308 injected 2v Cam pulley bolt o ring

Have a look at the diagram on Eurospares uk web site- i think it might be item 17 sealing ring on the timing system controls drawing. Pt no 101031. I am not up to speed on this engine

 

McMaster Carr will sell you 100 of them for $9.59 USD. Part # 9262K224.

 

I have used 18x23x2.5mm Viton (1982 308GTSi)

 

That's a big difference than the size given by Wayne?
Width 2.4 mm
ID 12.3 mm
OD 17.1 mm

18x23x2.5mm

 

For my application 1982 308GTSI

 

I guess Wade made a mistake... I have the same vehicle and I agree with your description

 

Just for another data point, I have the 101031 o-ring as:

McMaster-Carr 9464K28
Viton (black)
.103" width (free-state)
.674" ID (free-state)

(Which agreed well with free-state measurements I made of other 101031 parts received from AFP, and generally matches Wayne's numbers -- sometimes o-ring sizes are given for the nominal sizes of the metal parts where the o-ring is to be used, and, in my case, the metal parts where 101031 is used are 18mm ID and 23mm OD.)

 

out of curiosity just measured the diameter of the bolt 18.38mm