3 blade or 2 blade prop

[Bandit 286]

Right now I am using a 3 blade 66" IVO prop with a 2.58 B gear box. Would I get a little more performance if I took one blade off, or should I have a 72" 2 blade to get more? Right now I am turning 6050 rpm on take off. At cruise I am showing 5750 rpm to get 70 mph.

[C5Engineer 1170]

Right now I am using a 3 blade 66" IVO prop with a 2.58 B gear box. Would I get a little more performance if I took one blade off, or should I have a 72" 2 blade to get more? Right now I am turning 6050 rpm on take off. At cruise I am showing 5750 rpm to get 70 mph.

2 blade 70" warp tapered tip 2.62:1...1100fpm climb at 6350rpm cruise at 85mph at 57-5800... at 6100rpm cruise was 93mph. I pitched it for 6000 at climb recently and I picked up 10mph indicated. I could hit 100mph in level flight fairly easily but my climb suffered quite a bit. You guys with IFA have it made!

[Bandit 286]

Could I take one blade off and try it as a 66" 2 blade or is that to short?

[akflyerbob 41]

I think I would look at other things.

If you have enough pitch in the prop that you only get 6050 on take off

your cruse should be higher.

I think I would look at the IAS,

what tach and how accurate.

Are you getting full throttle, and ballanced carbs

Are any of these things different than before?

An example..my airspeed will change by 20mph if I open the door

or 10mph if I close the heatmuf vent..changes the air psi

in the cabin

[Bandit 286]

Could I take one blade off and try it as a 66" 2 blade or is that to short?

Yes, you are right. My airspeed is off about 7mph. At 76 IAS, my ground speed is around 69mph. I am using a Tiny Tach for rpm. I am going to try pitching my prop down so I show around 6350 on takeoff. It seems if I keep my IAS above 76 my airplane flys so much better, anything under it seem's sluggish. Can I run the 503 at 6000-6100 cruise? Would it be any advantage to use a C gear box, with a 3.47 ratio turning a 72" 2 blade prop?

[herman pahls 9]

My Kitfox airspeed indicator is optimistically off.

GPS should tell the truth if you fly opposite directions and average the speeds.

A static port system to your airspeed indicator and calibration would give better airspeed accuracy.

Herman

[Trackwelder 12]

The B -box is designed for the 66 inch prop, I have one mounted on an E- box but would like to step up to 72 inch blades.

[C5Engineer 1170]

Keep in mind he is running a 503 and not a 582. Bandit have you looked at the inertia limits for the B box. That is going to be your limiting factor.

[Trackwelder 12]

The inertia limits with a wardrive propeller limit a B Box to 66 inch, I need to get a bigger prop or new blades for mine. The C and E box have about twice the inertia limit.