Hi not up- to - speed on the batter situation and how many cups will be needed to fill a tin. 

Ive got a tin - 8.5 inch x 3 inch high tin 

Wanting to use a basic Victoria sponge reciepe (4 eggs, 8oz of sugar & flour) 

Can somebody help on how many times i need to double the recipe (if i need to), and temp / cooking time if possible for the best result. (always seem to get a "burnt" top and sides)

Many Thanks 

I *NEVER!* measure batter - expecially by the cup.  I fill my pans 2/3rds full/deep.

I am not familiar with the pan you mention but an 8"x2" pan will use about 2/3rd of a cake mix batter.  I'm guessing your pan will take all of the batter in your sponge recipe.   

Since you are not in the states I can't advise on the temp as I use only degrees F.  I would use 300 and bake it about 20-30 minutes until one can smell that wonderful aroma in the next room.  If you are getting burnt sides and top your oven is most likely too hot.  Turn it down some.  Always better to bake at a lower temp for a bit longer than burn it :)