Kempf tool VS porsche 9201 tool PROBLEMS HERE!
08-13-2011, 10:50 PM
#61
Rennlist Member
Thread Starter
AFAIK Porsche invented 9201 for 944 cam and balance shaft belts and only aplied it to 928 as it was available. Other simpler tool was never replaced in a way that it could not be used anymore. Porsche just expected every shop to have 9201 so they did not bother to update other tool when later MY 928 had HTD and 32V changes.
but we dont know the history, so we are left to assume a bunch of this
Im just uneasy with the fact that the kemp tool is .5" out of the window area when set at 4.0, not even the 4.5 that the spec sees. plus, on the S4, however, it seems to match perfectly.
ill know for sure, when I test the kempf tool and 9201 on the S4.
no one answered my question about the tensioning checking method. ....
08-13-2011, 11:12 PM
#62
Addict
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Years ago we did little experiment with 9201 vs several different Kempf tools. All four Kempf's gave exact same results in '87 S4. 4.5 on 9201 was at lower end of Kempf scale and 5.2 (5.2-5.3 is correct for 32V) was right at the middle. Based on that test I haven't had any reason to suspect different Kempf's would give different results. Maybe there is manufacturing difference between individual Kempf's or batches of them. Ones we have have always worked and given results where belt warning is clearly below Kempf's lower limit. Way to measure belt with Kempf is to use 9th free opening counted from cam gear. This is right at edge against center cover and on top of tensioner housing.
How to use 9201 is matter of personal reference. It will give different results depending on how its turned. I think important thing is to be consistent. If you cannot replicate same result time after time you are doing something wrong.
How to use 9201 is matter of personal reference. It will give different results depending on how its turned. I think important thing is to be consistent. If you cannot replicate same result time after time you are doing something wrong.
08-14-2011, 01:00 AM
#63
Rennlist
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Greg, let me also ask you about the proper techique and reading of the 9201
Do you press on the body of the 9201 and then when you click the vertical slide into place, measuring belt tension, so you read the value that the max needle will read, or the final resting value that the measuring needle reads as you let go of the device???
in other words, when measuring the tension, there are two needles, one max and one actual. when you click in the measurment, and release the max value is higher than the final resting value and they are about 1 full point off each other.
Anyone can chime in here too!
as a side note, the pulleys from the euro that i showed were aluminum. the pulleys on the Petty motor here, are steel. both are OB style, non-HTD belt design. when did they change to steel?? or visa versa?
Do you press on the body of the 9201 and then when you click the vertical slide into place, measuring belt tension, so you read the value that the max needle will read, or the final resting value that the measuring needle reads as you let go of the device???
in other words, when measuring the tension, there are two needles, one max and one actual. when you click in the measurment, and release the max value is higher than the final resting value and they are about 1 full point off each other.
Anyone can chime in here too!
as a side note, the pulleys from the euro that i showed were aluminum. the pulleys on the Petty motor here, are steel. both are OB style, non-HTD belt design. when did they change to steel?? or visa versa?
__________________
greg brown
714 879 9072
GregBBRD@aol.com
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
greg brown
714 879 9072
GregBBRD@aol.com
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
08-14-2011, 02:55 AM
#64
Rennlist Member
Thread Starter
The actual value, is the one that finally is what it rests at. Anyone want to venture why???
So if this is what you use and thats what ive used too, the readings off the 9201 are even much farther off wtih the old bugger non-HTD belt. again barely at a true 3.5 or so, and the kempf scale is WAY off the scale, passed the window!
So if this is what you use and thats what ive used too, the readings off the 9201 are even much farther off wtih the old bugger non-HTD belt. again barely at a true 3.5 or so, and the kempf scale is WAY off the scale, passed the window!
