Dr Vanos Cryo hub or Beisan?

[elbert]

I posted a similar picture of my hub on the old forum (I'll need to dig through my photos at home). One tab broke off, the other was partially cracked.
I think terra had a partially cracked tab on his hub too.

IMO if using an old hub, it needs to be removed and tested with either dye or magnaflux. Oil got wicked in the crack in my hub so it was easy to see, but better safe than sorry. Again, just my opinion.

OK, I found the pictures of my hub.
The reason I suggest having the hubs removed for inspection is the crack was only visible on the inside part of the tab, which is hard to see when the hub is in place. IIRC, the outside part of the tab appeared to be OK (I'll need to dig deeper in the archives to see if I have a pic of that).

[Grke46m3]

I thought that was one of his main points and the reason to show the before and after videos documenting the noise (and lack there of). Imran posted in the comments he was asked not to film it.

Yeah thought that was strange. He somehow knows a way to change it without removing the front cover i guess? its like some sort of secret. i never once remember in the past 12 years on the forums of chain stretch being any issue.

[elbert]

. I have never witnessed a VANOS line blowing up.

That's happened to me too. Started leaking where the banjo attaches to the hard line, made a big mess as oil sprayed everywhere.
Got it replaced under warranty, and the replacement has been OK for 16 years so far (knock on wood).

[George Hill]

Or just skipped it. Never seen any evidence the s54 needs it done.

I thought that was one of his main points and the reason to show the before and after videos documenting the noise (and lack there of). Imran posted in the comments he was asked not to film it.

[digger]

Timing chain stretch is simply wear. It will keep wearing until something breaks

[bigjae46]

I haven't seen many issues outside of rod bearings, VANOS related stuff, ignition coils, camshaft sensors, and water pumps. I have never witnessed a VANOS line blowing up.

Head gasket, bad piston rings, chain stretch, oil pump failures...I have not seen any of those issues being the root cause or heard of a verified failure. I'd have to guess that the S54 is an engine that sees more high abuse miles relative to total production than anything outside of a P-car. The S54 is a very tough motor outside of the rod bearings. I'll take that all day long vs what I see happen to LS engines.

I'd have to see a pattern of timing chain failures to believe that it is a weakness.

[sapote]

If you concerned about chain stretch, then remove the tensioner, remove the piston, remove the spring and replace the spring with a spacer such that when together the piston protrudes out at its mid range. Install this fixed tensioner hand turn until the chain is tight. If the tensioner threads are visible then the chain is still usable. (I really don't know how far the tensioner piston protrude limit, but mid point seems to be safe.)
Check the cams timing and adjust as needed, and it should work as good as new.
Too much chain stretch will cause bad chain-sprocket engagement though.

[sapote]

That said, I've long wondered if the chain is continually stretching longer every mile, or if it stretches to a point and then stops. If all the stretch in the first, say, 10,000 miles, replacing it makes a lot less sense than if it's forever getting longer.

Chain will continue to stretch as being used.
Chain stretch should not be an issue as long as the tensioner is not bottomed out. Chain stretch can affect the cams timing, but after re-setting the vanos timing again, the system should again work like it is new from the factory, because the timing relationship from crank to cams are restored to factory, even with a stretched chain.

[sapote]

FYI Popped into my feed today and may be of interest to this thread:

https://www.youtube.com/watch?v=_jzNPBuySDs

Claims that I thought were interesting (not necessarily agreeing with):
- observed several failures on the rebuilt/potted solenoid packs and only uses brand new solenoid packs from now on
- used to use sleeves on the pump disc vs drilling, now just opt's to drill the holes
- claims S62 diaphragm springs can reduce VANOS response times in "race car" applications
- has noticed several stretched timing chains and this leads to engine noise and lazy timing adjustments
- uses the 10.9 cam bolts from e36 versus the updated torx head bolts
- no need to use the anti rattle kit in the helical cut splines

Not saying any of the above is true but info to consider nonetheless.

He said:
- chain slack after pulling up the chain between the 2 sprockets. How did the chain have the slack after the crank pulled and turn the cams? He either caused this after turning the cams with the 24mm wrench. It's impossible to know if it's stretch or not by pulling the chain.
- chain stretch will be compensated by tensioner, and after vanos timing done, it should work as new chain and no affect on lazy timing adjustment.
- anti rattle kit needs when there is plays in the roller bearing on the splined shafts. How do you eliminate the plays if not using the kit?
- use sleeves to reduce the disk hole diameter? it won't last because the sleeve wall thickness is too thin.

[Slideways]

Or just skipped it. Never seen any evidence the s54 needs it done.

That's what I thought, but some of the links on the chain are not as oily in the after shot. I remember SliM3 rebuilding his engine and showing some chain stretch when comparing old with new. I wouldn't mess with it unless the engine needs a teardown. It looks like IWIS manufactures the chain and it is available as OEM.

[Obioban]

He probably splits the chain, attaches one end of the new one to the old, spins the engine over until the new chain is wrapped around all the components and then installs a new link pin

Or just skipped it. Never seen any evidence the s54 needs it done.

[George Hill]

I didn’t see him remove the timing cover to change the chain. Can you change the chain without taking the cover off?

He probably splits the chain, attaches one end of the new one to the old, spins the engine over until the new chain is wrapped around all the components and then installs a new link pin

[eacmen]

I didn’t see him remove the timing cover to change the chain. Can you change the chain without taking the cover off?

[George Hill]

Chain stretch is a common issue on the S62, probably because it's so much longer. I replaced mine when I did the VANOS on it.

That said, I've long wondered if the chain is continually stretching longer every mile, or if it stretches to a point and then stops. If all the stretch in the first, say, 10,000 miles, replacing it makes a lot less sense than if it's forever getting longer.

Maybe so, but it's the first I've ever seen it mentioned as an "issue" on the S54. It would have been interesting to see data on it, I mean I imagine he's splitting the chain to remove and install, it would be cool to see the data on the lengths being different vs the mileages.

[Obioban]

First, I thought the video was well done and I enjoyed it.

I noticed a lot of those points to and thought it interesting. I wish they had touched more on the chain stretch idea, I imagine there is some IP they don't want to release but a bit more info would have been quite interesting considering THAT is an idea that doesn't get thrown around much.

Also interesting about the cam bolts in the second car, they use a different bolt but in that car they had been done "properly" with a stock bolt so its ok, just thought that was an interesting justification for not replacing them with what they think is better.

Chain stretch is a common issue on the S62, probably because it's so much longer. I replaced mine when I did the VANOS on it.

That said, I've long wondered if the chain is continually stretching longer every mile, or if it stretches to a point and then stops. If all the stretch in the first, say, 10,000 miles, replacing it makes a lot less sense than if it's forever getting longer.