Tensioning woes

[3liter914-6]

'88 944S. Was parked for approximately 7-8 years before it came to me so I'm doing a full front end refresh. Came with a 920X and I'm really struggling to get it to work. Timing is spot on, but things aren't behaving like the instructions make me think they should.

I've calibrated the 920x -- inserted the bar and moved the dial to the correct setting (84). With belt tensioned on spring loaded tensioner I turn the crank 2 full rotations to get back to #1 TDC. Based on the somewhat arbitrary metrics (twist test, WP pulley turn) this is too tight. I've then installed the tool, turned the engine CCW (~10º or 1.5 teeth) until the gauge stops increasing to move the slack to the upper span. Here it's way too loose (
I get a reading of .16x or .17x and attempts at adjusting the tensioner barely move the needle in either direction. I'm probably going to just try and set the tension based on the WP turn test, but before I just send it I just want to make sure I'm not missing something so I can still do it right.

[3liter914-6]

Tracked down the instructions for the newest 920X (I seem to have the original V6) and the instructions no longer give the advice to turn the engine CCW until max slack is achieved on gauge. With that in mind I think I've gotten it reasonably close. I just used my hands to free up as much slack as possibly by tugging on the upper span and then tensioned according to the gauge. Seems to be roughly within spec per the twist test and WP spin test. Retensioning the balance shaft belt seemed to work fairly smoothly with the tool, although I ended up having to retime the shafts to each other a few times. Everything's spot on now, so back to getting the rest of it buttoned up.

[Tom]

I really need to adapt my 3D printed tool for use with the 16 valve motors. The 920x is a highly accurate tool, but simplicity isn't its strong suit. Glad you got yours sorted.

[3liter914-6]

Yeah, I printed your tool back when I was about to buy an 8V car. The guy sold it out from under me, but I ended up finding a lower mileage 16V car for less money two days later so I was pretty happy with how it all worked out, until it came time to tension the belt. Then I was wishing I had the option of some PLA printed simplicity.

[JamesM]

I have found myself using a mix of the 920x manual and what the factory service manual says to do and haven't had any issues. I always turn over twice and then one counter turn 10 degrees then read tension then to check I do the same and adjust as necessary. fwiw, I found the arnnworks throttle body reseal kit manual for my s2 somewhat confusing so although he made great products I don't find his manuals on how to use them particularly great.

[walfreyydo]

I believe all 8V and 16V cars 87 and later have an auto-tensioner which does not require the tensioning tool.

Are you are just wanting to double check the auto-tensioner tightness or did you (or PO) convert to a manual/early model tensioner? I guess there is no harm in double checking

[3liter914-6]

Opinions seem to be mixed on whether the tool is required on the springloaded tensioner. I know at one point there was a technical bulletin from Porsche describing the tensioning procedure with just the spring tensioner but following that and confirming that I had completely free movement it felt way too tight -- completely unable to turn the WP even with both hands (and I have a very strong grip) -- and I've seen others report that checking with the tool revealed incorrect tensioning with the trust the spring approach. So I wanted more of a belt and suspenders approach.