Setting timing TDC on compression or exhaust cycle
 

Hi.

I'm setting the timing on a 2002 Durango 4.7 V8 after replacing guides and tensioner.
Haynes manual says TDC on exhaust cycle???
Doesn't that have to be on compression cycle?
I'm confused.
Any ideas?

Thanks.

That was a Mercedes Designed engine if I remember correctly, so who knows about the timing? I’d look for another source of information Because it’s always been number one on intake.

I think it doesn't change anything. The crank rotates twice, with TDC coming up twice on every revolution of the valve timing. Setting it after the intake is opened and the piston is at TDC, you'll see after a full crank rotation it comes up TDC after the exhaust valve is opened. I don't know if that helps with your question. When i would set TDC after replacing a timing chin I would have the crankshaft alignment mark at 12 oclock with the camshaft sprocket at 6 oclock with alignment holes almost touching. Some, and one a very experienced guy would set the crankshaft dimple or mark at 12 oclock and the camshaft gear dimple at 12 oclock as well. My way was set on compression and the more experienced guy set his on exhaust. They both worked.