Thank you guys so much! I did a proper measurement of the curve in question and it is 8.5 inch radius. Knowing this i will be buying the loco. Thank you again for all the help.
The Arnold loco can negotiate a minimum radius of 190mm, that´s 7 1/2"
The curve fits into a loop of 9-3/4" track? If that means your curves are less than 9-3/4" you may have problems. The only way to know is to try it with the loco in question. With that minimum curve radius I would only use short four axle diesels, short wheelbase 2-8-0, 2-6-0, 0-6-0 steamers along with 40" freight cars and 60' passenger cars.
Without any doubt - yes, the Arnold 4-6-2 will have no problem negotiating the 9 3/4" radius curves.
i recently bought a pre-made layout from a yard sale in my city, so i went to my local hobby shop to check out what trains they had available. surprizingly, they had an arnold BR18 4-6-2 and a couple of electric locos. before i buy it, id like to ask for a proffesional oppinion. my minimum curve on the layout is made of flex track, and just fits just inside the basic loop of 9 3/4 inch radius track. could the BR18 make it around that kind of curves?