Last week I posted the following question:
I have recently had the cylinders overhauled on my Lyc IO306a1a. All 4 nitride , honed with new rings. Ground run was held to the Lycoming minimums. 1 run at 800 rpm until the oil reached 140 then let cool completely. The next day I let the oil warm up th 140 then took off ASAP. Max oil temp 222 then dropped to 195 , max cht on the engine monitor was 380 then dropped to 320 or less ,all within the first hour.
I ran the next 4 hours at 75-80% power every 30 min slowly changing power up and down for 10 min. Always 100 degrees ROP.
I am still burning 3/4 quart of mineral oil per hour. When should this stop and drop to the expected 1 quart in 15-20 hrs ?
The response I recieved was beyond expectations. They have educated me in many ways. I now have 7 hours and oil burn is exactly 1 quart per hour. Please help with a few more questions.
I spoke to my cylinder OH shop and they seemed stumped to. I am now burning as much oil as before my overhaul. The engine has no leaks, where can this much oil go ? I have separator on the crankcase vent line and it drains into a bottle so I can tell if any oil is blown out the breather. I have straight stacks and all the pipes are an even color grey inside. Can anyone think of any other way to burn/leak this much oil and it not be obvious?
Thinking from a different direction:
If I wanted my engine to burn more oil what could I do ??
How is it that I followed Lyc. procedure and failed so badly?
Could I have messed it up worse following no procedure at all?
Can an internal oil pump or oiling system problem cause this?
I have all new piston cooling nozzels.
I guess that the most frustrating part is that I am not looking for an improvement from 1 in 10 to 1 in 15. I would be happy with a low 1 in 7.
I can not even meet my low expectations.
I think I will go to about 15 hours then see how I stand. I just can't believe at this point things will improve much. I have built to many motors of all kinds to not be frustrated by this.
Sorry to vent like this, any further suggestions or VOODOO would be appreciated.
LMB
I have recently had the cylinders overhauled on my Lyc IO306a1a. All 4 nitride , honed with new rings. Ground run was held to the Lycoming minimums. 1 run at 800 rpm until the oil reached 140 then let cool completely. The next day I let the oil warm up th 140 then took off ASAP. Max oil temp 222 then dropped to 195 , max cht on the engine monitor was 380 then dropped to 320 or less ,all within the first hour.
I ran the next 4 hours at 75-80% power every 30 min slowly changing power up and down for 10 min. Always 100 degrees ROP.
I am still burning 3/4 quart of mineral oil per hour. When should this stop and drop to the expected 1 quart in 15-20 hrs ?
The response I recieved was beyond expectations. They have educated me in many ways. I now have 7 hours and oil burn is exactly 1 quart per hour. Please help with a few more questions.
I spoke to my cylinder OH shop and they seemed stumped to. I am now burning as much oil as before my overhaul. The engine has no leaks, where can this much oil go ? I have separator on the crankcase vent line and it drains into a bottle so I can tell if any oil is blown out the breather. I have straight stacks and all the pipes are an even color grey inside. Can anyone think of any other way to burn/leak this much oil and it not be obvious?
Thinking from a different direction:
If I wanted my engine to burn more oil what could I do ??
How is it that I followed Lyc. procedure and failed so badly?
Could I have messed it up worse following no procedure at all?
Can an internal oil pump or oiling system problem cause this?
I have all new piston cooling nozzels.
I guess that the most frustrating part is that I am not looking for an improvement from 1 in 10 to 1 in 15. I would be happy with a low 1 in 7.
I can not even meet my low expectations.
I think I will go to about 15 hours then see how I stand. I just can't believe at this point things will improve much. I have built to many motors of all kinds to not be frustrated by this.
Sorry to vent like this, any further suggestions or VOODOO would be appreciated.
LMB