One man's tensioner solution
03-15-2007, 09:12 PM
#31
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Thread Starter
Originally Posted by marton
I can not believe that Volvo would build a tensioner that had different design requirements (in concept) from the Porsche one. I mean that it would be designed to maintain the correct belt tension as the motor cycled from cold to hot, etc.
Marton
Marton
That's exactly the premise which started me on this idea!
Hammer
03-15-2007, 09:15 PM
#32
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Thread Starter
Originally Posted by 928ntslow
Hammer, I think the reason some of us are making comments just beyond observing, is because it certianly would be nice to have a tried and true tensioner that does NOT need to be adjusted manually. As Jim said, most belts aren't even close to spec...and I know this first hand from checking several myself. It's a wonder there aren't more failures! This is an important subject because it is the difference between peace of mind having an automatic, reliable, constant belt tension and ...well, catastrophic failure. Stuff like dis get attensheeown! 
I agree. I pursued this for that reason. I want to build the motor, set the tensioner & forget it. There's too many other things that also need attention on the car. I like, no, love the 928 concept. Just tryin' to polish it.
Hammer
03-15-2007, 09:44 PM
#34
Rennlist Member
Thread Starter
Hi Adam,
Off the top of my head, 30730060? (I'm at home with beer & company.)
You obviously discard the leverage assembly. It changes the dynamics & would make it unsuitable for this application.
Hammer
Off the top of my head, 30730060? (I'm at home with beer & company.)
You obviously discard the leverage assembly. It changes the dynamics & would make it unsuitable for this application.
Hammer
Last edited by 6.0-928S; 03-15-2007 at 10:12 PM.
03-16-2007, 10:11 AM
#37
Addict
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Porsche designed washers to contract x distance when they heat up. This x can be measured by experimenting same as its possible to measure what Volvo part does when its heated and cooled. If both give close enough results then I can't see any problems on updating to Volvo part.
03-16-2007, 10:40 AM
#38
Three Wheelin'
Hammer, congratulations on the excellent work. Please allow me to babble about tensioners while everyone's here. 
Sounds like a damped spring would be ideal as long as the force applied by the spring was enough to tension the belt tight enough and the damping was enough to prevent flutter and allow it to slowly move with temperature change.
That seems simple, what's missing? Is the reason Porsche used the 928 system because it requires more force on the belt than a spring plunger would allow? Blown87 once made an observation that the tension specified for a 928 is much more than he sees working on other cars. Did the Porsche engineers feel that they needed to really clamp down on the belt and not permit it to fluctuate? Who wants to get a job at Ferrari and see what they do with their modern V12's. They seem to have a long timing belt on the new generation 612 engine, I wonder how they tension it?
Sounds like a damped spring would be ideal as long as the force applied by the spring was enough to tension the belt tight enough and the damping was enough to prevent flutter and allow it to slowly move with temperature change.
That seems simple, what's missing? Is the reason Porsche used the 928 system because it requires more force on the belt than a spring plunger would allow? Blown87 once made an observation that the tension specified for a 928 is much more than he sees working on other cars. Did the Porsche engineers feel that they needed to really clamp down on the belt and not permit it to fluctuate? Who wants to get a job at Ferrari and see what they do with their modern V12's. They seem to have a long timing belt on the new generation 612 engine, I wonder how they tension it?
03-16-2007, 11:30 AM
#40
Rennlist Member
Originally Posted by JKelly
Very cool. I hope it works! 
With all due respect:
you are a brave man. that idea looks GRRRREAT... but you have a lot at stake if it doesn't work. You got ***** buddy, I like that in a fellow p-guy.
Last edited by Shark Attack; 03-16-2007 at 02:17 PM.
03-16-2007, 11:56 AM
#41
Supercharged
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Originally Posted by Shark Attack
You got ***** buddy, I like that in a fellow p-guy.
(Hey, It's Friday!)
sick and wrong 
