment Share on other sites More sharing options...
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