97 mercruiser 5.7 timing marks 180 degrees out for motor to run

[jlamb2]

normally i would expect the crank/camshaft marks to line up with each other at their closest point. the rotor button would be pointing to the number 1 spark plug. (engine will not run)
what i have is, the cam timing mark must be at the 12 o'clock position and the crank mark also at the 12 o'clock position.
the rotor now points to number 6 plug (on the cap) but actually home to the #1 spark wire. (engine will run here, but poorly)

whats up with the timing?

 

[bruceb58]

recheck your firing order.
1-8-4-3-6-5-7-2

Distributor rotates clockwise.

 

[Bt Doctur]

you line up the dot on the crank gear and the cam gear, then forget about them.
rotate the motor until the #1 intake valve opens and closes, continue to rotate motor until timing mark is at "0" on the timing tab.
you now have #1 cylinder at TDC compression stroke, install dist with rotor indexing on the #1 plug position in the cap.

 

[NHGuy]

Yes, to put it another way, after you line up the dots you THEN find top dead center. The dots just get the cam and crank synched, it's not TDC. I did that same thing you did. If you are installing your cam using the Mercruiser manual it's an easy mistake to make. The Merc manual is not very forthcoming about finding TDC after aligning the dots.

 

[Bondo]

Ayuh,... Agreed,.... Cam timin' has Nothin' to do with ignition timin',.....

 

[alldodge]

normally i would expect the crank/camshaft marks to line up with each other at their closest point. the rotor button would be pointing to the number 1 spark plug. (engine will not run)
what i have is, the cam timing mark must be at the 12 o'clock position and the crank mark also at the 12 o'clock position.
the rotor now points to number 6 plug (on the cap) but actually home to the #1 spark wire. (engine will run here, but poorly)

whats up with the timing?

Agree with above and will add, that when the marks are both at 12 o'clock the rotor would point to number 6 which is 180 degrees out. The cam rotates once for every two rotations of the crank.

 

[Bt Doctur]

Alldodge, that's the pic I wish people would forget about.Always confuses the new mechanic. When you install a cam you line the dots up , put the cover on, and forget it. Those dots have no bearing on anything .Besides ,why would you be installing a dist in a motor that's not even put together yet and triyng to set the timing.? with the harmonic balancer installed, rotate the motor until #1 intake opens and closes, then slowly rotate motor until timing tab has "0" ,install dist with rotor pointing to #1 in the cap