Kubota D1803-CR-E4, Workshop Manual

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2.2 Feature of engine body
The engine body is the main part of the engine.
It is made up of cylinder related, primary motion, and
valve train mechanisms.
Each of the parts are designed and assembled with
passages for lubricating oil and coolant for circulating
within the engine.
2.3 Crankcase
2.3.1 Outline of crankcase
The main function of the crankcase is to support the
main parts.
2.3.2 Structure of crankcase
The crankcase for 03 series is used tunnel type.
(1) Crankcase
2.3.3 Function of crankcase
The crankcase has cylinders inside and supports the
crankshaft and camshaft.
Further, it has an internal water jacket and oil
passageways to cool the cylinders.
(1) Fuel camshaft
(2) Idle gear (3) Camshaft
(4) Crankshaft
2.3.4 Specification of crankcase
Cylinder liner diameter (D)
87.000 to 87.022 mm
3.4252 to 3.4260 in.
Finish machining Honing (1.4 to 2.2 μmRz)
Oversize
+0.25 mm
+0.0098 in.
2.4 Cylinder head
2.4.1 Outline of cylinder head
Along with the crankcase, the cylinder head is the most
fundamental part that makes up the engine.
2.4.2 Structure of cylinder head
The cylinder head is provided with valve guides and
valve seats.
(1) Valve guide
(2) Valve seat (3) Intake port
(4) Exhaust port
2.4.3 Function of cylinder head
1. Along with the crankcase, the cylinder head is the
most fundamental part that makes up the engine
forming the combustion chamber along with the
crankcase and piston.
4. ENGINE
MECHANISM
2. Engine body
4-4
D1803-CR-E4,D1803-CR-TE4,D1803-CR-TIE4,V2403-CR-E4,V2403-CR-TE4,V2403-CR-TE4BG,V2403-CR-TIE4
KiSC issued 12, 2018 A