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-   -   Chain tensioner Question (http://forums.pelicanparts.com/911-engine-rebuilding-forum/1157708-chain-tensioner-question.html)

jonesb930 02-19-2024 11:23 AM

Chain tensioner Question
 
After installing my chain tensioners I have a gap between the idler arm and the tensioner. The arm is able to move freely back and forth. Is this correct or am I missing a spacer. It is seated completely on the threaded stud.looking for some assurance before I button this up.

Bill

http://forums.pelicanparts.com/uploa...1708374104.jpg

Henry Schmidt 02-19-2024 12:00 PM

Quote:

Originally Posted by jonesb930 (Post 12197046)
After installing my chain tensioners I have a gap between the idler arm and the tensioner. The arm is able to move freely back and forth. Is this correct or am I missing a spacer. It is seated completely on the threaded stud.looking for some assurance before I button this up.

Bill

http://forums.pelicanparts.com/uploa...1708374104.jpg

There should always be a little clearance to allow the chain to align properly.
That gap seems a little larger than most but you should be good to go.

porschedude996 02-19-2024 01:43 PM

Quote:

Originally Posted by Henry Schmidt (Post 12197076)
There should always be a little clearance to allow the chain to align properly.
That gap seems a little larger than most but you should be good to go.

Henry, I thought there was a spacer. I looked up in the parts manual and found on Illustration: 103-10
Item: 10A
930 105 513 00
Spacer Sleeve 1
See technical information GRUPPE 1 NR.29A

I'm about to assemble this part of my build and what is ironic is that I can't find spacers in all my parts.

Knowing that you know what you're talking about, can you shed some history on this? I think I had these in my '72 911T, way back in 1986 when I rebuilt. I can't find reference to "See technical information GRUPPE 1 NR.29A" as stated in parts manual.

Thanks

jonesb930 02-19-2024 05:07 PM

Quote:

Originally Posted by porschedude996 (Post 12197164)
Henry, I thought there was a spacer. I looked up in the parts manual and found on Illustration: 103-10
Item: 10A
930 105 513 00
Spacer Sleeve 1
See technical information GRUPPE 1 NR.29A

I'm about to assemble this part of my build and what is ironic is that I can't find spacers in all my parts.

Knowing that you know what you're talking about, can you shed some history on this? I think I had these in my '72 911T, way back in 1986 when I rebuilt. I can't find reference to "See technical information GRUPPE 1 NR.29A" as stated in parts manual.

Thanks

I believe the older style arms needed the spacers. The newer arms have a spacer integrated providing a larger bearing surface as well. You can see it in my photo just to the left of the tensioner. I upgraded my arms to the newer style so I don’t need the spacers.

jonesb930 02-19-2024 05:08 PM

Quote:

Originally Posted by Henry Schmidt (Post 12197076)
There should always be a little clearance to allow the chain to align properly.
That gap seems a little larger than most but you should be good to go.

Thank you Henry! I appreciate the fast response. I’ll button the chain housings up tomorrow and keep moving forward.

targa72e 02-19-2024 05:10 PM

The spacer is used when you have early narrow idlers and late narrow tensioners. You have the late wide idlers with bushings.
Good information and pictures in this thread.

http://forums.pelicanparts.com/porsche-911-technical-forum/1101489-chain-tensioner-questions.html

John

Turbo_pro 02-19-2024 05:11 PM

Quote:

Originally Posted by porschedude996 (Post 12197164)
Henry, I thought there was a spacer. I looked up in the parts manual and found on Illustration: 103-10
Item: 10A
930 105 513 00
Spacer Sleeve 1
See technical information GRUPPE 1 NR.29A

I'm about to assemble this part of my build and what is ironic is that I can't find spacers in all my parts.

Knowing that you know what you're talking about, can you shed some history on this? I think I had these in my '72 911T, way back in 1986 when I rebuilt. I can't find reference to "See technical information GRUPPE 1 NR.29A" as stated in parts manual.

Thanks

Simply put, early idler arms were narrow where they pivot on the pin.
Early tensioners were wide enough to restrict their side to side movement. When the Carrera tensioner was released, they also created a wider idler arm. They discovered that most tensioner failures were the result of the idler arm binding on the support pin.
Around that same time, memory escapes me, the 930 tensioner body was narrowed where it supported the pin. Probably to be combined with the Carrera idler arm. With the early narrow arm and the narrow bodied 930 tensioner you needed a spacer. The spacer was about a 1/2".
I apologize if this is a clumsy description.
Many year back, the left side Carrera lder arm became rare/back ordered so we took the early idler arm an added a full width bushing to improve idler arm support, reduce friction and delete the spacer.


http://forums.pelicanparts.com/uploa...1708394516.jpg

porschedude996 02-19-2024 05:29 PM

Thank you Turbo-Pro. for clearing that up in my mind. I couldn’t find them today. I was about to got the scuba tanks and search my parts washer. The ones in my memory are from many years ago.

In your photo, there is a bushing that is attached or part of the tensioner. Are thoee the one Henry does?

What do we know about bleeding the Carrara Tensioners? I can’t seem to get then to bench bleed like a brake master cylinder.


Quote:

Originally Posted by Turbo_pro (Post 12197341)
Simply put, early idler arms were narrow where they pivot on the pin.
Early tensioners were wide enough to restrict their side to side movement. When the Carrera tensioner was released, they also created a wider idler arm. They discovered that most tensioner failures were the result of the idler arm binding on the support pin.
Around that same time, memory escapes me, the 930 tensioner body was narrowed where it supported the pin. Probably to be combined with the Carrera idler arm. With the early narrow arm and the narrow bodied 930 tensioner you needed a spacer. The spacer was about a 1/2".
I apologize if this is a clumsy description.
Many year back, the left side Carrera lder arm became rare/back ordered so we took the early idler arm an added a full width bushing to improve idler arm support, reduce friction and delete the spacer.


http://forums.pelicanparts.com/uploa...1708394516.jpg


Turbo_pro 02-19-2024 06:03 PM

Quote:

Originally Posted by porschedude996 (Post 12197345)
Thank you Turbo-Pro. for clearing that up in my mind. I couldn’t find them today. I was about to got the scuba tanks and search my parts washer. The ones in my memory are from many years ago.

In your photo, there is a bushing that is attached or part of the tensioner. Are thoee the one Henry does?

What do we know about bleeding the Carrara Tensioners? I can’t seem to get then to bench bleed like a brake master cylinder.

Hi Dude
Those idler arms are the ones made by Supertec. Henry is a good friend and at one point I was helping him design some after market parts. He was building one of my engines when the Carrera arms became unavailable.
I should have given credit where credit is due.

I'm not a mechanic so I have no idea how the bleed the Carrera tensioners.

porschedude996 02-19-2024 06:22 PM

Thanks for the reply. Design Engineer here, I would enjoy working on design projects like the his.

Quote:

Originally Posted by Turbo_pro (Post 12197358)
Hi Dude
Those idler arms are the ones made by Supertec. Henry is a good friend and at one point I was helping him design some after market parts. He was building one of my engines when the Carrera arms became unavailable.
I should have given credit where credit is due.

I'm not a mechanic so I have no idea how the bleed the Carrera tensioners.



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