FJC Posted August 17, 2022 Report Posted August 17, 2022 Hi Everyone, This is the most hot time of the year in many places and so I am once again focused on a high CHT upon climb out. Anyone want to take a gander as to what the issue is? I'm including a couple of example graphs. Issue: Never overheat during pattern work. Overheat mainly occurs when it is hot out. I allow speed to increase any time I see the high CHT but it is a challenge to keep things cool in #4 when it is 85+. Getting >400 degrees on #4 is pretty easy to experience...even when it is down in the 80's. Other than the cylinder head temp, Continental runs strong and smooth for all phases of flight. Here are the graphs: https://apps.savvyaviation.com/flights/5651424/f1ceac98-412c-49a0-893f-c30c504d3733 https://apps.savvyaviation.com/flights/5651416/c636ea4c-9b99-42a6-9b47-65f54343e88a Any ideas? What else might be needed? Thank you. Freddy Quote
FJC Posted August 17, 2022 Author Report Posted August 17, 2022 I was hoping to open up a discussion rather than jump to a conclusion! What is your thought process? Is #4 the usual suspect for overheating? Did you review the data? Etc... Quote
ilovecornfields Posted August 17, 2022 Report Posted August 17, 2022 I like the Gee Bee baffle kit, too. I fly out of the desert and Central Valley sometimes when the OAT is over 100 F. If I climb out at 2700 RPM my CHTs get high. If I climb out at 2400 RPM I never have a problem. If replacing the baffles doesn’t work you might try running richer/leaner or have someone who actually knows what they’re talking about take a look at your graphs. I have no idea how to interpret them but I know @kortopatesdoes. Hopefully you purchased a Savvy subscription and submitted a ticket as well as doing their GAMI lean checks and LOP mag checks. Otherwise, you are just going to waste your time getting advice from randos on the internet that doesn’t let the fact that they have no formal training stop them from authoritatively telling you what to do. Like me. 1 1 Quote
Niko182 Posted August 17, 2022 Report Posted August 17, 2022 What baffles do you have. Whats your takoff fuel flow and do you have 280 or 310 hp? Quote
Cruiser Posted August 17, 2022 Report Posted August 17, 2022 my guess is the JPI is mis-wired and the probe is actually the #5 CHT. 1 Quote
carusoam Posted August 17, 2022 Report Posted August 17, 2022 #5 is typically the hot and mis-behaved CHT on IO5550 powered LBs… The alternator and cowl baffling are different enough for that cylinder… the pixie hole was invented. Since other cylinders are showing the phenomenon… We are now looking for wear and tear issues that may have arisen… Inspecting the silicone baffling looking for good contact with the top cowling is the usual next step… Older silicone may be showing gape hoses… (mom terminology for something similar) Or… it may be as simple as the existing silicone wasn’t specifically cared for when putting the cowl back on. Check to see if the silicone baffling is behaving properly… if it is old, find the right GB. Guy Ginsby….(?) He has pics of properly installed silicone baffles… PP thoughts only… Best regards, -a- Quote
carusoam Posted August 17, 2022 Report Posted August 17, 2022 I seem to have lost contact with @gee-bee??? and the search functions seems a bit more temperamental than usual… and Google search finds things that are no longer connected… yikes… could be just me. -a- Quote
FJC Posted August 17, 2022 Author Report Posted August 17, 2022 This is all super helpful information. Given me ideas on how to proceed. Hopefully @kortopates can weigh in. Engine:280HP, FF: 26 (was set lower previously which presented bigger challenges) Not aware of any baffle changes. Cowl has been on and off multiple times and problem has persisted each time. I suppose the probes could be reversed which would say alot. I probably need to ID each to ensure they are installed correctly. Probably should also consider upgrading subscription to Saavy... Freddy 1 Quote
oregon87 Posted August 17, 2022 Report Posted August 17, 2022 You can remove the suspect probe and submerge it in an ice bath (70% ice/30% water). Whatever channel that probe is wired to should report a temp of 32-33°F. To verify accuracy, you can also perform a similar test with boiling water, looking for a temperature right at 212°F. 1 Quote
