This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Durability of Low-Emissions Small Off-Road Engines
Technical Paper
2004-32-0058
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
The goal of the project was to reduce tailpipe-out hydrocarbon (HC) plus oxides of nitrogen (NOx) emissions to 50 percent or less of the current California Air Resources Board (CARB) useful life standard of 12 g/hp-hr for Class I engines, or 9 g/hp-hr for Class II engines. Low-emission engines were developed using three-way catalytic converters, passive secondary-air induction (SAI) systems, and in two cases, enleanment. Catalysts were integrated into the engine's mufflers, where feasible, to maintain a compact package. Due to the thermal sensitivity of these engines, carburetor calibrations were left unchanged in four of the six engines, at the stock rich settings. To enable HC oxidation under such rich conditions, a simple passive supplemental air injection system was developed. This system was then tuned to achieve the desired HC+NOx reduction. Engines were then aged for either 250 hours (Class 1), or 500 hours (Class 2), with emission testing at intervals to track muffler-out emissions and catalyst performance. Results demonstrated that emissions from these engines could be significantly reduced.
Recommended Content
Authors
Topic
Citation
White, J., Lela, C., Lourenco, J., and Salardino, D., "Durability of Low-Emissions Small Off-Road Engines," SAE Technical Paper 2004-32-0058, 2004, https://doi.org/10.4271/2004-32-0058.Also In
References
- “Staff Report - Initial Statement of Reasons for Proposed Rulemaking,” Air Resources Board Aug. 8 2003
- White, J. J. Lela, C. “Durability of Low-Emissions Small Off-Road Engines,” Interim Report Southwest Research Institute May 30 2003
- Regulatory Documents for the Small Off-Road Exhaust and Evaporative Emission Control Regulations