How to set timing for Duratec 1.6 Petrol engine

[LTIronWolf]

I'm changing the timing belt on my Mk2 Focus and I've lost the timing as the exhaust camshaft's sprocket loosened while I was trying to undo the crank pulley bolt. While I was turning over the crank, the inlet camshaft rotated while the exhaust camshaft did not, so I have no idea what my timing is. I have the locking pins for the crank, and I have the bar that locks the cams as well but unfortunately I've bent (along with damaging the end on my inlet camshaft) it as I accidentally left it locking the cams while I tried to undo the crank pulley.

I think I've got the cams set correctly, as the inlet cam is currently set to just about open Cylinder 1's valves, and the exhaust cam is 180 degrees out of phase with the inlet cam, i.e. after 180 degrees of rotation, Cylinder 1's exhaust valves will open. The two timing grooves at the end of each cam are slightly staggered and will not accept a locking tool, which I think confirms that the cams are correctly timed with each other.

What I'm now unsure of is how to correctly set the crank relative to the cams. As the cams are currently set to begin the compression cycle on Cylinder 1, it's my understanding that the crank needs to have Piston 1 be near the bottom, ready to move upwards and compress rather than be at TDC. Is this correct? Annoyingly, non Ti-VCT engines don't have any timing marks on the cam sprockets or the crank pulley, so you can't simply line up the timing using these indictors.

 

[JW1982]

There is a chance that by rotating the crankshaft without 1 camshaft turning you already damaged 1 or more valves. You should check the valves and pistons for any signs of interference damage.

If no signs of interference are found proceed with the following procedure:
 

Install the timing pin inside the engine block and rotate the crankshaft clockwise until the crank touches the timing pin. Now that the crankshaft is at the correct position install the flywheel locking tool to lock the flywheel/crankshaft.

Rotate both camshafts in the correct position.

     

Note that the slots in the camshafts are out of center. The camshaft locking tool can only be inserted one way (when the slot is fully horizontal in the upper position).

Once the crankshaft and both camshafts are timed correctly the timing belt can be installed conform the instructions. Note that to tighten the camshaft pully's a camshaft pully holding tool is required. 

 

 

 

[JW1982]

I suspect that you only have a part of the special tools that are required. If this is the case you should get all required special tools before proceeding.

[LTIronWolf]

@JW1982 So just to confirm I understood this correctly, the crank is correctly aligned when it contacts the locking pin, and the cams are correctly aligned when the cam locking tool can be inserted?

[JW1982]

That is correct.

[LTIronWolf]

I think I've now set the timing correctly. I found that in all rotations where the cams are horizontal, that the grooves designed for being locked in place were always a bit offset - the inlet cam was a bit too far clockwise, and the exhaust valve was a bit too far anticlockwise. Regardless, I left the cams resting (no valves open) just after springing up from the previous stroke.

Cylinder 1 is about to open on inlet (with exhaust 180 degrees later) and the crank is locked in place (couldn't turn clockwise any more with the pin in) while currently down but on its way up in the compression cycle. Belt + tensioner replaced and crank pulley bolt torqued to spec, with the engine turning over by hand as before - here's hoping I got the timing correct.

[JW1982]

The slots in the camshafts needs to be perfectly aligned. An offset is not permitted. You need to loosen the camshaf pulley bolt, adjust the camshaft pulleys until everything is perfectly aligned and fasten the camshaft pulley bolts.

Since all pulleys are keyless it is very easy on this type of engine to have the crankshaft and both camshafts perfectly aligned.

Note that both the crankshaft pulley bolt and the camshaft pulley bolts are torque to yield bolts. These bolts can not be reused and once removed these bolts must always be replaced.

[LTIronWolf]

To any future readers:

I managed to successfully set my timing, but my original setting was not correct; I had set my crank correctly, but not my cams. Wilco's instructions were correct, so I ultimately used his instructions to set my timing. As the timing groove was broken on one half of the inlet cam (due to stupidly leaving the cam locking tool in while trying to crack open the pulley bolt 😬), I had to very carefully check the alignment on said cam.

I had my cams set up based on their 4 different spring-loaded positions - each turning of the camshaft will have 4 different positions 90º apart, due to the spring loaded valves. Using the crank pin, this will position the crank in a position where Piston #1 is at the bottom and on its way up. What I thought was the correct setting was to simply have the cams set based on what I call the spring loaded values. The inlet valves were set to just about open on Cylinder #1 (where they will rest after a spring loaded value when turning over the cams by hand), with the exhaust port 180º degrees later also on spring loaded value.

