Need some help/advice timing my S54 rebuild

[sapote]

1. The next issue that I hit was when I followed the beisan instructions for tightening the top three hub bolts, then removing all of the timing bridge locking components and rotating 180 to get to the bottom bolts. Every time I came back around my top bridge pins were no longer in time

2. Looked at the NAM3 forms Vanos thread and the guy that wrote that said that instead of just tightening the top three bolts, he went ahead and took the whole Vanos unit off. So I did that by disconnecting the splines since they were already held in place secured by the top three bolts. Then I torqued all of the hub bolts 12 ft. Lb then I reinstalled the Vanos unit at the helical gear reverse thread bolts and pushed the Vanos unit back on and tightened it up.

1. It seems the hub was slipping when you rotated it 180 deg with the top 3 bolts tighten. I don't like this method as I can't use the torque wrench, and did suggest to others to remove the vanos off the head and use the torque wrench to torque up the 6 bolts to spec.

2. 12 ft lbs seems high. I believe the spec is 14 Nm which is 10 ft lbs.

Glad the issue is not about the thinned head.

[Cubieman]

1. It seems the hub was slipping when you rotated it 180 deg with the top 3 bolts tighten. I don't like this method as I can't use the torque wrench, and did suggest to others to remove the vanos off the head and use the torque wrench to torque up the 6 bolts to spec.

2. 12 ft lbs seems high. I believe the spec is 14 Nm which is 10 ft lbs.

Glad the issue is not about the thinned head.

Looks like he might have used the Lang hardware which has 12.9 instead of 8.8 grade cam sleeve bolts. I used those and an torqued about the same, I also used the included red loctite which will prove to be an enormous mistake whenever it needs to be taken apart.

[bmwfnatic]

I don't like this method as I can't use the torque wrench, and did suggest to others to remove the vanos off the head and use the torque wrench to torque up the 6 bolts to spec.

What was the entire point then of this procedure if one can just do it prior to installing the VANOS?

[heinzboehmer]

What was the entire point then of this procedure if one can just do it prior to installing the VANOS?

You want to make sure the vanos pistons are fully bottomed out against the caps on the vanos unit when timing the engine. No good way to do that without installing the vanos unit first, unfortunately.

[Slideways]

^ This

If you do enough VANOS rebuilds, you can probably get the depths close to perfect by inserting the splined shafts without the VANOS unit. On the E86/85 chassis, you almost have to as you cannot insert the VANOS unit with the splined shafts installed; however, there is a way of inserting the splined shafts into the hubs, mounting the VANOS, then pulling the splined shafts out of the hubs and towards the VANOS unit with a open ended wrench, and finally bottoming them out against the VANOS unit before installing it all as one like you do on the E46. All of this is not necessary if you have the OE VANOS actuator tool, but no one wants to buy that lol.

[sapote]

On the E86/85 chassis, you almost have to as you cannot insert the VANOS unit with the splined shafts installed;.

Even for the E46, it's easier to insert the splined shafts alone into the hubs first, then pre-tension the hub two bolts, then install the vanos and connect the pistons to the splined shafts and bolt down the vanos bolts to set the timing.

What was the entire point then of this procedure if one can just do it prior to installing the VANOS?

You cannot set the hubs timing without knowing the inserted position of the splined shafts (pushed by the vanos pistons) without an installed vanos with its pistons FULLY FORWARD (matching the retarded cams). So when bolting down the vanos, the pistons are bottomed out then push the splined shafts into the hubs and ROTATE them CCW to the proper position for the max retarded cams position, then lock up the hubs by tightening the bolts at the final timed position.