1. Home
  2. Honda R&D Technical Review Vol.27 N...
  3. Downsizing as Evolution of High The...

Technical Review e-Book: Summary

Downsizing as Evolution of High Thermal Efficiency Gasoline Engine

Article of Honda R&D Technical Review Vol.27 No.2

Summary

In order to achieve downsizing as an evolution in the high thermal efficiency engine, the possibilities of increasing specific power were examined.
In order to achieve a balance between the specific power that is required for downsizing the engine and the high compression ratio (high expansion ratio) that is the basis for thermal efficiency, high knock resistance in the high engine speed range is necessary. The issue in realizing high power was that sufficient reduction in effective compression ratio through valve timing could not be obtained in the high engine speed range. It became possible to reduce the effective compression ratio by enhancing the intake system, and an increase in specific power was obtained by knock enhancement, but the increase was limited to the equivalent of a naturally aspirated engine. Raising thermal efficiency and downsizing are mutually contradictory techniques, and it became clear that any further increase in specific power would necessitate lowering the mechanical compression ratio itself.
At the same time that downsizing is a technique for improving fuel economy by reducing the displacement, it can also be expected to heighten dynamic performance by achieving lighter weight and greater compactness. In that sense, the approach of downsizing by increasing specific power is crucial for achieving evolution of the high thermal efficiency gasoline engine. In order to achieve this, it will be necessary to build and apply variable compression ratio mechanisms and other such radical technology.

Reference

(1) International Energy Agency: Part4 Scenarios and Technology Roadmaps, Chapter13 Transport, Energy Technology Perspective 2012, p. 443 (2012)
(2) Ota, T., Kono, R., Ito, N., Matsumura, Y., Takahashi, N.: Development of Gasoline Turbo Engine Conforming to U.S. ULEV2 Regulations, Honda R&D Technical Review, Vol. 18, No. 2, p. 36-43
(3) Tagishi, R., Ikeya, K., Takazawa, M., Yamada, T.: Technology for Realization of Gasoline Engine Brake Thermal Efficiency of 45%, Honda R&D Technical Review, Vol. 27, No. 2, p. 1-11

Author (organization or company)

Nobu TAKAHASHI(Automobile R&D Center)

We would like to get your opinion on this research paper. (This is only applicable to registered members.)

The readers of this research paper have also selected these research papers.

Technology for Realization of Gasoline Engine Brake Thermal Efficiency of 45%
Article of Honda R&D Technical Review Vol.27 No.2
New In-Line 4-Cylinder Gasoline Direct Injection Turbocharged Downsizing Engine
Article of Honda R&D Technical Review Vol.28 No.1
Development of 2.0 L Engine for New Accord Hybrid
Article of Honda R&D Technical Review Vol.30 No.1