I think I asked.
Now I do wonder: was this bracket fitted to his engine and can the chain actually slip here? Just seen that it appears to protect from that scenario… something would need to be wrong.
Um… is the lower chain intact? The drive?
I hope so because Lou had a similar issue with his XJ didn’t he - more photos and maybe a video (doesn’t have to be much) would help clear things up a little more.
Phillip, I believe you mentioned that you were trying to line up the two bolts that attach the sprocket to the cam shaft. Any chance since you do not have both bolts inserted into the cam shaft that one of the cam sprockets has actually dropped down too low and not centered on the cam shaft?
Tom
Lou was miles out on several aspects, more than once, and damaged a lot of valve gear as I recall? I asked in the end if he ever got the head on and running but don’t think I got a reply…
The upper chain cannot in my opinion be fitted over the two fitted cam sprockets end be slack enough slip on the lower twin sprocket, no matter how slack the adjuster is. There is too much wrap-around. He may not have fitted the cam sprockets so the verniers engage but even then the chain would move round and the cams be static.
Is that what the 4.2 aluminum timing carrier cage looks like, with 3 plates? The 3.8 only has a rear plate and a front plate.
Oh okay. Yes, this is the back of the 4.2 carrier.
Lou was miles out, that is true. Still no idea what it was…
The sprockets are a positive enough fit and my picture is good enough (at least something) to show that it really is rather unlikely that slack in the upper chain leads to slippage.
Please give us a video or a dozen photos.
My bad, I though it was a front view, but that’s not possible since the upper chain is in the foreground.
I googled and they look similar, the 4.2 only has two cast aluminium plates but it seems like the sheet metal bracket was different. Wonder why? It does look like something to keep the chain in place but it doesn’t make much sense.
I’m under the impression the OP stopped turning the crank when he noticed no camshaft sprocket movement. If he turned the crank more than 15 degrees or so he may have pranged valves but since he’s being observant he will have stopped turning the crank before then. Otherwise another conversation.
These are original chains and sprockets as I understand it. The cam sprockets are not going to move perfectly in sync with the crank if there’s slop in the outer run of the upper chain. The inner gear of the intermediate sprocket will turn until it takes up the slack in the chain before engaging it.
As you surmise David, the strap stops the the top chain disengaging from the intermediate sprocket when the cam sprockets are removed. Can be fitted to earlier engines.
Edit On the early engines. the bottom chain top damper served the function re the disengagement of the top chain, but when the bottom chain top damper was repositioned to the two bosses on the block a retainer was required. I recall
that the early version of this retainer is a flat link that utilizes the two set screws under the intermediate sprocket , then changed to the strap shown in photo.
I am not sure how to respond to above posts except for two cases. Some suggest pictures or video but I can’t see how this will help much as the problem is pretty basic. I turn the crank and the top chain and sprockets do not rotate.
This leads me to Nick Saltarelli’s post. I think he is saying that because I only turn the crank 30 degrees or so, then the slack or play in the old top chain doesn’t result in its rotation.
But he acknowledges that if I turn the crank more - and the cams don’t rotate - then I will damage the valves.
So what do I do? Crank more and trust that the cams will start rotating before crashing a valve? Would you take that chance?
Yeah I did that once. Only took me a few days to remove the head and replace the bent valve. Is there any possibility that you can get an experienced local jag guy to check it out with you?
Hi Phillip…the bottom line is that as soon as you turn the crank the camshafts should move…irrespective of the tensioner position…slack or tight …lets go back to basics… you had the engine apart and just reassembled it… so you now need to backtrack…dont try to turn the crank if the cams arnt turning…Steve
As much as a pain it is to backtrack in a build, I think to be on the safe side the head should come off, and then you can turn the crank as much as you want without any dramas - the timing chain assembly can stay in place and you can witness all of the chains and sprockets interact. Jon.
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I think you should post as many photos as possible. The cams, the sprockets, the chain, looking down at the chain, etc. Obviously no one can say what the issue is, as it is still not solved. But since you have not solved it, give the rest of us a better chance with photos. Most here I believe are having trouble as to how this chain could be that loose that it totally drops below the intermediate sprocket and does not even try to engage. It seems very implausible someone else went to the effort to replace the chain with one that was too long just for kicks. Can you reach down along the chain with a hook and grab and lift the chain to see how much slack there is? How have you moved the eccentric adjuster? It seems to me if all the slack is hanging at the bottom of the chain and you simply try to adjust the eccentric, you will not be able to gather that lower slack with out moving one of the cams/sprockets. Since you have or had a bolt in the sprocket to cam, that means the cam will have to turn. What if you remove the bolts from the sprockets so the sprockets can once again turn, then adjust the adjuster to take up the slack?
Edit, and if has not been said enough, do not turn crank without the cams, or cams without crank
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We don’t know yet if the bottom chain is moving. Peter C hinted at this possibility. Whatever is going on I agree with the suggestion to remove the head as a start.
I had that happen once. Crappy old engine in a crappy old MkII that someone wanted to bubble gum together.
Didn’t end well.
We all want a video because if everything was in place it would work and we can’t check it out in person, so it might be something obvious. And Phillip said the lower chain turns.
Unless of course it doesn’t 
‚Bubble gum together‘ 
Good point, have you actually verified somewhere that the intermediary gear set is actually rotating?
Yes, but we can only go by what Phillip says. He said very early on that the chain does turn. Unless he was assuming.
Tom