08-14-2011, 02:59 AM
#65
Rennlist Member
Thread Starter
Years ago we did little experiment with 9201 vs several different Kempf tools. All four Kempf's gave exact same results in '87 S4. 4.5 on 9201 was at lower end of Kempf scale and 5.2 (5.2-5.3 is correct for 32V) was right at the middle. Based on that test I haven't had any reason to suspect different Kempf's would give different results. Maybe there is manufacturing difference between individual Kempf's or batches of them. Ones we have have always worked and given results where belt warning is clearly below Kempf's lower limit. Way to measure belt with Kempf is to use 9th free opening counted from cam gear. This is right at edge against center cover and on top of tensioner housing.
How to use 9201 is matter of personal reference. It will give different results depending on how its turned. I think important thing is to be consistent. If you cannot replicate same result time after time you are doing something wrong.
How to use 9201 is matter of personal reference. It will give different results depending on how its turned. I think important thing is to be consistent. If you cannot replicate same result time after time you are doing something wrong.
I dont think the 9201 is about consistancy, its about using it right and having it near the air pump bracket for actuation. you should do it slowely, because with a quick test you get a larger deflection , which is temporary and will show a much higher value. i wonder how many shops listen/watch for the actuator to "click" and then look at the roaming needle to see what its max position was. This is incorrect and will yeld a value .5 or 1 full point than what the actual value is.
08-14-2011, 03:29 AM
#66
Rennlist Member
Thread Starter
calibration is easy with the kempf tool!!
I just did a test with a 5lb weight and some speaker wire. no disassembly nesessary. Just feed the wire throught the kempf tool and hand the weight. 5lbs goes to full scale.
check out you kempf tool !!!
I just did a test with a 5lb weight and some speaker wire. no disassembly nesessary. Just feed the wire throught the kempf tool and hand the weight. 5lbs goes to full scale.
check out you kempf tool !!!
08-14-2011, 07:31 AM
#68
Rennlist Member
Are you saying the kempf top of window should be achieved with application of a 5 lb weight?
How did you derive the 5 lb target?
Why did you disable the light on your other car? I love that tension warning light on the 32V cars and intend to install one on my 16V Euro 84. (85 & 86 Euro's got the light)
Washer thickness, though, will change the tension at which the trigger occurs. BTDT.
The spare 87 stock tensioner setup from Jim's Perl car is going to be retrofitted onto my 84 Euro car this winter in place of the aftermarket tensioner & bracket. The plan is to install a warning light along with it but with a washer thickness that allows me to run slightly less tension for the 16V car.
How did you derive the 5 lb target?
Why did you disable the light on your other car? I love that tension warning light on the 32V cars and intend to install one on my 16V Euro 84. (85 & 86 Euro's got the light)
Washer thickness, though, will change the tension at which the trigger occurs. BTDT.
The spare 87 stock tensioner setup from Jim's Perl car is going to be retrofitted onto my 84 Euro car this winter in place of the aftermarket tensioner & bracket. The plan is to install a warning light along with it but with a washer thickness that allows me to run slightly less tension for the 16V car.
08-14-2011, 10:12 AM
#69
I think you are over thinking this.
08-14-2011, 11:33 AM
#70
Rennlist Member
Thread Starter
really? Im building an engine for Petty and the two ways of checking tension, that have worked fine on the S4, or 84 models, is WAY different as far as measured values. what would you do if im "overthinking this"?
the porsche tool, as used on the S4 belt (which is about 1mm thicker, and directly coorelates to 1 full point higher on the scale) is reading so far of the kempf scale its scary! im setting it at 3.0 on the porsche tool, and its still way outside the window.
look at all the aluminum pulleys that have been grooved beyond recognition, and i think the steel pulleys have had the coatings worn away. maybe due to porsche tool overtension??? Its a good discussion because no one has answers and im seeing disparate results from both accepted measuring methods.
