I am looking for the most powerful .46-size motor that is reliable.

The plane currently has an old, worn-out Magnum 46 that , and is underpowered as-is.

From the manufacturer's specs, the Tower Hobbies motor is listed as the most powerful, but most reviews in this forum have been poor. The OS FX gets great reviews for reliability, but it is not listed as the most powerful. My newer Magnum 46 runs great, but I know there are more powerful motors out there.

Does anyone know what the most powerful .46-sized motor is that is reliable?

When you say power are you talking about torque or prop speed? If you are leaning toward speed I would stear you towards the 46FX or the 50SX by OS, on a pipe both sing. If you want exotics that will outperform those go with the nelson, Jett, Rossi stuff. If your looking torque, I would lean toward the YS 52 One strong little brute, I think it is a .52, but I'm not sure. Really can't speak from experience though. I have only seen all these outperform others. I have helped break-in, tach, and tune all the above though. I started with a .60 and never went smaller personally except electrics.

I suppose I am looking for torque.

The guy I bought the plane from said the motor had over 200 flights on it. On the plane's first flight, it took off well, but went sluggish when gaining altitude. Then the engine quit, and, due to its low speed, it lost a bunch of altitude when turning around. It disappeared behind the steep drop-off by the runway, so I could no longer see or control it. At that point I waited for the "crunch" and picked up the pieces.

10 hours of rebuilding later, I want a reliable, more powerful motor. I want to do freestyle aerobatics. Speed is not a desire at this point.

I also have a Magnum 52 FS slated for my Kyosho Super Stearman, but that seems like it would be too small. The plane is a Balsa USA Smoothie, which is no longer made.

Go with the YS you probably gained some wieght in the rebuild, and could use the extra zip/torque.

More power = less reliability, more reliability = less power and less features.

The most reliable engine is probably the ole Fox .35 Stunt. It has no carb and no way to attach one, course this makes it more reliable and the power of a modern 25, but more torque, it will pull a 10-6 at 9 to 10,000 RPM.

You can get a very exotic engine made in places like Moldovia, or Czechoslovakia and start with the letter Z, X, or PZ. I'm talking about engines made for record speed runs, and you can expect to tinker, repair, and modify before and after each run.

So you must be talking about a compromise, and for me it would be a TT .46, but if you are racing it would probably be a Jett or Nelson, and aerobatics probably OS or YS.

Short, only you can determine the best compromise.

My interest at this point is aerobatics. I can't affort the exotic stuff. From what I have read, the TT 46 makes about the same power as the Magnum 46, but weighs more. I know you can't always believe what you read, though, so I thought I'd ask people who actually use them via this forum.

From what I have heard and read, I am leaning towards the OS 46 FX.

The TT .46 is somewhat more powefull than a .46 FX, the magnum is a clone of the OS FX and if you get a good one is also about the same power, I.E. you may not notice any differance between the three of them. If you are going into competition I wouldn't recommend either of them, too small.

There are many dependable powerful sized engines in this class.
In testing done by CLARENCE LEE there is 5 very powerful!,

("THESE ARE NOT IN ORDER OF MORE TO LESS POWERFUL")

1. TOWER HOBBIES 46 (HAVEN'T TRIED ONE)
2. K&B 48 "SCREAMING 48" (MY FAVORITE)
3. THUNDER TIGER PRO 46 (ANOTHER ONE OF MY FAVORITES)
4. GMS 2000 46 (HAVEN'T TRIED ONE)
5. OS 46 FX (TRIED MANY)

Also remember you can go to a 70 sized 4 stroke in an 40 size aerobatic ship and you'll like it also.
(i fly a OS 70 4 stroke in a GLOBAL AVENGER)
( A MAGNUM 91 4 STROKE IN A GLOBAL ULTIMATE BIPE)

The 4 STROKERS GIVE YOU THE TORQUE TO PULL LARGER PROPS and in turn you generally can pull through the vertical manuevers with out needing "built up" airspeed.


