Champ
Well Known Member
I now have 160 hrs on my IO-375-M1S and my oil consumption has consistently been 5 to 6 hr per quart since first flight. The engine is by AeroSport with ECI nickel carbide cylinders, Superior cold air sump and dual PMags, NGK BR8ES plugs. Performance has been flawless and I am very happy with it except for the oil consumption.
Background:
1. AeroSport had two test runs of 47 and 40 minutes with two 30 minute runs at 2700 rpm and 26?. Max CHT recorded was 339F. Aeroshell 100 mineral was used. Leak downs were #1-78, #2-78, #3-77, #4-78.
2. AeroSport ran the engine for an additional 2 hrs again cycling up to 30m runs at 2700 rpm and 26?. Max CHT recorded was 340F.
3. Approximately 6 ground runs prior to first flight with cowl off and CHTs never above 350F.
4. Diamond Aircraft?s test pilot flew the initial 5 hrs using Diamond?s break in procedure. The first 2.5 hrs were flown at 4000 to 5000ft, mostly at 2400 to 2700 rpm and 24.5 to 24.8?mp. Oil temps ran 185-195F with average CHT 358F.
5. Leak downs on last Condition Inspection at 120hr were #1-75, #2-76, #3-76, #4-78.
6. Aeroshell 100 Mineral was used for the first 50 hrs and Aeroshell 100W+ and 80W+ since as recommended by AeroSport.
7. It was 3.5 yr from when the engine was delivered til first flight (slooooow build). It was not technically pickled during this time but kept in a dry heated shop with desiccant plugs maintained, exhaust ports capped, minimally rotated and only near the end for spinner installation.
8. Normal cruise is LOP with oil temps around 180F.
9. Aircraft is normally flown once a week and is in a heated hanger.
10. No contaminants have been found in the oil screen at CI?s or filter at oil changes.
11. Oil samples were taken and stored at each oil change but have not been submitted for analysis.
12. Engine is run between 4.5 and 6.5 quarts.
13. No leaks or appreciable oil on the belly.
14. Oil does darken.
15. Can?t say the plugs or exhaust pipes show any real oil wetness or carbon build up.
16. Borescopes showed some scoring on the cylinder walls which AeroSport thought could come from power application before the cylinders were warm enough. Take off power is applied with oil temp above 100F. Borescopes show oil on cylinder walls after pistons are raised & lowered. Cyl 1 borescopes at 120 hr attached if interested
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Questions:
1. Have others had similar experience with similar engines ? ie stroked, ECI, nickel carbide?
2. Could the test runs or first flights have glazed cylinders?
3. I seem to recall a VAF post where someone changed from Aeroshell single grade to Phillips multigrade and saw significantly lower oil consumption. Could this help?
4. Could the extended storage have been a problem?
5. Could my ground runs have been a problem?
6. I don?t plan on honing and reringing until oil consumption gets much worse as right now the cost of oil is less painful then the repair and the down time.
7. Would a crank case pressure test be worthwhile?
8. Is oil on the cylinder walls typical? Since compression rings are not wiping the cylinder walls unless the engine is firing.
9. Additional thoughts/advise/things to look for at my next annual?
Background:
1. AeroSport had two test runs of 47 and 40 minutes with two 30 minute runs at 2700 rpm and 26?. Max CHT recorded was 339F. Aeroshell 100 mineral was used. Leak downs were #1-78, #2-78, #3-77, #4-78.
2. AeroSport ran the engine for an additional 2 hrs again cycling up to 30m runs at 2700 rpm and 26?. Max CHT recorded was 340F.
3. Approximately 6 ground runs prior to first flight with cowl off and CHTs never above 350F.
4. Diamond Aircraft?s test pilot flew the initial 5 hrs using Diamond?s break in procedure. The first 2.5 hrs were flown at 4000 to 5000ft, mostly at 2400 to 2700 rpm and 24.5 to 24.8?mp. Oil temps ran 185-195F with average CHT 358F.
5. Leak downs on last Condition Inspection at 120hr were #1-75, #2-76, #3-76, #4-78.
6. Aeroshell 100 Mineral was used for the first 50 hrs and Aeroshell 100W+ and 80W+ since as recommended by AeroSport.
7. It was 3.5 yr from when the engine was delivered til first flight (slooooow build). It was not technically pickled during this time but kept in a dry heated shop with desiccant plugs maintained, exhaust ports capped, minimally rotated and only near the end for spinner installation.
8. Normal cruise is LOP with oil temps around 180F.
9. Aircraft is normally flown once a week and is in a heated hanger.
10. No contaminants have been found in the oil screen at CI?s or filter at oil changes.
11. Oil samples were taken and stored at each oil change but have not been submitted for analysis.
12. Engine is run between 4.5 and 6.5 quarts.
13. No leaks or appreciable oil on the belly.
14. Oil does darken.
15. Can?t say the plugs or exhaust pipes show any real oil wetness or carbon build up.
16. Borescopes showed some scoring on the cylinder walls which AeroSport thought could come from power application before the cylinders were warm enough. Take off power is applied with oil temp above 100F. Borescopes show oil on cylinder walls after pistons are raised & lowered. Cyl 1 borescopes at 120 hr attached if interested
Questions:
1. Have others had similar experience with similar engines ? ie stroked, ECI, nickel carbide?
2. Could the test runs or first flights have glazed cylinders?
3. I seem to recall a VAF post where someone changed from Aeroshell single grade to Phillips multigrade and saw significantly lower oil consumption. Could this help?
4. Could the extended storage have been a problem?
5. Could my ground runs have been a problem?
6. I don?t plan on honing and reringing until oil consumption gets much worse as right now the cost of oil is less painful then the repair and the down time.
7. Would a crank case pressure test be worthwhile?
8. Is oil on the cylinder walls typical? Since compression rings are not wiping the cylinder walls unless the engine is firing.
9. Additional thoughts/advise/things to look for at my next annual?