z20net tensioner for z22se engines

rookee

Member
i currently got lost. :eh:

what needs to be done when changing chains on z22se engines? :think:
1. timing chain: mount z20net tensioner or z22se tensioner?
2. balancer chain: mount z20net tensioner or z22se tensioner?

for the timing chain there is also an official statement by opel advising to mount the z20net tensioner along with chain.
for the balancer chain i did not hear anything about mounting another tensioner because the z22se balancer chain tensioner is already activated by a spring.
 

ATOM X

Senior Member
adam4412 said:
if you take the NET tensioner apart you will find it too contains a spring adjuster the same as the SE, this needs to be activated otherwise the chain is not under tension when there is no oil pressure.

I have never seen a oil pressure only tensioner.
I have edited both my statements
 

rookee

Member
@atom: what's the reason for you to only recommend NET-tensioners? i still don't understand the advantage of it; both have a spring and are more or less dependent on oil pressure... :eh:
 

rushy

Senior Member
rookee said:
@atom: what's the reason for you to only recommend NET-tensioners? i still don't understand the advantage of it; both have a spring and are more or less dependent on oil pressure... :eh:
All i can tell you that in 5 years on the vec c forum I have not seen 1 chain/tensioner failure on any net, yet I still see plenty on the se and the yh, with most yh failures being the tensioner. The net has to be the most reliable lump in the fleet.
 

jwalker

Senior Member
Does the end of the z20net tensioner need to be oriented in any particular way when it is fitted, or is just a case of activating and bolting it in?
 

favo

Member
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?
 

favo

Member
Apologize for wrong citation of ATOM X in my previous post
Correct citation is:
"z20net has a spring but is wholly dependant on oil pressure (similar principal to hydraulic tappets)"
 
Top