Vanos/marathon underway

[enuff_zed]

One more question though; my kit came with the needle bearings and spacer rings, but the x8r instructions don’t even mention these anywhere. Looks like they belong inside the pistons but looks like you need a specialist tool to get the piston apart? Anyone gone to this level on their vanos? Can the bearings be swapped out using normal tools?

Glad the jacking trick worked.
Can't help with the rebuild as I bought a rebuilt one and did a straight swap.

 

[TheDan]

One more question though; my kit came with the needle bearings and spacer rings, but the x8r instructions don’t even mention these anywhere. Looks like they belong inside the pistons but looks like you need a specialist tool to get the piston apart? Anyone gone to this level on their vanos? Can the bearings be swapped out using normal tools?

I have done a lot of research on this as I will be carrying it out in the coming weeks. I believe the process is to clamp the piston in a vice (soft jaws needed) and apply an impact wrench to undo the nut. I am not sure the nut will be able to be undone with just a breaker bar, but it may.

See here: https://youtu.be/gHuAtmxQRCE?t=831

 

[bigwinn]

I did this on the current car

Once pistons are out and before you do the seals

Pop them in a soft faced vice
Get an impact wrench (24mm from memory) on the main bolt and blast them off

Once off use a pick to remove all the bearing races, shims etc and remember order/orientation

Reassemble using new kit

Re torque head bolt up- not sure of torque setting but google will say

Then do your seals

It’s good practice to not mix up which piston sits in which side

Ok?

 

[parabolica]

Cheers guys; decided to leave the bearings alone as I already repacked the vanos. All done and dusted now; my old gaskets and seals were in pretty good nick but still made a difference; engine is so much smoother now

 

[enuff_zed]

Cheers guys; decided to leave the bearings alone as I already repacked the vanos. All done and dusted now; my old gaskets and seals were in pretty good nick but still made a difference; engine is so much smoother now

And if my experience is anything to go by, it will continue to improve as the engine 'learns' to adapt to the new parts.

 

[rdgreen]

Cheers guys; decided to leave the bearings alone as I already repacked the vanos. All done and dusted now; my old gaskets and seals were in pretty good nick but still made a difference; engine is so much smoother now

Might have been a good idea to check the thrust clearance's first as mine were way out of spec (around .3mmm as I recall) when I checked them. Makes for a much quieter engine when adjusted properly.
Incidentally, I found the best way to remove the vanos nuts is to wrap plenty of masking tape around the piston and then attach a suitable size hose clamp to it then you can put them in a vice with soft jaws and not have to clamp them so tight as to possibly distort them. The hose clamp against one side of the jaws will prevent the pistons from turning and remove any potential damage when applying the impact wrench. Don't even bother with a breaker bar as chances are you will not be able to remove the nut.....but you might easily damage the piston.