V6 Timing chain questions.

[delcowizzid]

On way the chain stretches enough it slaps the tensioner off seen many a vn with it in the sump lol. The chain allready gets a lot of oil from the front main bearing if you want more file a slight angle on the parting line/end of one bearing shell so it squirs more oil forward

[vlad01]

I haven't had that happen personally, but a mate of mine had it happen to his VY and it drove fine for years with the shoe missing on the damper. We changed the engine out when it died at 355k when it broke a valve spring and damaged the valve guide a little. Not knowing if it kissed the piston or not, we changed it out to be safe. I took the engine apart a few years later, the bottom end was in top shape despite bits of plastic floating around in there.

[OZ38]

Never liked the stock OEM Tensioner slipper/shoe material used. Seems way to brittle & most seem to have a built-in crack running across them. Recently replaced the chain & tensioner in my ecotec VY ute with 420,000k with OEM replacements.
There was a small chunk missing from the bottom of the old tensioners, so assume it is sitting in the sump somewhere now. I did have two new ZZp Tensioners, but did not want to waste either on my old 400k+ engine.

[vlad01]

That split is actually an illusion, it is the flow boundary where the molybdenum disulphide flakes are turned edge on due to the direction of flow change during injection moulding from where flow boundaries meet. Exactly the same like when you stir metallic paint and you get those dark/black lines in the patterns no matter how much you mix.


Going back to my VW days, often people complained of bad NOS front arm thrust bushes (made of exactly the same moly impregnated hard resin plastic). The claim was all NOS bushes were cracked due to age, but there where no cracks in 90% of cased and real cracks that formed from wear and tear seldom followed the apparent cracks. To a blade, nail run over them or even sawed in half. these lines where just an optical illusion. It's the same in these dampers. But the plastic is hard and somewhat brittle despite good wear properties.

Sometimes those boundies can form weak spots if the injection was a bit on the low temp/pressure side for the plastic used. But looking at the dampers I have all removed and installed, none had dry moulding and appeared done well. Mine that did chip or wear pitted, none had any evidence of that line causing any issues.

I have seen micro pitting from what looks like friction burning/lack of sufficient oil. That one was on my shitbox which has lived most of it's life at way higher rpm than typical.

My gist on the ZZP ones is that they sound like they might be a little more pliable and softer. This should prevent breakage and may help with being less bouncy, but might wear quicker in certain conditions. That should take a beating better on a performance cam and chain though, so should be better for this type of application in my mind over the OEM material.

[vlad01]

On way the chain stretches enough it slaps the tensioner off seen many a vn with it in the sump lol. The chain allready gets a lot of oil from the front main bearing if you want more file a slight angle on the parting line/end of one bearing shell so it squirs more oil forward

That's a good tip!

Probably better to do on the driver side to avoid reducing the oil wedge before it does it's job though. I could be making the wrong assumptions though.

I feel like this sort of stuff needs a dedicated stand mounted r&d motor, where you can have openings and windows in the timing cover to watch what is going on under operation and have a means of measuring oil flow/consumption of the oiling system. High speed cameras are a great tool for this type of thing too.

[Rhysk94]

Or just run the Rollmaster dual row kit without a tensioner and be done with it....