Development Aim
The engine developed for the first YZF-R1 model achieved a 10kg weight reduction and 81mm longitudinal length reduction compared to the existing engine, and one of the features that made this high-performance engine design possible was this single-unit crankcase-cylinder block.

Structure and Function 
The formation of a thin film of oil between the piston rings and the Ni (P) metal imbedded with hard silicon carbide particles produces outstanding sliding efficiency. And, since aluminum with the same heat expansion rate can be used for the opposing faces of the piston and cylinder, there is minimum heat-induced change in the gap between the piston and cylinder as well as better cooling characteristics, thus resulting in more stable performance. As a result it also produces excellent oil economy.

Effect 
The effects of this construction include:
(1) reduced weight,
(2) excellent strength to support a high compression ratio,
(3) excellent cooling performance,
(4) improved abrasion resistance and
(5) excellent oil economy.