| name | oil-analysis |
| description | Log oil analysis results from Blackstone Labs. Use when the user has received oil analysis results and wants to record and interpret them. |
| argument-hint | ["lab results or \"show trends\""] |
| user-invocable | true |
Oil Analysis Entry
The user has oil analysis results to log, or wants to review trends.
Input
$ARGUMENTS
Steps
If logging new results:
-
Read oil-analysis.tsv at:
~/Library/CloudStorage/GoogleDrive-sritchie09@gmail.com/My Drive/N720AK/Private/Maintenance/
-
Extract or ask for these fields:
- Date: When the sample was taken
- Tach / Hobbs: Readings when oil was drained
- Hours on Oil: Hours since last oil change
- Lab: Default "Blackstone Labs"
- Wear metals (ppm): Iron (Fe), Chromium (Cr), Nickel (Ni), Aluminum (Al), Copper (Cu), Lead (Pb), Tin (Sn), Silver (Ag), Silicon (Si), Boron (B)
- TBN: Total Base Number (oil remaining useful life)
- Viscosity: Measured viscosity
- Water: Water content in ppm
- Lab Notes: What Blackstone said
- Our Notes: Any additional observations
-
Append a row to oil-analysis.tsv
-
Interpret the results — flag anything abnormal:
Universal action limits for Lycoming IO-540 (approximate, per Blackstone):
| Metal | Normal (ppm) | Watch | Concern |
|---|
| Iron (Fe) | < 30 | 30-50 | > 50 |
| Chromium (Cr) | < 5 | 5-10 | > 10 |
| Nickel (Ni) | < 2 | 2-5 | > 5 |
| Aluminum (Al) | < 10 | 10-20 | > 20 |
| Copper (Cu) | < 15 | 15-30 | > 30 |
| Lead (Pb) | < 30 | 30-50 | > 50 |
| Tin (Sn) | < 5 | 5-10 | > 10 |
| Silver (Ag) | < 1 | 1-2 | > 2 |
| Silicon (Si) | < 20 | 20-30 | > 30 |
- Iron: Primarily from cylinder walls, cam, gears
- Chromium: Piston rings (chrome-plated)
- Aluminum: Pistons, case halves
- Copper: Bearings, bushings, oil cooler
- Lead: Bearing overlay, fuel contamination
- Silicon: Dirt ingestion (air filter), sealant
- Silver: Silver-plated bearings (if equipped)
-
Compare to previous samples — trend analysis is more important than absolute numbers. Flag:
- Any metal that doubled from the previous sample
- Any metal consistently climbing over 3+ samples
- Sudden appearance of a metal not previously present
- TBN dropping unusually fast (suggests oil degradation)
-
Also update engine-log.tsv with a maintenance entry noting the oil analysis was logged.
If reviewing trends:
- Read
oil-analysis.tsv and present a summary table
- Highlight any concerning trends
- Note hours between oil changes and whether the interval is consistent
