RE: Sundowner 50 Arf
 

Pedro was who i was talking about. man he had that ys humming. that is a good looking pkg. btw, he has the ys inverted so there isn't much to see in the cowl. it hides pretty well.

david

RE: Sundowner 50 Arf
 

It looks good to, my dad custom painted it that wicked blue. It will be the perfect plane for the November rat race.

RE: Sundowner 50 Arf
 

Well I just ordered a Sundowner 50 and .75 AX. I hope it rips.

RE: Sundowner 50 Arf
 

I received my sundowner today and started working on installing the Tower 75. Things were going well until it was time to install the muffler and that where I stop. I did have to move the mounting holes less than 1/2 inch out. The problem I ran into was installing the muffler. The length of the Tower muffler is to long and it does not have enough room to clear the fuselage. I did take pic with my phone but for some reason can’t download it on my computer. I have to wait until the wife return home to get her camera. I did have to cut little area of the cowl to clear engine head. I have to go to a Bisson Pitts Muffler for it to work.

RE: Sundowner 50 Arf
 

Ok wife got home and was able to take a few pic on plane. Have to go with pitt style

RE: Sundowner 50 Arf
 

I got little to happy on the cowl.

RE: Sundowner 50 Arf
 

I see what you are saying patzane. The tower muffler looks like the muffler of a os 91. That was the main reason I didnt go with that and used the os 75. The 75 uses a shorter power box muffler. The powerbox muffler stops short of the fueslage. You should be good using a pitts.

RE: Sundowner 50 Arf
 

When you were drilling holes for the new mount location, did you bolt the engine to the mounts with them off the plane, then hold the mount with the engine on it up to the fuselage to mark and drill them?

Also are the blindnuts installed from the factory, or do you install them seperately? Is there enough space between the original mount holes and the new mount holes you drilled to keep the wood from splitting due to one hole being so close to the other?

Thanks in advance. My stuff should be in tomorrow and Friday, so hopefully I'll be able to maiden it on Sunday if the weather co-operates. Same setup as you, .75AX

RE: Sundowner 50 Arf
 

Yes the blindnuts and holes were already installed by the factory. I screwed in one of the mounting screws and popped each one out. I filled the original holes with tight fitting wooden dowels and glue. Let dry then grind till the are even to firewall. I then clamped the engine to motor mounts using small c clamps and used thrust lines and old holes for orientation. It came out to 10 mm wider so ended up splitting the dirference by measuring from the center of the old holes 5mm on each side. I also marked the centerof the engine onto the motor mount so I could line up the thrust line that way. Oh also measure from thrust washer to back of motor mount. It cameout nice. Oh also the old holes actually overlap part of the old holes that is why you fill them with wooden dowel. The plane goes together quick so you shouldnt have any problems getting it ready to maiden in time. You wont be disappointed with the combo. Balance it right at 2.5 in. and she will be a sweet flying plane.

RE: Sundowner 50 Arf
 

That all sounds pretty straightforward. I can't wait to get started :rock:

How far is it from your firewall to the front of the thrust washer on that .75AX?

RE: Sundowner 50 Arf
 

I cant remember I used what manual stated plus 1mm.

RE: Sundowner 50 Arf
 

Thanks for the all info easton.

RE: Sundowner 50 Arf
 

Order the pitts muffler today from tower for the 75. Will be here next week Thur and looking to have this bird in the air on Friday.

RE: Sundowner 50 Arf
 

Man, it's a ***** getting that 75AX lined up so the crank is even with the center of the cowl hole, but that's probably because I don't know what I'm doing. I decided to ditch the 75 idea and put a .46ax on it instead.

Anyway, there might be a firewall problem with mine. I don't know if this is normal or not because this is only my third ARF and I haven't noticed this before..

