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Discussion Starter · #1 ·
I'm not sure if I have a problem here, perhaps someone who has done a timing chain recently can help.
Following Haynes and Quasimotor, I set the flywheel on 0 degrees, lined up the notch on the exhaust cam with the notch on the bearing cap, set the line on the exhaust sprocket perpendicular with the head and fitted the chain nice and tight.
They both say that you need to fit the intake pulley next and put the chain over it, ensuring that it is taut between the sprockets.
The only way I can get the intake cam lined up (notches matching, line perpendicular) is to turn it against the valve spring pressure. If I let go, it moves towards the exhaust cam (if you see what I mean).
This means that I have to use the chain tensioner to maintain tension between the two sprockets. Is this right? Or should I be able to get the chain taut between the sprockets BEFORE I fit the tensioner?
Oh and before anyone asks, it runs a bit rough, yes, but that could be a number of things!
Any input appreciated, thanks.
 

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I'm sorry if this is not of help, but what if you just maintained the intake camshaft in the position the notches are matching, then drop the chain onto the intake sproket, then let the camshaft turn? Yes, the chain between the two wheels would be loose, but, when the tensioner is in place and tight, everything should be timed. I don't see why the chain should be taut between the sprockets before installing the tensioner.

Sorry if this makes confusion.
 

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I don't really think it matters how you do it, jaut so long as you have the correct number of links between the sprockets, and it's still timed to 0 degrees after you've manually turned the engine over twice.

Andrew
 

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Discussion Starter · #4 ·
Thanks for the replies. What Stefano says is basically what I did, and the timing seems OK.

It was just that Haynes etc seem to make a big thing of the chain being taut between the sprockets.

Incidentally, the old chain was in reasonable nick but the sliding guide rail was totally shot- the chain had chainsawed two deep grooves in the metal (in 89000 miles) - and the replacement rail is plastic


Anyway, I'll cross timing off my list of rough-running possibilities. Thanks for your help.
 

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It was just that Haynes etc seem to make a big thing of the chain being taut between the sprockets.
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I think that the chain HAS to be taut as long as the notches are matching, if the chain doesn't jump a tooth when the valves spring turn the shaft then it's no problem.
 

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Discussion Starter · #7 ·
Andrew, yes, that's exactly how it looks before I drag it taut with the tensioner.

So what it means is that you can't get the two cams lined up until the tensioner is in and tight - always useful to know.

Thanks to both of you for your input!
 

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Is the replacement chain you are using a genuine SAAB one or a pattern part?, if it's a genuine one then there should be 3 yellow painted links on it which line up with the timing marks on the cam pulleys and the crank pulley ensuring that they are in the right place, hope this helps.
 

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Discussion Starter · #9 ·
Dazzel, it was an ECP aftermarket one I'm afraid, so no bright or painted links.

There are 15 pins in the chain between the cams, though, which I believe is correct.

What I was concerned about was that I was using the tensioner not to take up the slack between the intake sprockets and the bottom sprocket but to hold the intake cam in position against the pressure of a valve spring, as well.

If, as everyone says, that is correct, and at TDC the intake cam is pushing a valve spring down, then fair enough. I'm afraid I don't know enough about multivalve engines to understand the mechanics of it all.

Thanks for your input.
 
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