Can someone tell me if a 11X4 prop will be OK on the Avistar running the OS 40 engine?
Thanks.

I use an 11-4 on a Jerry's Little Boy and on a Big Lazy Bee, both with an OS.40. Both are very slow, fun-fly planes. I think an Avistar would be happier with a 10-6. An 11-4 will accelerate you down the runway faster, and probably climb more steeply, but I don't think you'l ever get to what feels like "cruise speed".

It only costs 3 bucks to try, tho'.

use a 10x6 or 10x7. 11 prop is to big.if you fly off grass you will be cutting it. if you fly off pavement you will strike it on landing. the landing gear tends to sag after a while.
curly

Ditto on the 10 x 6
Go with a black nylon Master Airscrew, they can take a beating.

Hi Jim,Thanks for the post.
I think i'm gonna try the $3.00 investment and see what that Avistar does with a 11X4.
Have a great week

Why do you want to stay away from 10x6 ??

Well,
I guess it's called experimental?
Just like to see what it will do.
Also I may put the 40 LX engine on it as I remember reading some back post about the Avistar doing 130-to 150 MPH.
That was in a dive and he did say he tore the wings off so it had to be fast.
I'd like to see what it will do in a straight and level flight.
Getting rid of the big nose wheel and converting it to a tail dragger will also give more speed

The only way an AVISTAR will go "130-150 mph" is if it's in Michael Waltrip's trunk.

My fearless Scientific Calculator predicts 45 mph with an 11-4, assuming you can get 12000 rpm out of the OS. (68 with a 10-6)

Jim

What ever,
I had the trainer clocked at close to 50 MPH.
Thats the Select 40.
The Airstrike will do 60+ but I have not clocked it yet.
Calculations also say a BEE can't fly but it sure does a good job.
BTW,
My OS 40 cranks out close to 18,000 RPM

Have fun!!, after all, that is what this hobby is all about!!!!!

YOU BET AND I'M SURE HAVING FUN.
THEN SOMEONE WILL COME ALONG AND SAY YOU CAN'T PUT THAT PROP ON THAT ENGINE.
THAT PLANE WON'T DO MORE THEN 30 MPH.YOU NEED A LOW WING.
YOU NEED A BIGGER ENGINE.YOU NEED 100% NITRO FUEL.
They think i'm not having fun because I don't do it their way
It's funner the way I do it

do what i do... grab a few different reasonable props, they are cheap and replaceable anyway, and then randomly and blindly pick one and fly it. land, change, and fly again. now fly on what you LIKE to fly on, ignore what those little numbers say...

(btw, fly my avistar/os 40 la on a 10x6 apc most of the time, but also used 30% fuel and a 12.25 apc funfly prop every once in awhile! Also used stock gear on a tall grass field. had a nice area 'mowed' out area)

I ordered a few props of all different sizes.
I also ordered the black carbon 11X4.
My package from TH will arrive on Friday so this weekend i'll be busy converting the Avistar to a tail dragger.
BTW,
What kind of speed do you thing your getting with that high abount of nitro?

I <<used>> to have an avistar with a .46 LA engine (slightly more powerful than the .40 LA). I did run a APC 11X4 from time to time. It was alot of fun. the plane will fly very slow, but have a great climb rate. You could get out of trouble with that prop very nicely. I agree with the others ... buy a bunch of props and try 'em all. Now the 11X4 will go on to a Modeltech Magic with the same .46LA.

Well the UPS man came and I have a box full of props.
My Avistar is going to be converted to a tail dragger.
Plus the big open gap at the nose is going to be covered up to the carb intake.
The main wheels will be smaller so I should get some good speed with a 10X4 prop.
HUH? :idea: