Conclusion

The K-series engines contain all the design techniques Mazda has developed, including combustion chamber, intake/exhaust systems, electrical controls, noise reduction and reliability, for high performance engines.

The K-series engines described in this paper are mounted in the new Mazda 626, MX-6 and MX-3 vehicles. The authors are quite confident that the various development objectives required to these vehicles have been achieved at a high level, making use of the above techniques. The following four points summarize the accomplishments made in developing the K-series engines.

1. K-series engines have achieved low fuel consumption and low emissions by adopting a compact, high-squish combustion chamber and optimizing all controls by microcomputer.

2. High smooth vehicle acceleration characteristics that give excellent "acceleration and top-end feel" have been gained because of two improvements: a compact design that makes full use of intake and exhaust dynamic effect; and an engine control system that optimizes ignition timing.

3. With a more rigid cylinder block and a more rigid crankshaft support structure, low-frequency noise was reduced and rumbling noise suppressed, resulting in a pleasant engine sound.

4. A design that aimed for reduced weight and compactness, realized by such modifications as an aluminum cylinder block and an integrated surge tank/inlet manifold, has made the K-series engines the lightest and most compact in the same displacement class of V6 engines, thus contributing to improve fuel consumption and realize a lower hood styling.

ACKNOWLEDGEMENTS

The authors would like to express their gratitude for the full support given by all those inside and outside of Mazda involved in the development and production of the K-series engines.

REFERENCES

1. N. Hashimoto et al., "Development of High Efficient Combustion Chamber for 4 Valved Engine", The 9th Internal Combustion Engine Symposium, Japan, 1991, pp. 233 - 238

2. H. Yamamoto et al., "A Study Based on Investigation of Consciousness for Drive Feeling", Mazda Technical Report, No.4, 1986, pp. 3 - 10

3. K. Hatamura et al., "Mazda's New V-6 Gasoline Engine and Its Innovative Induction System", SAE Paper No. 871977

4. H. Abe et al., "Study on Evaluation and Improvement of Acoustic Quality in Vehicle Passenger Compartment", Mazda Technical Report, No.6, 1988, pp. 44 - 51