928 tming belt tensioner
06-06-2016, 03:32 AM
#1
1st Gear
Thread Starter
Join Date: Jun 2016
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
928 tming belt tensioner
Hello all, I am planning to have my timing belt replaced for my 928S Automatic from 1983. I could have that done in the original 'normal' way with standard belts.
However I read about the 'porkensioner', an additional timing belt tensioner. Do any of you have experience with this tensioner? Is it really needed or is is it sufficient to install everything in the original way? Thank you for your reactions!
Regards,
Johan
However I read about the 'porkensioner', an additional timing belt tensioner. Do any of you have experience with this tensioner? Is it really needed or is is it sufficient to install everything in the original way? Thank you for your reactions!
Regards,
Johan
06-06-2016, 03:57 AM
#2
Hello all, I am planning to have my timing belt replaced for my 928S Automatic from 1983. I could have that done in the original 'normal' way with standard belts.
However I read about the 'porkensioner', an additional timing belt tensioner. Do any of you have experience with this tensioner? Is it really needed or is is it sufficient to install everything in the original way? Thank you for your reactions!
Regards,
Johan
However I read about the 'porkensioner', an additional timing belt tensioner. Do any of you have experience with this tensioner? Is it really needed or is is it sufficient to install everything in the original way? Thank you for your reactions!
Regards,
Johan
Here is the most recent thread
https://rennlist.com/forums/928-foru...-extended.html
06-06-2016, 09:54 AM
#3
Rennlist Member
This has become a bit of a religious debate on this forum. I elected to go with a PKT and I'm happy with it. That being said, the stock tensioner system does what it's supposed to do, however you do have to take a bit more post-installation care to ensure it continues to do so. One of the many gripes (some) people have with the PKT is that it removes the tension warning, but I'm pretty sure '83 doesn't have that (?) so that issue would be a moot point for you.
06-06-2016, 10:13 AM
#4
Nordschleife Master
Oh my.
This is a somewhat controversial topic.
If you read the linked thread, you will find it to be a rather contentious discussion. The actual developer of the PKT (PorKen) participated, but abandoned it after repeated vicious personal attacks by a couple people who really don't like it.
The original tensioner is perfectly adequate. It was installed on over 60,000 cars and has probably logged in excess of 300,000,000 miles (three hundred million miles - estimate 60k cars each going 60k miles).
One of the more experienced mechanics has said that the tensioner itself never fails. It's always another component along the belt path (water pump, cam nose breaking, ect).
But, the factory tensioner only adjusts for heat. It retracts as it heats up to reduce the tension as the block heats up and expands. It doesn't adapt for any other condition. As such, the set (static) tension on the belt has to be fairly high. This puts a fair amount of stress on the other components in the belt path (like the water pump, cams, ect). Also, when a belt is installed, the tension must be checked and usually adjusted as the belt breaks in and stretches.
The PKT is an Audi tensioner with a bracket to mount it on the 928 motor. It's a "tensioner/damper", similar to a suspension strut. It expands under spring pressure to maintain reasonably constant tension, with the ability to extend and take up any slack in the belt as needed. It will also retract as needed, but the design makes it retract slowly, so as not to allow the belt to slack too much.
The PKT allows the static tension on the belt to be a lot lower, which puts less stress on the components along the belt path. One of the arguments against the PKT is that it doesn't put enough tension on the belt, yet there is only one known case of the belt jumping time with a PKT installed when the mounts stayed put (there were a couple where the mount failed, PorKen revised the bracket and hardware as a result of that). And on that one, the installed T/D was over extended.
There's a huge argument on why Porsche used the tensioner they did, and why they didn't go with a T/D like the PKT (they put a similar one on the later 968 motor).
There aren't any really good numbers for how many PKTs are out there. Guesses run from the low thousands on up. Some people have installed them, and then gone back to factory, but those are a minority.
Even one of PorKen's worst detractors admits that it's a viable alternative for a 16v motor (which your 83 has).
I strongly suggest doing your own research and making up your own mind.
Disclaimer: I like PorKen and his ideas and products. I have a PKT on my car (85 Euro 16v) because after doing the research I liked it. Easier to maintain and check, less tension means less stress on the components. I also have a set of his liftbars. I got one of the first sets when he resumed production of the "Old Body" style ones.
This is a somewhat controversial topic.
If you read the linked thread, you will find it to be a rather contentious discussion. The actual developer of the PKT (PorKen) participated, but abandoned it after repeated vicious personal attacks by a couple people who really don't like it.
The original tensioner is perfectly adequate. It was installed on over 60,000 cars and has probably logged in excess of 300,000,000 miles (three hundred million miles - estimate 60k cars each going 60k miles).
One of the more experienced mechanics has said that the tensioner itself never fails. It's always another component along the belt path (water pump, cam nose breaking, ect).
But, the factory tensioner only adjusts for heat. It retracts as it heats up to reduce the tension as the block heats up and expands. It doesn't adapt for any other condition. As such, the set (static) tension on the belt has to be fairly high. This puts a fair amount of stress on the other components in the belt path (like the water pump, cams, ect). Also, when a belt is installed, the tension must be checked and usually adjusted as the belt breaks in and stretches.
The PKT is an Audi tensioner with a bracket to mount it on the 928 motor. It's a "tensioner/damper", similar to a suspension strut. It expands under spring pressure to maintain reasonably constant tension, with the ability to extend and take up any slack in the belt as needed. It will also retract as needed, but the design makes it retract slowly, so as not to allow the belt to slack too much.
The PKT allows the static tension on the belt to be a lot lower, which puts less stress on the components along the belt path. One of the arguments against the PKT is that it doesn't put enough tension on the belt, yet there is only one known case of the belt jumping time with a PKT installed when the mounts stayed put (there were a couple where the mount failed, PorKen revised the bracket and hardware as a result of that). And on that one, the installed T/D was over extended.
There's a huge argument on why Porsche used the tensioner they did, and why they didn't go with a T/D like the PKT (they put a similar one on the later 968 motor).
There aren't any really good numbers for how many PKTs are out there. Guesses run from the low thousands on up. Some people have installed them, and then gone back to factory, but those are a minority.
Even one of PorKen's worst detractors admits that it's a viable alternative for a 16v motor (which your 83 has).
I strongly suggest doing your own research and making up your own mind.
Disclaimer: I like PorKen and his ideas and products. I have a PKT on my car (85 Euro 16v) because after doing the research I liked it. Easier to maintain and check, less tension means less stress on the components. I also have a set of his liftbars. I got one of the first sets when he resumed production of the "Old Body" style ones.
06-06-2016, 11:47 AM
#5
Rennlist Member
If only the OP had asked what kind of motor oil to use also, then we could cover both of the most highly debated topics in one Thread!! 