S54 Vanos post Beisan/DV Rebuild Timing Issue

[bmwfnatic]

Thanks Sapote

Vanos test via Tool32

Timing seems off here, it would still pass if it were ran in DIS [-5. +5], but it's not amazing, enough so that I would consider opening things up again.

EVANOS FRUEH ISTWERT -> -3, should be 0.
EVANOS SPAET ISTWERT -> 56, should be 60.

AVANOS FRUEH ISTWERT -> -2, should be 0.
AVANOS SPAET ISTWERT -> 46, should be 48.

So you are between 3-4 degrees off on the intake side, and 2 degrees on the exhaust side.
I would like to note that I don't exactly know how adaptions would play here, clear them and then go on a long drive (1hr+) with varying load/rpm, some WOT, some cruising, not sure what it needs to fully adapt.
Perhaps it will show different results then, you can also check your adaptions, the easiest way without DIS is using the ECUworx tool.

[BL92]

Thanks Sapote

Vanos test via Tool32

[sapote]

"under a 0.05mm gap on both sides with intake installed and exhaust installed"

It's more than perfect!

[BL92]

Thank you, both methods worked to drop the pins,

under a 0.05mm gap on both sides with intake installed and exhaust installed, next will be vanos testing via Tool32 until i set up DIS

[sapote]

OP, tilt the bridge one way or the other so the pin drops in the hole, then tell us the gap of the bridge one leg off the head with the other leg on the head. Small gap means timing is fine.

[Slideways]

Thank you again for the input

So I pulled it apart again today, as i didn't preload the hubs

Followed Sapote method this time, rotated the engine, pins line up, just wont drop
Can't tell if the pistons are bottomed out

Yes, the pistons look bottomed out based on where the splined shafts are located in the hubs. Nudging the cams with the 24mm wrench will allow the pin to drop down fully. Seen it happen quite a few times where the pin won't drop down like that, but the timing was still good. There is sometimes a little play where the crank locking pin sits in the vibration damper and a hair of a degree off there will cause the cam tool pin not to drop through like it did before rotating the engine.

[sapote]

Pin won't drop: for each cam, find out if it's too advance or too retard from the pin drop position.

With the hubs being pretensioned by the 2 bolts each, when the vanos was bolting down did you see the splined shafts were pushed in the hubs and the hubs rotated CCW?

[BL92]

Thank you again for the input

So I pulled it apart again today, as i didn't preload the hubs

Followed Sapote method this time, rotated the engine, pins line up, just wont drop
Can't tell if the pistons are bottomed out

[Ramage]

I'm interested to know how the DME uses the adaptation value such as -5.9 in this case, as it has no idea where is the vanos piston to add the 5.9 offset to its travel position.

That is a good point.

Thanks again for the enlightenment.

All of these discussions will help others in the future. For now, I will leave my Vanos and open it up after tackling my rod bearings in April.

[sapote]

• Vanos piston extended retards timing
• Vanos piston retracted advances timing

This depends on the context:
* in operation, extended piston (rearward) to advance the cam;
* during timing setup, extended pistons leading to retarded cams and DME has to adapt more advanced data to get it right.

My car calls for -5.9 °cr Intake adaptation and -4.3 °cr Exhaust adaptation, which, if I understand correctly, means that when I installed the Vanos onto the head, the Vanos pistons were not fully retracted into the Vanos. To get the expected range of travel, the DME has to pull the pistons back -5.9°cr and -4.3°cr, respectively.

For me, adaptation -5.9 means adding 5.9* advance, which also means your timing result is too retarded due to the piston is not bottomed on the cap with the cam aligned to bridge pin.

Do my adapted Vanos values have any real-world impact on the performance of my car? In other words, if I have no reason to open it all up again, should I bother now or wait until I have another reason to crack it open?

The book says the IN cam timing variation range is 70* to 130* for max advance to max retard. I also don't think the cam when aligned to the bridge pin is 130* but something like 140* with 10* margin, and if I'm right then the IN piston bottomed on the cap when the cam is 140* retard, and so during operation between 130 to 70 the piston never near hitting the cap. I also think the piston rearward limit is less than 70* but not too far advance to cause valve/piston interference. So even with -5.9 adaptation the piston has full travel to cover 70 to 130, and the engine has no negative impact.

I'm interested to know how the DME uses the adaptation value such as -5.9 in this case, as it has no idea where is the vanos piston to add the 5.9 offset to its travel position.

[Ramage]

Locking the cams using the bride pin is to set the cams timing to the crank, but this has nothing to do with setting the vanos pistons in correct relation to the cams.
To set the vanos pistons in correct relation with the cams, is to have the pistons bottomed on the caps while there is zero backlash from piston to the cam.
In the steps you wrote below, the vanos bolts are torqued to spec with the shaft inserted so the splines are just visible. This description of the shaft and hub relation is vague and not precise. Just visible could mean the shaft is off relative to the hub and a few thousands, or more. Let's assume that the shaft is 0.020" too deep into the hub as compared to the ideal position, then this means with the vanos installed the piston is 0.020" too advanced with the cam at TDC.
The correct way to set the spline shafts into the hub at the correct position is to have the installed vanos pushing the shaft into the pretensioned hub, not just by eye ball the shaft to have "splines just visible".


6.) Place the Spline gear so the teeth are just visible.
7.) Now torque the Intake hub down using a star pattern.

Thanks for the detailed response.

