gevertex Posted August 12, 2023 Author Report Posted August 12, 2023 Question for the hive mind. I noticed oil on both cowl flaps this morning during pre-flight. This picture is from the cowl flap below the exhaust. The other one has a similar amount of oil. The engine can hold 8 quarts of oil, and I noticed it'll loose 3/4 of a quart every 3 hours or so until it gets to ~6 1/4 quarts and from there oil consumption is very low. I flew it an hour at the 6 1/4 qts level and didn't notice any consumption during that hour (I waited until next day for the oil to cool to measure the level). I have heard you should run these engines at 7 qts, but 6 1/4 seems a low place for the level to stabilize. I am still in the break-in period with ~30 hours total tach time on the engine. Any ideas what this is from? Is it normal? I couldn't think where the oil would be coming from under the exhaust. On the other side there are several tubes just inside the engine cover above the cowl flap and IIRC one of them can vent oil. Quote
redbaron1982 Posted August 12, 2023 Report Posted August 12, 2023 11 minutes ago, gevertex said: Question for the hive mind. I noticed oil on both cowl flaps this morning during pre-flight. This picture is from the cowl flap below the exhaust. The other one has a similar amount of oil. The engine can hold 8 quarts of oil, and I noticed it'll loose 3/4 of a quart every 3 hours or so until it gets to ~6 1/4 quarts and from there oil consumption is very low. I flew it an hour at the 6 1/4 qts level and didn't notice any consumption during that hour (I waited until next day for the oil to cool to measure the level). I have heard you should run these engines at 7 qts, but 6 1/4 seems a low place for the level to stabilize. I am still in the break-in period with ~30 hours total tach time on the engine. Any ideas what this is from? Is it normal? I couldn't think where the oil would be coming from under the exhaust. On the other side there are several tubes just inside the engine cover above the cowl flap and IIRC one of them can vent oil. I use Savvy for maintenance guidance, and they recommend not adding oil until it is at 4qt, and then only add 2qt to get it to 6. I'm doing that without any noticeable effect on oil pressure. 2 Quote
EricJ Posted August 12, 2023 Report Posted August 12, 2023 In the O-360 and IO-360 engines anything above about six quarts rises above the bottom of the crankcase and is within the windage of the crankshaft, where it can get aerated and go out the crank vent. However, that should be going on the belly after the vent tube, not on your cowl flaps. If the dipstick isn't secure or the dipstick tube is leaking at the bottom a bit, this could be where that oil is coming from. It might be easy to see with the cowl off, or maybe by shining a light down the oil hatch or up from the right side cowl flap. It's an easy fix if that's where it's coming from. Quote
gevertex Posted August 13, 2023 Author Report Posted August 13, 2023 19 hours ago, redbaron1982 said: I use Savvy for maintenance guidance, and they recommend not adding oil until it is at 4qt, and then only add 2qt to get it to 6. I'm doing that without any noticeable effect on oil pressure. I've taken the approach of making sure I am above 6 before takeoff. I don't check the oil after the flight, only before the next flight. Quote
gevertex Posted August 13, 2023 Author Report Posted August 13, 2023 19 hours ago, EricJ said: In the O-360 and IO-360 engines anything above about six quarts rises above the bottom of the crankcase and is within the windage of the crankshaft, where it can get aerated and go out the crank vent. However, that should be going on the belly after the vent tube, not on your cowl flaps. If the dipstick isn't secure or the dipstick tube is leaking at the bottom a bit, this could be where that oil is coming from. It might be easy to see with the cowl off, or maybe by shining a light down the oil hatch or up from the right side cowl flap. It's an easy fix if that's where it's coming from. So then this is possibly a leak somewhere in the engine when the plane is at rest, not something happening while running? The other cowl flap looks the same. I wonder how a localized leak would cover both cowl flaps (just curious). Quote
EricJ Posted August 13, 2023 Report Posted August 13, 2023 39 minutes ago, gevertex said: So then this is possibly a leak somewhere in the engine when the plane is at rest, not something happening while running? The other cowl flap looks the same. I wonder how a localized leak would cover both cowl flaps (just curious). Even if it is the oil filler tube leaking, oil gets splashed up there and leaks primarily during engine operation. Any oil leaking or pooled or adhering to the engine will get stirred up and blown around during operation, and anything blown around inside the cowl winds up on the cowl flaps on the way out. Drips that leak at rest usually just drip from the leak or where it gets pooled. 2 Quote
M20F Posted August 14, 2023 Report Posted August 14, 2023 On 8/12/2023 at 7:42 PM, EricJ said: In the O-360 and IO-360 engines anything above about six quarts rises above the bottom of the crankcase and is within the windage of the crankshaft, where it can get aerated and go out the crank vent. This all has to do with minimum oil certification in the regs. Somebody will come along and correct but essentially if you have 8 max you get 4 min or something to the effect. The reality is 6 which would mean something like 2 min which is unachievable. Hence the published 8 which everyone just uses 6 for. Quote
