'additional' Timing Belt Tensioner Xu 8v

[mistabe 0]

Happened to get a look under the bonnet of a 'friend of a friends' aging garaged 205 the other day - A long time retired group-A car claiming to hold a few lap records from back in the day...

 

Regardless to the validity of these claims, I spotted the interesting use of a single eccentric type roller fitted to the front run of the timing belt... Obviously making the lower cambelt cover a little tricky to refit (most of it hadn't been!)

 

Has anyone come across this before? I'm told it was there to help keep the belt wrapped to the lower pulley, however the more I think about it - the more it I question it's use to resolve the issues of timing belt 'tooth out' on heavily skimmed heads (cam timing being slightly off)

 

Had a search about on here but can't find any posts on the matter - so here we are...