I too am building a TF P51 B (1/7 scale) version that I just purchased a RCS 140RE (Moki) engine to use in it. I am in contact with Zinger on the appropriate 4 bladed to use. RCS suggest a 16x8 for break in. I questioned Zinger about their 14x6-10 4 bladed... Is this a suitable match? I hear alot of rumble about props other than 2 bladed as far as performance but I had a Graupner 3 bladed with my trusted ole K&B 61 in a Goldberg Chipmunk and it pulled it around like a scalded ape (to use a phrase I saw here...)! It was amazing so I don't quite understand the argument that multiple bladed (read more than 2) props cut performance... My $0.02.

Justrfb (checking all my options)