it would be dissapointing on an 18x10, I normally use a 16x15, this has achieved 140mph straight and level, I tried a apc 18x12 pattern 2 peice component, and would describe it as ok, I think with nitro fuel the 16x16 would be on the button. If using this as a reference, remember that I do have a os tuned pipe. on a factory muffler or pitts the bgx is a little dead, but your nitro fuel may make up for this.

With regard to snap, go back through this thread and refer to c of g and snap, h9s recomendation is 1/4 too far back.

I am thinking of puting a 29cc gas motor on this plane. Do you think it will pull it well? Any help please! Thanks Gerry

Thanks for the input mate! I have come to a similar conclusion about prop size. I have ordered a 16 x 14 Bolly. With any luck it will be available this weekend. I have the custom Bisson muffler for it, which is a lot better than stock but not like a tuned pipe.

With regard to the CG, on its back it requires a little pressure on the elevator to keep it from droping its nose. However, moving the CG forward 1/4" shouldn't bother it too much and any snap improvement would be great.

Thanks again,

Gerry,

29cc is about 1.8 cubic inch. For that displacement you would get much better high speed performance from a Moki 180. Most gas engines won't turn up as high as an equivilant glow engine. You also want high prop pitch (14 or 16) which tends load gas engines. I'm flying mine with an OS BGX 3500 (2.13 cubic inch displacement) with an 18 x 10 and it sucks for speed. I'm going to a 16 x 14 Bolly

If you're really looking for speed stay with big displacement glow or 45 - 50cc gas. Of course, opinions are worth what you pay for them. Good luck

I cant believe I've only seen one other post picking up on the fact that Evolution Engines no longer lists the 35 on their website, and now shows a 40 in its place. Is anyone wondering what this will mean to the Sundowner spec class USRA racing? Will guys looking to join the class be forced to try to locate a no-longer-produced 35 engine in stock somewhere or will current 35 owners be forced to buy into the new 40? And will the class be changed to accept the new Evo 40 at all? Either way something will have to change. Opinions???

http://www.horizonhobby.com/Products...odID=EVOE35GT2

But you do raise a good point about the racing class. If Horizon/Evolution means to end the 35's, then the class will have to adapt. It was probably going to anyway as it progressed. Maybe they finally will allow an open (or limited) class.

The specs for the new 40 do look sexy though, with the engine weighing in at less weight than 35 and the canted plug design. But another $50.00 for basically the same design is kind of goofy. Same thing happened with the 26GT2 though when it morphed into the 26GX.

I still have this incident problem. I meassured everything even with the incident meter but I still have to move the left Ail 5mm down (right 5mm up) to get a straight flight.
Never had a plane before with such a bad behaviour. Now I have in mind to correct it by moving the back fixing hole (towards tail) of each wing to have this missmach corrected.
But this means that the left wing will be about 2-3mm lower then the right wing having the canopy surface as a reference. Hopefully this will improve the flight conditions.

Could it be that the wings are a little bit twisted? If that is the case what kind of corrections are recommendable ?

By the way the elevators are in the correct positions.

Rgds

Bruno

easy to detect a twist, just run your incedence meter up & down the wing

Bruno,

I've got a similar problem, but not quite so severe. Are you using any ail differential? I found a lot of adverse yaw in the original setup and programed in about 30% differential which removed the condition. I also increased the ail throw substantially to improve the roll rate. If you are going to seriously race at high speed the slow roll rate is probably apporpriate, but most of us just want to have fun. The plane still required a slight offset for level flight, but its only a minor annoyance. I also moved the CG forward 1/4" to reduce the snaps.

Good luck

My Sundowner has a Saito 180 and I am using a APC 15x12 .Wondering what other props are being used with this motor?

Dear All,
the trouble which I had with the Ail trims is solved. I just put the ignition batteries from the tail to the factory GC and the plane is now flying like my others. But unfortunately subjectively not as fast then I thought with my DL50 and a 19x14 wooden Menz prop which revolves above 8100 rpm (tuned KS pipe). The only problem I still have is the flip over tendency on landing. i.e. I must move the landing gear a little bit forward. Had somebody simular problems and a has a good hint how to solve it in an efficient easy way?

Rgds

Bruno

put apprx a 1/4''X1/4 x the width of the fuse spacer at the back of the gear were it mounts on the fuse, this angles the wheels forward about an inch, worked great for me, you may have to increase the bolt hole size in the gear to allow for the angle.

