sal2006

Hmmmm, I don't know...I would personally go the 2 stroke 91.......this motor still doesn't push the plane to its limits. a 120 2 stroke would have done the job perfectly. A 4 stroke at 10k will fly it...but don't expect any aerobatic moves, this will just give you general curcuit flying.I still can't get over them recommending a 60 2 stroke, the plane would barely take off. The plane weighs about 2.7 kilos and the 91 2 stroke is great with a 13x7 or 14x8 if you want to slow it down a little. This is a beautiful plane and will be great for precision aerobatics. How much does the 4 stroke weigh compared to the 120 4 stroke? I would put the 120 4 stroke if it only weighs 100grams extra. Let me know how you go.
Cheers Mate
Sal

akaram

Personally I believe a 91 4 stroke will be too little power for this plane (especially that it is a magnum). A friend of mine has a Contender (originally designed for a 46 2 stroke), he put on it a 91 4S and it performed like S*H*I*T*, it was like driving a diesel car ! Then he put an OS 50AX and the plane came to life !!!! so much increase in speed and power !!!
Notice that on Tower [link]http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXAN96&P=ML[/link] nothing is mentioned about power output which means something !

IronCross

I love the Mag .91 4s.. It is my experiance it will outperform the OS and will almost hang in there with the Saito .91.. It is IMHO one heck of an engine for it's price... I also have several Saito's which are excellent engines but a bit pricey.....
As for having enough power for this plane it is beginning to sound like it doesn't... I like the OS 1.20 AX suggestion... Guess I will do a little more research on that engine...
Can anyone tell me if there is enough ground clearance for a 16 inch prop on this plane ?..
Thanks
IC

Incidentaly.. The published HP ratings mean nothing... So why bother with them...

akaram

With a 16x4W prop you are left with 12cm ground clearance with the fuselage parallel to the ground which is OK.

A for the 120AX I also scratched my head a lot when I was chosing between it and the 90 and then went for the 90

120AX
Power Output: 3.1ps/9000 RPM
Weight of engine:22.82oz (647g) without muffler,extension or adaptor
Weight of muffler:7.074oz (219.2g) with 90° adapter installed
Weight of muffler:7.907oz (245g) with extension installed

91FX
Weight: 550g (19.42oz) (688g)24.3 oz w/muffler
Horsepower: 2.8 BHP at 15,000 RPM

the 120AX will be 180 grams heavier than the 90 and you will have to use a bigger tank so you will end up with a nose-heavy plane. with the 90 mine is just a bit nose heavy. the bhp figures are very close but definitely the 120 should give more torque at lower rpms just what you need for hovering

IronCross

Thanks for the info
Can you hoover yours with the 91fx on it ?... What prop are you using ?..

akaram

I am still flying with a 14x7, the engine has done only 6 flights, still being broken in. When broken in I am going to try APC 15x4W and 16x4W . I hope it will hover.

sal2006

i think it will hover with the 91fx if you have a really low pitched prop, 14x4 would be perfect....but I would go the 120ax if you are going to do some true hovering.. I love the way this plane knife edges.. it does spastic snap rolls which look awesome in the air. It is by far one of the best planes I have flown and seen...Everyone at the firld was jelous hahahahahha, they just didn't want to admit that it was a brilliant plane...They all told me to go the 61 2 stroke, and I started laughing at them, at 2.7 kilos, the plane would barely take off.. Mate, if I were you, get the full potential of the plane and chuck in the 120ax, I will be selling my 91fx on ebay and buying the 120. If anyone wants to buy the 91fx off me, I will sell it to you for 270 AU which is dead cheap....the motor is still like new.....so guys let me know.

IronCross

So how are are you mounting your engine ?.. Sideways or inverted... You don't feel the 1.20 would present any major mounting problemss ?.. Sounds tempting..

sal2006

mount it at the angle specified, 270 degrees i think. It will fit fine, even better if you have a pitts muffler for it..

akaram

Note that if you want to fit a pitts muffler, you have to mount the engine horizontally (this mounting position is not illustrated in the manual, but the predrilled holes align just fine with the engine mounts in the horizontal position.)

