Where should the cam be for TDC I took the head apart without marking it. I have heard that the two front lobes should be pointing straight up, but that makes no sense being as the lobes are on different points on the cam. Where should I put the cam to line up for TDC? Is it possible to get the head 180 degrees off? im doing a head gasket do you guys have any tips for me, this is my first time tearing apart an engine?

1982 280zx

l28 engine

f54 head

Ryan

When folks say that the lobes should be straight up, they mean that as a pair they should be as upwards as possible -- think Mickey mouse ears

Except straight up would be both valves open. Really you want the cam lobes pointing down. There is a timing mark for the camshaft that will take all the guesswork out of this. If you don't already have one, go get a Haynes or Chilton and they'll have the mark in their instructions on timing.

Except straight up would be both valves open. Really you want the cam lobes pointing down. There is a timing mark for the camshaft that will take all the guesswork out of this. If you don't already have one, go get a Haynes or Chilton and they'll have the mark in their instructions on timing.

Watchu talkin' bout Willis? If the lobes are pointed skyward, that means they're not pushing the valves down and therefore they are NOT "open". Remember this is an OHC(overhead cam) engine. I know you know this stuff. Am I missing something?

Except straight up would be both valves open. Really you want the cam lobes pointing down. There is a timing mark for the camshaft that will take all the guesswork out of this. If you don't already have one, go get a Haynes or Chilton and they'll have the mark in their instructions on timing.

HOLD IT ! THE LOBES MUST BE UP N O T DOWN!! If the lobes are down then the cam will NOT BE A TOP DEAD CENTER . Gary

Holy smokes boys... This guy asked for help and he got all kinds of answers. I am not an expert but I have changed 50 cams in my lifetime, all Datsuns. I just remember to make certain the #1 cylinder is at TDC (cam lobes up) and the timing mark at "TDC" on the front pulley. If you are 180 degress out, the cam lobes will be down. (Look at #6 when you have it on TDC... Cam lobes are down)

REMINDER: Don't forget to put a chain tensioner device in place.

Holy smokes boys... This guy asked for help and he got all kinds of answers.

Zsaint this guys had 4 correct answers and 1 rather strange and uncharacturistic reply from JM -- hardly as you would put it "all kinds of answers"

I guess I thought this guy needed more info then "the cam lobes must be up". If the head is off, then he needs to know about the 'V' mark in the cam and the mark on the front cam retainer. I hope he also marked his chain on #2or#3 mark before he removed the sprocket. He may be past all of this and will need some help putting the head back on and getting the cam timing correct. Maybe he will come back with more info.