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MG MGB Technical - Timing chain tensioner backplate missing

Hi,

In stripping down the front part of an engine, I noticed that the back-plate for the tensioner was missing. It does not seem to have had much of an adverse effect, am I right in this assumption?

Ta
IA Jones

At times, when we use a vernier pulley, by the time we have corrected the teeth to back plate distance on the sprockets and equalised them the chain can just rub on the tensioner guide plate, with this removed we have seen no problems.
Peter
Peter Burgess Tuning

Hi,

Thanks Peter. Engine seems to be fine. I was just wondering 'out lout' if there would be any effects.

Ta again,

Iwan
IA Jones

IA-
The spacer plate is appropriate for simplex (single-row) camshaft drive chain mechanisms, and should be omitted when employed with duplex (double-row) camshaft drive chain mechanisms. Note that the metal sleeve on the back of the 'foot' of the camshaft drive chain tensioner is not centered in the tensioner, but is offset to one side. This sleeve is centered on a simplex drive chain by means of the spacer plate, but when using the duplex chain both the foot and this sleeve are centered on the duplex chain by omitting the spacer plate. It is, however, important to use a gasket between the tensioner and the front engine mounting plate.
Stephen Strange

Hi Stephen,

Thanks for the information. However, I do have an early mgb manual (published in 1968 with only a duplex chain in the diagram) and an earlier MGA manual (again duplex chain). They both have backing plates for the tensioner shown.

Cheers,

Iwan

IA Jones

This thread was discussed between 28/06/2017 and 02/07/2017

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