Reduction of HC Emission from VTEC Engine During Cold-Start Condition
940481
03/01/1994
- Event
- Content
- In the cities of the U.S. the worsening ozone problem has attracted attention and prompted reinforcement of regulations against emissions of hydrocarbons (HC) from automobiles. To cope with this situation, a reduction of HC is a vital challenge for the automotive industry. HC emission comes mainly from a cold engine, which usually uses a richer air-fuel mixture to achieve stable combustion and secure good driveability.The purpose of this paper is to show that using a engine with variable valv1e timing and lift system (VTEC) (1)∼(2) it is possible to reduce considerably HC emission in cold-start conditions. In other words, it is able to employ a leaner mixture than in existing engines (A/F=15.5) by using the VTEC system to alter the valve timing and lift according to various driving conditions, thereby considerably reducing HC emissions due to the improvement and stabilization of engine combustion.
- Pages
- 12
- Citation
- Nakayama, Y., Maruya, T., Oikawa, T., Fujiwara, M. et al., "Reduction of HC Emission from VTEC Engine During Cold-Start Condition," SAE Technical Paper 940481, 1994, https://doi.org/10.4271/940481.