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#1
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'Hot' cylinder after overhaul?
Since a major overhaul about 60 tach hours ago now,
I've noticed my #3 cylinder (O470R, 182) is running consistently hot. It is typically 30-40 degrees warmer than the average, which puts it at 4-bars in the EDM700 display. To keep this cylinder temp down, I'm having to leave the cowl flaps open in cruise, which slows me down some 6knots or so. EGT's are all equal. Does this indicate extra friction in that cylinder which could be a problem? The engine as a whole is using about 1qt every 15 hours or so now & I followed the Continental break-in procedure to the letter. It's running great. Did someone miss a bit of baffling in reassembly? Can missing baffle really make that much difference? Perhaps things will return to normal after a few more hours and I should stop worrying. Comments? -- Dr. Tony Cox Citrus Controls Inc. e-mail: http://CitrusControls.com/ |
#2
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Tony Cox wrote:
Since a major overhaul about 60 tach hours ago now, I've noticed my #3 cylinder (O470R, 182) is running consistently hot. It is typically 30-40 degrees warmer than the average, which puts it at 4-bars in the EDM700 display. /snip/ Tony, Baffling certainly could be the issue here, make sure the flexible baffle seal in this area is laying down correctly. Also, you may want to swap CHT probes with another cylinder, and see if the indication follows the probe. Also check if this jug has the factory CHT probe in it, in which case the sparkplug gasket probe for the EDM *will* read differently than the others. Good luck, and Happy Flying! Scott Skylane N92054 |
#3
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How hot is the CHT reading?
"Tony Cox" wrote in message thlink.net... Since a major overhaul about 60 tach hours ago now, I've noticed my #3 cylinder (O470R, 182) is running consistently hot. It is typically 30-40 degrees warmer than the average, which puts it at 4-bars in the EDM700 display. To keep this cylinder temp down, I'm having to leave the cowl flaps open in cruise, which slows me down some 6knots or so. EGT's are all equal. Does this indicate extra friction in that cylinder which could be a problem? The engine as a whole is using about 1qt every 15 hours or so now & I followed the Continental break-in procedure to the letter. It's running great. Did someone miss a bit of baffling in reassembly? Can missing baffle really make that much difference? Perhaps things will return to normal after a few more hours and I should stop worrying. Comments? -- Dr. Tony Cox Citrus Controls Inc. e-mail: http://CitrusControls.com/ |
#4
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"Jim Vadek" wrote in message
news:aABXa.65943$Ho3.9080@sccrnsc03... How hot is the CHT reading? I can keep the hot cylinder down to around 375 with the cowl flaps almost fully open, at around 5000' here in the desert southwest. The rest hover around 340. -- Dr. Tony Cox Citrus Controls Inc. e-mail: http://CitrusControls.com/ |
#5
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"Sydney Hoeltzli" wrote in message
... It's also possible it might be a sign of problems (exhaust valve not seated quite right? what say the engine gurus?) but let's hope for something simple. Compressions are all 73+-1 /80. I'll rechekd the baffling... Ta! -- Dr. Tony Cox Citrus Controls Inc. e-mail: http://CitrusControls.com/ |
#6
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Roughly...temperatures are worth the coin. That is, a dime size hole in the
baffling will cause 10° rise, a quarter 25°, and so on up to the 50° half-dollar. Jim "Tony Cox" shared these priceless pearls of wisdom: - -Did someone miss a bit of baffling in reassembly? Can -missing baffle really make that much difference? Jim Weir (A&P/IA, CFI, & other good alphabet soup) VP Eng RST Pres. Cyberchapter EAA Tech. Counselor http://www.rst-engr.com |
#7
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"Jim Weir" wrote in message ... Roughly...temperatures are worth the coin. That is, a dime size hole in the baffling will cause 10° rise, a quarter 25°, and so on up to the 50° half-dollar. Interesting rule of thumb. But how come I'm only seeing an increase in the middle cylinder on the passenger side? |
#8
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is this by any chance the cylinder on which the stock cht probe
is installed? in my installation, (t-arrow iii), the stc on the edm-700 required that the stock cht be retained (it's #1 on the tsio-360fbfc). so on that cylinder, instead of a bayonet probe, the edm-700 uses a "gasket" probe under the spark plug. the gasket probes are notorious for reading high -- on my t-arrow, #1 reads about 50 deg higher than the hottest of the other 5 cylinders. we've replaced the gasket probe to no avail. when the jpi flags a warning in climb (470 degrees), the stock cht still shows a good 16th or 3-32nds of an inch below the red line. our a & p has checked the temps and found the gasket probe to read high. so, at least in our case, it is a "false alarm". don't know if the same is true for you, but you might want to check it out. g_a "Tony Cox" wrote in message rthlink.net... Since a major overhaul about 60 tach hours ago now, I've noticed my #3 cylinder (O470R, 182) is running consistently hot. It is typically 30-40 degrees warmer than the average, which puts it at 4-bars in the EDM700 display. To keep this cylinder temp down, I'm having to leave the cowl flaps open in cruise, which slows me down some 6knots or so. EGT's are all equal. Does this indicate extra friction in that cylinder which could be a problem? The engine as a whole is using about 1qt every 15 hours or so now & I followed the Continental break-in procedure to the letter. It's running great. Did someone miss a bit of baffling in reassembly? Can missing baffle really make that much difference? Perhaps things will return to normal after a few more hours and I should stop worrying. Comments? |
#9
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"gross_arrow" wrote in message
om... is this by any chance the cylinder on which the stock cht probe is installed? Yes, indeed. I checked today and this is exactly what the problem is. I'll check on availability of the part (5050-A) from JPI. -- Dr. Tony Cox Citrus Controls Inc. e-mail: http://CitrusControls.com/ |
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