Development Status of a Small, Direct-Injection Diesel Engine at Isuzu 850068
Development status of small direct Injection diesel engine at Isuzu Motors Ltd. is reviewed.
There is much difficulty in combustion optimization of small DI engines, due to small combustion chamber volume, large surface to volume ratio, wide engine speed range and so on, Novel ideas in the area of injection system, combustion chamber and induction swirl were tried to solve these problems and their effects are presented here.
Our prototype DI engines which adopted some of these ideas has turned out to have better fuel economy by about 15 percent, 2-3 dB(A) higher noise level than IDI and almost the same power output performance as IDI.
As to exhaust emissions, they have a possibility to conform to ′86 California emission standards, in inertia weight classes up to 2625 LBS.
The remaining problem areas are noise emission, durability of injection pump and cabin heater performance. These problems must be solved by further innovation, before DI engines will be successful in passenger car application.