It's a Saturday. The sun is bright and sky is crispy clear. There's a slight breeze in the air. It's time to play.

When you were a child that might have meant bike-riding with friends. But now you're a pleasure-seeking adult. You've put in a long week at the office. It's time for adventure. So you hop in your shiny, gasoline-loving sports car and hit the road. Vroom. Vroom.

But, revving that engine isn't as fun as it used to be. You feel a bit guilty when you put the pedal to the metal. Growing public concern for global and urban environments has increased your awareness of automobile pollution and its impact on air quality. You'd feel much better if you could drive a sports car that placed fewer burdens on the environment. Now you can, thanks to Honda Motor Company.

With the new Honda S2000 and its two liter DOHC-VTEC engine, you can have your "rev" and clean air too. To commemorate its 50th anniversary, Honda developed and launched the Honda S2000. The Honda S2000 is a sports roadster that provides the fundamental requirement of a sports car: genuine driving pleasure. One of the many amenities that makes it special is its engine - code named "F20C."

For the past several years, development efforts at Honda have been dedicated to establishing a benchmark for the 21st century sports car engine. The result is a new 2.0 liter in-line four-cylinder powerplant - the F20C.

This power unit is unique because it boasts a high output power at astonishingly high engine revolutions while ensuring low levels of exhaust emission. The engine produces 179kW (240HP, which is 120HP per liter). It has the highest output power among all naturally aspirated two liter engines ever mass-produced. In addition, it achieves an exhaust emission level within National LEV standards.

The new F20C engine utilises a redesigned VTEC cylinder head, in which MIM (metal injection molding) rocker arms are used. This ultimate power unit also features a new cylinder block with a ladder frame structure for its lower part, a newly developed camshaft drive chain and gear system, and a metal honeycomb catalyst with an air pump start-up system.

The Honda S2000 is a genuine sports car with the engine installed aft of the front axle (dubbed as "behind-the-axle engine layout"). Honda engineers achieved this layout while satisfying the requirements of high power output and response by developing an engine that was short in overall length and also light in weight, realizing a 50:50 front and rear weight distribution.

The Honda engineers achieved all of their technology targets. These included:

• high engine speeds allowing the output power of 89.5kW (120HP/liter);
• compliance with the National LEV standards;
• compact in size and light in weight; and
• a high degree of response.

The engines of the Honda S2000 and Prelude Si are common to one another in terms of bore diameter and cylinder pitch. Major specifications of the F20C as compared to the Prelude Si's H22A as table on previous page.

For those who want more technical details on how the F20C engine was designed, learn more by obtaining SAE technical paper 2000-01-0670.

In this recently published SAE paper, Yutaka Otobe, Hiroshi Kawaguchi and Hideo Ueshima of Honda R&D Co., Ltd., describe the new technology in depth. They presented the research last March at the SAE '2000 World Congress, Detroit, Michigan, USA. The paper was a best seller during the four-day event, which attracted nearly 50,000 attendees from all over the world.

To order a copy of SAE paper 2000-01-0670, visit www.sae.org or contact SAE Customer Sales and Support at 1-724-776-4970; facsimile: 1-724-776-0790; or e-mail publications@sae.org

SAE publishes thousands of technical papers and hundreds of new books each year. Visit the SAE Bookstore on line to browse our collection of over 600 book titles at www.sae.org/bookstore. Individual copies of SAE technical papers are also available in print or electronic format.

The Society of Automotive Engineers (SAE) International is a not-for profit organisation dedicated to advancing mobility technology: land, sea, air and space. Visit www.sae.org for more information.

Added to the database on 27^th September 2001

Keywords: Honda, low-emission engine