3AC-00011-0 Tohatsu PISTON RING TOP

Engine Specifications
Note: The front end of the engine is opposite the flywheel end of the engine. The left side and the right side of the engine are determined from the flywheel end. The number 1 cylinder is the front cylinder.Cat C32 Marine Engines
Illustration 1 g00531921
Cylinder and valve locations
(A) Inlet valves
(B) Exhaust valves
(C) Front of the engine
Table 1
C32 Marine Engine Specifications
Cylinders and Arrangement 12 cylinder vee block
Bore 145 mm (5.7 inch)
Stroke 162 mm (6.4 inch)
Compression Ratio 15:1
Aspiration Twin Turbocharged Aftercooled Aspiration
Displacement 32 L (1953 in3)
Firing Order 1-10-9-6-5-12-11-4-3-8-7-2
Rotation (flywheel end) Counterclockwise Electronic Engine Features
The engine has built-in diagnostics to ensure that all the components are operating properly. In the event of a system component failure, the operator will be alerted to the condition via the diagnostic lamp on the control panel. Cat Electronic Technician (ET) can be used to read the numerical code of the faulty component or condition. Intermittent faults are also logged and stored in memory.These Cat Marine Engines are designed with electronic controls. The integral on board computer controls the operation of the engine. Current operating conditions are monitored. The Electronic Control Module (ECM) controls the response of the engine to these conditions and to the demands of the operator. These conditions and operator demands determine the precise control of fuel injection by the ECM. The electronic engine control system provides the following features:
Engine monitoring
Electronic engine speed governing
Automatic air/fuel ratio control
Torque rise shaping
Injection timing control
System diagnosticsThe engine ECM will automatically provide the correct amount of fuel to start the engine. Do not hold the throttle down while the engine is cranking. If the engine fails to start in 20 seconds, release the starting switch. Allow the starting motor to cool for 2 minutes before using the starting motor again.For more information on electronic engine features, refer to the Operation and Maintenance Manual, "Features and Controls" topic (Operation Section).Engine Cooling and Lubrication
The engines have water-cooled exhaust manifolds, risers, and turbochargers. These components will minimize the heat that is radiated into the engine room. Changes to the cooling system of these engines minimize the weight and the size of the engine. These changes also improve the engine performance. The cooling system heat exchangers, the expansion tanks, and the deaerator help to prevent cavitation of the water pumps. Water pumps that work properly help maintain the performance of the jacket water pump.The cooling system consists of the following components:
Centrifugal jacket water pump that is driven by gears
Two water temperature regulators which regulate the engine coolant temperature
Oil cooler
Auxiliary water pump and a SCAC water pump
Treated water aftercoolingThe engine lubricating oil, which is supplied by a gear-type pump, is cooled. The engine lubricating oil is also filtered. Bypass valves provide unrestricted flow of lubrication oil to the engine components during the following conditions:
High oil viscosity
Plugged oil cooler or plugged oil filter elements (paper cartridge)Marine Transmissions
Several manufacturers of marine gears offer marine transmissions through local distributors. Lubrication oil for the marine transmission can be cooled by an optional engine-mounted transmission oil cooler (certain engine ratings).Engine Service Life
Engine efficiency and maximum utilization of engine performance depend on the adherence to proper application guidelines and operation and maintenance recommendations. In addition, use recommended fuels, coolants, and lubricants. Use this Operation and Maintenance Manual as a guide for required engine maintenance.Expected engine life is predicted by the average power that is demanded. The average power that is demanded is based on fuel consumption of the engine over time. Reduced hours of operation at full throttle and/or operating at reduced throttle settings result in a lower average power demand. Reduced hours of operation will increase the length of operating time before an engine overhaul is required. For more information, refer to the Operation and Maintenance Manual, "Overhaul Considerations" topic.Aftertreatment system description
Illustration 2 g06031628
Caterpillar supplied aftertreatment components are illustrated with dashed line rectangles.
Selective Catalyst Reduction (SCR) catalyst technology is used to reduce NOx emissions and particulate matter.The aftertreatment system is composed of the following components:
Air compressor
Bulk Urea Transfer Pump
DEF Dosing cabinet
DEF Filter
DEF Mixing tube
DEF Nozzle
DEF Supply tank
SCR catalysts
SCR reactor housingEngine exhaust flows into the SCR System reactor housing through the exhaust inlet. Once sufficient temperature is achieved, the DEF is injected into the exhaust. Exhaust flows through a mixer assembly in the mixing tube to ensure that exhaust is not stratified for uniformity. This mixing will ensure complete disbursement across SCR catalyst section. Precise DEF injection is monitored and controlled by an electronic controller in the dosing cabinet. The following components provide signals to the controller to control DEF injection for emission reduction:
Thermocouple located in the reactor housing.
Inlet NOx sensor located in the exhaust before the inlet to the SCR catalyst reactor housing.
Outlet NOx sensor located in the exhaust at the outlet of the SCR catalyst reactor housing.When engine operating conditions dictate, DEF fluid is injected into the exhaust stream before entering the SCR. When injected into the exhaust stream, the DEF is atomized into droplets. The atomized droplets are then sent through the mixer. The mixer disrupts the exhaust flow and allows DEF to be distributed throughout the exhaust gas. Water evaporates due to the h