F....... up TB/WP job
#61
Code:
"The factory tensioner is FINE. It is superior in that it has a low belt tension warning."
And the tracking fails on the stock tensioner due to the use of plastic bushings that wear over time. The hydraulic tensioner has no such failure point.
Furthermore, don't kid yourself if you think you will be as lucky as Imo if your water pump freezes and the tension light comes on with the stock tensioner. By the time most people will realize what is happening, it will be too late.
Dan
'91 928GT S/C 475hp/460lb.ft
#62
Haha, wow. My reading comprehension is just fine, because you said exactly:
In this case, "It" in the "It is superior" statement refers to what was written in the previous sentence, which was "The factory tensioner".
And the tracking fails on the stock tensioner due to the use of plastic bushings that wear over time. The hydraulic tensioner has no such failure point.
Furthermore, don't kid yourself if you think you will be as lucky as Imo if your water pump freezes and the tension light comes on with the stock tensioner. By the time most people will realize what is happening, it will be too late.
Dan
'91 928GT S/C 475hp/460lb.ft
Code:
"The factory tensioner is FINE. It is superior in that it has a low belt tension warning."
And the tracking fails on the stock tensioner due to the use of plastic bushings that wear over time. The hydraulic tensioner has no such failure point.
Furthermore, don't kid yourself if you think you will be as lucky as Imo if your water pump freezes and the tension light comes on with the stock tensioner. By the time most people will realize what is happening, it will be too late.
Dan
'91 928GT S/C 475hp/460lb.ft
My stance is there is no need to change the design of the tensioner. It works perfectly. Yes it needs to be maintained but any of them do (the roller on the Audi tensioner can cause tracking issues too, just not as likely). I have never seen a properly maintained Porsche tensioner fail. Greg Brown uses the factory tensioner. And while there may be personal issues between Ken and Greg, he wouldn't hesitate to do something to make his engines better. His reputation rides on it.
#63
And the tracking fails on the stock tensioner due to the use of plastic bushings that wear over time. The hydraulic tensioner has no such failure point.
Furthermore, don't kid yourself if you think you will be as lucky as Imo if your water pump freezes and the tension light comes on with the stock tensioner. By the time most people will realize what is happening, it will be too late.
Dan
'91 928GT S/C 475hp/460lb.ft
Furthermore, don't kid yourself if you think you will be as lucky as Imo if your water pump freezes and the tension light comes on with the stock tensioner. By the time most people will realize what is happening, it will be too late.
Dan
'91 928GT S/C 475hp/460lb.ft
#64
With as new components, a functional warning light, and routine service, the belt may be kept tight on the gears by the factory tensioning system.
For all the reasons mentioned in the dissertation above, the belt on a performance engine is better managed by a PKT, 04 cam gears, and a Racing belt.
Last edited by PorKen; 05-02-2013 at 02:08 PM. Reason: formatting, B.
#65
For all the reasons mentioned in the dissertation above, the belt on a performance engine is better managed by a PKT, 04 cam gears, and a Racing belt.
Don't get me wrong, Ken, I respect what you do. I just prefer data to speculation and conjecture. I also don't believe in change for change sake.
By the way, I use the 32v'r tool to set my timing.......
#66
Timing belt failure, from my reading here, has mainly come from three sources:
1. Water pump failure. Factory warning system will give you a heads up (a very short one).
2. Shoulder bolt failure. Factory warning system will give you a heads up. Bolt is not required with PK tensioner so that failure is eliminated.
3. Oil pump gear comes off. Factory warning system will give you a heads up ( again, a very short one).
I have never seen a failure from an old belt or under tensioned belt. It is always a mechanical device that fails which in turn destroys the belt. The PK tensioner in one of these failures will just keep sucking up the slack until it runs out of adjustment room and/or the belt snaps with no warning to the driver.
The PK tensioner has its advantages, no need to manually adjust, less stress on gears and rollers and more even, steady tension at varying temperatures. It all comes down to your risk tolerance.
1. Water pump failure. Factory warning system will give you a heads up (a very short one).
2. Shoulder bolt failure. Factory warning system will give you a heads up. Bolt is not required with PK tensioner so that failure is eliminated.
