brianrheffron

While jumping from linK to link on 928 sites recently I came across an article about a very simple home made TB tension tool. It was basically a rectangle of 1/4 inch acrylic sheet with one end that slotted over the TB. It twisted the TB by its self weight and the other end deflected an amount hat could be easily measured. Once calibrated (on a belt correctly tensioned using the official tool) it gave an accurate and repeatable way of setting the tension. The article had a dimensioned diagram and full instructions for making and using the device. Despite hours of searching I can't find this information again. Can anyone help? Also does anyone have any comments on this method of tensioning the TB.

Jim bailey - 928 International

Seems much simpler to just buy a calibrated Kempf tool for $59 Than to make a tool then test it against a known correct tension. But I am probably biased because they are made for us and we sell them. There is also a method of adjusting them to a musical note Jaeger Engineering has a sound clip as I recall.

RyanPerrella

although the Kempf tool is simple in its design, I WOULDNT TRUST ANYTHING home made for something as critical as timing belt tension on a 928. Unless of course it came from PorKen, then maybe, but buy the Kempf tool, or come to think of it, there is something from Ken..... buy a porkensioner and not ever deal with tension issues again!

SharkSkin

If it's a non-interference engine then it's not so critical. Where are you located? Not many people will loan tools to people they don't know(and who are far away) but maybe someone near you would be willing to bring their tension tool by and help you out for the cost of a beer and a pizza(or less).

Lizard928

Sorry Ryan, but I am going to have to respectfully disagree with you on this.

A timing belt is a timing belt.
The 928/944 are the ONLY cars that I know of that everyone appears to be **** retentive over.
I have done timing belts on everything from hondas, vw, audis, 924/931. As well as the 928 and 944.

Sure they need to be in an acceptable range, I agree, but anyone who has done timing belts on other cars and has mechanical knowledge should be able to set the belt tension close enough just by hand/ear. I did it that was for years till I got the porkensioner. I have never had ANY issues related to it.
The factory tensioner says to set the 32V engines at what 5.3 yet the belt light doesnt even go off till the belt is at 4.0 That is a very wide range of adjustment.

I have 5+ other 928s and 2 944s running around with no issues on belts which I have just tensioned to ear. All of them have had ZERO belt issues, light never goes off either.

IMHO it is not as big of a deal as most make it seem. Regular scheduled belt/pulley changes are still required with inspection of the gears etc. If that is done it is not an issue.
The only 928s I know of that have suffered a broken belt, or a problem related to the belt have been from a siezed waterpump, lack of maintenance, or being tensioned WAY WAY too tight and destroying bearings and cams faster.

UKKid35

Here's some thoughts on the different tension tools

https://rennlist.com/forums/showpost...1&postcount=32

And here is the pattern

http://jenniskens.livedsl.nl/Technical/TensionTool.htm

However I don't recommend it, it's simply too awkward to use.

RyanPerrella

I'm sure your right about it being no different. But there are consequences to being too loose or too tight. So for a DIYer like myself the tool is a must, if for nothing more then to get any doubts out of your mind at a later time. After spending 8-10 hours going through and replacing the belt and pulleys and possibly gears, i think its foolish to pay such little attention to the belt. Some people check it once, not me i go over EVERYTHING 3-4 times, why not, i am not working on the clock.

Yes i am **** about it, i checked it a half dozen times to just to be 600% sure.

On a Non interference engine it is of much less concern. Hell you may even just run those things and only replace belts when they break!

blown 87

The 928 belt seems much tighter than any other belt I have ever put on, and that is a bunch of them.
If you are used to "what feels right for other motors" I will almost promise you it will be to lose for a 928.

Greg Nettles

mark kibort

twist it as hard as you can at the measuring point. if it goes 90 degrees, and not any farther, its about right

OR, you can use the easy check method. the back side of a drill bit or allen wrench, pushed in until about as hard as you can. (with a mark calibrated from using any of the specified tools )

see attached pic