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Discussion Starter · #1 ·
Hey guys, I just came in from putting the head back on my short block, and I'm a little confused as to the cam timing chain alignment. I put the cams in with the chain and tensioner on and put a few cam caps on, including the rear one with the timing marks. After releasing the tension on the chain tensioner and turning the cams via a ratchet on the exhaust cam gear bolt, I noticed that when rotating the cams clockwise as I believe they're supposed to, when the timing marks on the cams come up, the exhaust cam is a little more advanced than the intake, partially due to the load on the intake cam pulling the bottom of the chain tight and pulling the spring (bottom) side of the tensioner up. If I rotate the cams past tdc marks, then back them up, it pulls the top of the tensioner down and the marks line up perfectly. I think even one link different would throw it way off, though to be honest I haven't tried. Under oil pressure, is the tensioner constantly fluctuating? Obviously is i suppose, but how much? What about the idea of 16 rollers between the top tips of the cam gears? Can I safely go by that and ignore the half-mark discrepancy?

This first picture is the exhaust cam when rotated around clockwise and paused on the timing mark.

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The second picture is the intake cam at the same time.

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The third is a picture of both when rotated past the marks, then backed up, hence compressing the top of the chain tensioner and lining up the marks perfectly.
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no
 

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The marks need to line up with the CCT extended at the top. If they don't the chain is off a link.
This should show how they are lined up:
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Discussion Starter · #4 ·
PZ.
Thanks for the diagram. As Tomvw said, I thought I was only set at 15 rollers, but I wasn't sure how exactly I was to count them as straight up on one side was in a valley on the gear. Ill definitely have to change that then.
 

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The third is a picture of both when rotated past the marks, then backed up
That is a no-no. DO NOT go the opposite direction.
Turn the crankshaft clockwise only when checking the timing marks.
 

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Discussion Starter · #6 ·
Ok guys. I corrected the cam chain timing, torqued the cam caps, installed the valve cover and did the timing belt. Now it suddenly just struck me, do I need to put silicone under the front cam cap? The wide one that goes across both cams? Its the outside sealing surface between the two cam seals. Do I need to take it apart and put silicone in there?
 

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You want to put silicone along the RED lines. But use it sparingly!! A line about as big as what is in the picture nothing more.
You also have to keep silicone from getting into the notches (blue arrows).
The notches (blue arrows) are what allows oil to get to the back side of the cam seal and lubricate it. If those notches get blocked off the seal will run dry and get torn/ripped = oil leak.

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Discussion Starter · #10 ·
Kinda glad I caught it now. I've got silicone on the valve cover gasket so that'll be a pain to take off and clean up again but it'll be easier than finding out the hard way. It never really crossed my mind that that was a exterior sealing surface until I had it all together and was looking at it.
 

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At least you caught it before buttoning up the whole project and then finding out weeks later when you've got fresh oil laying on the driveway.
Nothing like doing a job on the engine only to create a new oil leak. :unsure: I've been there in my early days.
 

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Kinda glad I caught it now. I've got silicone on the valve cover gasket so that'll be a pain to take off and clean up again but it'll be easier than finding out the hard way. It never really crossed my mind that that was a exterior sealing surface until I had it all together and was looking at it.
why all the silicone? only need in the gaskets corners
 

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why all the silicone? only need in the gaskets corners
Good point. Gasket sealer is not needed / recommended on the valve cover gasket.

Only a small dab of silicone is needed in the 4 corners (red circles).
The valve cover gasket kit has a piece of paper along with it specifying these locations.

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By the way, this is the V6 engine I rebuilt for my wife's car 6 years ago.
No silicone except in the specified areas, ZERO oil leaks after 6 years of hard service.
 

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Discussion Starter · #15 ·
Not sure why I didn't get notified with regards to the responses in this thread but whatever. Yes, the only place I put silicone was the four corners. I've been in Guatemala for the last week so just got back to it today. I took the valve cover off and sealed up the front cam bridge and reassembled everything. After throwing the new exhaust manifold on, (high flow manifold from UroTuning) which was an absolute pita to tighten the top nuts, and hanging the trans, I stuffed it back in the car. Now to hook it all up. I already ran into a memory issue with regards to where the wire off the starter goes. It goes on the same post as the positive from battery, and it goes around the back of the engine and hooks somewhere on the other side. Nothing makes sense as its a power wire and nothing over there needs that much juice as I recall. Anyone know off the top of their head? If not, I'll have to quit being lazy and look it up😀
 

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Discussion Starter · #16 ·
Well, I found a great pdf wiring diagram. Turns out I'm a slow-brained guy. As you may have guessed, it goes to the alternator for the charging circuit. Yup, I'm not that bright sometimes.
 
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