Dropped cam pin down head...help

[sapote]

The thing that has me a but confused is at TDC my cyl 1 cam lobes do not point to each other at a 45° as per Beisan. This was the case before I touched anything.

As long as the bridge pin inserted into the cams holes, that’s all matter, ignore the 45 degrees— optical illusion.

[Mspir3d]

I wonder if one could re-use the gasket in this case. Although it does crush when the vanos is fully tightened to the head so maybe not. I've got one more gasket on hand, hopefully I'll get the timing right next try.

I was able to reuse mine after tightening the vanos down a couple times. Just be sure to run a small bead of sealant along the top where the vanos sits against the head. The vanos gasket does not come completely flush with the surface and it can leak a lot of oil there.

[mrgizmo04]

At the bottom of the rattle procedure page, Raj/Beisan has a procedure for re-timing the engine after vanos has been bolted down to the head, "Adjustment of timing". You only need to re-loosen the 6 hub bolts, you do not need to remove and reinstall the vanos unit itself, and therefore no need to worry about the vanos unit to head gasket. That gasket is one use because the valley gets crushed.

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[sapote]

At the bottom of the rattle procedure page, Raj/Beisan has a procedure for re-timing the engine after vanos has been bolted down to the head, "Adjustment of timing". You only need to re-loosen the 6 hub bolts, you do not need to remove and reinstall the vanos unit itself,

This method is not reliable, bc without having the vanos removed and then during install and bolting down, it pushed on the spline shaft and turned the hub to the precise location for the right timing (between hub and sprocket). Without the vanos pushing, there is slash or plays in the whole gear train and the timing is just a trail error, as the OP had done a few times and failed.

[mrgizmo04]

This method is not reliable, bc without having the vanos removed and then during install and bolting down, it pushed on the spline shaft and turned the hub to the precise location for the right timing (between hub and sprocket). Without the vanos pushing, there is slash or plays in the whole gear train and the timing is just a trail error, as the OP had done a few times and failed.

I think that method works fine, but obviously it assumes that steps before it did not go south, one of the primary ones that the cams moved.

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[Cubieman]

One of the main issues I think I am having is feeling by hand 10.5 ft lb for the hub bolts.
On the Beisan instructions you are to "tighten" the 2 left/right bolts on each hub and then loosen 1/4 turn. I don't know how much to "tighten" these bolts, tighten to me is somewhat ambiguous.

Beisan instructions also states that the hub bolts will protrude slightly from the back hub plates when fully torqued. When I FEEL that the bolts are at 10.5(ish)ft lb by hand the bolts do not protrude from the face of the plates.
On the back of each plate hole there is a recessed area around each bolt hole, the bolts protrude out of the recessed area slightly but do not protrude out of the face of the rear plate itself if that makes any sense.
I am using the Lang bolts by the way, I may measure them against the OEM.

I see that in the Vanos mega thread on here there is talk about using plastic spaces (5mm?) to use when tightening down the left/right hub bolts directly after vanos is installed. There is also talk of using two bridge timing pins and loctite on the hub bolts as well.

I feel like I should only follow the Beisan procedure as it is tried and true however when it comes to final vanos install/timing there are slightly different ways to go about it would seem.
Any tips from anyone with experience would be greatly appreciated.

[sapote]

One of the main issues I think I am having is feeling by hand 10.5 ft lb for the hub bolts.
On the Beisan instructions you are to "tighten" the 2 left/right bolts on each hub and then loosen 1/4 turn. I don't know how much to "tighten" these bolts, tighten to me is somewhat ambiguous.

Beisan instructions also states that the hub bolts will protrude slightly from the back hub plates when fully torqued. When I FEEL that the bolts are at 10.5(ish)ft lb by hand the bolts do not protrude from the face of the plates.
On the back of each plate hole there is a recessed area around each bolt hole, the bolts protrude out of the recessed area slightly but do not protrude out of the face of the rear plate itself if that makes any sense.
I am using the Lang bolts by the way, I may measure them against the OEM.

I see that in the Vanos mega thread on here there is talk about using plastic spaces (5mm?) to use when tightening down the left/right hub bolts directly after vanos is installed. There is also talk of using two bridge timing pins and loctite on the hub bolts as well.

