A series of engines for the consumer market has been developed that responds to a range of demands by maximizing the sharing of constituent parts, which also realizes a reduction in the total number of parts employed across the series, a reduced cost, and a high level of environmental performance. Three different displacements engines have been realized in the series by changing only the cylinder modules, consisting of uniblock cylinders of differing bore diameters and pistons. Parts, for which a range of specifications are demanded across the series of different displacements depending on the engine framework, have been shared as a crankcase module, reducing the total number of parts employed in the engine block for engine variations by 43% against the previous models. Simplification of the crankcase shape and the realization of an increased cooling performance reduced the mass of materials in the engine block by 25% against the previous engines. These innovations have reduced the cost of the engines by approximately 15% against the previous models. The combustion chamber shape was modified and a long stroke was employed in order to boost the environmental performance of the low-displacement model, and each of the three different displacement models clears environmental regulations in its countries of sale. In addition, crankcase configuration modification and valve mechanism position have made it possible to realize a greater ease of maintenance than the previous models.
Article of Honda R&D Technical Review Vol.31 No.2 (27 - 33)