REMEMBER one thing though, the more powerful you go, the more advanced the timing and internal complexity of the engine is.
They can be very touchy on the needle valve settings. when you get a carb,timing and porting combination that is easy to tune, you're going to loose power. when they get more involved in the above settings(timing,porting etc.) then the more precise you have to be in the tuning, setting up. and more powerful the engine "usually"is.
I have bought three K&B 48s from guys I fly with who say they can't get them to run! (my gain their loss) The SCREAMING 48 just takes a little more tinkering to get everything set for quick response,idle and top end. but what an engine when it's set up right.
The THUNDER TIGER PRO 46 is very dependle,powerful and easier to tune.. I have one with a tuned pipe ( in a HOBBICO SPECTRUM)and one with the stock exhaust.(in a H-9 advance) both are easy to adjust and you don't have to mess with them once they are set up. (THIS WOULD BE MY ENGINE RECOMENDATION FOR YOU!)
I will give OS credit where credit is due, but you're paying for the name! they are more expensive then any but the K&B 48. (last i checked they were the same price, but the K&B will run circles around the OS 46)

In reading what you said the problem your engine gave you IN THE AIR, I'm going to guess that YOU HAD IT SET TOO LEAN!!!!

When you set your needle valve on the ground remember the engine is going to "UN-LOAD" in the air. (forward air speed is going to make the prop turn faster) and that will can you a LEAN run in the air.and by what you described yours was doing that's what it sounds like. When you set your high speed needle on the ground, do "THE PINCH TEST" I do mine with a "TACH" I want 200 RPM increase AT FULL THROTTLE when I pinch the fuel line to kill the engine.(on a well broke in engine) I do this for the TOP END and BOTTOM END (idle) many hold the nose of the aircraft in the air AT FULL THROTTLE to make sure the rpm doesn't drop, there is nothing wrong with this and if you don't have a "tach", do it.
But if you have a tach or can get one use it as I have described, I think you'll be pleased.. I'll add one more thing, BREAK THE ENGINE IN THE "EXACT" WAY THE DIRECTIONS TELL YOU TO! And on a test stand NOT in "THE AIR".

JUST MY LONG WINDED OPINION!

// OH YEA, there isn't a thing wrong with the MAGNUM 46 BB engine (I have two of them in trainers) they're just not as POWERFUL. and that's what you asked for!

RON in NEVADA

Well put Desert Rat.
I too vote for the Pro 46.

200 flights is a bit of time for an engine. If run hard it would probably be past its prime. Does sound as though you had it set lean. The higher reving the engine is the more it will lean out at speed. It should be set at least 300 rpm on the rich side more if a high reving engine. 100 RPM rich with nose pointed straignt up. Thats about a click or two on most engines.

Also it sounds like you may be reading manufactures specs. I know OS weignts are without muffler and TT engine weights are with muffler. Thats an ounce or two differance right there. Also TT horsepower figures are lower for engines that are very similar, for example the TT .46 Pro and the OS FX. They should probably be withen less than .1 HP of each other. Maybe OS HP figures are without muffler and TT is with. I don't know but manufactures HP figures are always suspect. That is why the magazines no longer measures the HP figures. Back when they published charts of the HP and torque at all practical RPM ranges. I think manufactures threatened to pull their ads or something because the magazines stoped this practice about the same time.

I think what you really need is a 53. I run Irvine 53 and Rossi 53 in 46 size planes. Rossi is very powerfull and top quality but seems to run best at medium to high rpm. Irvine is not quite as strong as Rossi in terms of hp, but it performs smoothly even with APC 13x6 or 12x7.

Depite having a 40 size case, Rossi 53 is little larger than other engine in this category. The muffler is also real crap and itys porting seems to work best with pipe.

For you Iirvine 53 is the way to go. The muffler is very OS like, it fits same mounts as & most of the Chise stuff. It is true ABC and has an extremely nice carb. Anything bad in it? Some have had corrosion problems but I guess is about the same with all engines.

So the TT 46 Pros have the same power as the OS 46 FX? My LHS carries the TTs for $70!

FYI: The reason the engine died was because the carburetor fell out. When I got the plane, the motor would not stay running. I found bad O rings on the main needle (fuel spitting out all over) and on the carb base. I used too thick of an O ring on the carb base, which did not give enough "meat" for the retaining bolt to hold, allowing the carb to vibrate and fall out during flight. D'oh! I have since replaced the O ring with high-temp silicone sealant, allowing the carb to seat fully, and giving the retaining bold lots of "bite". I always tune my motors for peak RPM with a tach, then richen them until the RPM drops about 300.

I have both the TT46 and the OS 46FX (with the remote needle valve) and after using my TT46 on my Magic, I would never buy another OS. Two resaons: I hate the remote needle valve (leakage) and the high price! Buy the TT46. You won't be sorry!

I just called my LHS to buy a TT 46. I was told by them that the OS is more powerful. aaaaaaaaaaaaaaaaah!

