[alfa] the workings of V6 tensioners

[f.rastinejad@xxxxxxx]

I have tried to understand the oil-fed tensioner, but one thing just doesn't seem right.  I accept that the high oil pressure functions at high revs to loosen the tension, and that when starting the engine (zero oil pressure) the tension is at its highest as one would want.  However, with the cold engine, the oil pressure is always high (at least for a few minutes after start-up) causing the belt tension to get loose.  I would think that during this time one would need higher tension since the aluminum has not yet expanded.  So does it stand to reason that the oil fed tensioner can't possibly be there to adjust for expansion of the aluminum block as stated by some?

On the other hand, the "replacement" tensioner, being thermally controlled, can compensate for the thermal expansion, but when one tries to start a hot engine the tension is low just as we need the belt to be tight. 

Am I missing any key facts?

-Farzan (never had a belt slip when starting from cold or hot!)


Original message from Joe Elliott : -------------- 

I understand why 
> Alfa did it the way they did it, but it was really overkill, and 
> perhaps more importantly, had some drawbacks. Eliminating the oil 
> feed gives you pretty much constant tension all the time, and it 
> actually responds to thermal expansion directly (which it did all 
> along--the added feature of the oil feed was that it would back off 
> the tension at high RPM when the cams have more momentum--clever, but 
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