IronCross

Is there a pits style muffler available for the 1.20 AX yet ?... The stock muffler looks pretty bulky running at 90 degrees..
After looking at the price on the 1.20 I am also checking out the Saito 1.25.... Heck before I am through I will probably end
up with a small block Chevy in it... Cost less then some of these engines too

akaram

Of course there is


Bisson 1.20 AX Pitts Muffler Tower stock number LXMKK3 costs 40$

IronCross

Thanks again for the info... Means I could order the 1.20 without the muffler too..

akaram

By buying the 120AX without the muffler you save 30$.
Looks like you are decided on the 120AX ! Though I didnt recommend it, I am now curious to see how things will go, if it works well with you I will be getting one myself When approximately will your plane be ready to go ? Keep us updated and try to post some pics of the engine in place without the cowling and with the cowling !

IronCross

I am still in the plannning stage.. Do reasearch to see what kind of setup I want..
I think sal2006 will have his going pretty soon from the sounds of it..

IronCross

I understand there is a problem with the cockpit interior melting in the sun on this plane... Has anyone contacted WM about this ?... Are they standing (as in replacing) behind their melted parts ?

akaram

But what is the use ???? If they replace it, the replaced part will melt also )))))))) and it doesnt take much to melt, in light sunshine with the sky cloudy mine started melting, the canopy works like a small solar cell used to heat water on roofs
Do what I did , it is the best solution.

sal2006

Hi Guys,

I sent a complaint email to the world models about this issue of the canopy melting in minimal heat and sunlight. They basically told me to fcuck off and buy another one, and that they couldn't help me. I found this very rude and So I just replaced the cockpit with blue monokote which looked awesome and had no issues. The world models told me that I could not speak directly to them and wouldn't provide me with a phone number so I could speak to some form of managment, they emailed me telling me to speak to a wholesaler who imports directly from them......So I called the wholesaler in Australia, and he's like....NA MATE...YOU GOTTA BUY A NEW ONE AYE in a very heavy aussie accent..LOL I'm like, this should be replaced, but he wouldn't do it.....So i bit the bullet and rebuilt the canopy, I didn't want to speand 70 dollars AU on another canopy which would have meleted again...Well, I got a new job, contract role which is paying really well, and I will buy the plane again in 2 weeks or so...I'll keep you guys updated

IronCross

Funny, I eaild Airborn the USA distributor about the "melting cockpit" to see if they had a fix for it... They didn't even bother to answer my email... Too many other Extra's out there for this BS....

CVTEFLYER

Saw this plane at Radar with the new Zenoah G200 PU 20cc gas engine with electronic ignition! Looks like I need to have one with this combo. Engine is now available.

toninhosilveira

Hey guys! Anyone who's using an O.S. 91 FX with this plane has already accomplished the task of torque rolling it some how? By the way, is it ok to use Futaba s3004 on the ailerons and two s3004 for the elevators? If it's not, what servos would you recommend? I don't have much money left, so, i would prefer using HITEC or Hobbico servos from now on =)

fay

hi guys,

If i'm using 120AX what is the best for engine mounting?
Inverted mount or inclined mount?

and what size prop is the best for hovering with this 120AX?

thanks

akaram

APC 16x4W will do the job. The 120AX mounts in the same space as the 90 or 60 so it all depends on the muffler you are going to use. With the stock muffler it will mount inclined with the cylinder tilted down, with a pitts it will mount horizontally with the exhaust port facing downwards.
As for hovering the plane, I have a 91FX on it with a 15x4W prop, it has unlimited vertical and i hovered it for some time far away up, it did hover very well but at that height I couldnt get a feel of how powerful is the escape from hover with full throttle. I am still afraid to hover low.

drewbags

That's the one I saw too. Wonder what the performance will be like with this engine? From what I understand the performance of smaller gas engines is not very good? Looks cool though and the engine price (in Hong Kong) is very competitive.

fay

thanks akaram.. i think get some idea for this..

drewbags: any online hongkong shopping cart good to share? maybe can buy online for those engine