Niko182 Posted August 17, 2022 Report Posted August 17, 2022 1 hour ago, FJC said: This is all super helpful information. Given me ideas on how to proceed. Hopefully @kortopates can weigh in. Engine:280HP, FF: 26 (was set lower previously which presented bigger challenges) Not aware of any baffle changes. Cowl has been on and off multiple times and problem has persisted each time. I suppose the probes could be reversed which would say alot. I probably need to ID each to ensure they are installed correctly. Probably should also consider upgrading subscription to Saavy... Freddy Id probably start by increasing the fuel flow to 27. After that baffles will do wonders. Mine knocked off about 25 to 40 degrees. Nik 1 Quote
carusoam Posted August 17, 2022 Report Posted August 17, 2022 3 hours ago, FJC said: I was hoping to open up a discussion rather than jump to a conclusion! kind of tough mid day on a Wednesday….. The usual quality of discussion takes about 24hrs to occur… This gives everyone the opportunity to match their free time with MS time…. Some people have to be in the OR or prepping for surgery…. Others are in various time zones around the world… Our friend Oregon brings another level of insight to this conversation… he has the most experience with engine monitors… thousands of them…. Best regards, -a- Quote
ilovecornfields Posted August 17, 2022 Report Posted August 17, 2022 4 hours ago, FJC said: This is all super helpful information. Given me ideas on how to proceed. Hopefully @kortopates can weigh in. Paul is extremely kind, knowledgeable and generous with his time but when I want him to weigh in on my engine monitor data I submit a ticket through Savvy instead of posting it online and expecting him to do it for free. I think it’s well worth the price. 3 1 Quote
FJC Posted August 19, 2022 Author Report Posted August 19, 2022 @ilovecornfields good to know! Looks like a few things...check probe location, check baffles, if indeed cht 5 this pixie it, etc. Thank everyone for looking at the graphs! 1 Quote
carusoam Posted August 22, 2022 Report Posted August 22, 2022 Freddy, Once you have been through the easy list… If for some reason you still don’t have an answer… This is when you involve the big guns…. Savvy is an awesome resource… The hard part of getting data out of the plane and up on their computer… you got covered! Good luck with the next steps… Best regards, -a- Quote
cliffy Posted August 24, 2022 Report Posted August 24, 2022 Why not try swapping the location of the probe to another cylinder and see if the problem follows the probe. Mine did! Have a bad probe by 25+ degrees which is going to be replaced. Also check the connections on the probe for corrosion before you jump to costly maintenance. 1 1 Quote
LANCECASPER Posted August 28, 2022 Report Posted August 28, 2022 On 8/17/2022 at 12:56 PM, FJC said: I was hoping to open up a discussion rather than jump to a conclusion! What is your thought process? Is #4 the usual suspect for overheating? Did you review the data? Etc... @Niko182 is correct, that's the first place to look when the cowling is off - the baffles are the most likely culprit, even though I agree the number 5 cylinder is usually the hottest. Especially is you still have the factory baffle seals on, they get "lazy" and get blown back and allow air to escape above the engine rather than being forced down over the cooling funs. When I owned my last Bravo I lowered my cylinders a minimum of 20 degrees across the board withe the Gee-Bee baffle Seals. I also did the same with an earlier Encore with similar results. Quote
BlueDun Posted September 22, 2022 Report Posted September 22, 2022 (edited) I had consistently high #5. Pixie holes did not help. Put in GAMIjectors and Gee-Bee baffles this spring and #5 behaved in the hottest weather this summer. Edited September 22, 2022 by BlueDun 1 Quote
carusoam Posted September 22, 2022 Report Posted September 22, 2022 Nice pirep for Gami and Gee-Bee Blue Dun! Thanks for sharing the details… Best regards, -a- Quote
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