Cracked Vanos Hub Cover

[Ajolives]

One more of the tabs, they're small.

[Helmsman]

Originally Posted by Ajolives

@Helmsman Sure do! I bought a spare one to learn. I didn't really understand how oil pressure adjusted the timing of the cams so I did some homework.

I had some time to kill so took some pics:

The first series is taking off the cover to show the tabs. There's six tabs that hold the cover down using a ridge underneath the cover plate. Basically start with a pic and pop them out, walking the cover as you go. I suggest starting 45 degrees from the hole and travel away so the last tab to pop off is that one so it doesn't crack. Once you get three or four loose you can pop it off.

Second series is a disassembled unit I bought for an extra cover and once again to get a good idea of how this BS works. The consist of the spring unsprung, cover plate off, chambers and center piece removed. Basically those chambers fill with oil and move the camshafts laterally to change the degree.

Bought one to learn?? Well, a million thanks for that and the sharing mate, lovely series of photos!

Questions, questions...:
1. One aftermarket alternative Im hoping for is a sort of OEM replica. Would you judge a separate new cover is just to "snap on" without getting too stretched out? Read your earlier post they got flimsy.
2. If above is OK, why don't you use the covers you have. Or will you just fill out with Dinan plates to sort all 4 Vanos?

Ps. Comparing with your pictures it seems my lower cover pretty much has let let go completely from the edge?

[Ajolives]

Originally Posted by Helmsman

Bought one to learn?? Well, a million thanks for that and the sharing mate, lovely series of photos!

Questions, questions...:
1. One aftermarket alternative Im hoping for is a sort of OEM replica. Would you judge a separate new cover is just to "snap on" without getting too stretched out? Read your earlier post they got flimsy.
2. If above is OK, why don't you use the covers you have. Or will you just fill out with Dinan plates to sort all 4 Vanos?

Ps. Comparing with your pictures it seems my lower cover pretty much has let let go completely from the edge?

You're welcome, my pleasure really!! There wasn't much public info on this so I (and Ethan too) feel like trailblazing this for the community, learn as we go kind of thing. I got the used (disassembled) unit off eBay for a just a couple hundred and at the time I was down a cover (thanks for nothing FedEx) and through it was necessary at the time.

An aftermarket solution still may be viable, I really don't know. Im just assuming flimsiness and looser fitment is not as ideal. They could go the mileage, just not sure at this point.

Yeah there's a tab on the cover that goes perpendicular to the other tabs that I believe aligns it to the gear; proper orientation. Looks like yours has spun and is protruding out. I would make sure the other sides are engaged. Purely speculation, but I think 4 out of 6 tabs engaged is still pretty safe all else equal.

And the CarBahn is only for peace of mind; same with RBs.

[Redd]

Wow Ajolives. Thanks for that!

Based on your pics, I can see that:
1. The plastic cover is just clipped onto the gear assembly? There's no washer holding it in place.

2. The spring is held in place purely by spring tension, there's no other retainers/pins? The only thing preventing the spring from 'walking' off the gear is the plastic cover, which is held on by its own clips.

If the above observations are correct, it doesn't seem like a very secure fitment to me. If for any reason the spring loosens and walks forward, I doubt the flimsy plastic cover can stop it. This may be why some of the covers are coming loose - cos the spring is pushing it out. Which also warns us that the spring is already loose and failure is imminent.

If that's indeed the case, a bolted in retainer like the metal Carbahn washers will definitely be a much better long term solution to prevent the spring from loosening. Next question is, how thick/strong does that washer need to be? Does it need to be as thick as Carbahn have made it (which requires us to grind down the surrounding metal for clearance). Does it also need to be that large diameter? Or will a regular large washer be sufficient to secure the spring just by holding it in at the inner portion.

Also, if the spring is just loose, can it just be pushed back in? Or do you need to replace the gear+spring assembly with a good unit?

Just thinking out loud.

[Ajolives]

Originally Posted by Redd

Wow Ajolives. Thanks for that!

Based on your pics, I can see that:
1. The plastic cover is just clipped onto the gear assembly? There's no washer holding it in place.

2. The spring is held in place purely by spring tension, there's no other retainers/pins? The only thing preventing the spring from 'walking' off the gear is the plastic cover, which is held on by its own clips.

