Extension of Lean Burn Range by Intake Valve Offset

Using a 109.2 cm3, four-stroke, single-cylinder, two-valve gasoline engine, improvement of fuel economy by extension of lean burn range has been attempted with invented way to intensify tumble flow from a simple mechanical arrangement. With a part of the intake valve was jutted out beyond the perimeter of the cylinder bore, the masking effects from the valve recess on top of the cylinder sleeve created a strong tumble flow, which enabled lean burn at an air fuel ratio leaner than the conventional design by two points. The motorcycle equipped with this engine attained better fuel economy by 5.7% to the base model when measured in Indian Driving Cycle (IDC). The outward-laid intake valve also increased the clearance from the exhaust valve, which enabled use of a large-diameter intake valve to minimize the reduction of maximum power.

• Record URL:
  • https://doi.org/10.4271/2013-32-9032
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/19463936
• Supplemental Notes:
  • Abstract reprinted with permission of SAE International.
• Authors:
  • Saito, Hideki
  • Shirasuna, Takamori
  • Nomura, Tomokazu
• Conference:
  • JSAE/SAE 2013 Small Engine Technology Conference
  • Location: Taipei , Taiwan
  • Date: 2013-10-8 to 2013-10-10
• Publication Date: 2013-10-15

Language

• English

Media Info

• Media Type: Web
• Pagination: pp 2072-2084
• Serial:
  • SAE International Journal of Engines
  • Volume: 6
  • Issue Number: 4
  • Publisher: SAE International
  • ISSN: 1946-3936
  • EISSN: 1946-3944
  • Serial URL: https://www.sae.org/publications/collections/content/E-JOURNAL-03/

Subject/Index Terms

• TRT Terms: Exhaust valves; Fuel conservation; Internal combustion engines
• Subject Areas: Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 01791218
• Record Type: Publication
• Source Agency: SAE International
• Report/Paper Numbers: 2013-32-9032
• Files: TRIS, SAE
• Created Date: Dec 9 2021 10:12AM