Updated chain wheel support?

[project 911]

Hi All-

I'm thinking of updating my 70 2.2 to the newer style chain wheel supports. From what I've seen, I'm looking for the 80.5 and up versions. I found some advertised as follows:

These are from an early 80's 3.0L engine but the part numbers on the gears are the same 84 Carrera 3.2L which was the same for 3.3L Turbo's as well.

My question - Is there an easy way to tell visually if these are the wider ones? Do they have a bronze bushing or anything?

Also, can these be used with my original 2.2 tensioners (rebuilt + collars), or do you have to have the 930 tensioners?

Pressure fed versions aren't in the budget just yet.

Thanks for any advice.

[Early_S_Man]

The latest chain wheel supports have two bronze bushings and a gap in-between the bushings ... if you look carefully with a flashlight.

[oldE]

Steve,
The description sounds like the newer style. If these are, they will have a mounting ring which is about 10 mm wider than the one on your current chain wheel supports.
That means you have to upgrade your tensioners to a later style (either pressureized or non pressure with collars).
Les

[project 911]

Here's a pic of them. I can't see any bronze bushings in there. Can you tell anything from the pic?

[1yearonLy]

This may be a dumb question but what's the procedure to switch the wheel from the older style idler arm to the newer style? Is there any special tool and/or any special preparation needed?

I would think something spinning non-stop like that would require some care in assembling.

Thanks.

[Jeff Higgins]

Those look like the narrow ones, Steve. The newer, wider ones have the side of the pivot boss that can be seen in your photo (the side towards the tensioner "foot") coming out about flush with that tensioner foot. That's the whole idea; to better support it in line with where the tensioner puts pressure on it.

You can't use your old tensioners with the new idler arms. They share that common mounting pin. When the boss on the idler arm gets wider, it intrudes into the space needed for the boss on the tensioner. The 930 tensioners have a narrower boss to accomodate this.

Take a look at the price of a new set of 930 tensioners. You will notice it's not much less than the Carrera pressure-fed kit. I just went through this myself. I wound up with the Carrera tensioners.

[project 911]

Thanks for the input everyone, I appreciate it. Guess I'll pass on these.