EricJ Posted August 14, 2023 Report Posted August 14, 2023 9 minutes ago, M20F said: This all has to do with minimum oil certification in the regs. Somebody will come along and correct but essentially if you have 8 max you get 4 min or something to the effect. The reality is 6 which would mean something like 2 min which is unachievable. Hence the published 8 which everyone just uses 6 for. It has to be able to run a full tank through at max allowed consumption, or something along those lines. So, for example, at 1qt/hour (or whatever the max allowed is) and six hours of fuel you'd need to have enough capacity to burn six quarts and still have the minimum allowable oil remaining. This is how it was explained by the Lycoming guy at an IA seminar a few years ago, anyway. So even though oil above 6qts can get blown overboard in many engines, it's there to comply with a reg as you suggest. The fact that many can put in 7 quarts or so and not just blow it overboard seems to be a desirable feature, and I don't know why some do and some don't. Quote
gevertex Posted August 16, 2023 Author Report Posted August 16, 2023 I know others have posted about it, but I was shocked that it actually worked. I took my ignition key to ACE Hardware and they made me two copies in ~5 minutes for $8. Lowes didn't have the blanks. I have the key that looks like a filing cabinet key. Cheapest part on this thing . Quote
redbaron1982 Posted August 16, 2023 Report Posted August 16, 2023 1 hour ago, gevertex said: I know others have posted about it, but I was shocked that it actually worked. I took my ignition key to ACE Hardware and they made me two copies in ~5 minutes for $8. Lowes didn't have the blanks. I have the key that looks like a filing cabinet key. Cheapest part on this thing . I did copies for mine in Lowe's... never thought on getting much fancier than that for a key. Quote
wombat Posted August 16, 2023 Report Posted August 16, 2023 On a previous plane I removed the door lock and luggage lock and had them rekeyed to match the ignition key. They were all the same style as the common office file cabinet. My Cessna is a single-key machine too. Such a pleasure to never again put the wrong key in the ignition. Quote
wombat Posted August 16, 2023 Report Posted August 16, 2023 Now that I think about it..... I wonder if I can get them both rekeyed so I have only a single key for both planes... 2 Quote
Fly Boomer Posted August 17, 2023 Report Posted August 17, 2023 3 hours ago, wombat said: Now that I think about it..... I wonder if I can get them both rekeyed so I have only a single key for both planes... I think getting an ignition switch re-keyed is challenging. Quote
gevertex Posted August 21, 2023 Author Report Posted August 21, 2023 (edited) Flew to breakfast Saturday and noticed some light streaking on both blades of the prop after the flight. The prop has roughly 30 hours since new and is about a year old. I've never seen streaking before. I took off the spinner to take a look and get some pictures. I wanted to get your thoughts. I ran up the airplane twice and cycled the prop 5 times each time per McCauley's recommendation in Service Letter 1998-24 and did see some very light streaking afterward on one blade, barely noticeable. I cleaned the spinner inside and out before putting it back together. Thoughts? Edited August 21, 2023 by gevertex Clarity Quote
gevertex Posted August 21, 2023 Author Report Posted August 21, 2023 This is one blade after run-up and 5x prop cycles. You can see some light streaking on it. This is new. I never noticed any streaking prior. Quote
gevertex Posted August 28, 2023 Author Report Posted August 28, 2023 After a couple hours of operation, it seems to have stopped. Weird. Quote
Shadrach Posted August 28, 2023 Report Posted August 28, 2023 Clean everything thoroughly, assemble, and run it another ten hours. Quote
gevertex Posted August 28, 2023 Author Report Posted August 28, 2023 2 hours ago, Shadrach said: Clean everything thoroughly, assemble, and run it another ten hours. Appreciate the advice. This is what I am going to do. Quote
Pinecone Posted August 29, 2023 Report Posted August 29, 2023 Without going back over the thread, how long did the prop sit? We noticed a bit of streaking on the back of one blade during my transition training. Wiped it off before flying home, and haven't seen it come back in over 100 hours. Quote
gevertex Posted August 29, 2023 Author Report Posted August 29, 2023 1 hour ago, Pinecone said: Without going back over the thread, how long did the prop sit? We noticed a bit of streaking on the back of one blade during my transition training. Wiped it off before flying home, and haven't seen it come back in over 100 hours. I’ve been flying it about 2x a week since I got the avionics done. Prop streaking started well after that. Prop is just about new being built in Q2 2022 Quote
EricJ Posted August 29, 2023 Report Posted August 29, 2023 23 minutes ago, gevertex said: I’ve been flying it about 2x a week since I got the avionics done. Prop streaking started well after that. Prop is just about new being built in Q2 2022 Probably just things getting seated fully and wearing in. 1 Quote
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