Engine Mounting Brackets
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| Illustration 1 | g00743329 |
Refer to Table 1 for the mounting dimensions for the engine mounting bracket. | |
| Mounting Dimensions for the Engine Mounting Brackets | ||
| Location | 3054 and 3054B Marine Engine | 3056 Marine Engine |
| (1) | 541.0 mm (21.30 inch) |
787.0 mm (31.00 inch) |
| (2) | 76.2 mm (3.00 inch) |
76.2 mm (3.00 inch) |
| (3) | 275.0 mm (10.83 inch) |
275.0 mm (10.83 inch) |
| (4) | 275.0 mm (10.83 inch) |
275.0 mm (10.83 inch) |
| (5) Dimensions of the slotted hole | The slotted hole is 36.0 mm (1.42 inch) by 17.0 mm (0.67 inch). |
The slotted hole is 36.0 mm (1.42 inch) by 17.0 mm (0.67 inch). |
The engine mounting brackets provide mounting points which are 76.2 mm (3.00 inch) below the centerline of the crankshaft. The engine mounting brackets are parallel with the centerline of the crankshaft. The brackets may be used to mount the engine directly to the engine stringer. Caterpillar recommends flexible engine mounts instead of directly bolting the engine mounting bracket to the engine stringer. The flexible engine mounts bolt directly to the engine mounting bracket.
The engine mounting brackets have slotted holes. This allows small movement of the engine for final installation. The bolts should be positioned at the end of the slots when fine adjustment is not necessary. This provides additional security in mounting.
Flexible Engine Mounts
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| Illustration 2 | g00743332 |
The dimensions that are shown are for a flexible engine mount with no load. (A) Centerline of the crankshaft (1) Minimum of 125.0 mm (4.90 inch) and a maximum of 137.0 mm (5.40 inch) (2) 4.0 mm (0.16 inch) (3) 140.0 mm (5.50 inch) (4) Engine mounting bracket (5) Flexible engine mount (6) Shims are used in order to achieve the correct dimension with no load. (7) 75.0 mm (2.95 inch) (8) 183.0 mm (7.20 inch) (9) Radially slotted hole | |
Flexible engine mounts are mounted to the engine mounting brackets. Caterpillar recommends flexible engine mounts for all applications. The flexible engine mounts reduce the transmission of vibrations from the engine to the hull. The flexible engine mounts also reduce the shock that is transmitted from the hull to the engine. This is true especially during severe weather. The engine should not be a structural part of the vessel.
The standard flexible engine mount should not be used when a transmission ratio of 2.5:1 is used. The standard flexible engine mount should not be used when extreme weather conditions are expected.
Engine Stringers
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| Illustration 3 | g00743334 |
(1) 690 mm (27 inch) minimum | |
There are many different types of engine stringers. It is difficult to have a guideline that is specific and universal. However, the engine stringer should be capable of supporting a static load of about eight times the weight of the engine.
The engine stringers should be connected together in order to give lateral rigidity. This will allow the propeller shaft to maintain alignment. Engine stringers that are connected together will also prevent unwanted forces from being applied to the engine.
To achieve a minimum distance for the length of the propeller shaft in a twin engine installation, a common center engine stringer should be used. Refer to Illustration 3. The minimum distance for the centers of the propeller shafts is 690 mm (27 inch). However, wider spacing is recommended for ease of engine service.