However, the way I set up the cams resulted in the cam locking grooves at the end being staggered - they were close to the angle they needed to be in order to use the tool, but both were slightly staggered, so the tool wouldn't fit. While my logic was sound, the problem is that the crank's position was designed for the location of the grooves, rather than using logic and knowledge of the 4-stroke cycle. In other words, my method would have worked if I knew the position the crank needed to be at based on the setting of my cams. As I only had the crank pin to go by, that's all I could use. As Wilco mentioned, the grooves on the end of the cams are off-centred, which conveniently allows the locking tool to only go in one possible way. This avoids the camshafts from being accidentally 180º out of phase with the crankshaft.

To summarise, if you've lost your timing:

1. Remove the spark plug from Cylinder #1, and (Optional) insert a long screwdriver or a straight rod into the cylinder - something you can see moving up and down as you turn the crank over so you can visualize the piston's movements
2. Remove the crank timing pin cover bolt to the left of the crank pulley - this will be a 10mm bolt that will be identical dimensions to the timing pin you will use, but shorter
3. Screw in the timing pin all the way in until it won't screw anymore. If the pin won't fully screw in or you meet resistance, then you may be contacting the crank at a phase where it is close to the pin. If this is the case, turn the crank over some amount until the pin can fully screw in.
4. Once the crank pin is all the way in, start to turn over the crankshaft clockwise until it contacts the pin and will not turn anymore. Be gentle/careful as you don't want to unnecessarily slam into the timing pin¹. Where the crank sits unable to turn is the crankshaft's position relative to the correct camshaft position. You will notice your screwdriver/rod moving up and down as you do this - Piston #1 should be just on its way back up as it approaches the correct point and contacts the pin.
5. With the crank pin in place, turn over the camshafts by hand (13mm bolt) until the off-centred grooves are in the top half of the circle, i.e. towards the sky, and run parallel to the surface. Turn the cams slightly such that you're able to slide the locking bar across both camshafts so that it sits flush with the engine². Leave the locking tool in while you add the belt on.  
6. Once the crank and camshafts are aligned in place, loop the timing belt around the crank and cam sprockets. Ensure that the teeth of the timing belt sit even on both cam sprockets. You may need to slightly turn over one cam or the other to ensure this - we're talking less than a degree in movement, so be precise!
7. Add the timing belt, ensuring not to disturb the crank sprocket. If it moves, you can ensure its timing by turning the crank over clockwise and having it rest against the pin so it will not turn clockwise anymore.
8. Once the belt is properly tensioned, the belt will now preserve the timing between the cams and crank. Remove the locking bar across the cams and remove the timing pin from near the crank. 
9. To double-check your timing is correct, turn the crank over two full rotations and check there are no dead stops or complete resistance; for every two full turns of the crank, the cams will complete one full rotation. As you turn the crank over, you will regularly encounter resistance - assuming you have 3 out of 4 spark plugs in, this is the air inside those 3 sealed chambers being compressed. This is normal, and will feel quite spongy, but you can turn through this and will eventually be easier again. If you're turning over your crank and eventually reach a hard resistance and cannot turn anymore, even with the timing pin out - do not force or turn the crank over anymore! You might have set your timing wrong and are contacting valves with pistons! Go back and ensure you've set your timing correctly if this is the case. If you continue to apply force while pistons are contacting valves, then you risk bending your valves which will require a timely and costly cylinder head repair. If at any point your hand strength is not sufficient to turn over the crank, then you're doing something wrong.

¹You'll know this is the case when the crank will not move at all and the pin won't unscrew while contacting the crank. In addition to this, if you then turn the crank anti-clockwise while the pin is in - you'll hit another stop when you can no longer turn the crank. This is the range in which the timing is set. It's quite a wide range, so focus on the clockwise motion. Once again and without removing the pin, turn the crank over clockwise until it won't turn any more - this is your crank setting. Be very careful to make sure to not move the crank pulley while moving the timing belt as it can easily move out of place. Leave the crank pushing into the pin while you set the rest of your timing.

²Ensure that the cams are as centred as possible, i.e. not too far clockwise or anti-clockwise. If you find that one cam's groove is too far clockwise/anti-clockwise and is digging into the locking bar to the point where it's difficult or not possible to remove the bar, then the cam is too far off to one side. Turn back the cam slightly until neither edge of the groove is touching the locking bar and that the locking bar can slide in and out easily. This is important as even that slight deviation to one side or the other could cause the cam sprocket to be out of time by even 1 tooth on the gear, or the timing belt will not sit flush in the valleys and could slip or skip over. If the cam is even 1 tooth out of place, then your engine will run very poorly at best or will crank but won't start.

