Reduction of HC Emission from VTEC Engine During Cold-Start Condition

Yukio Nakayama; Takeshi Maruya; Toshihiro Oikawa; Mikio Fujiwara; Masashi Kawamata

doi:10.4271/940481

1994-03-01

Reduction of HC Emission from VTEC Engine During Cold-Start Condition 940481

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.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Digital $37.00 Print $37.00

Preview Document

We also recommend:

Standards

SAE Mobilus®

Publications

News

Events

Professional Development

A World in Motion (PreK-12)

Participate with SAE

SAE Membership

Donate

Reduction of HC Emission from VTEC Engine During Cold-Start Condition 940481

SAE MOBILUS