I must admit it took me some time to go over your reply to understand fully how the seemingly slight procedural difference of installing the spline gears and torquing the hub bolts down before attaching the Vanos/ Vanos pistons impacts the final timing.

It was only after reviewing what you wrote in post 90 of this thread that it fully clicked how my eyeballing it (I also run a V2 Turbo Toy exhaust hub, which makes it harder to eyeball) resulted in my adapted Vanos values below:



My understanding is:

• Vanos piston extended retards timing
• Vanos piston retracted advances timing

My car calls for -5.9 °cr Intake adaptation and -4.3 °cr Exhaust adaptation, which, if I understand correctly, means that when I installed the Vanos onto the head, the Vanos pistons were not fully retracted into the Vanos. To get the expected range of travel, the DME has to pull the pistons back -5.9°cr and -4.3°cr, respectively.

I like the method you fully described in post 90 of this thread.

1. The hole on the hubs don't have to be aligned to anything nor to the vertical top posiiton, and these holes can be anywhere as they have nothing to do with vanos timing.
2. No need to mark on hub and splined shape for indexing, or the need to find the sweet tooth.
3. I don't like the method of bolting the splined shafts to the vanos pistons before inserting the shafts into the hubs, as it's more difficult to pre-tension the hub bolts and inserting the shaft into the hubs. The easier way is to insert the shafts into the hubs first, pre-tension the bolts, then bolt the pistons to the shafts later.
4. The timing: turn both hubs full CW, then insert the splined shafts into the hubs and if needed, turn the hub not more than 1 tooth to align the splines to get the shaft inserted in about 5mm.
Edited: pretension the two hub bolts for each hub.
5. Mount the vanos with gasket (with the solenoid plate removed) on the head with about 10mm gap in between or more, bolting the shafts and pistons together, then evenly tightening the vanos bolts to pull it into the head fully. This set the final timing. Now try to tighten all the hub bolts down. To torque these hub bolts to spec using standard wrench, then disconnect the pistons off the shafts, remove the vanos, and torque the hub bolts to spec. Install the vanos and finish all the bolts. Rotate the crank 4 turns or so and verify the cams timing.

One final question that is open to all. Do my adapted Vanos values have any real-world impact on the performance of my car? In other words, if I have no reason to open it all up again, should I bother now or wait until I have another reason to crack it open?

Cheers

[sapote]

Really?

Please explain how this could result in the timing being wrong. Both cams are locked down using the timing bridge basically from the moment the VC is off.

Also if my timing is wrong would that not result in the Vanos test failing?

Cheers

Locking the cams using the bride pin is to set the cams timing to the crank, but this has nothing to do with setting the vanos pistons in correct relation to the cams.
To set the vanos pistons in correct relation with the cams, is to have the pistons bottomed on the caps while there is zero backlash from piston to the cam.
In the steps you wrote below, the vanos bolts are torqued to spec with the shaft inserted so the splines are just visible. This description of the shaft and hub relation is vague and not precise. Just visible could mean the shaft is off relative to the hub and a few thousands, or more. Let's assume that the shaft is 0.020" too deep into the hub as compared to the ideal position, then this means with the vanos installed the piston is 0.020" too advanced with the cam at TDC.
The correct way to set the spline shafts into the hub at the correct position is to have the installed vanos pushing the shaft into the pretensioned hub, not just by eye ball the shaft to have "splines just visible".


6.) Place the Spline gear so the teeth are just visible.
7.) Now torque the Intake hub down using a star pattern.

[Ramage]

This is not good.
Step 7: the hub bolts should not be torqued down to final spec when the vanos module is not bolted down to the head. This will give wrong timing.

Really?

Please explain how this could result in the timing being wrong. Both cams are locked down using the timing bridge basically from the moment the VC is off.

Also if my timing is wrong would that not result in the Vanos test failing?

Cheers

[BL92]

The above steps can cause timing error, as the pre-tension the two hub bolts is missing.





"I tried sapote method, was unsure how far back to install splines,"

I clearly said insert the shafts in about 5mm into the hubs here.

I wrote: " The timing: turn both hubs full CW, then insert the splined shafts into the hubs and if needed, turn the hub not more than 1 tooth to align the splines to get the shaft inserted in about 5mm. " Although I forgot to write pretension the 2 hub bolts at this step.

Thank you for helping sapote, OK, i will measure 5mm back and strike a line on both shafts and insert them up to the 5mm line,

[sapote]

I pulled my Vanos out yesterday to check on my cam bolts.

Back in 2013, I replaced all the original cam bolts with the new T30 bolts while also applying blue Loctite (non-oil resistant). A few weeks ago, I heard a very faint "Marbles in a Can" sound, so I figured I would inspect the bolts to see if any were loose. The plan was to replace any bolts that were loose and /or replace the non-oil resistant Loctite with Loctite 243.

None of the bolts were loose , but I still used the Loctite 243 for peace of mind.

All of this is to say the timing on these engines does not In short
1.) Lock the Intake and Exhaust cams using the timing bridge
2.) Install the Intake hub hand-tight so you still have the full range of motion.
3.) Rotate the intake hub all the way clockwise.
4.) Take the Intake spline gear and insert it into the Intake hub - You want to find the spot where the intake hub has to move the least for the spline to go in.
5.) Check the range of motion by moving the spline gear in and out.
6.) Place the Spline gear so the teeth are just visible.
7.) Now torque the Intake hub down using a star pattern.

This is not good.
Step 7: the hub bolts should not be torqued down to final spec when the vanos module is not bolted down to the head. This will give wrong timing.