Thanx RCer123 its a beast and i think i love it. I may try to save up to get one for my self.

Leserif I used the solid steal stab rods that are heavy as hell and the total weight came to 14 pounds 2 oz. I beleive i can cut more than a pound if i use the Aluminum stab tubs and put the batteries in the tail hatch, but the plane fly great and fast as is so there wont be any retro fits.

The prop im running on this is an APC 17X18 and it has very little ground clearance so maybe a taller landing gear will be used later.

This is from the USRA web site: www.usrainfo.org

Thanks to a lot of people for testing various props, we were able to get down to two props that we thought would make the Sundowner a faster and fun plane to fly. The two props were the APC 16x12 and APC 16x14.

I installed the Eagle Tree flight data recorder in my Sundowner. If you have never tried to use any type of flight data recorder it takes some getting used to how the data is recorded and what is the usable format that you want to display.
In any test program you have to have goals and a method that could be reproducible later if you need to go back and run the numbers or if you wanted to try to test some other props at a later date and be confident that you would be getting comparable data.

All that being said my tests flights were conducted yesterday 13 October at our local flying field near Bloomington Indiana about 700' MSL. The winds were less than 10 mph, most of the time calm. temp less than 75.

I would take off and immediately turn onto the course. I did not mill about for the start, just full power into the pylon turns. I did make slight adjustments to the needle valve between flights if I saw a downward slope in engine RPM as the flight progressed indicating the engine was getting too lean as the flight progressed.

I was using a timer box set at 5 seconds so when the plane passed in front of me we hit the timer and I was turning after 5 seconds of straight away. If you do the math that works out to around 800' I would fly laps until my 7 minute countdown timer signaled and then land. I made 3 flights on the 16x14 and two on the 16x12. The numbers that I was recording was indicated airspeed and engine rpm. The Eagle Tree is capable of recording a heck of a lot more info but I was only after the important numbers. I would have recorded the engine temp but I burned up my temp sensor during earlier tests.
After landing I downloaded the information from each flight then put the info on a graph showing airspeed and RPM over time. Comparing between the props and validated by a Nuclear Physicist. The 16x14 is a little faster. The other good thing is that the engine is turning a lower RPM and is noticeably quieter which is good for flying at club fields.
The 16x12 turned an average rpm of 8642 compared to the 16x14 at 8151.
How fast was the airspeed? it really isn't too important I was looking at difference in speeds between the two props. Straight away speeds are influenced by a lot of things not to mention that the airspeed in a full scale airplane has to be calibrated so that installation variables are accounted for. The 130+ MPH claimed other places was not anywhere near what this engine/prop/plane is capable of in level flight.
After all I went supersonic in a Prowler once! (43,000 feet 60 degrees nose down at full power) See why I only did it once, it took me 20,000 feet to pull out!

APC 16x14 is the prop for Parker!!!
Now I am going to go out and try a few really off the wall props just for fun.

Sparky
USRA V.P.

Lessions learned from Parker.
The Sundowner class had 14 entries. All planes were run through tech and items verified. The weights were all over from 13.58 ponds to almost 14.5 ponds. Grunk made a little carb air deflector from fiberglass available to any one who asked, thanks Grunk! I think the races were pretty good with the combination of plane, prop, engine. the planes were quiet during the race. Eyeball speeds were about 110 mph maybe. I think most had done some work to add some color to ease the turn judges work I believe we had only one refly as a result miss identification.

My plane being flown by Blue Moon Racing team member Terry Williams who won the Gold with my plane. Terry hadn't flown any races this season and did not have a plane so he was the logical choice for our race entry. He flew the plane one time prior to the first checkered flag dropped
The plane was the one I used for the prop testing so the plane had about 20 flights sorting out the
various props. These flights were about 7 minutes long and I only did simulated pylon turns in race conditions. No stall turns, rolls, (OK one roll) loops. Just race laps. Control throws were optimised for race conditions they were maybe even a little soft Terry confirmed they were "Sluggish". In racing conditions the plane was not the fastest many thought that Mike Friesel's Sundowner was the fastest which was also part of our race team.

