Getting ready to do the upper tensioners on my 2000 XK8 using the method of lifting the exhaust cam with tie wraps holding the chains in place. I do have one question. Even though this method does not require any special tools I would like to know how the cam lock bars hold the cams in place when they are used? Are there flats machined on the front of the cams where the cam lock bars lock the the cams in place? Haven't found a good picture that shows this.

Thanks guys.

EZDriver 2000XK8 1995 XJ6

 

Yes there are machined flats. Look between the first cam and bearing cap in the picture.

 

Thanks for the picture. That is what I thought, but could never find a picture that showed that detail. Now if you don't mind I have another question. If I use the method of lifting the exhaust cam to replace the tensioner and when resetting the cam I don't get perfect alignment of the flats what is wrong with loosening the exhaust cam sprocket and aligning the flats then retightening the sprocket? I would think you could do that without the special cam locking tool.

Ez Driver

 

Very important: Do not ever loosen the cam sprocket without the the flats aligned with the special tool. The sprocket IS NOT KEYED to the camshaft, so there is no way to maintain the timing relationships and you will mess up your timimg.

If you are going to use the camshaft lift method, you are going to tie wrap the chain to the cam-shaft to prevent slipping the chain. You do not have to worry about the position of the camshaft flats when you use this method, they will remain aligned as well as they were before (or very close anyway) wherever they happen to be in their rotation. You do not loosen the cam sprocket when you use this method.

 

Thanks WhiteXKR for your input. I am aware of the situation you referred to regarding the sprocket having no spline or key-way on the cam. What I was considering was a method of correcting any slight cam misalignment following the installation of the tensioners that might effect idle performance. That has been mentioned in other postings as a possibility when using the cam lift method. After rethinking this I have decided that if I want to correct any slight misalignment that would show up by the cam flats not being in perfect alignment I would use the cam locking bar. Install the bar and snug it to the cam flats so the cams could not move any significant amount. Then loosen the cam sprocket only a slight amount. Then tighten the locking bar to accurately align the cams. Then retighten the sprocket. The only thing left is what is the method for putting the correct tension on the chain?

Hope all this make sense.

EZDriver 2000 XK8

 

If you are going to get the tools, why not just use the factory method? The main advantage of the zip tie/cam lift method is not needing the tools.

I used the zip tie method myself. In order for your suggestion to work, you will need to put the cam cover back on and run the engine for at least a few seconds, because until the hydraulic tensioners 'tension up ' and fill with oil, there will appear to be misalignment and chain slack, even if there really is none. You would then have to remove the cover again and rotate the engine and check for alignment on the flats.

I have never heard anyone actually say they had bad idle after the zip-tie method, that was a theroetical issue. If you are concerned about this, or about breaking the cam, then just use the tools and the factory method.

 

I have to agree with your logic. And, I think I will go ahead with the cam lift metod and just see how things go. The main thing I want to do is get the car in a safe driving condition so I can determine if I am satisfied with the fact that I have Naksil cylinders and want to keep the car or sell it. I don't feel right about selling it to anyone without at least replacing the upper tensioners. If I am satisfied with the car and feel it will be a long time companion then I will go back in and do all the mods that need to be done to put it in first class condition including the top hydraulics.

Thanks for the good discussion.

EZDriver