Prop size for os 55 ax
 

HI I have an cm pro extra with a os 55 ax because of noise restictions we have to prop up so which will give it the best performane a 13 x 7 or a 14 x 4 wide ? thanks

RE: Prop size for os 55 ax
 

Hi!
Depends on what airplane you have got.

RE: Prop size for os 55 ax
 

G'day Mate,
I doubt a 55AX will spin a 13x7 well enough to give good performance, I would try the 14x4, which is what I'm planning on using on my 61FX, on a Yak54.
I have flown my Diablo, with 61FX, running a 13x7, was ok, but a 12x8 was better, so a 55AX, may struggle, with the 13x7, & give good performance.

RE: Prop size for os 55 ax
 

I have a 55AX, but haven't flown it yet. To cut down noise, I feel you need to stay below 10,000 rpm. You also want an APC or a prop with tips like the APC. Definitely do not use a square tip prop like a Master Airscrew. They are more noisy.

RE: Prop size for os 55 ax
 

I was trying first an APC 12*7 on my new 55AX, and now using APC 12.25*3.75 of a Great Planes Reactor.
Unfortunately I can't make the engine work well, and it keeps on "cutting" on me in midair, mainly when I throttle back.
I'm afraid to go with the 14*4 though the noise is quite high with the 12.25*3.75, but am afraid to add load which might make life even more complecated

Any ideas?

Thanks