This is how the Gold Class winner was set up.
I did not put tape on anything for streamlining or covers over the landing slot in the fuse. I even had the antenna dangeling out the hole provided.
I was at about 13.75 lbs with a 5 cell 2100 NImH in the rear. A 2S 2100 Lipo under the rx. Hollow tubes in the tail of the plane. I used the Radial engine mount instead of the beam mounts.
CG was 3" control throws were about the book values although I think I could have used a little moe up elevator for landings most likely due to the forward cg.
The ignition module was mounted on the bottom of the engine box. I reinforced the firewall with Bamboo pegs around the edge just as extra insurance. slapped on an extra coat of thinned epoxy for furl proofing. I ran a 10 oz tank over the CG which I think would be better served with a 12 oz tank, Terry ran out of fuel at the end of one race while we were trying to figure landing order.
The cowl had tape over the left intake, lower "carb", and half of the right opening. I did not use Grunks air deflector. Just kept the stuff that works the same. I had no cooling ducts or baffels inside and I did have a additional cooling air exit on the bottom.

The way that Terry won the race was smooth consistant flying, paitence (it takes a while for the plane to fly the length of the course (1600')) and a great turn caller Bobby Slaughter. I wll be more than happy to answer your questions about flying the Sundowner.

We are installing a Moki 2.1 and will do additional testing with the combination and see haow things go I think everybody wants to go faster with these fun little planes.

Lets race!
Sparky

Moki Update, I have three flights on the Moki 2.10. I used the same testing methods as listed above and yes the plane stayed together. The plane lost about 1 pound so now I am down to about 12.75 pounds. Stock Fuel tank (22 oz I think) mounted forward. Wildcat 10% fuel. I was concerned about fuel draw. Rx battery was moved to get CG at about 3" which leaves it still behind the wing. Bission Muffler for the Moki 2.10.
I only have made one flight that I consider valid data from. The engine swings the APC 16x12 about 600 RPM faster than the Evo 35 and the speed is up by 14 MPH. I need one more flight with this configuration and then I will try the 16x14 if the plane survives that my testcard calls for a 16x16 then 17x12 (the Dominator prop) Then I want to check a Saito 1.80 a Moki 1.80 and the OS 1.6 when I get done my cowl and firewall will look like swiss cheese.
Sparky

Originally Posted by dptp9lf

Hi...
Would a ZDZ Super 80 be plum ridiculous or just overpowered?
I mean would it shake it apart?
I can handle a overpowered plane but I don't want it to tear it apart either.
Reason... I just need something that's in the air quickly.
Any comments?
Cheers,

I put a BME 50 in mine as it was only "slightly" heavier than an Evo 35. Some of the other guys in our club use Moki 2.10's. There's not much difference in speed but I prefer gas over glow fuel. The difficulty with a larger gas engine is finding suitable props for this aircraft with a 50cc in it. You have very limited ground clearance...

Originally Posted by mfuess

I put a BME 50 in mine as it was only "slightly" heavier than an Evo 35. Some of the other guys in our club use Moki 2.10's. There's not much difference in speed but I prefer gas over glow fuel. The difficulty with a larger gas engine is finding suitable props for this aircraft with a 50cc in it. You have very limited ground clearance...

I put a DA50 in my buddies Sundowner he had me build for him. I used APC 18x17 or 17x18 I cant remember exactly and also welded up a straight header pipe for exhaust. It sounds mean as hell!

Oops, I didn't realize I posted that info here already lol.

Originally Posted by Flatlandman

I put a DA50 in my buddies Sundowner he had me build for him. I used APC 18x17 or 17x18 I cant remember exactly and also welded up a straight header pipe for exhaust. It sounds mean as hell!

I seriously looked at putting a DA-50 in mine, as I really love those engines. What I found was, the firewall to prop hub length was about 1" too long with the DA-50. Did you encounter this? Your photo suggests there's a large gap between the prop & cowling. Is this correct? Or did you shorten your stand-off box?

With my BME 50, I could set the proper 5 3/4" distance so the spinner would match up to the cowling. BME engines are OK, but I really prefer DA.

The really good news is, my BME-50 is 4.5 ounces lighter than an Evolution 35. I used the long steel rod and the short aluminum rod on the stab for balance. It still weighs close to 14. Lbs even with a BIELA 18x12 carbon fiber prop. I may consider moving my receiver pack to the back hatch if you think it'll drop some weight off...

