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Timing Chain Tension Ring for BN2

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bj8bn2

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I'm changing the cam on a BN 2 and when I took there timing chain cover off I expected to see the rubber ring that serves as the chain tensioner - it was not there. Where does the rubber ring go? All the repair manuals I have don't explain it very well so it must be intuitive - right? Does it even work - is it worth the trouble to install tensioner ring?

Thanks
 
Perhaps it was left off during previous work? Or disintegrated from age?
Having suffered a broken timing chain caused, I believe by a failed tensioner ring, I'd be putting one back on.
 
The 4th manual I dug up shows where it goes - in the large grove between the two rows of teeth on the cam gear. And it was not there when I took things apart. Good advice, I am going to install it on reassembly.
 
G'day bj8bn2,
You may be interested to know that the 100S does not have a tensioner ring, or any other type of timing chain tensioner! So my earlier thought that the timing chain failure that I suffered was probably not related to any tensioner problems.
 
I just posted a question about this tensioner ring on the AH Experience. I'm wanting to know if it is truly necessary and if so, why. And, how exactly does it work?
 
Richard and BJ8bn2: Here is the response I just wrote to Richard's query over on the 100 Experience site:

"Richard--

While the tensioner may not be absolutely necessary it certainly quiets what is otherwise a loud and distracting rattling noise that results from the chain's hitting the cover. I know this because I had such a noise on my car which I could not pin down and finally discovered what seemed like hard, black plastic chips about the size of a thumbnail in the sump.

Knowing there was no plastic used in the engine I finally put two and two together and realized the shards were what was left of the tensioner belt and that the noise was being caused by the chain's banging against the front cover. I pulled the cover, verified that the tensioner was history and took the occasion to install a new chain as well as a new belt. I did this with the engine in situ from under the car and it was not easy getting the big sprocket started back upon the nose of the crank but after a number of tries I succeeded.

I'd recommend you install the tensioner belt and replace it whenever the opportunity presents itself.


Best--Michael Oritt
1954 Austin-Healey 100 (street)
1959 Elva MK IV sports racer (track)
1961 Ginetta G4 (track)"

Best--Michael
 
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