I feel like I should only follow the Beisan procedure as it is tried and true however when it comes to final vanos install/timing there are slightly different ways to go about it would seem.
Any tips from anyone with experience would be greatly appreciated.

Follow Tis instruction on how to pretension the hub: torque those 2 bolts to spec, then back out 1/4 or 1/2 I forgot, but it’s in the book. You do this with the spline shaft 1/3 inside the hub but no Vanos mounted, and so you can use torque wrench. Beisan instruction has the spline shaft connected to the Vanos, then insert spline shaft into the hub, and I don’t like it bc you cannot use the torque wrench!

[Cubieman]

Follow Tis instruction on how to pretension the hub: torque those 2 bolts to spec, then back out 1/4 or 1/2 I forgot, but it’s in the book. You do this with the spline shaft 1/3 inside the hub but no Vanos mounted, and so you can use torque wrench. Beisan instruction has the spline shaft connected to the Vanos, then insert spline shaft into the hub, and I don’t like it bc you cannot use the torque wrench!

Say you get the timing right and turn the engine over 15 times by hand and its still correct. I worry if the bolts aren't torqued properly that it could slide out of timing when the engine is running and valves hit pistons.
I guess I am sort of starting to get so nervous about this I won't even want to start the car when I'm done for fear of having done something incorrectly.

I am almost to the point of having the car towed to the dealership, the local specialty euro shop here doesn't seem like it would be any better. Screwing up and dropping that pin down the head started me down this attitude that maybe I am indeed over my head here.

A few questions that may ease my mind

- How far out of timing do the cams have to be before "interaction" with the valves/pistons? Do you really have to mess up and get it way off or is just a little tiny bit off enough to cause catastrophic issues?

- Is turning over the engine by hand enough to tell if your valves/pistons might collide? Or must the car be running/vanos active before you really would know?

- How much slack is there in the timing chain after the vanos is installed? I understand this may be difficult to describe.

- Can the the hub bolts be used/torqued multiple times? i.e having to keep backing them out/and in to re-time.

Thanks for all the help, really.

[ATB88]

Say you get the timing right and turn the engine over 15 times by hand and its still correct. I worry if the bolts aren't torqued properly that it could slide out of timing when the engine is running and valves hit pistons.
I guess I am sort of starting to get so nervous about this I won't even want to start the car when I'm done for fear of having done something incorrectly.

I am almost to the point of having the car towed to the dealership, the local specialty euro shop here doesn't seem like it would be any better. Screwing up and dropping that pin down the head started me down this attitude that maybe I am indeed over my head here.

A few questions that may ease my mind

- How far out of timing do the cams have to be before "interaction" with the valves/pistons? Do you really have to mess up and get it way off or is just a little tiny bit off enough to cause catastrophic issues?

- Is turning over the engine by hand enough to tell if your valves/pistons might collide? Or must the car be running/vanos active before you really would know?

- How much slack is there in the timing chain after the vanos is installed? I understand this may be difficult to describe.

- Can the the hub bolts be used/torqued multiple times? i.e having to keep backing them out/and in to re-time.

Thanks for all the help, really.

Obvs take this with grain of salt as I'm by no means an expert, but have done this job a few times now (alone and with in-person help). While I understand your concern about it drifting out of time while running because you didn't torque the hub bolts tight enough, this seems *pretty* unlikely given that a large number of people on this forum have done the job at least once if not multiple times, and I would guess most (myself included) don't use a torque wrench on the hub bolts. I've read a lot of VANOS diy threads and I've never ever heard of anyone's engine destroying itself after they re-timed it and checked that the timing was correct in DIS afterwards. Nor of timing ever drifting at all in this way.

FWIW I feel confident that if you stay the course on this and just be patient until you're happy with it, the odds of anything going wrong are quite low. I know that can be hard thing to convince yourself of if you have a mind like mine that is technical and detail-oriented/OCD enough to start sweating every small detail of this. But I think if you take a step back and just consider that the failure rate on this job as a DIY is actually quite low, it may help. I don't think there's any risk of the hub bolts becoming fatigued from what you're doing unless you're tightening them *hard*. Also, at this point, you might have a hard time getting any dealership to consider touching your engine in this state. Even a lot of indie mechanics around here will refuse to finish someone else's engine-open job for obvious liability reasons. You got this

[heinzboehmer]

Say you get the timing right and turn the engine over 15 times by hand and its still correct. I worry if the bolts aren't torqued properly that it could slide out of timing when the engine is running and valves hit pistons.
I guess I am sort of starting to get so nervous about this I won't even want to start the car when I'm done for fear of having done something incorrectly.

