Refitting the timing chain...

[anutz]

So I am putting my cylinder head back on....and have hit the first real issue...

The camshaft chain...

The issue is I cannot get the marks on the cams to line up 100% with the marks on the camshaft caps...

I tried several times last night and each time they were slightly off :eek

I need to consider what is causing it - I don't have the pictures I initially took of them due to my phone failing....so having to assume the always were spot on...

As a warning as well I have had the timing chain drop off the crank sprocket initially as when I put in the Exhaust timing guide it knocked it off - that's sorted now! :lol

My process is:

1. Set Piston #1 to TDC using Socket on the flywheel
2. Hold Exhaust side of Timing chain tight and place Exhaust Camshaft in place,
3. Seem to be able to always get it spot on BUT then the chain shifts it over as it engages with it about a 1mm
4. Keeping it tight I then feed the Intake Cam in - seems to be spot on

So I suppose I need to consider

1. Was it ever spot on
2. How much tolerance is ok - I assume non
3. Could it be the chain
4. The manual says take the sprockets OFF the cam slightly whilst adjusting and mesh them with the chain, issue is due to the way the fixings are graded i.e. distance between them I suspect this would make it worse

Adding pics so you can see what I am on about...

[Jules-C]

If it's within 1mm you're OK.  If you got it wrong you would be 1 tooth or more out which is a lot more than 1mm

[anutz]

here we are

[Paulfzs]

that looks fine to me, fill the hole make a new one in line with the arrow it wont bother you then

[anutz]

I will get my drill - you have seen how accurate I can be with that  :rollin

[rhinoeli]

Correct chain pitch? You can check against the old one.

[anutz]

hi, sorry this is the original chain, I have not replaced it, just had the cylinder head off....so its in the process of being put back on...

[rhinoeli]

oh ok


On the photo you attached the camshaft cap bolts are not in place. I think they should be... (?)
If the chain is tensed between the two sprockets, the marks should align near perfectly.

[Paulfzs]

I will get my drill - you have seen how accurate I can be with that  :rollin

good point..


get a sharpie and a lazer level.

[Jules-C]

The exhaust one does look a bit out. Have you tried moving it round by one tooth and see if it looks any better?

[anutz]

just re-done them both, looks a little better, will add a photo....but now I have slack in between the sprockets, but there is no way I can avoid that - tried all sorts...

might end up taking the cam sprockets off whilst the cams are in and rotating them around....Its the only other variable I have...

[BBROWN1664]

Check to see if you are 360 degrees out.

TDC on each cylinder appears twice for each time the valves operate.

[anutz]

So alignment is good...but look at the chain lol

I cannot keep it any thighter when I install the Intake cam, issue is that piston 2 cam lobes are pushing down on the valves so once its bolted down there is slack available...



if I pop my finger on to the tensioner at the back of the engine it does take up this slack...will rotate 360 and see what happens, might be the wrong part of the chain

[paulchucky]

i know it sounds obvious but have you taken the chain adjuster out completely
then tried to set the timing 


then re-install the adjuster 

[anutz]

its out and I have not put it back in yet....

looking at the manual I do that once I have things set up to - I figured with all the slack In between the sprockets there was an issue there first to fix...?

[greenman]

How Many miles has it done? Just thinking, high mileage, stretched can chain, maybe, would set things slightly off.

[anutz]

18,000

Will have another go a little later over the weekend, not go much free time coming up so its going to be stood for a while....

Issue I keep having is simple dealing with the lobes that will be tightened down on to open valves, changes the tension on the chain no matter how taught I keep it...

Most likely needs the sprockets mobilising whilst on the shafts so I can rotate either component and position the marks ok else rotate the sprockets to take up slack...

[thunderpantz]

I had this problem. What you'll find is that because of the slack in the middle of the two cams, when you wind the crank round one/or both or the cams will go out of time. Took me bloody yonks!

[anutz]

was it just trial and error or was the are process you could use to sort it - do you think the idea about the sprockets would work?

It always was a rattily engine to be honest, even @18000 miles always had rattles

[thunderpantz]

I can't remember exactly but i know it involved a lot of bloody swearing. I think i ended up having to set both cams to "1 o'clock", wound the crank a couple of times and the were spot on. Its all about getting rid of that slack in the middle though first before winding.


Where abouts are you based chap?