Hi, i have just bought a PAW 35 diesel engine and the rec. prop size is 11/6 to 14/6 i bought a 11/8 prop for the engine. I am a model engineer and will be making twin engines, so the total engine size will be 70ci. What prop size should i use for this engine, the propellor is mainly to give some torque behind the engine and may not be used in a plane, also this engine will be diesel so will have higher torque and lower rpms compared to the nitro engines. So please dont rec. a prop size from a table like this as the table below is for nitro

help will be appreciated, im new to the aero stuff and just need the right proprange for the engines im going to make