Thank you so much for your response. According to the article, you use the formula of 2 oz x cc in. of engine. So for my 2 cc in OS engine I would install a 4 oz weight on the right wing tip.

The article info:

The Antitorque Device
Twisting forces can do horrible things to a well-built model
John Hunton

http://www.modelaircraft.org/mag/OCT09/toc.htm

Bert