High-Octane and Mid-Octane Detonation Performance of Leaded and Unleaded Fuels in Naturally Aspirated, Piston, Spark Ignition Aircraft Engines

Details

• Creators:
  Atwood, David
• Corporate Creators:
  United States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical Center. Airport and Aircraft Safety Research and Development Division.
• Corporate Contributors:
  United States. Department of Transportation. Federal Aviation Administration. Office of Aviation Research and Development
• Subject/TRT Terms:
  100 LL Alternate Fuels Aviation Aviation Fuels Clean Air Act Detonation Gasoline IO320 Engine IO540 Engine Isooctane Motor Octane Number Octane Piston Engines Supercharge Rich Rating Unleaded Gasoline

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• Publication/ Report Number:
  DOT/FAA/AR-TN07/5
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Technical Notes
• Corporate Publisher:
  United States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical Center
• Abstract:
  The full-scale engine detonation performance of mid-and high-octane leaded and unleaded fuels were compared at the onset of light detonation in a naturally aspirated Lycoming IO540-K and a naturally aspirated Lycoming IO320-B engine. The fuels were stressed by performing both mixture lean-outs and by increasing the manifold pressure. The high-octane fuels (100 motor octane number (MON) and above) were tested in the IO540-K engine, and the mid-octane (91 to 95 MON fuels) were tested in the IO320-B engine. For this testing, the MON was determined by ASTM International (ASTM) specification D 2700 and the supercharge rich rating was determined by ASTM D 909. A specially blended 100 low-lead (100 LL) aviation gasoline was tested. The 100 LL blend contained the maximum amount of allowable lead, while meeting the minimum MON of 100 and the minimum supercharge rich rating of 130 (described as 100/130 lead (L)), and met all current ASTM aviation gasoline specification D 910. The 100 LL blend performed significantly better than a 100 MON unleaded isooctane and a 100 MON and 161 supercharge rich rating unleaded amine-laden fuel in the IO540-K engine. The 100 LL did not perform as well as a 104 MON and 161 supercharge rich rating unleaded amine-laden fuel. The 100 LL fuel performed the same as a 100 MON and 100 supercharge rich rating leaded (100/100 L) fuel at the lower cruise power settings but performed much better at the higher power settings. This testing showed that the 100 LL significantly outperformed unleaded fuels of equivalent MON, even those with much higher supercharge rich ratings. The data also showed that the supercharge rich rating for leaded, hydrocarbon fuels is of greater significance at the higher power settings.
• Format:
  PDF
• Collection(s):
  FAA William J. Hughes Technical Center for Advanced Aerospace
• Main Document Checksum:
  urn:sha-512:925810ebd2026c00dd8947d5e79915fa458a7cbe226abde5d826315770b9c9ee86fd908a51b620dee0f64f2bbdef756e596f10745f7404d4c78102d313c3a535
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/90094/dot_90094_DS1.pdf
• File Type:
  [PDF - 5.08 MB ]