alextstone Posted November 26, 2020 Report Posted November 26, 2020 12 hours ago, alextstone said: My usage also is one quart per 8 hours when the engine is healthy. Recently, that quickly went up to one quart every 3 hours and this sudden change was my early warning sign of a cylinder suffering from blow by of the rings and impending exhaust valve failure. BTW, Lycoming provides a formula for "normal" maximum oil consumption: "Lycoming uses the following formula to determine maximum oil consumption: (. 006 x BHP x 4 )/ 7.4 = maximum quart/hour consumption. This means that...." For the Bravo: (. 006 x 270 x 4 )/ 7.4 = .087 qaurt/hour consumption maximum!!! I think the biggest takeaway is to know your engine and watch for trends. Also, I'm going to go out on a limb here and say that Mike Busch's messaging has really more to do with condition based maintenance (for part 91 ops) rather than hours, time in service or arbitrary "swapology" of parts such as a full top overhaul just because one or two cylinders are in need of replacement. Alex Sent from my Pixel 3 XL using Tapatalk Sorry for the confusion I created here....I am at home recovering from surgery (bored and medicated)and I had no business doing math problems online. I’m not going to correct the post though because it’s been addressed in detail and the correction might just serve to muddy the waters further.
tmo Posted November 26, 2020 Report Posted November 26, 2020 1 hour ago, alextstone said: I’m not going to correct the post though because it’s been addressed in detail and the correction might just serve to muddy the waters further. If I may - perhaps editing the post and adding a comment about the issue would help some people that won't bother reading the whole thread? Just a thought! Get better!
affricate Posted March 17, 2021 Report Posted March 17, 2021 I'm burning 1 quart every 3 to 4 hours. All compressions are good, and I'm 40 over TBO.
carusoam Posted March 17, 2021 Report Posted March 17, 2021 18 minutes ago, affricate said: I'm burning 1 quart every 3 to 4 hours. All compressions are good, and I'm 40 over TBO. welcome out into the open... Any idea where the oil is going to? If it is one cylinder, or the turbo, or a single point that can R&R’d that would be great... Best regards, -a- 1
affricate Posted March 17, 2021 Report Posted March 17, 2021 Yeah, doing a MOH soon. In the meantime, changing the oil / oil analysis every 25 hrs
carusoam Posted March 17, 2021 Report Posted March 17, 2021 1 hour ago, affricate said: Yeah, doing a MOH soon. In the meantime, changing the oil / oil analysis every 25 hrs It’s going to be a brand new plane! If you haven’t already... read up on exhaust system issues related to aging (hours on the parts) exhaust systems for TC’d engines... Be on the look out for things like thinning tube walls, exhaust leaks, and be familiar with re-use of v-bands... All typical safety issues of TC’d engines as they get used... That short distance between the exhaust valves and the turbine... is a hellish environment... high pressure, high temp... continuous... PP thoughts only, not a mechanic... Best regards, -a- 1
irishpilot Posted March 18, 2021 Report Posted March 18, 2021 If you're doing a lot takeoffs 5 hours/quart would not be too abnormal in my experience. When I'm flying 4-5 hours legs I go around 10 hrs between quarts and 6 hrs when I'm doing short flights around Florida.Same here. Flew 15 hours last week and used 1.5 qts.Sent from my Pixel 3a using Tapatalk
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