Usage:
3500 Series Marine And Industrial Engines
Reference: Engine News, this issue, the article "Correct Location And Rotation Of Front Timing Gears"; Engine News, April 1985, Page 18, the Supplement to the Service Manual: 3500 Series Engine Disassembly And Assembly Modules; Engine News, May 1985, Page 4, the article "New Camshafts Used In SAE Standard (CCW) Rotation Engines".
In some applications it may be desirable to change the direction of rotation of an engine. The following procedure and illustrations can be used as a guide to change the direction of rotation of a 3500 Series Marine or Industrial Engine from SAE Standard Rotation (CCW when viewed from the rear) to SAE Opposite Rotation (CW when viewed from the rear) or vice versa.
Procedure To Change The Direction Of Rotation Of 3500 Series Marine And Industrial Engines
1. Use the Service Manual procedures and observe the notes and notices as the direction of engine rotation is changed.
2. Remove all rocker arm assemblies before removing the rear gear train.
NOTE: To avoid damage to the valves, do not install the rocker arm assemblies until the engine has been timed.
3. Remove the crankshaft. Turn the crankshaft end-for-end and install it using new 1W6974 and 1W6977 Crankshaft Seals as shown in Special Instruction Form SMHS8000.
4a. To change the direction of rotation of any engine shown in Chart A, the camshafts must be changed end-for-end and bank-to-bank as shown in Illustration 1.
Illustration 1. Change camshafts end-for-end and bank-to-bank.
4b. To change the direction of rotation of any engine with SAE Standard Rotation shown in Chart B, the camshafts that do not have a tapered end must be replaced (see Illustration 2). Change the other camshafts (with tapered ends) end-for-end and bank-to-bank as shown in Illustration 2.
Illustration 2. Camshaft arrangements for later engines.
5. Change the flywheel ring gear, as needed, to obtain the correct direction of rotation.
6. Use the Service Manual and the Reference Articles to time the camshafts.
7. On 3508 Engines only, refer to the Balancer Group section of the Service Manual, and align the marks on the balancer and crankshaft for the correct direction of rotation.
8. On earlier engines equipped with a mechanical (gear driven) service meter, install a correct (rotation) service meter.
9. Changes must be made to the front gear train of the engine when the direction of rotation is changed. The article "Correct Location And Rotation Of Front Timing Gears", in this issue gives additional information about changes to the front gear train.
NOTE: The accessory drive gears and the auxiliary drive gears must always rotate in the same direction, regardless of the direction of rotation of the engine (see Illustrations 3 and 4). Unless additional attachments are added to the engine or the governor is changed to the other side of the engine, no new parts are needed to change the front gear train.
Illustration 3. Front gear train with SAE Standard Rotation.
Illustration 4. Front gear train with SAE Opposite Rotation.
10. If the engine is equipped with an engine reversal protection device, it must be changed to operate in the new direction of rotation.
11. Install a starter that is correct for the direction of rotation of the engine.
12. Install the push rods and rocker arm assemblies.
13. Use the procedure in the testing and adjusting section of the Service Manual (Form SENR2352) to adjust the valves and the fuel injection timing.
14. If the location of the governor was changed to the opposite side of the engine, reset the rack and adjust the injector synchronization.