I got the 5 lb weight, because everyone can find a 5 lb weight, and just by luck, it ends up at the full window position. if anyone tests their kempf tool and it doesnt end up full window (actually slightly over by 1mm) then there would be variance in the tool! VERY easy to check with speaker wire (or thin wire) and a 5lb weight. Ill even convert it to water weight if someone wants to use a water bottle.
as far as the sensor, dont get me wrong, i love it when it works, but it never had. I replaced the electrical socket, but the main wire (male part) has always been suspect Ive soldered it several times and it just doesnt seem to work right, even though continuity has been good. the insulating washer is there, etc. why does the washer thicknss increase or decrease sensiitivity? doest the system look for a break in ground from the nose of the tensioner losing contact wih the tensioner arm? looks like it only sees a loose belt when its REALLY loose for that ground to break. I just lost patience and disconnected it since i check mine regularlly with another method as well. (through the peak hole I drilled in the plastic cover)
who said this? me?
the porsche tool, as used on the S4 belt (which is about 1mm thicker, and directly coorelates to 1 full point higher on the scale) is reading so far of the kempf scale its scary! im setting it at 3.0 on the porsche tool, and its still way outside the window.
look at all the aluminum pulleys that have been grooved beyond recognition, and i think the steel pulleys have had the coatings worn away. maybe due to porsche tool overtension??? Its a good discussion because no one has answers and im seeing disparate results from both accepted measuring methods.Are you saying the kempf top of window should be achieved with application of a 5 lb weight?
How did you derive the 5 lb target?
Why did you disable the light on your other car? I love that tension warning light on the 32V cars and intend to install one on my 16V Euro 84. (85 & 86 Euro's got the light)
Washer thickness, though, will change the tension at which the trigger occurs. BTDT.
The spare 87 stock tensioner setup from Jim's Perl car is going to be retrofitted onto my 84 Euro car this winter in place of the aftermarket tensioner & bracket. The plan is to install a warning light along with it but with a washer thickness that allows me to run slightly less tension for the 16V car.
How did you derive the 5 lb target?
Why did you disable the light on your other car? I love that tension warning light on the 32V cars and intend to install one on my 16V Euro 84. (85 & 86 Euro's got the light)
Washer thickness, though, will change the tension at which the trigger occurs. BTDT.
The spare 87 stock tensioner setup from Jim's Perl car is going to be retrofitted onto my 84 Euro car this winter in place of the aftermarket tensioner & bracket. The plan is to install a warning light along with it but with a washer thickness that allows me to run slightly less tension for the 16V car.
as far as the sensor, dont get me wrong, i love it when it works, but it never had. I replaced the electrical socket, but the main wire (male part) has always been suspect Ive soldered it several times and it just doesnt seem to work right, even though continuity has been good. the insulating washer is there, etc. why does the washer thicknss increase or decrease sensiitivity? doest the system look for a break in ground from the nose of the tensioner losing contact wih the tensioner arm? looks like it only sees a loose belt when its REALLY loose for that ground to break. I just lost patience and disconnected it since i check mine regularlly with another method as well. (through the peak hole I drilled in the plastic cover)
who said this? me?
08-14-2011, 11:44 AM
#71
Rennlist Member
Thread Starter
I used the Kempf tool twice and the tension belt kept coming on....brought it to mechanic with 9201 tool and was way low. he verified the kempf was way off.. that was mo in wichita and I sold the tool promptly....may be the kempf spring needs to be stronger for the proper calibration..I dont know but it didnt work well at all
Greg, let me also ask you about the proper techique and reading of the 9201
Do you press on the body of the 9201 and then when you click the vertical slide into place, measuring belt tension, so you read the value that the max needle will read, or the final resting value that the measuring needle reads as you let go of the device???
in other words, when measuring the tension, there are two needles, one max and one actual. when you click in the measurment, and release the max value is higher than the final resting value and they are about 1 full point off each other.
Anyone can chime in here too!
as a side note, the pulleys from the euro that i showed were aluminum. the pulleys on the Petty motor here, are steel. both are OB style, non-HTD belt design. when did they change to steel?? or visa versa?