Anything you can offer in setting up a DA-50 in the H9 Sundowner will be greatly appreciated!

JUST SO YOU WILL KNOW,
I have a Great Planes 1/4 scale RV-4 powered with a DA-50 using a 20x12 Mejzlik prop, and no one has come even close to keeping up with it. My thought is, an H9 Sundowner being a super clean airframe profile powered with most anything "should" out run my RV-4. So far that hasn't happened (yet). It will happen eventually. My RV-4 just isn't built for speed. That's and why I bought a Sundowner in the first place.


THANKS,

Mark Fuess
Greater Southwest Areo Modelers
http://flygsw.org/

Their is ~ 1/2 inch distance from the cowl to the back of the spinner. We were going to relieve it buy getting shorter stand off and drill a hole in the fire wall for the carb. The owner decided we would just build up the cowl to meet the spinner.
The Da is a smidgen lighter than the bme but not enough to make a diff on a non aerobatic plane.

You can save over 1 pound by using the other Aluminum stab tub and moving the batteries back to balance the plane. We did not, I used the steel long stab tube and the aluminum short stab tube. That allowed me to place the batteries in the hatch 2 inches behind the wing tube. He wanted and used 2 2700 ni-metal batteries on the rx and 1 2700 ni-metal on the ignition. All 3 batteries are on top of each other in the same spot for balancing.

The plane has only flown 3 times to reach a speed of ~120 by questimation of the 5 people watching me fly it but their is a huge airflow restriction for the carb and its not getting up to speed some time this semester I will rework the engine carb firewall area to allow proper air flow and the plane should wake up and hopefully achieve the 150 mph mark we are shooting for.

I remember we ran it on the ground no cowl and no obstructions to the carb and got 7600 rpms with that apc prop and i think it will unload a bunch to maybe 8500 in the air once the carb is allowed to breath.

For comparison my da50 vess 23a proped Wild Hare extra was scanned at 100 mph against the wind and 106 with the wind by a local state trooper, so there is a lot more speed to be had out of the sundowner.

Flatlandman,

I appreciate the INFO! For what it's worth I am currently using a Mejzlik 20x12 on my DA-50 powered RV-4. I tried a Biela 19x10 prop first, and it's OK but doesn't generate good topend. I am using a differential speed indicator which is supposed to be accurate to 1 MPH. My RV-4 hits an air wall at about 133 MPH, that's where the Sundowner will really show off its stuff. The BME 50 has a slightly shorter stroke than the DA 50. This "could" be an advantage with the correct prop.

Because I didn't know where the BME would hit the CG scale, I used only the long steel rod. My 5 cell NiMh pack is 1" behind the CG. Here is an early photo of my RV-4...

Very nice! I agree with the shorter stroke, You should have a slight advantage for speed. If you find a better prop than the apc 18x17 or 17x18 let me know.

Originally Posted by mfuess

Flatlandman,

I appreciate the INFO! For what it's worth I am currently using a Mejzlik 20x12 on my DA-50 powered RV-4. I tried a Biela 19x10 prop first, and it's OK but doesn't generate good topend. I am using a differential speed indicator which is supposed to be accurate to 1 MPH. My RV-4 hits an air wall at about 133 MPH, that's where the Sundowner will really show off its stuff. The BME 50 has a slightly shorter stroke than the DA 50. This "could" be an advantage with the correct prop.

Because I didn't know where the BME would hit the CG scale, I used only the long steel rod. My 5 cell NiMh pack is 1" behind the CG. Here is an early photo of my RV-4...

thats awsome!!!!! no spinner?
mike

I have a spinner on my Mejzlik, but not the Biela. I'm having a tough time finding an APC 18x17 prop... Where do I find one?

I did locate Pro Zinger Laminated Props: 18x16, 18x18, and 18x20... I couldn't find where APC even offers 18x17.

I called apc and asked for the props.

THANKS!

I will give that a shot. I'm not too sure what will be an ideal prop for the BME 50 on a Sundowner. I normally use 22x8 but that's not going to cut it for pylon. These props carry a heafty price tag... so I'm trying to plan this out a bit.

Here is a photo of my SUNDOWNER waiting for the engine to arrive...