If the above observations are correct, it doesn't seem like a very secure fitment to me. If for any reason the spring loosens and walks forward, I doubt the flimsy plastic cover can stop it. This may be why some of the covers are coming loose - cos the spring is pushing it out. Which also warns us that the spring is already loose and failure is imminent.

If that's indeed the case, a bolted in retainer like the metal Carbahn washers will definitely be a much better long term solution to prevent the spring from loosening. Next question is, how thick/strong does that washer need to be? Does it need to be as thick as Carbahn have made it (which requires us to grind down the surrounding metal for clearance). Does it also need to be that large diameter? Or will a regular large washer be sufficient to secure the spring just by holding it in at the inner portion.

Also, if the spring is just loose, can it just be pushed back in? Or do you need to replace the gear+spring assembly with a good unit?

Just thinking out loud.

Thanks! Yeah my thoughts exactly on the CarBahn washers - why so thick? I thought maybe they just over-engineered to be safe. Pretty sure steel is safe at whatever our internal temps get to at an extreme, so no warping or material fatigue. I also like to think out loud

Yup, the cover is literally just snapped on.

The spring is just held on by those 4 pins in the picture, and yeah you nailed it. It's basically 'free floating' in one direction only being held tight by the friction of the spring. I will say the spring is pretty taught; I haven't tried resetting the disassembled unit yet because it looks like a PIA.

Edit: Forgot about the washer, and I agree those are all solid questions. People have run them without covers with just the washer (assuming) and bolt, which doesn't keep the spring in. I guess a washer big enough to grab like one or two revolutions of the spring would do, not sure if there be any flex at all. Hell, can probably grab one at Ace Hardware.

Either way, there's a crap ton of tension on that spring, I would imagine it's enough in normal operation to keep things steady.

[e92zero]

Originally Posted by Ajolives

Thanks! Yeah my thoughts exactly on the CarBahn washers - why so thick? I thought maybe they just over-engineered to be safe. Pretty sure steel is safe at whatever our internal temps get to at an extreme, so no warping or material fatigue. I also like to think out loud

Yup, the cover is literally just snapped on.

The spring is just held on by those 4 pins in the picture, and yeah you nailed it. It's basically 'free floating' in one direction only being held tight by the friction of the spring. I will say the spring is pretty taught; I haven't tried resetting the disassembled unit yet because it looks like a PIA.

Edit: Forgot about the washer, and I agree those are all solid questions. People have run them without covers with just the washer (assuming) and bolt, which doesn't keep the spring in. I guess a washer big enough to grab like one or two revolutions of the spring would do, not sure if there be any flex at all. Hell, can probably grab one at Ace Hardware.

Either way, there's a crap ton of tension on that spring, I would imagine it's enough in normal operation to keep things steady.

Ajolives Since you have the gear, would you mind taking some measurement? How much of the spring would a washer with OD 58mm cover? Wonder if these would work. < $5 a pop compare to $40?

https://www.accu.co.uk/en/flat-washe...-HDW-M12-V1-A4

[Helmsman]

Originally Posted by e92zero

Ajolives Since you have the gear, would you mind taking some measurement? How much of the spring would a washer with OD 58mm cover? Wonder if these would work. < $5 a pop compare to $40?

https://www.accu.co.uk/en/flat-washe...-HDW-M12-V1-A4

Very good question, a washer is a washer right! However I'd love to avoid the thicknes, surely a couple of mill stainless would do the job?

[Ajolives]

Originally Posted by e92zero

Ajolives Since you have the gear, would you mind taking some measurement? How much of the spring would a washer with OD 58mm cover? Wonder if these would work. < $5 a pop compare to $40?

https://www.accu.co.uk/en/flat-washe...-HDW-M12-V1-A4

Sure, 58mm is roughly 2 1/4 inches, so radius of roughly 1 1/8 inch puts you right about there.

[Ajolives]

Originally Posted by Helmsman

Very good question, a washer is a washer right! However I'd love to avoid the thicknes, surely a couple of mill stainless would do the job?

It's a very nice outside the box solution; can't really think of any downsides to having the spring partially exposed…unless there's rotation forces at play that would cause the exposed bits to dance on the pegs?

[Redd]

Originally Posted by Helmsman

Very good question, a washer is a washer right! However I'd love to avoid the thicknes, surely a couple of mill stainless would do the job?

