3D printed tensioning tool for 944S/S2 model

[SE_944ER]

Hello!

I own a 1987 944S 16V (M44.40) model and I found that the tensioning tool designed for the 8V already available does not work with the 16V model. It will be great if we can have one set up for the 16V models as well as when I tried modifying the current 3D printed tool it did not seem to work correct. Anyone who can lend a 16V motor to @Tom would be helpful for all of us.

Some reference images from my work.

Bigger boss under cam gear for 16V:

image1235.jpeg (115.03 KiB) Viewed 1577 times

Modification to 3D printed model for 8V:

image1237.jpeg (140.28 KiB) Viewed 1577 times

Placement after modification:

image1236.jpeg (163.73 KiB) Viewed 1577 times

[SE_944ER]

Hi,

I should have checked for compatibility of the tool over a 16V engine well before printing it as another fellow member pointed out in their thread. But I decided then, not to think any more and just give it (3D printed tensioning tool for 8V) a try. Even though that was not a good idea, it made me motivated to do the job (not with perfect tension but good enough), which I completed yesterday (AUG 17).

Issue was that the cam gear and the timing belt for 944S (same for 944S2) are different from rest of the 944 engines. So the tool for 8V wont have the calibration for a 16V one.

image (1).png (13.54 KiB) Viewed 1572 times

That being said, if I had known this before I would have not dared taking this job up and doing it myself.
All good in the end. Next week I'll take the car to Porsche center for checking tension and make it perfect.

So, a dedicated tool for the S models would be good to have as I'm not sure on buying a Porsche 9201/2 tool for a lot of money or wait till I get hands on a used 'Arnnworx' tool (not able to get new).

[icb]

Hi there!
When and if you can get your hands on the Arnworks tensioning tool, you'll have the exact same problem - It's not calibrated for the 44.40 engine's wider timing belt either. In my opinion, the best way to deal with this is to learn how to tension the belt by feel, and then you can can use your tension tool of choice with your own cal values. Take a look at my blog post on this subject for a more in-depth explanation of what I'm talking about: https://icb-machinations.blogspot.com/2 ... rd-it.html.

[ROB III]

SE_944ER
Good lord that engine looks clean!

[SE_944ER]

SE_944ER
Good lord that engine looks clean!

Thanks @ROB III
It was not great when I got the car and there are more areas that need attention which I hope/plan to do in the coming years. I lack the necessary tools though, probably acquire some day.

A shot from before if you're interested.

WhatsApp Image 2023-08-20 at 10.44.24 PM.jpeg (146.18 KiB) Viewed 1559 times

[SE_944ER]

Hi there!
When and if you can get your hands on the Arnworks tensioning tool, you'll have the exact same problem - It's not calibrated for the 44.40 engine's wider timing belt either. In my opinion, the best way to deal with this is to learn how to tension the belt by feel, and then you can can use your tension tool of choice with your own cal values. Take a look at my blog post on this subject for a more in-depth explanation of what I'm talking about: https://icb-machinations.blogspot.com/2 ... rd-it.html.

Hey @icb,
That is a great blogspot you've got and I admit I've almost similar experience going through the process.
But I was borrowing my friends garage for 4 weeks (or until I get to finish the job) and so I had less time to try and get a feeling for the tension for the belts and get my hands synced with it. Might get to that level some day but I'm still happy. Glad to see your page as well.
Thank you!

[ROB III]

SE_944ER
Good lord that engine looks clean!

Thanks @ROB III
It was not great when I got the car and there are more areas that need attention which I hope/plan to do in the coming years. I lack the necessary tools though, probably acquire some day.

A shot from before if you're interested.
WhatsApp Image 2023-08-20 at 10.44.24 PM.jpeg

Makes the current status all the more impressive.

[SE_944ER]

Hi @icb, @Tom,
Do you think if I get the Porsche special tool 9201/Volvo 998/8500, can I make use of it to verify belt tension and make it correct? I've not used them in person and so not sure how those tools work on any 944 engine including the 16v!

It would have been easier if there was opportunity to get the tool 3D printed but of course Tom will have to get hands on a 16V engine first.

[icb]

Hi SE_944ER
FWIW, I've not been fortunate enough to ever get my hands on a 9201. I had the chance to buy one that came up on ebay a couple years ago, for only about 500.00 (!!) if I remember correctly, but I let it go, thinking that I already have the arnworks tool, and I tension mainly by feel anyway. Of course it would have been great to get it and compare its readings with my Arnworks tool and also see how it fares when using the service manual procedure, which incidentally doesn't give a separate tension value for the 16v engine, which I think is an oversight/omission by Porsche, rather than an implied "it's the same as the 8V engine". Given the physical differences between the 8V and 16V belt size, and also taking the additional loads that rotating the M44.40 valve train puts on the belt, there's no way, in my opinion, that the same reading should be valid for both the 8V and the 16V belt.
But in my rambling way I'm getting off track. If you do get yourself a 9201, and learn to tension the belts by feel (water pump pulley method) as I suggested, I don't think there's any reason why you couldn't use the 9201 to set your own sensible tension reading value and use it for consistency.

[blueline]

Great Blogspot site you have - impressive, even to a mostly non-mechanic like myself. I skimmed part of the "Used Oil Testing" entry - talk about detail - wow!

"Gretchen" is obviously in good hands!