Page 47 - E BOOK ENGINE MECHANICAL M2

1. GENERAL

4. COMBUSTION CHAMBER
The diesel engines that MMC manufactures are classified into two types depending on the combus-
tion chamber configuration. These are the DI (Direct Injection) type and the IDI (In-Direct Injection)
type. The comparison of the differences on these is shown below.

IDI (In-Direct Injection),
Item DI (Direct Injection)
Swirl chamber
Simple Rather complex

Configuration of combustion
chamber

Heat loss Small Rather large

Compression ratio 15-22 20-23
Easiness of engine start Easy Hard
Multi-hole type Throttle type

Nozzle type

Injection pressure (MPa) 16-28 10-15

Combustion pressure (MPa) 8 5.5-6.5

Diesel knock occurrence Very high Rather high
Fuel consumption (g/kWh) 185-230 245-290

Max. engine speed Low High

1 - 4 Pub. No. PTAE1228