Has anyone seen, done, or know of any published side-by-side bench testing of motors? I don't imagine any of the major publications would do one due to the obvious repercussions from the manufacturers of the engines that did not perform well.

Who is Clarence Lee, and where can I find what he wrote?

I will repeat the above posts. Buy the TT46Pro. Best value in its class - bar none.

Its 1 hobbyshop (probably with a bunch of OS's in inventory) vs. a bunch of independent modelers. Take my (our) word for it - get the TT46Pro.

Think again. How big is the power difference between various 46 size engines. If OS is the strogest, it might well be, is it strong enough to make your now underpowered plane peform?? Will it be worth the investment.

Personally I like OS 46 FX, and I have nothing against the Chinese offerings, but I still think that the best way to you is a 50-53 size engine. For you I recommend Irvine over Rossi, but there also many others: Webra & Enya 50, OS 50 SX... even ASP has a 53.

BTW a suprising amount of power can be gained with a absolutely right propeller selection. If your plane is one of the slower ones, try APC 12x4 or 11,5x4.

Very good engine, one step below OS FX series at about half cost.

Yes, I have done a side by side test of the OS 46FX and the TT 46 Pro. Both engines were well broke in and the OS was marginally more powerful than the TT. Not $30 more powerful, but it was more powerful. I have since thrown out the notes I made so I don't have RPM figures (it was nearly 2 years ago!). I can say this with confidence, though - the OS was significantly more powerful with larger props like the 11 x 6 and 11 x 7. And if you put a Tower Hobbies .46 muffler on it the TT isn't even in the same league. While both engines will turn darn near the same RPM with a 10 x 6, the OS will turn an 11 x 6 at least 1000 rpm more when both are fitted with the Tower muffler. Since the port timing of these two engines is almost identical I was curious why the OS did so much better than the TT with the Tower muffler so I measured the compression of each with one of those little pressure gauges you screw into the glow plug hole. The OS had more compression.

BTW - the OS 46 is not that expensive. They're $110 in the latest Tower Talk. I remember paying more than that for a 46 SF back in 1988.

The head engineer/designer left OS and WENT ON BOARD TO THUNDER TIGER. He took "his" designs with him!

The TT and OS are virtually the same engine, (the newer ones)

I have a KYOSHO CAP 232 ARF and have ran BOTH engines in this plane, I FLEW IT WITH 10x6,10x10,11x5,11x6 AND 11X7 PROPS (MANY DIFFERENT BRANDS) and found absolutely NO difference except the TT had a LITTLE better verticle. ( I NOW FLY IT WITH A k&b 48) My personal preference (BETWEEN THE tt AND os)is the THUNDER TIGER and at a CONSIDERABLE SAVINGS FOR THE WALLET!
I have a "MACS" tuned pipe that I have ran on the THUNDER TIGER and it turns this engine into a rocket engine, unreal power gains! I like it so well I just bought a SPECTRUM just for this engine! (because of the tunnel for the tuned pipe)
Yes I do build but I hold down two jobs and don't have the time to build as I like so I depend on ARFS.

OS has gotten way out of line with the price of their engines just because at ONE TIME they were the "KINGS" of small engines. not so any more! many engine companies are running them competition in power and especially price! I do not have a thing against OS, so please do not take me wrong, I fly OS bushing engines in my trainers, and my grandsons sport planes. (GOLDBERG EAGLE,GLOBAL RIGHT FLYER AND HANGER NINE ADVANCE all have OS 46 LA engines) very dependable powerful engines for bushing engines! very easy to set up! very consistant for beginners! But when it comes to powerful/ dependable then I vote for either OS or THUNDER TIGER, But when price comes into play, THUNDER TIGER TAKES OS HANDS DOWN!
You can buy OS (NORMALLY $119.95)and pay an addional $50.00 for the name, or buy a THUNDER TIGER ($69.95)(virtually the same engine)and pick up 5 gallons of 15% fuel to run it with for the same price! hmmmmm And even if you do find it for less differential in price it's still a lot of other needed stuff! I'll have to think about that one for a while... "NO BRAINER!"

BY THE WAY, THERE WAS A TIME NOT TOO LONG AGO I WOULDN'T HAVE CONSIDERED ANYTHING EXCEPT OS..(I have an OS 70 4 stroke,OS 91 4 stroke,3 os 40 FPs 3 OS 46 LAs 1 OS 25FP and I know there is more there but just can't think of them right now) THE OS 52 4 STROKER IS ANOTHER I HAVE, Yes it's a power house and real smooth. There's a very good OS engine.

