Expert: Waheed Shittu - 10/23/2009

Question
QUESTION: Do I have to move the timing letters a, b,and c 360 degrees for each valve setting? Making a total of 6 moves.

ANSWER: No Felix. you need only two revolutions to complete the setting of the six cylinders.
If you start from A 1-6 vs you will adjust the corresponding injector and valve. Then move to B 2-5 vs and do the same, then to C 3-4 vs as well. you would have completed adjust on 3 injectors and three set of valves. You will move to A 1-6 vs on the second revolution to complete the remaining 3 cylinders of injector/valve setting.

You cannot adjust on TC (Top Dead center) mark, only on the vs marks.
If you still need further clarifications, pls. let me know.

Cheers.

---------- FOLLOW-UP ----------

QUESTION: Are the cylinders 1,2,3,4,5 and 6 or 1-6,2-5 and 3-4? This is a n-14 plus cummins engine.

ANSWER: Cylinders in a 6 cylinder engine are numbered 1,2,3,4,5,and 6 from the front of engiine to the rear.
However, for the purpose of setting the valves and injectors, Cummins arranged the adjustment points in the order 1 and 6, 2 and 5, and 3 and 4 VS (valve setting points) These cylinder pairs have pistons that move together in accordance with the con rod journals arrangement of the crankshaft. i.e. Both pistons 1 and 6 are reciprocating in the same direction at the same time although on different strokes. For instance, as a 4 stroke cycle engine, if piston no 1 is on intake stroke, piston no 6 must be on compression stroke and vice versa. Same for the other remaining pairs in accordance with the standard firing order for N14, i.e. 1-5-3-6-2-4. this denotes the order at which injection and firing occurs in the engine assy.

Should you require further clarifications, pls. don't hesitate to write.

Regards,

---------- FOLLOW-UP ----------

QUESTION: Let me make sure I have it right.  Adjust s follows:
Valve  Injector    Valve    Injector
A-1      6          6         1
B-5      2          2         5
C-3      4          4         3

Is this correct waheed?
Thank you verry much.

Felix

Answer
No, pls find the correct order:

Vs Mark       Injector      Valve
A 1-6 VS         3          5
B 2-5 VS         6          3
C 3-4 VS         2          6
A 1-6 VS         4          2
B 2-5 VS         1          4
C 3-4 VS         5          1

The above simply means that if you rotate engine and the mark corresponds with A, you will ensure that both valves for cyl. No 5 are closed. i.e. push rods free. Then you can adjust injector No 3, then you can proceed to adjust valves No 5. If both valves are not closed on cyl. No 5, then valves No 2 will be closed and will be ready for adjustment, then you can adjust inject No 4. (Note that you will encounter the timing mark A,B,and C two times to complete the adjustment sequence).
Regards,