How did you manage to get the c of G so far out ? A plane like this must be hung up and balanced 'bang on' before flying, 3'' is really good.

I thought the GC was correct to check it by lifting the plane on the very end (towards nose) of the wings. It was really good balanced but it seems was not good enough. So is solved now.
Regarding the landing gear; Thanks for the hint which I also considered to be might the easiest solution to get rid of this problem.

Have a nice day!

Rgds

Bruno

Hey everybody,

This was just posted on the USRA forum:

That's at the El Mirage Dry Lake Bed in California, Oct 30-Nov 2

Mike

wow! hang it up and do the job correctly, 10mm can make a world of difference, you say solved now, get it bang on 3 inches and you plane will fly even better. The total safe flyinfg c of g range would be no more than 20mm, so fingers are usless !

I had got into a very heated debate with some of hte GIant scale racing board members on trying to increase the size to a 40cc a year ago....
Looks like they will have to update the rule book again or perhaps they will just leave it as is....
I have a Lightweight 40cc just waiting to go into this one if they would just give it a go-ahead........
The ZDZ 40F3A would just decimate most anything else ... Light as a 26cc..... so you would still retain the wonderfull flying you get with the Evolution 26.... but musch more exciting to fly.....

But if H9 will not change there specks to include 40cc.... The Giant scale racing association just may be too concerned with being sued if someones wings fold and puts a hole
threw someones helmet.!!!!!! Can you blame them??/

It is interesting to see those guys make it clear that it isn't Sundowner scale racing it is Giant scale racing, yet the Sundowner class was one of the largest classes they have had in years....

I feel the same way. I'm putting an Evo 40 in mine. Same dimentions as the 35. I think the 40 might be able to hang with the bigger moki's. Even if it doesn't I'll be happy with the 40.

It seems that those that are placing the 50cc engines in this plane are doing just fine with them....
No Wing failures that I am aware of, due to too much stress caused by a larger than suggested engine....

I had purchased my 40 for a pattern plane set up that didn't materialize...... As I don't think that many people would pay the now 600$ engine
I guess though It all depends on what you want.....
If you want the Lightest most competitive setup, it is the way to go if you are racing these planes.....

Our economy is in the toilet right now, so I really didn't feal that I missed out on much.....
Some of those drives to attend the races would have cost me over 500$ just for gas to there in back...

Not to mention the entry fees....

I hope things do turn around soon though....

Put me in Coach [sm=49_49.gif] I can whoop em all with my Saito 180 using a 2x4 prop and one of them special muffeling dealys. Why i just had it all the way up to 30 ft. high and it only took 10 min. If they would allow it I would use my SBC 350 It would scream then maybe hit 50ft. and probly 45mph. I can do it Coach just put me in I gots on my game face now[sm=bananahead.gif]

I'm a racin man I race when i can yeah I'm a racing maaaan give you a tip if I can I"m a racin man. With the correct music i have a # 1 knock off there you think.

Here is my yellow beast....

I wish.....

http://www.youtube.com/watch?v=SKjmh...eature=related

I have just switched from the Evolution 35 setup to a moki 180. Much better setup in my opinion.

Question....

For the Evolution setup, the consensus was that half of the inlet hole on the carb side should be blocked off. Additionally holes should be added to the bottom side of the cowl for cooling and some even believe baffling is required.

Are people finding that this is also the way to go with glow/moki setups?

Forgive me if this has been posted. I didn't have time to search through all of the post.

I've just got a large outlet at the bottom rear of my cowl, cooling is not an issue (os bgx 35cc glow)
I suppose the gas engine just does not make the revs.
nice to see this thread re started, my downer has been hanging in the hanger for too long now- time for a dust off and sorte.
see if you can get your hands on a gps to slip into the fuse-you've got 140mph to beat !

I've inherited a sundowner which i need to repair undercarrage mounting on fuz. The wood has broken away.
I've been studying everyones pros and cons with this fab model.
I notice some are using a 160 os.
I was wandering how a 120ax would measure up in this model as its only .6 down on bhp from 160 and considerably lighter.
Perhaps a tuned pipe would give it more grunt too.??

Guys...

Just switched out my Moki 180 for a 210. I put a 16x16 prop and started her up and got 7200 rpm. Is that the right range for a 16x16?