Yeah the 58mm looks sufficient. If you retain the center and 2-3 revolutions of the spring, I highly doubt the outer edge will walk off the gear. Remember its held on by spring tension and a clipped on plastic cover.

As for thickness I'm thinking 2mm will be sufficient also.

[e92zero]

Ajolives Thanks for the measurement. I think the 58mm should work also given the spring is radially wounded so that last strip shouldn't be able to get onto the other edge of the washer when the rest of the spring is covered. What do you think given you have the actual gear and spring to make the evaluation?

I couldn't find anything thinner than this one at 6mm unless maybe go custom. I found a titanium one that's 20mm thick actually, haha. Maybe other member that has connection with a machine shop can work or look for some solution?

Were we able to confirm that the bolt does or doesn't have a washer attached already? If it doesn't, then maybe the 6mm thickness doesn't matter?

[Ajolives]

Originally Posted by e92zero

Ajolives Thanks for the measurement. I think the 58mm should work also given the spring is radially wounded so that last strip shouldn't be able to get onto the other edge of the washer when the rest of the spring is covered. What do you think given you have the actual gear and spring to make the evaluation?

I couldn't find anything thinner than this one at 6mm unless maybe go custom. I found a titanium one that's 20mm thick actually, haha. Maybe other member that has connection with a machine shop can work or look for some solution?

Were we able to confirm that the bolt does or doesn't have a washer attached already? If it doesn't, then maybe the 6mm thickness doesn't matter?

No problem! The spring itself isn't very strong laterally, I can manipulate it with my hand in the awkward picture below. If flimsy plastic can (arguably) keep it in place for 10s of thousands of miles any thickness washer would probably have no issues keeping it in place as such.

My only concern would be warping or breaking caused by heat, so I'm personally not sure how well an of-the-shelf washer would do in those conditions. Could become brittle after continuous exposure to operating temps. Not sure if there's any experienced engine builders who could chime in on that. A bit out of my circle of competence…..

Edit: and yeah I have a bolt with no washer attached in the pics I took yesterday. I have the part number right next to it. I believe I got them from ECS or turner, couldn't remember which.

[Helmsman]

Originally Posted by Ajolives

No problem! The spring itself isn't very strong laterally, I can manipulate it with my hand in the awkward picture below. If flimsy plastic can (arguably) keep it in place for 10s of thousands of miles any thickness washer would probably have no issues keeping it in place as such.

My only concern would be warping or breaking caused by heat, so I'm personally not sure how well an of-the-shelf washer would do in those conditions. Could become brittle after continuous exposure to operating temps. Not sure if there's any experienced engine builders who could chime in on that. A bit out of my circle of competence…..

Edit: and yeah I have a bolt with no washer attached in the pics I took yesterday. I have the part number right next to it. I believe I got them from ECS or turner, couldn't remember which.

Loads of good info here Ajolives, thanks again.
Not a machine eng but I don't believe temps going between say 0C and 100C could effect stainless steel at all.

The bolt you have is for this specific spot, but without the OEM attached washer?

[Pedalkick]

Been following along with the washer solution and wonder about the balance/weight and securing to the camshaft. The cams can spin up past 4K rpm and the washers are heavier than the plastic caps. Potential vibration due to imbalance of metal washers might be a concern. Also using the gear mounting bolt to secure the washer to the gear could be an issue. The only thing preventing a washer from spinning wrt the gear is the clamping force of the bolt. I would imagine the cams experience some accel and deccel loads that could potentially let the washer spin or even loosen the bolt. Not saying there is a problem as Dinan and others have been using them OK I guess.

[Ajolives]

Originally Posted by Helmsman

Loads of good info here Ajolives, thanks again.
Not a machine eng but I don't believe temps going between say 0C and 100C could effect stainless steel at all.

The bolt you have is for this specific spot, but without the OEM attached washer?

Correct, got the below from my order.

https://www.ecstuning.com/b-genuine-...h/11367840998/

And did some reading and stainless steel should most definitely fine in this application. Works for exhausts - should be the same here as far as heat goes. Just begs the question of why did Carbahn make theirs so robust.

