New Engine
 

Hey all,

I want a new engine for my Avistar so it will have more "umph" or "get-up-and-go" to it...plus I am sick of buying those needle valve assemblys on my OS 40 LA. (bought 5 so far at $8 a piece, $40 on assemblys! and they all broke) also, I broke the carb and the crankshaft had a crack in it from my last crash so...here are the contenders...others welcome...and what do you think of the remote needle versus the needle on the carb?...

[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXKF97&P=0]Thunder Tiger Pro .46 BB ABC[/link]

[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXALM2&P=0]OS .50 SX Ringed[/link]

And would the remote needle on the .50 SX break like the "train" on like a OS 40 LA?

Thanks for all the help,
IBrakeForNobody

RE: New Engine
 

You can buy 2 of the tt46 pro for the price of the os50 sx - unless you need a bit more power than the 46. I have enjoyed using both engines - both are good user friendly engines.

RE: New Engine
 

For only $20 more than the TT Pro-46 you can get the K&B .61 Twister. Only about 1 oz more, but significantly more horsepower. Model 6170 on this page http://www.mecoa.com/kb/aero/aircraft.htm

RE: New Engine
 

I thought he wanted a new eng for the 40 size avistar trainer - the 46 would probably be better for it - even though the k&b 61 is a good engine.

RE: New Engine
 

You could also go for a OS 46AX. Cheaper than the 50SX and more than enough power for that plane. [8D]

RE: New Engine
 

The magnum 46's are nice too I had one on my Kadet LT-40 and it had plenty of power. Now it's on my 40 size cap, and can pull it vertical

RE: New Engine
 

k thanks for all the help...so is a remote needle better or is the needle on the carb better? The only thing I'm worried about is having my hand an inch away from a prop churnuing 17,000 RPMs...

RE: New Engine
 

I love my O.S. .50 SX's, very nice engines and have never let me down. Smooth, and full of power,they just need to be broken in Per the instructions, nice and rich for the ring. It would work great on your plane, and be great for other planes down the road where you will need some extra power i.e. more aerobatic, sport, or 3D, whatever your poison is. :D I have never had any problems with the Remote Needle on either of the 3 .50's I own. I prefer front mounted "old " style needle valves, but these are holding up. Most of my O.S. Engines are old FSR's, but the .50 SX is a great engine. If you can afford it, if not one of the Chinese .46's would work great. That is my vote........Good Luck.

RE: New Engine
 

I have a TT Pro .46 and I love it. Very user friendly... good power and reliable. I good bargain too.

RE: New Engine
 

I would go for the AX as others have mentioned. My 40 LA was giving me problems, so my instructor put his 46 AX on and my plane was SCREAMING by. Easily hitting 60. BTW it was my superstar select

RE: New Engine
 

The only thing I don't like about the 46 AX is the remote needle...I broke 5 of those things at a cost of $40

http://img.photobucket.com/albums/v1...mg0547edit.jpg

RE: New Engine
 

The current tt46 pro has the needle angle back away from the prop. I have not had any problems with the remote needle on either of my 2 os50 sx engines. You might be better with the tt46 pro without the remote.

RE: New Engine
 

.50 SX is all metal, if that helps, how are you breaking them? Crash, Hangar rash, etc, etc.

RE: New Engine
 

IBrakeForNobody,
Between the two motors you first mentioned I would suggest the OS, but that's just my personal preference towards OS motors. Now for the other worry, the remote needle valve. I love the remote needle valve. On the older FX motors the needle valve mount was part of the backplate of the motor, every time you crashed it was guaranteed to snap off and cost you $40 like you said. But with the AX motor they got smart, they made the mount out of metal that is bolted to the rear of the motor. Because of this it can now survive a crash, the mount may bend but can be bent back into shape. And if it does break you can fabricate a new one yourself. This make the 46 AX a great motor IMHO. The only thing you really need to remember about a remote needle valve motor is to wait a second or two when adjusting it, it will take a second or two for the change to happen. As long as you remember that you will love the remote needle valve. And as said above, it gets your fingers away from a spinning prop.

Now for your exact situation, I would recommend the OS 46 AX. Here's why. As I said above at remote needle valve problem has been fixed. The 50 SX might be bordering on almost too big for your trainer, and for the cost difference the 46 AX would be a better fit. The 46 AX has tons of power and there are a lot of planes that will fly great with it when you get ready to move on to other planes.

Hope this helps

RE: New Engine
 

Dude, get the 50SX, I put one on my avistar and the thing had UNLIMITED vertical with an APC 11X6 or 11X7. You will be smiling from ear to ear and all others will be saying "what you got in that thing...it screams!!!"

RE: New Engine
 

The TT 46 Pro is the best performance fit & buy for the Avistar -- the SX is a great engine, but it's too expensive for an engine of that size & output, & it is actually more powerfull than the Avistar can comfortably deal with (so is the TT for that matter). If you are very brave, for barely more than the price of the TT Pro you can put a GMS .76 on the Avistar -- that would be a highly entertaining experience that the rest of us would like to hear about.

RE: New Engine
 

46 AX would fly this plane great. It is a super engine!

RE: New Engine
 

I don't know how they break...they just snap or crack apart...maybe my fuel softens them up?

New one on right...broken one on left and the piece that is stuck in the fuel tubing

http://img.photobucket.com/albums/v1...n/Rusty108.jpg

RE: New Engine
 

I would go with a 50 AX

RE: New Engine
 

That is strange, anyone else have some input/help on this???

RE: New Engine
 

The 46ax still has the plastic nipple on the needle assy. The 50sx has a metal nipple on the needle valve fitting. enlarge the picture in BigSkyRCer post. The 50sx doesn't have that problem.

RE: New Engine
 

That has never happend to me...

RE: New Engine
 

So could I fit the 50 SX's needle valve assemby on the 46 AX?

RE: New Engine
 

You could do that but the 46ax eng plus 50sx backplate assy would cost very close to the 50sx and the 50sx has more power than the 46ax.

RE: New Engine
 

Okay...so is there any dis/advantages to having a ringed engine over that 46 AX? Sorry, I haven't gone flying for 5 months and I probalby forgot everything my instructor taught me about engines...