C of G

Hi
I'm building a rv9a. I have purchased a io 320 170 hp engine, and am uncertain as to what prop to purchase. The engine has a hollow crank and a mt governor and was on a lancair with a mt prop. With this engine what are the likely Cof G issues or tendencies with various props? Thanks for the input.
Jack

Little likelihood of a CG issue. Many 9As run a 320 with a Whirlwind CS prop .... no worries.

My former 9A with an 0-320 and Hartzell constant speed made it somewhat biased to the nose and impossible to get aft CG even in worst condition with overloaded baggage even using over 150# in the spreadsheet. For the 9A the extra weight up front helps. A very light prop permits aft CG and the associated problems.

With a light Catto FP prop, my RV-9A is slightly baggage-limited (80 lb. instead of the max 100 lb.) with reserve fuel and a couple of 200-lb. humans aboard, so a little extra nose weight is not a bad thing.

For my mission profile, my setup works fine and keeps nose gear loading to a minimum.

Everyone is going to have a slightly different particular build, in my case I hung an IO360 and CS prop up front, plus dual alternators and the Anti-Splat nose gear mod, so I was nose-heavy. I moved my battery and some avionics way aft to keep it centered. I also have 68 gallons fuel capacity in the wings, and to carry full fuel and keep both the CG in range AND keep the nosewheel weight below 325 pounds for taxi and takeoff, I needed to move some pounds aft for those times when I carry full fuel.

I see a lot of folks paying close attention to the CG when heavily loaded, and ignoring the max 325 pound on the nosegear. You should be cognizant of both of those limitations. It's easy to find yourself in a situation where you need a lot of baggage weight to move the CG aft to keep the nosewheel under 325, and it puts you right up against your max gross weight limit trying to do that.

Thanks for the information I am leaning to a hartzell blended airfoil at this time. This may change a few times before committing. Thanks

Jack