Setting up cams

The foward intake cam om my carb'd 308 seems to have 2 timing marks on it, and they are truly both timing marks, not scratches. I'm not sure why, but things don't seem to line up correctly with either mark. What I mean is that the intake cam lobes should be 180 deg of the opposite exhaust cam lobes, but aren't with either timing mark. Ideas?

 

Need a little more info here. When you have both valves on #1 cylinder closed and the high lob of the cam sticking straight up where is the mark on the cam.

 

with engine at TDC, #1 piston intake points right and exhaust points left, however, the double marked cam is on the foward bank, and # 8 piston intake points either left or slightly higher depending on which timing mark is chosen, while the #8 exhaust points down.

 

Alternatively, if anyone has a picture of the 5-8 cams lined up, I could work off that by seeing where the lobes are pointing.
Vince

 

Bring engine to TDC PM5-8 and you will have the same situation where both exh and int valves are closed and cam lobe points straight up. Then check for mark.

 

which cylinder's cam lobes should point up?

 

With the engine on TDC for #1 cylinder, all cam marks should be aligned with thier register marks. Only #1 cylinder, on the rear bank, will be at TDC on its compression stroke all others will be in varying degrees along thier four cycles. #8 in particular would be 5 pulses behind it, or 3 before it.

I too was a bit confused when I began working on my car, I also somehow felt the front bank should be timed differently. What I am more concerned about is your having multiple marks on your one cam. There should only be one mark. But generally, all four cams should be on thier marks with the crank at TDC for #1, rear bank. Do you have a pic of that cam?

If you are really unsure of your valve timing, you can degree wheel the engine.