Modification on 3.0 V6 timing belt tensioner

[danv6lx]

Hi, all,

I have just finished a small "project", or rather a part of the minor restoration of my Thema and I thought I'd share it with you.
Fear not, I have not reinvented the wheel , I have only converted the hydraulic belt tensioner on my Thema 3.0 V6 to a mechanical Bi-Metallic tensioner, of the newer V6 models.
I have attached some pics and would be happy to supply further information, pics and help on how to do it and what is involved, should anyone need this.

Dan

The new tensioner, original part.

Small detail, the small nut that blocks the oil return passage of the old tensioner.

[ALFAHEIDA]

Thnx, for sharing. Personally I don't like the mechanical tensioner and rebuild the hydraulic tensioner incl. new bearing.
I order these kits from Jason Minos at Alfissimo.com.

Regards,

Erwin

[danv6lx]

Hi,
Thanks for the tip for the source of the rebuild kit for the tensioner.
Only it came to me too late, I must admit that I haven't been able to find a rebuild kit, let alone the bearing, so I had to go for this solution as my only alternative for peace of mind as far as the timing/distribution on my V6 is concerned.
The last bearing I could get my hands on was gone the moment I saw it and since it is out of production and no sustitutes are around, I was disappointed.

I am aware that a rebuild gives one peace of mind for a very long time, especially since these bearings are practically indestructible.

Why would you consider the mechanical tensioner to be inferior to the hydraulic? I am really interested in your views, since it seems that you know what you're talking about.

Dan

[ALFAHEIDA]

I drive my cars only three months a year, the rest of it they spend in a huge garage. Sometimes they have to move, and if you don't have a key and begin to push the car it will harm the timing belt. You can (with a mechanical one) push it out of time, with all kinds of trouble that can happen. That's one minor thing, but further the hydraulic tensioner is much saver, and stronger.
Only thing is that they can begin to leak oil.
Since Jason is selling them, and as long as it's for sale I will buy these.

But the mechanical solution is also a nice one Dan.

[danv6lx]

Hi, Erwin,

I totally agree with you, this is probably the reason why Alfa Romeo themselves emphasise at least ten times in the instructions video, never to rotate the engine counterclockwise, as there's a very high possibility for the belt to slip a tooth or two.

On the other hand, I hate the idea that the hydraulic tensioner might start leaking, not much, so to leave a stain on the ground, but enough to moisten the belt with oil and make it again slip a tooth or two.

I read somewhere that this conversion is only possible and advisable on later V6 models (Thema, AR 155/164), which have the cam and crank pulleys for the thicker and rounded-up teeth on the belt, as opposed to the not-so-thick and squared ones on e.g. 2.5/3.0 GTV6 and 75 models, as there is a higher chance for the belt to slip teeth. Do you know anything about this?

Would you happen to know whether there is a slight power improvement if the cams are advanced by a tooth or two on the belt. I was told that it is possible, and still safe, without any danger of bending the valves.

Dan

[ALFAHEIDA]

Dan,

I even have done this with my 75 3.0 America. No problem at all. Abouth the setting from the cambelt, I know abouth this but never done it on my cars.
The 3.0 version is quick enough, and every version has it's own caracter. I like it like that.
There are other options to make the car a little more agressive.....

Regards,

Erwin