N81FM Posted January 5, 2019 Report Posted January 5, 2019 Hello, During last flight on my Ovation (more than 1 hour at 65% power and even more) oil temperature was not higher that 145°F ! Outside was at 34°F. What could be the reason ? Thanks Quote
RobertE Posted January 5, 2019 Report Posted January 5, 2019 I’m not an expert, but my oil shows something similar in similar conditions (freezing temps + fairly low power). If I’m going to face this situation for multiple flights I typically put a dam in front of the oil cooler that blocks about 50% of the air flow. That solves the problem. Quote
DVA Posted January 5, 2019 Report Posted January 5, 2019 Hello, During last flight on my Ovation (more than 1 hour at 65% power and even more) oil temperature was not higher that 145°F ! Outside was at 34°F. What could be the reason ? Thanks What was your average CHT during the flight? Sent from my iPhone using Tapatalk Quote
N81FM Posted January 5, 2019 Author Report Posted January 5, 2019 CHT's were above 300°( 305-310°) except one which was just below 300°. Quote
carusoam Posted January 5, 2019 Report Posted January 5, 2019 What year is your O? Is it an O1? Something to look into... When the thermistor fails... it starts reading lower before it doesn’t read at all... Pull the thermistor and check it’s resistance... or put it in boiling water to see what temperature the gauge thinks boiling water is... Let us know what thermistor part number you have. Include a pic... if you can. Best regards, -a- my O1 had a Norwich (manufacturer) thermistor. Norwich got bought by Esterline. Esterline seems to have been purchased by Transdigm.... 1 Quote
DVA Posted January 5, 2019 Report Posted January 5, 2019 CHT's were above 300°( 305-310°) except one which was just below 300°. That’s a pretty cool run with a rather cold oat, not unusual to see this. In theory you want your oil temp to exceed 212dF during the time the engine is constantly operating. This allows moisture to boil off and indeed I bet your engine oil was that hot - prior to the oil cooler which is the location of the oil temp probe. What you see on the gauge is cooled oil temp, and based on the oat and the efficacy of the cooler it can drop the oil temp that far. The oil will quickly heat up as it travels through the engine only to be cooled again. I would not suggest blocking the cooler fins. Even if the oil is cooler than normal occasionally there is no harm in that. Sent from my iPhone using Tapatalk 1 Quote
StevenL757 Posted January 5, 2019 Report Posted January 5, 2019 1 hour ago, N81FM said: Hello, During last flight on my Ovation (more than 1 hour at 65% power and even more) oil temperature was not higher that 145°F ! Outside was at 34°F. What could be the reason ? Anthony and Dave make good points. Sometimes I see similar temps in cold weather. I would also have the thermostatic bypass valve checked to ensure it’s opening and closing at the proper temperature ranges, but as Dave indicated, do keep in mind that the temp reading you’re getting is cooled oil and will read a bit lower than the effective temp needed to cook off water and prevent corrosion and rust forming. Steve 1 Quote
Guest Posted January 6, 2019 Report Posted January 6, 2019 There is absolutely nothing wrong with adding an oil cooler baffle. In fact both Mooney and Continental produce one for the 550G. Clarence Quote
DVA Posted January 6, 2019 Report Posted January 6, 2019 There is absolutely nothing wrong with adding an oil cooler baffle. In fact both Mooney and Continental produce one for the 550G. Clarence Clarence, I get the impression that I may have provoked this based on my comment that I wouldn’t add any baffling in this case. Sorry if I wasn’t clear, I meant no disrespect. However, occasional low oil temps in cold weather are fully acceptable and require no baffling as in the case of this thread. His temps were actually not even close to too cold. Where baffling is suggested and often needed is in climates that are very cold all of the time. Areas of Alaska and Canada come to mind, this is why there are manufacturer recommendations for the proper way to reduce effectiveness of the cooler. Dave Sent from my iPhone using Tapatalk Quote
Niko182 Posted January 6, 2019 Report Posted January 6, 2019 Looking at the prop you have, I'm guessing you have a 94 to 99 O. Which means possible moritz gauges. Id check those first. Quote
Guest Posted January 6, 2019 Report Posted January 6, 2019 7 minutes ago, DVA said: Clarence, I get the impression that I may have provoked this based on my comment that I wouldn’t add any baffling in this case. Sorry if I wasn’t clear, I meant no disrespect. However, occasional low oil temps in cold weather are fully acceptable and require no baffling as in the case of this thread. His temps were actually not even close to too cold. Where baffling is suggested and often needed is in climates that are very cold all of the time. Areas of Alaska and Canada come to mind, this is why there are manufacturer recommendations for the proper way to reduce effectiveness of the cooler. Dave Sent from my iPhone using Tapatalk Dave, Just trying to clarify for others that there are approved cooler baffles for these engines. I’ve seen and installed the Mooney version, but never the Continental version. Clarence Quote
