Note: Do not operate the engine if a misfire condition exists. Operating the engine in a misfire condition will cause engine imbalance and lead to engine and or coupling damage if not corrected.
Observe the gauges frequently while the engine is operating. Record the data from the gauges in a log regularly. Compare the data to the specifications for normal engine operation. Comparing the data over time will help to detect changes in engine performance.
Investigate any significant change in the gauge readings. Monitor the engine operation so that problems may be quickly corrected.
Operating the Engine and the Driven Equipment
Check the gauges and the driven equipment frequently while the engine is operating under a load. At certain ratings, the engine can be operated for extended periods of time at full load.
Extended operation at reduced load (less than 30%) may cause increased oil consumption and carbon buildup in the cylinders. Extended operation at reduced load may also cause fuel to slobber through the exhaust system. This fuel slobber and oil consumption can result in either loss of power, poor performance, or aftertreatment system damage.
To maintain engine efficiency and performance, apply a full load each hour or operate the engine at a load level greater than 30%. These actions will burn excess carbon from the cylinders.
Note: Do not idle the engine for longer than 12 hours without fully loading the engine. Loading the engine will burn off excess hydrocarbons in the aftertreatment system. Failure to load the engine could result in damage to the aftertreatment system and result in thermal events (explosion, fire, and other events).
If the engine idles for long periods of time or operated at low loads, severe aftertreatment system damage can occur.
To maintain engine efficiency and performance, apply a full load each hour or operate the engine with a greater load if possible. These actions will burn excess carbon from the cylinders and clear contaminants from the aftertreatment system.
Table 1 lists the ratings for 3500 Marine Engines and the corresponding rated rpm. Table 1 also lists the engine rpm that is suggested for optimum fuel efficiency. For data regarding a specific engine, consult your Caterpillar dealer.
Table 1 assumes the use of a fixed pitch propeller. If the vessel has a variable pitch propeller, consult your Caterpillar dealer for information on marine engine performance and reduced engine rpm.
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Operating an engine above the engine's rating will reduce the service life of the engine before overhaul. |
Note: For the definitions of the engine ratings, see this Operation and Maintenance Manual, "Engine Rating Definitions" topic (Reference Information Section).
| Marine Engine Ratings and Suggested RPM for Cruising | |||
| Rating | Time That Is Allowed At Rated Power | Rated RPM | Suggested RPM for Cruising |
| “A” | 100% | n/a | n/a |
| “B” | 80% | 1200 | 1150 |
| 1600 | 1520 | ||
| 1800 | 1700 | ||
| “C” | 50% | 1200 | 1110 |
| 1600 | 1450 | ||
| 1800 | 1620 | ||
| “D” | 16% | 1800 | 1600 |