Do you press on the body of the 9201 and then when you click the vertical slide into place, measuring belt tension, so you read the value that the max needle will read, or the final resting value that the measuring needle reads as you let go of the device???
in other words, when measuring the tension, there are two needles, one max and one actual. when you click in the measurment, and release the max value is higher than the final resting value and they are about 1 full point off each other.
Anyone can chime in here too!
as a side note, the pulleys from the euro that i showed were aluminum. the pulleys on the Petty motor here, are steel. both are OB style, non-HTD belt design. when did they change to steel?? or visa versa?
does anyone know why? there is a good reason for it. I remember one porsche mechanic using the tool and using that value. in the end the belt would be way too loose. (hint)
08-14-2011, 12:34 PM
#72
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Mark:
Gear wear happens from loose belts, not tight belts.
If using the 9201 tool on an early belt was such a big problem, don't you think Porsche would have cautioned against its use....or given a different specification? It would have been pretty easy for them to issue a different specification....
Gear wear happens from loose belts, not tight belts.
If using the 9201 tool on an early belt was such a big problem, don't you think Porsche would have cautioned against its use....or given a different specification? It would have been pretty easy for them to issue a different specification....
08-14-2011, 12:39 PM
#73
Rennlist
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it would be interesting to see what that kempf tool's spring values were. again, ive done the comparison on the S4 and saw a direct correlation. Ill know more today or tomorow when i do the check again on my S4.
So, Greg doesnt use the floating needle value. (and most that know how to use the 9201 tool) do NOT use the max postion that the floating needle ends up with. thats the value that the "click" would see as the slide finds the final tension value.
does anyone know why? there is a good reason for it. I remember one porsche mechanic using the tool and using that value. in the end the belt would be way too loose. (hint)
So, Greg doesnt use the floating needle value. (and most that know how to use the 9201 tool) do NOT use the max postion that the floating needle ends up with. thats the value that the "click" would see as the slide finds the final tension value.
does anyone know why? there is a good reason for it. I remember one porsche mechanic using the tool and using that value. in the end the belt would be way too loose. (hint)
08-14-2011, 01:28 PM
#74
Nordschleife Master
Way, way back, Porsche sold a tool that worked just like Jay's tool. It was simple and cheap. There are problems with that approach because twisting the belt is only indirectly tied to the lengthwise tension. This leads to the 9201 and also its technical cousin the "Krikit"from Gates.
The biggest risk with the timing belt (IMHO!) is that people make it too tight. So easy to do with that bolt tensioner. Then there's the issue of the warning light. Crap thing that it is, requires the belt to be tight and leads, again, to over-tightening as owners freak out when it comes on. ("It's really hard to get the belt on. It's not going to jump a tooth if it's tightened at all so relax.")
So...
What procedure are you following during each test cycle?
What brand of belt(s) are you using?
What is the belt age?
How many tools of each type are you using?
Is the 9201 calibrated?
"I made some measurements and the numbers aren't what I expected" is the opener for further testing and not a basis for a conclusion.
08-14-2011, 01:41 PM
#75
Burning Brakes
you could also just fit a Pkensioner, throw the Kempf tools and alike in the trash, and forget about these discussions 
Yes I read the total thread, but I really think the old tensioner design is much more prone to failure/overtensioning than the pkensioner.
No, I do not have statistically relevant test-data, but have seen a lot of old style tensioner (also used by Alfa Romeo) cause failures, whereas I have never seen any failure in thee newer style tensioners Ken uses for the Pkensioner.
Cheers
Yes I read the total thread, but I really think the old tensioner design is much more prone to failure/overtensioning than the pkensioner.
No, I do not have statistically relevant test-data, but have seen a lot of old style tensioner (also used by Alfa Romeo) cause failures, whereas I have never seen any failure in thee newer style tensioners Ken uses for the Pkensioner.
Cheers