gsxrpilot Posted January 6, 2019 Report Posted January 6, 2019 On a recent two hour flight from FLG to CNY my oil temp got to 150 during the climb but then settled back down in the mid 130's for the entire flight. https://savvyanalysis.com/flight/2914893/5c3e1da4-b1e6-4d57-937d-9a4a09d324a4 Quote
Guest Posted January 7, 2019 Report Posted January 7, 2019 3 hours ago, gsxrpilot said: On a recent two hour flight from FLG to CNY my oil temp got to 150 during the climb but then settled back down in the mid 130's for the entire flight. https://savvyanalysis.com/flight/2914893/5c3e1da4-b1e6-4d57-937d-9a4a09d324a4 Paul, You too can have one f these. Clarence Quote
gsxrpilot Posted January 7, 2019 Report Posted January 7, 2019 49 minutes ago, M20Doc said: Paul, You too can have one f these. Clarence I need to get one. Thanks. Quote
EricJ Posted January 7, 2019 Report Posted January 7, 2019 I'm guessing the vernatherm is not a very precision device as it doesn't really do much to keep oil temps above minimum, no? Quote
carusoam Posted January 7, 2019 Report Posted January 7, 2019 Keep in mind how a vernatherm works... simple, mechanical, light weight, lasts forever.... 1) it is oil temperature controlled... 2) it controls volume of oil cycling through and/or past the oil cooler.... 3) It doesn’t have any high tech process controller like it would need to do any better... (those would be called PID type controllers... proportional, integral and derivative) (expensive electronic devices, back in the day cost a ton and took up the volume of the radio stack...) today, it would be on a chip hidden in your iPhone.... 4) It has no forward looking way of knowing what the outside temp is... (it relies on the pilot to cover the extra cooling fins) 5) these things are holey cow inexpensive, and work incredibly well for what they need to do... 6) Fortunately we have oil that can bridge a large range of OATs... 7) If you want to raise the oil temperature because Your OAT is so cold... talk to your mechanic and ask him about the best way to be blocking off a percentage of the oil cooler... there is some good knowledge required for doing it right... 8) My O has a plate that fits in front of its oil cooler... I don’t typically use one in NJ... Best regards, -a- Quote
Pete M Posted February 7, 2019 Report Posted February 7, 2019 Regardless of oil temp at the temp guage when water in the oil comes in contact with hot engine parts, my sense is, it likely vaporizes, for the most part. Quote
Browncbr1 Posted February 9, 2019 Report Posted February 9, 2019 After each flight, open your dip stick. If no steam is coming out, it probably didn’t get hot enough. I do this after every flight to try and get as much moisture out of the case as possible before putting it to bed. 1 Quote
Cody Stallings Posted February 9, 2019 Report Posted February 9, 2019 53 minutes ago, Browncbr1 said: After each flight, open your dip stick. If no steam is coming out, it probably didn’t get hot enough. I do this after every flight to try and get as much moisture out of the case as possible before putting it to bed. I do the same thing. after I let it sit an “stem off” when I check the oil before the next flight I don’t see any condensation on the bottom of the oil cap. But if I don’t open it after a flight, there is always droplets on the bottom side of the cap. Quote
Bob_Belville Posted February 9, 2019 Report Posted February 9, 2019 The vernatherm, at least the one on my IO360, closes at 185F sending oil through the cooler. That assumes the vernatherm seats and seals completely. Unless the oil temp get to 185F the oil doesn't go through the cooler, does it @M20Doc? I am not visualizing what reducing air flow to the cooler accomplishes under this situation. Since Mooney and LASAR make the baffle I suppose I am wrong and I'll be thankful for an education. Quote
ArtVandelay Posted February 9, 2019 Report Posted February 9, 2019 The vernatherm, at least the one on my IO360, closes at 185F sending oil through the cooler. That assumes the vernatherm seats and seals completely. Unless the oil temp get to 185F the oil doesn't go through the cooler, does it [mention=12030]M20Doc[/mention]? I assume it opens as it gets hotter, so it’s not as on/off as you imply, so some of oil gets through at 180F...maybe 170 or 160?Tom Quote
elimansour Posted February 9, 2019 Report Posted February 9, 2019 My engine pre and post overhaul seems to always run cool. Yesterday during breakin flight at 75% the oil temp was approx 170. Upon shut down, we tested the oil temp with a probe and it was 170. CHTs were in the mid 300s. This is consistent with what happened prior to the overhaul. Any issue with oil temps not rising above 170? OATs yesterday were less than 40F. Quote
Browncbr1 Posted February 9, 2019 Report Posted February 9, 2019 20deg btdc timing will also make it a challenge to run warm enough in winter. Even in the summer Quote
LANCECASPER Posted February 10, 2019 Report Posted February 10, 2019 On 1/5/2019 at 6:11 PM, Niko182 said: Looking at the prop you have, I'm guessing you have a 94 to 99 O. Which means possible moritz gauges. Id check those first. N81FM is a '99 so yes it has the Moritz gauges, or at least had them when it left the factory. Quote
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