Cam Position?

[Greenthumb]

82' 185s. The cam itself has a mark on it, a small triangle mark. Which position does this need to be when the engine is tdc? I am not talking about the cam sprocket that has the o mark on top! The cam itself can be turned inside the sprocket 180 degrees then bolted in place. I was told that the lobes need to be facing toward the piston when the engine is tdc. My mark on the cam is on the opposite side of the cam when this is true. I will post a pic if I need to. Thanks everyone.

[Yamaha_Rules69]

Probably one of the most important things to mention first is - what machine is this work being done to? Does the cam sprocket have a mark as well? If so, I would think that the mark on the cam, and the mark on the cam sprocket should line up, if possible. Good luck!

[Greenthumb]

My bad its an 82' 185s. And there is a o mark on the cam sprocket that is to be lined up at the top mark on the cam cover when the engine is tdc.

Probably one of the most important things to mention first is - what machine is this work being done to? Does the cam sprocket have a mark as well? If so, I would think that the mark on the cam, and the mark on the cam sprocket should line up, if possible. Good luck!

[RodKnockRacing]

Cam lobes have to be facing down

[WilliamJ]

Remember that the cam turns at half engine speed, so at TDC the cam lobes could face down or up, and the piston will still be at TDC.

When the lobes face down they face away from the cam followers. The valves are fully closed (there will be a clearance) and the engine should have just fired. When the lobes face up both valves are slightly open together. No way the engine is going to fire then with no compression.

[Greenthumb]

I have seen the error of my ways. The cam was upside down. Runs fine now. Thanks everyone