I was installing the engine tonight and I realized the firewall, I guess you could call it the outermost firewall since there is a main firewall and then one that sticks out farther that the engine mounts to,.. anyways, the outermost firewall is 2 3/8" ahead of the main firewall on one side and 2 9/16" on the other. It really angles the engine. I tried washers between the engine mounts and the firewall, but then the engine is offset to one side once the cowl is on. I know some have built in thrust angles, but this just looks excessive...thoughts?

www.lxcoupe.com/images/firewall1.jpg
www.lxcoupe.com/images/firewall2.jpg

RE: Sundowner 50 Arf
 

They did it for a reason so its probably needed, would not change it since it came from manufacturer that way. Some of my planes have more than that and fly straight as an arrow.

RE: Sundowner 50 Arf
 

I just checked mine and it has the same thrust angle built in. It does not look like a mistake. All of the laser cut parts are glued tight with no gaps or mis-matches.
The 55 AX has the same bolt pattern for mounting as the 46 AX. Everything should bolt up with factory hardware. I will find out soon. The engine should be here next week.

RE: Sundowner 50 Arf
 

The angled firewall is for the thrust of the engine. Almost all arfs will have some angle built in the firewall. That is why the laser etched lines are offsett from the center of the firewall. With the engine angled if it is linedup center with the lines and is measured to the stated distance from firewall to thrust washer it will come out center of the cowl opening. If you go ahead and mount the engine to the plastic mounts. Go ahead and measure from the back of the mount to the thrust washer that will give you what you need for the distance for it to clear the cowl use the distance stated in manual. than line the mount with engine to lines etched in firewall. I believe the top of the beam of the motor mount is the center, make a line with a colored marker so you can see the line you make on the black motor mount. Do this on both mounts. Now just lineup the top and bottom lines with the lines you made on the mounts. You can also use the preinstalled holes as a reference also. Mark holes in mounts. I use a gp deadcenter drill finger thing it works great for this. For the 75 ax the new hole marks should be about 5 mm outside of the center of factory installed holes for 52 evo.

RE: Sundowner 50 Arf
 

Thanks for the replies guys.

RE: Sundowner 50 Arf
 

What do you guys think about a saito 100,, i have got my sundowner ready for a engine and i cant make up my mind, i was thinking a os .75 ax, but i have a os .91 fx on the shelf not being used,,, i really like 4 strokes so im leaning towards the saito 100. dont really know what to do.. the one thing i dont want to do is butcher the cowl all up.. and a big 2 stroke with a muffler is going to do just that, dont ya think???? anybody have an idea of speed from a saito 100 on this plane????
By the way, reefbluecoupe where do you fly at, im from old hickory, and fly at volunteer state model aviators field up close to clarksville..

RE: Sundowner 50 Arf
 

I have a satio 100 but I did not try it. I had my mine set on a 75 and as you see i did have to butcher the cowl a little. I also had to go to pitt style muffler which should be here on Thurs. Hope to have this baby in the air friday. Easton what size prop are you running with that 75.

Have anyone using the smaller motors weight theirs yet. Like to see where folks are at

RE: Sundowner 50 Arf
 

So far I have only used the recommended break in prop 14-6 apc. I am taking it easy on this engine letting it break in nice and easy because I plan on running this engine hard later. I have switched to a 13-8 apc but have not had a chance to fly it yet. I am going to see what it does with this before I jump to a 13-10.

RE: Sundowner 50 Arf
 

I weighted the sundowner today and she entered in at 6lbs 3 oz and the with everything expect the muffler. Hope she stay under the 7lbs once i add the muffler.

RE: Sundowner 50 Arf
 

My muffler arrived today and was able to finsh the bird up. Will be doing the madian flight 2morrow. Final weight was 6 lbs and 6 oz. Should rip good. Going to try a 12x10 prop to see what it does. Will try different prop tp see what gives me the top speed.

RE: Sundowner 50 Arf
 

Cool advise us of how it went.

RE: Sundowner 50 Arf
 

Any updated pics of the pitts muffler. I would like to see how it fits in the cowel. I sould be picking up my SD50 today. Thanks