In my family, the case of destroyed Z22SE engine occurred, due to its tensioner failure.
Therefore, I have been examining plenty of forum posts at many forums oriented to Opel and their Z22SE engine but still the information was not complete enough.
Happy to discover exactly the info source as offered in discussions here - thanks especially to rookeee, rushy and ATOM X.
In summary, the most valuable info for me as collected in this "z20net tensioner for z22se engines" topic are:
rookee: For the timing chain there is also an official statement by Opel advising to mount the z20net tensioner along with chain
rushy: All i can tell you that in 5 years on the vec c forum I have not seen 1 chain/tensioner failure on any z22net, yet I still see plenty on the z22se and the yh, with most yh failures being the tensioner.
The net has to be the most reliable lump in the fleet.
ATOM X:
- z20net is spring loaded with oil pressure override once activated
- z22se has a spring but is wholly dependant on oil pressure (similar principal to hydraulic tappets)
I ONLY RECCOMEND Z20NET/B207 TENSIONERS
At this web I have also discovered that Genuine GM Timing Chain Kit - Includes Chain, Z20NET Tensioner, Bolts , Guides and Sprockets - Part Number: 55570337. Fits the Z22SE engines
So, the kit already contains Z20NET.
My conclusions:
Right tensioner should operate so as the Z20NET probably works: similarly to hydraulic tappets.
After receiving that info, I studied the principle of such a device. The explaining article found to this purpose, may be reached here:
http://www.volvoclub.org.uk/tech/HydraulicTappets.pdf
So, the tensioner should remember the latest position of its piston - maximum reached extrusion from its cylinder. At the same time, this value represents the degree of the camchain extension (caused by its wear).
Even car brake control works based on similar principle enabling to take into account the brake plate successive reduction of its thickness.
Now, to trust the Z20NET tensioner definitely, I would like to see its internal arrangement distinctive from its cutting view.
Would someone be able to get such a drawing and publish it here?