ChuckW

I adjust the high speed on the ground for maximum RPM then richen it few clicks until I see a 200-300 RPM drop. That has never failed me. When I recently opened up the .46-AX from my Cherokee crash, the piston, liner, rod bushings, crank pin and bearings all were in pristine condition.

Jetdesign

My Feedback: (8)

Thanks Chuck. That's what I originally did a week or two ago; maxed out at 13,000, then dropped it to 12,600 by richening. I guess I'll do that again this weekend, was running like a top. Shouldn't have changed it.

HeliTB

I run a MA 11x6 on my Sig Kougar w/OS 46 AX and love the overall performance. I had my buddy tach it. It tached on the flight stand at 12,800 which means it will unload to about 13,000 in the air. I tried the 11x7 and really did like the drop in speed. Now on my trainer w/OS 46 AX I had an 11x7 for the additional pull for lower speed when learning to fly.

CGRetired

My Feedback: (1)

My only thought, GaRCfield, was to get you to think about the prop you are selecting. I was taught that noise may not equate to power, so a very fast spinning prop may make a lot of noise, as does the engine, the benefit you get is lost. Operating at the peak performance RPM is the key. It will pull any reasonable prop (those that are properly in range of your engine) with ease and pull that plane around equally at ease.

The way I always think of it is to use a low pitch for climb and acceleration. It will not have a very high top end speed, but it will climb like blazes. Higher pitch will give you less acceleration, and less climbing ability, but it will go like hell.. to an extent. It still has to pull the plane around (drag, weight, and so on).

Just think of the prop pitch as the gears in a car. Lower gears for climbing hills, engine turns at a higher RPM but the car goes slow, but has lots of power. Change gears, go from 2nd to 3rd of 4th, and you get more speed, but acceleration is much less.

Props are fairly inexpensive.. two or three bucks for a good quality APC prop in your size range. Just a side note, when I was training, I was buying replacement props by the bag.. and going through them just as quick. But, lately, I have not broken a prop in several months now. When I was flying the trainer, I bought several different sizes and played with them. At the time, it seemed like the thing to do, and I did it.

Aaaanyway, now, those 15-10 props are a tad more expensive.. so I don't just go out and buy three or four props to experiment. I may have one or two in different sizes, but that's about it. I just find one that performs and stick with it. Then, if I happen to chip or break one that is on the plane, I buy two.. one in the size and one experimental size. Then I play a bit, keeping power, performance, and noise in the picture. And, we do get complaints about noise, so we try to keep it down.

Best of luck with that.

CGr.

Jetdesign

My Feedback: (8)

Thanks, CGr. We have A LOT of land between us and anyone around us; noise isn't an issue, and my engine is not the loudest. The 11x5 gives me decent pull, and when the engine winding up to 13000 rpm it gets good speed, too.

I haven't broken a prop in quite a while now (knock on wood), and only had 2 prop strikes due to 15mph cross wind landings so it's time to experiment. After trying some different stuff I'm learning that the 11x5 is a great combination of speed and low end power on my 46AX. Can't wait for the 55AX though

CGRetired

My Feedback: (1)

You wanna hear loud.. we have SAM people in our club. Society of Antique Modelers. All great guys, mostly older (well, older than me anyway which is old, I guess.. ) and the planes they fly have no mufflers. These are old time engines, and they turn up some RPM as well as make a lot of exhaust noise. But, they only run for a half minute or so and then they glide. Neat to watch.

You are lucky. Actually, our field is quite remote, however there are three houses within about a half mile of the flight line. One of the residents claims to hear our planes. I've been out by his house when we had a meet going and never heard a thing. But, we try to keep it quiet because it is public land (state owned runway for the Department of Forestry.. land forest fire tanker aircraft there).

CGr.

ChuckW

When you get that .55 try 12x7 and 11x8. Both have worked well for me.

Gray Beard

My Feedback: (-1)

If you read the instructions they will state A working RPM range for that engine, A low and A high. A two stroke engine isn't too big of A deal but never let your four stroke over rev. You have all that RPM range to play with and try out different props, it's fun finding the prop YOU like for flying that plane.
A general rule is: A shorter prop with A bigger pitch will give you more air speed but less thrust or torque.
A longer prop with less pitch will give you more torque and thrust but less speed.
I like my planes to fly slower but have more thrust for stunt flying so I fly with the longest props I can with the smallest pitch.
After years of flying and testing props, engines and planes I have A pretty good idea of about the right size of prop I will like on A type of plane with A size and make of engine but I still have to spend the time to test and proove.
I enjoy it so it just makes for another fun day for me and I get A lot of surprises too.

Jetdesign

My Feedback: (8)

'K. Was hoping for a 13x5, but will try them all Will be for pattern flying.

hurk1

A 12x4 prop works good on a 46ax. I use a APC and have no problems with this prop. I also have noticed that this prop will slow the plane down alot faster on the landing approach. Sounds like you are running this engine too lean and trying to get to many RPM out of such a big prop. Again 12 x 4 is a great prop for a 46.

jaka

Hi!
Some of the modern .40.46 engines (Kyosho GX.40 /ASP and OS AX)are just fantastic.
Take the Kyosho GX.40 that comes with the Kyosho Calmato highwinged trainer for instance(same engine as the ASP .40)It swings a 12x6 prop with great authority.

When the a newbie arrived with his new Calmato trainer to our field two years and asked for help I was a little reluctant to fly his plane as the engine had a 12x6 Kyosho prop. But I did fly and was really surprised!!! That GX.40 was so powerful. This newbie used 16% nitro in his fuel but regardless of that the engine performed equally good on just 5% nitro which I ran myself in my GX which I bough some month later.
Speaking of prop sizes... 10x6 is way to small for these engines if you intend to use them in a high winged trainer or sport airplane. I use 10x6 in my Q-500 pylon racers and the Kyosho GX.40 /ASP.40 swings a RAM or Graupner 10x6 prop at more than 14500on the ground on just 80/20 fuel, equaling the Webra .40 GT which to date is the most powerful standard sport engine on the market.
I 'm really impressed.

Jetdesign

My Feedback: (8)

Thanks. I"m going to try the 12x6 and see if I get a little more speed.