You'll be able to get a feel for this as you're installing your timing belt. You can very lightly turn the cam sprockets one way or the other to make sure the teeth of the sprockets line up perfectly with the timing belt (all while maintaining timing of course). Keep in mind that we're talking about extremely tiny rotations, less than a degree.

[Cofty]

I would just add that Ford recommend you loosen the two cam pulleys so that they are free to rotate on camshafts, then replace your timing belt and release the locking pin on the tensioner. This will pull the cam pulleys into their proper location relative to each other with no need to disturb the position of the cams. Then use a cam holding tool and torque up the (new) cam pulley bolts.

[LTIronWolf]

30 minutes ago, Cofty said:

I would just add that Ford recommend you loosen the two cam pulleys so that they are free to rotate on camshafts, then replace your timing belt and release the locking pin on the tensioner. This will pull the cam pulleys into their proper location relative to each other with no need to disturb the position of the cams. Then use a cam holding tool and torque up the (new) cam pulley bolts.

Ah, so that's why timing belt kits come with new cam bolts - thank you!

I wanted to avoid taking mine off as I didn't have the correct tool to lock the cams in place, and using the locking bar to torque the cam bolts is a bad idea.

[Chris11122]

Hi all, Sorry to revive an old thread. I am in a similar position and starting to think I have caused damage.

I used the pins and locking tools on my 2005 1.6 ti vct. Found TDC of cylinder 1 (or so I thought). Everything was timed.

I then undid the crank bolt and went to bed...

Went outside today and thought I would rotate the engine again, just to be sure. Removed the pins and locks and turned away... Even forced the engine when it got hard to turn.

Now I cannot find tdc where everything lines up. So I am guessing the crank pulley has moved, since I undid the crank bolt...

But then I found this thread and if I am reading it correctly the crank pin doesn't set cylinder 1 to TDC!?

I am all of a muddle and not sure how to proceed... Could be head off and replace the valves I think.

 

[Focus_]

On 5/1/2022 at 7:40 PM, Chris11122 said:

Hi all, Sorry to revive an old thread. I am in a similar position and starting to think I have caused damage.

I used the pins and locking tools on my 2005 1.6 ti vct. Found TDC of cylinder 1 (or so I thought). Everything was timed.

I then undid the crank bolt and went to bed...

Went outside today and thought I would rotate the engine again, just to be sure. Removed the pins and locks and turned away... Even forced the engine when it got hard to turn.

Now I cannot find tdc where everything lines up. So I am guessing the crank pulley has moved, since I undid the crank bolt...

But then I found this thread and if I am reading it correctly the crank pin doesn't set cylinder 1 to TDC!?

I am all of a muddle and not sure how to proceed... Could be head off and replace the valves I think.

 

Firstly, have you attempted to start the engine at the turn of the key? If you haven't, and only rotated the engine by hand, I doubt you have the strength to bend valves unless you went at it like king kong! In which case you'd surely realize something was amiss. 

When tightening the crank pulley, how did you lock the crank? The crank pin is not sufficient means of locking the crank when loosening or tightening the crank bolt. It could be that you have snapped the crank locking pin which is what made you think you were turning it against valve resistance then it gave way...

Being a Ti-VCT, you additionally need the x-shaped cam pulley locking tool pictured below, did you use it? 

[Focus_]

On 5/1/2022 at 7:40 PM, Chris11122 said:

Hi all, Sorry to revive an old thread. I am in a similar position and starting to think I have caused damage.

I used the pins and locking tools on my 2005 1.6 ti vct. Found TDC of cylinder 1 (or so I thought). Everything was timed.

I then undid the crank bolt and went to bed...

Went outside today and thought I would rotate the engine again, just to be sure. Removed the pins and locks and turned away... Even forced the engine when it got hard to turn.

Now I cannot find tdc where everything lines up. So I am guessing the crank pulley has moved, since I undid the crank bolt...

But then I found this thread and if I am reading it correctly the crank pin doesn't set cylinder 1 to TDC!?

I am all of a muddle and not sure how to proceed... Could be head off and replace the valves I think.

 

Just to add, I don't fully understand what you were trying to do. 

You undid the crank bolt and then turned the engine over, for what purpose? I'd be more confident in the timing settings before you touched the bolt than afterwards. 

What makes you think you cannot find TDC? How are you looking for it, is the crank on the lock, are the cams locked, so where's the piston on Cyl 1, up or down? 

[victorioan01]

hello, after change one exhaust valve, my engine not working as well as the begining. must do somethingg? the ralanti is  fluctuating and  the power is poor.

[MJNewton]

7 hours ago, victorioan01 said:

hello, after change one exhaust valve, my engine not working as well as the begining. must do somethingg? the ralanti is  fluctuating and  the power is poor.

Start a new thread.