3. Oil pump gear comes off. Factory warning system will give you a heads up ( again, a very short one).
I have never seen a failure from an old belt or under tensioned belt. It is always a mechanical device that fails which in turn destroys the belt. The PK tensioner in one of these failures will just keep sucking up the slack until it runs out of adjustment room and/or the belt snaps with no warning to the driver.
The PK tensioner has its advantages, no need to manually adjust, less stress on gears and rollers and more even, steady tension at varying temperatures. It all comes down to your risk tolerance.
#67
Timing belt failure, from my reading here, has mainly come from three sources:
1. Water pump failure. Factory warning system will give you a heads up (a very short one).
2. Shoulder bolt failure. Factory warning system will give you a heads up. Bolt is not required with PK tensioner so that failure is eliminated.
3. Oil pump gear comes off. Factory warning system will give you a heads up ( again, a very short one).
I have never seen a failure from an old belt or under tensioned belt. It is always a mechanical device that fails which in turn destroys the belt. The PK tensioner in one of these failures will just keep sucking up the slack until it runs out of adjustment room and/or the belt snaps with no warning to the driver.
The PK tensioner has its advantages, no need to manually adjust, less stress on gears and rollers and more even, steady tension at varying temperatures. It all comes down to your risk tolerance.
1. Water pump failure. Factory warning system will give you a heads up (a very short one).
2. Shoulder bolt failure. Factory warning system will give you a heads up. Bolt is not required with PK tensioner so that failure is eliminated.
3. Oil pump gear comes off. Factory warning system will give you a heads up ( again, a very short one).
I have never seen a failure from an old belt or under tensioned belt. It is always a mechanical device that fails which in turn destroys the belt. The PK tensioner in one of these failures will just keep sucking up the slack until it runs out of adjustment room and/or the belt snaps with no warning to the driver.
The PK tensioner has its advantages, no need to manually adjust, less stress on gears and rollers and more even, steady tension at varying temperatures. It all comes down to your risk tolerance.
#68
I think it is a great system for tensioning the belt, but you have to be confident in the rest of the components in the system as they are usually the ones that cause the failure, not the tensioner.
#69
In my experience the oil pump gear remains in place when the nut is torqued properly with some blue loctite added.
Regular maintenance of the coolant system eliminates the pump seizing concern. Check the pump when replacing the belt at the recommended interval, 100k kms or 5 years, whatever comes first.......your level of maintenance may vary.
I have new cam, crank, oil pump gears with a new water pump, Gates belt and PK fitted to my GTS. Have approx 1000km on the car since with no concerns. Will report back in 6 months or much later
BTW I also added new coolant hoses, fluid and cleaned the rad while it was out. Car is 20 YO and is now good for another 20.
Last edited by the flyin' scotsman; 05-03-2013 at 05:34 PM.
#70
Mine got a new pump, gates belt and a pk tensioner. 12k later no issues.
The main advantage of the pk is automatic adjustment unlike the manual adjustment of the stock tensioner.
Granted if your stock tensioner is good there is no need to change it. But if like mine completely shot, the pk tensioner is a modern maintenance free alternative.
I like it.
Now lets get this thread back on topic an stop the tensioner pissing war.
😱
The main advantage of the pk is automatic adjustment unlike the manual adjustment of the stock tensioner.
Granted if your stock tensioner is good there is no need to change it. But if like mine completely shot, the pk tensioner is a modern maintenance free alternative.
I like it.
Now lets get this thread back on topic an stop the tensioner pissing war.
😱
#71
Sorry, I avoid tensioner threads these days (no need), but I often do my best thinking in the 15 minute post edit window.
It has taken many a tensioner thread and some arguing with folks for me to understand the concept behind the old belt tensioning systems vs. the new belt control systems.
To get past the 9201 stretch measurement to see that the overall goal was and is to maintain control of the belt between the crank and 1-4 gears.
The pre-stretch model works in a narrow temperature range, but, because it is an indirect method, it is weak at the extremes, hence the pulleys, and the startup delay on the warning light.
The control model directly manages the belt as it rolls past. Besides working at all temperatures/rpm, it can use lower overall tension, and it also has the benefit of not allowing belt flap.
#72
And...to reiterate...the reason I initially posted, the stock tensioner cannot be used with the Racing belt, as the Racing belt does not stretch.
(Which is good, if you like consistent cam/valve timing.)
(Which is good, if you like consistent cam/valve timing.)