The authoritative thread on chain tensioners

[VA_alfa]

I have searched the technical threads for chain tensioner upgrade details but could not find a step by step guide to determining what one currently has in their engine and what one does to complete the upgrade. Most threads i found are debates on hydraulic, mechanical, and 930 tensioners with or without guards but not a how to guide. My hope is that the check and subsequent upgrade does not require engine-out.

I have a 66 MY 911 with the original 2.0 motor and would like to know what I currently have for chain tensioning and then what I need to do to upgrade to the 930 tensioners (which seems to be the recommended solution for the 2.0 cars).

If I missed the solution in my search, I apologize in advance.

[beh911]

Alex,
To be absolutely sure of what tensioners are in your car, you need to pull the chain box covers and look.
Originally, your car had a splash fed cup tensioner that should (hopefully) be long gone by now.

So start there and report back what you see with pictures.

FWIW, I just finished putting the latest 930 tensioner$, 1980+ $procket bases (eliminating the spacer), and collars (guards) on my car. I had an (older rev) 930 tensioner collapse on me as I started my car to leave my mechanic/friend's shop a couple weeks ago. Great timing and luck on my part!

BTW, there are varying opinions on what is the 'best' tensioner solution. Getting consensus is not on the lines of 'best oil' discussions but gets fairly close. There are different ideas of what is best with tradeoffs between each approach.

[VA_alfa]

Thanks Bryce, can I pull the covers and check the tensioner type with engine in car?

[beh911]

Yes. You will have to remove the front piece of engine tin to do so.

[VA_alfa]

Okay, I've checked the tensioners and found solid-type by Pacific Designs, Inc. After extensive research here and consulting with my mechanic, I have decided to replace these with the 930 tensioners and guards. Parts are on order and installation will take place on Thursday. I hope to document the replacement with photos for verification to future owners.

[StephenAcworth]

Thanks for posting this: and look forward to the updates... (with photos).

[VA_alfa]

Took the car to the shop today to replace the solid tensioners with 930 tensioners. The doctor has been working on 911's and 356 since the early 1970's. My baby will be in good hands.



On the lift, anesthesia administered



Out with the old:



In with the new:



Job should be finished tomorrow.

[66DC]

Very nice!

But why did I think that 1966 engines would not accept a tensioner upgrade? I had long since given up hope of upgrading mine...

[edmayo]

The aluminum case engines won't accept the external oil line tensioner type because the cover is made to accept the oil line, but this was never made for the early alum. engines, only the mag and later alum. engines. The early and later covers are not interchangeable. But you CAN upgrade to the non-external oil line type, 930 tensioners on early engines.

[StephenAcworth]

What are the part numbers for the 930 tensioners? Please can you post them as I need to do this on my car too... Thanks!