If you're really worried about getting the torque right you can get a set of crowfoot wrenches. The Harbor Freight version is probably good enough for this job: https://www.harborfreight.com/7-piec...set-94427.html

Using a crowfoot wrench is actually how TIS says you should do it:



This is the 117200 special tool:



Just keep in mind that this will change the length of your torque wrench, so you'll have to do a little math to know that to set your torque wrench to in order to get the correct torque at the bolt. Found this calculator that does that for you: https://www.tekton.com/how-to-accura...rowfoot-wrench

[eacmen]

If you're really worried about getting the torque right you can get a set of crowfoot wrenches. The Harbor Freight version is probably good enough for this job: https://www.harborfreight.com/7-piec...set-94427.html

Using a crowfoot wrench is actually how TIS says you should do it:



This is the 117200 special tool:



Just keep in mind that this will change the length of your torque wrench, so you'll have to do a little math to know that to set your torque wrench to in order to get the correct torque at the bolt. Found this calculator that does that for you: https://www.tekton.com/how-to-accura...rowfoot-wrench

If you keep the crowfoot at 90 deg angle on the torque wrench it will not affect the torque value by any meaningful amount.

[heinzboehmer]

If you keep the crowfoot at 90 deg angle on the torque wrench it will not affect the torque value by any meaningful amount.

True

[Hollywood]

Cubieman glad you found the piece! I’m getting ready to do my valve adjustment & this thread is definitely a cautionary tale. Sorry you had to go through it!

[sapote]

Say you get the timing right and turn the engine over 15 times by hand and its still correct. I worry if the bolts aren't torqued properly that it could slide out of timing when the engine is running and valves hit pistons.
I guess I am sort of starting to get so nervous about this I won't even want to start the car when I'm done for fear of having done something incorrectly.
.

Why using a method that you can't torque the hub bolts to spec with a normal torque wrench?

This method allows using a normal torque wrench on the bolts:

Condition: Crank at TDC compression stroke, cams are timed by bridge pin.

1) turn the hub full CW
2) insert spline shaft to the hub by turning the shaft no more than 1 tooth CCW as needed, and only insert to 1/4 or 1/3 deep. Torque 2 opposite bolts to 10 Nm then back out 1/4 turns, leave all other bolts threaded but loose.
3) Use the 2 long top bolts to hold the vanos with a used gasket (loosen or remove the solenoid plate already) to the head, then reach in and connect the pistons to the spline shafts using the left-hand-threaded connectors.
4) evenly torque down all the vanos to head bolts to spec taking care not to cock the vanos to prevent jamming the pistons in their cylinders.
5) Check cams timing with bridge pin. If good goto step next step. If out of timing then the hub bolts are too tight in step (2) causing hub not able to rotate against sprocket and ended up turning the cam instead, then repeat from step (1).
6) reach in and torque as many hub bolts as possible by open end wrench to snug.
7) remove all vanos to head bolts, then try to pull it forward and disconnect the left-hand-threaded connector. Remove vanos off.
8) replace with new gasket (I reused the same old gasket and it's OK), torque down all hub bolt to 14 Nm with torque wrench
9) install vanos per step (3 and 4) above.
10) Rotate crank 4 turns, stop at TDC on CW rotation. Check cam timing with bridge pin. If good then finish up other parts.

You should have no fear running the engine after this, as all the bolted were torqued to spec. The crawfoot tool is not as accurate since the bolt is off center from the torque wrench.

[sapote]

I think that method works fine, but obviously it assumes that steps before it did not go south, one of the primary ones that the cams moved.

I don't understand how can you time the hub correctly to the sprocket after loosening the hub bolt and not pull the vanos out. How do you know where to set the hub relative to the sprocket before bolting down the hub bolts to lock it in correct timing? The only way to have the hub timed correctly to the sprocket is to have the vanos pushing on the spline shafts and turning the hubs until vanos bottomed on the head.