Putting the heads on, worried about timing. Please help

[Z_Fanatic]

I've been watching this forum for well over 3 months and I've finally gotten around to posting. There's so much information on here I never really had to ask, just had to look. Anyways I've gotten myself into the nitemare of rebuilding a VG30DETT.

I finally got it back from the machine shop last week and I've started reassembly, here's my current dilemma. I've gotten one of the heads on all the marks on the crank and the drivers side head match up with the marks on the rear timing cover/oil pump when I went to go put the passenger side head on (already reassembled by the machine shop)The mark always jumps 2 inches off the mark, no matter how many times I rotate it. Now if I rotate it just enough to line up with the marks on the timing cover it leaves the valves open, I realize this could be a really dumb question to a someone who has rebuilt and engine before, I have never done this before and want to make sure all my bases are covered since I've spent way too much on this project already. I've taken some pictures to show you what I'm talking about.

You can see in image:1





Now here's the side that doesn't line up:

The reason I'm worried is because I had the heads taken apart and cleaned by the machine shop and one of the heads lines up perfectly as you can see without opening the valves. For the other side, the one thats out of alignment I have put into rotation and then stop about half way before they slam shut. You can see this below.



Is this right?!

Also, I've looked over all the tech pages on TT.net I'm hoping for some first hand information, not links. Thanks in advance!

[bimrtech]

First I want to say that it has been years since I last worked on a z32 this is from 5+ years memory. Everything looks ok. The cams snaps back do to the push from the valve springs. (Cam lobes opening the valves, springs pushing back.) I think I remember the gears and cams are keyed so gear cannot be installed incorrectly.

It is also ok that the valves are open. Please make sure that you did not put the heads down on a bench with the open valves facing the table. They could bend if they are sticking far enough out of the combustion chamber.

You could map out the valve opening/closing events via the fireing order to triple check that the intake and exhaust valves are open at the correct piston position.

From the pics, both valves are closed and the piston is at TDC on #1 The other valves will be open as they are in their appropriate stroke.

This is probably not the recommended way and I am sure others will have issue, but this is how I put the t-belt on these cars to prevent the cam from walking back. When installing the t belt, wrap electrical tape around the ends of needle nose vise-grips. LIGHTLY hold the belt to the cam gear on each gear while the gears are lined up with the cover. Easier to do than explain. This will hold the cam in place and prevent it from wanting to snap back.

After you get the belt on turn the engine over by hand with no plugs in it. (you will not have the resistance felt by the compression stroke)If a valve contacts a piston due to incorrect install, it will obviously stop and it will cause little or no damage compared to turning over via the starter. After 720deg of crank revolution (2 turns) the dots should all line back up. (cam spins 1/2 the speed ofthe crank) If they do not, you are a tooth or more off, or your belt is wrong. +-tooth count (Have seen this on DSM's)

[Z_Fanatic]

Thanks so much for taking the time to write that, I really appreciate it