Now I want power, dependability and "price"!

If you want dependle power, GO THUNDER TIGER, If you want all out power, go JETT, NELSON or yes ROSSI! (BUT BE PREPARED TO TUNE!)

CLARENCE LEE is an engine reviewer and rebuilder,he's reviewing for RCM now. He used to take K&B engines and make them "sing" He's also done some designing! he's looked at very highly in the R/C engine industry/hobby on his engine knowledge. ( you can contact RCM and they will hook you up with the months these engines were reviewed and you can purchase the back editions) OR MAYBE ONLINE? BUT his reviews are done on the test stand!!


Someone needs to get their local CLUB involved in this TT/OS argument, not one person but a group! they could buy both new,break them as per mgr. instructions to the "T", put them into something such as a STICK, run THE SAME prop,fuel etc. at the same altitude,humidity and temperature. having the same specifications for tuning : ie. the same way of leaning the engines out for realtime flight. (300 rpm rich with pinch test or whatever, but the same TACH ETC)

The "seed" is planted, now GO FOR IT!!!!!

RON in NEVADA

Is spinning a prop at a high RPM what is considered powerful? The equations don't necessarily support this conclusion. Basically, torque X RPM = HP. Torque and RPM can vary but still yield the same HP.
Frankly, the O.S. 46 FX will outspin the TT Pro 46 on the ground or bench using some popular prop sizes.
Me, personally, I could care less. It has been said by many either in person or on posts that the TT will outperform the O.S. I will never buy a small O.S. two stroke engine; above .91 is a different story but I would still be reluctant.
I can't stand grandstanding or overcooked hams.

Still within the 46 class size engines are the Irvine 53, GMS 47 and the K&B 48.
I've heard nothing but praise regarding these three engines. (I admit I was suprised with the GMS 47).
Oh, look! I threw another brand in the well to pick from!
The important thing about making a decision is not what everyone else thinks but what you think. Compile as much info as you can about your choices and make your decision based on facts, figures, personal experience of others, user friendliness, reliability, and power. Or, just blindly pick one and go for it!

Best of Luck,
Jeff

I have had great experience with Rossi without having to 'tune and fiddle' to get good reliable performance. The only drawback is the weight. Go with a webra .50 if weight is an issue. Most european engines dont need to be fed 15-20 % nitro to really perform. 5% makes then behave how they where designed. Simple to use and very powerful. You get what you pay for and at $139 it isn't a huge amount extra to go ferrari over subaru.

My OS would turn about 400 rpm more than my TT with a 10/7 prop. The TT however gets stronger with age. They are built very well and really run strong after the first gallon. Best performance per dollar out there. Nationalhobbysupply had the TT for $69.

I don't own a OS 46. but I just bought a TT 46 w/ tower hobbies muffler I got economy shipping paid less then $85. I had a coupon for $10 off. My motor is new. Only has less than 30 oz of fuel ran through it. I put on stock muffler and then put on Tower muffler, the tower muffler gave me a little over 600 RPM increase.

I would buy the TT 46 before the OS 46. Even if the OS puts out a little more RPM its not worth $40.00.

If you need more power than those 46's. i would buy the irvine 53. A friend of mine has one on a Hanger 9 piazz it will torgue roll that bird about 1/2 throttle, at full throttle it will shoot out of a hover like a rocket. He said it takes a little over a gallon to break it in. I think he bought it a JUST ENGINES for $100.00 still cheaper than the OS 46, with much more power.

I have read somewhere here at RCU. If you need more than 500-1000 rpm out of any motor you need a bigger motor.

If your looking for a 46 buy the TT w/ tower hobbies 46 muffler. It will outperform a OS. and still save you around $25.00. Also the tower muffler weighs less than a stock OS or TT muffler so you can save a little weight.

Also if your LHS is like the one in my area. They will try to sell you something that makes him more money.

good luck,

If you can find a NIB or a LNIB Supertigre 45 or 51, both have more power than any 46 on the market with the 51 of course having more than the 45. The 51 having almost as much power as a 61. I know this from experience,becausen I have 4-51s and 3-45s. I have a H9 Pizzazz and started with a ST 61, but it liked fuel so much that I kept running out before I was through I was ready, switched to a 51 and noticed very little difference in performance with better fuel milage. Just my HMO. TeePee


Remember!! Throttle controls altitude and elevator controls airspeed!!

Forget the OS and TT! Find a NIB or LNIB Supertigre 45 and you will out perform both!! My MHO. TeePee