[Ajolives]

Originally Posted by Pedalkick

Been following along with the washer solution and wonder about the balance/weight and securing to the camshaft. The cams can spin up past 4K rpm and the washers are heavier than the plastic caps. Potential vibration due to imbalance of metal washers might be a concern. Also using the gear mounting bolt to secure the washer to the gear could be an issue. The only thing preventing a washer from spinning wrt the gear is the clamping force of the bolt. I would imagine the cams experience some accel and deccel loads that could potentially let the washer spin or even loosen the bolt. Not saying there is a problem as Dinan and others have been using them OK I guess.

Yeah those were my original concerns with the steel plates. Also making sure they're centered on the bolt too so it's not lopsided. The center bolt torque is no joke, I'll ask around if a modified torque value was used for the Carbahn plates. I would imagine it's the same but like you said it's more mass being kept in place.

[e92zero]

I actually have a few other questions and concern as well. As others have mentioned, being able to center the washer is key given that it's heavier. 4k rpm is pretty high too. With more mass, if there is any imbalance on the washer, would it cause more wear on the cam teeth, or the first camshaft cap area long term? Do we know if the Carbahn plates are balanced?

The other question is for Ajolives actually. Is there any room left for the spring to move if this big washer is put on there or it will squeeze the spring a bit? I can't tell from the pic if the platform for the washer/bolt extends further out than the width of the spring. Thanks again for helping answering these questions.

[Redd]

Originally Posted by e92zero

The other question is for Ajolives actually. Is there any room left for the spring to move if this big washer is put on there or it will squeeze the spring a bit? I can't tell from the pic if the platform for the washer/bolt extends further out than the width of the spring. Thanks again for helping answering these questions.

Was just gonna ask this same question - will a flat steel washer press down on the spring when installed, preventing the spring from doing its springy stuff?

[Redd]

I'm also trying to source for 60mm x M12 x 2mm washers made in Ti Gr2. They would need to be custom made. Will update if I find a supplier.

However, Ti Gr2 is lighter but not as strong as stainless steel. It's a common material used for washers tho.

[e92zero]

Originally Posted by Redd

I'm also trying to source for 60mm x M12 x 2mm washers made in Ti Gr2. They would need to be custom made. Will update if I find a supplier.

However, Ti Gr2 is lighter but not as strong as stainless steel. It's a common material used for washers tho.

@Redd lighter would be better if we have concerns about balance? If it's custom, how much extra it would be to have a little lip on the inside to ensure it is centered on the platform (for a lack of better term)? The concern I have with titanium is, from experience, all the titanium bolts that I use on my bike, they require retightening after initial use to retain their torque setting. Gr 2 is softer than Gr 5. Would that be a concern here? Although that bolt torque is pretty high at 80 Nm with 270 degree (2x).

[Redd]

Originally Posted by e92zero

@Redd lighter would be better if we have concerns about balance? If it's custom, how much extra it would be to have a little lip on the inside to ensure it is centered on the platform (for a lack of better term)? The concern I have with titanium is, from experience, all the titanium bolts that I use on my bike, they require retightening after initial use to retain their torque setting. Gr 2 is softer than Gr 5. Would that be a concern here? Although that bolt torque is pretty high at 80 Nm with 270 degree (2x).

1. 60mm won't cover the whole spring, so it would need to be flat. Also, to add the lip would be a significant cost increase cos material would need to be machined out from a block of Ti, vs a round flat washer which can be cut out of a flat Ti plate. Anyway I haven't managed to find a supplier yet...

2. Good points on bolt torque and hardness. I'm by no means an expert on materials so will defer to those who know more. But Gr2 is a more common material for washers. Gr5 is available as plate, but it will all depend on the supplier/machine shop how they intend to make it.

[Green-Eggs]

Originally Posted by Pedalkick

Been following along with the washer solution and wonder about the balance/weight and securing to the camshaft. The cams can spin up past 4K rpm and the washers are heavier than the plastic caps. Potential vibration due to imbalance of metal washers might be a concern. Also using the gear mounting bolt to secure the washer to the gear could be an issue. The only thing preventing a washer from spinning wrt the gear is the clamping force of the bolt. I would imagine the cams experience some accel and deccel loads that could potentially let the washer spin or even loosen the bolt. Not saying there is a problem as Dinan and others have been using them OK I guess.

If that were an issue, then it would be an issue for the VANOS too. The VANOS is not splined and is only held in place by the pressure of that bolt. There's some good reasons for that.