Pulling my hair out trying to get the right prop. Does a larger diameter prop take more HP to spin?

Assume hering 5 blade cleaver props for #6 drive
ie, will a 15.5in prop at 33 pitch be easier to spin than a 16.5in prop at 33 pitch?

Yes it does, assuming the drive height stays the same. You will probable have less slip, so lower rpms,so it loads the motor down more. Speed is the real question with prop slip you must take good notes every time you test. Usually prop diameter is played with for adjusting handling or very high x dimension. You may want to call Brett from BBlades he is very honest and has a world of experience.

Hello,

In most cases the answer to your question is yes. As 43sv eludes to, there are extenuating circumstances to investigate.
Email me with specifics and we can discuss this in more depth if you desire.

Brett