misterpanda

Hello Flying Friends:

I'm considering buying the ST .51 ring for my son's 40-sized Tower trainer. The price seems attractive enough. My only experience with the "Tigres" is with the G90, for which I can vouch, no problems. How's the reliability on the 51, considering it's destined for a trainer pilot? And the ease of operation for someone inexperienced with engines?

Your recs. and comments are most welcome. Thanks a bunch in advance.

Misterpanda

XJet

Some people have good luck with the ST51 but I've found them to be far harder to tune properly and certainly no more powerful than a good 46.

If it's a fuss-free experience you're after, go for a Thunder Tiger 46 Pro. As much power, *much* easier tuning and my oldest TT46 has now clocked up more than 400 hours of running but still pulls a 4.5lb 3D plane around like a ragdoll.

The ST is heavier, has a bulky ugly muffler (with a non-standard mounting hole spacing), takes an age to break in and just doesn't really spin my wheels.

The TT46 can be used straight out of the box (no real break-in required) and mine always start first-flip and you'll never get a dead-stick unless you run out of fuel.

ianwynne

Hello Misterpanda:

I have a G51 and they are good engines and run better on low nitro fuels than some other engines like OS. If you are used to the G90 then the G51 will seem quite familar. For example the carb is the same except for the spray bar.

I hope that helps.

Bye, Ian

jeffk464

You should only buy it if you cant afford the OS 55AX, an absolutely awesome engine. If you want a .46 then like xjet said Thunder Tiger's seem to be very good, but I still like my AX better then my TT40.

Jezmo

You mentioned price as being important to you. It's a very good engine for the money but like XJet said some out there are better for just a small bit more money. It is every bit as good as the G90 and if money is tight then that might be the way to go. It does take a while to break in (usaully between 1/2 gal. to 1 1/2 gals.) and during that time the idle settings will change frequently. Use an OS #8 plug and 5 or 10% fuel and it'll work out great. I have one that is now running on gasoline with spark ignition and it is holding up well. I've had several others that were run on glow fuel and were great engines. They were no stronger than my Magnum 46XLS nor my TT46 Pro but they did run great and were pretty much equal to the 46's. Good luck with whatever you end up with.

samtech

I had two... and they both sucked. Nothing but problems. I think both of them had errors in machining of the case itself. Head leaks, broken rings and finally a hole in the bottom of the case of one of them... Oddly, the ST-45 is the most troublefree engine I've ever had and it made more power.

fredscz

My Feedback: (47)

I'm definitely not a fan of super tigres. You will be much better off with a Thunder Tiger 46 or an OS 46 like the AX or even an older FX. The OS 55 is a lot more money but I really like it too. My opinion is from my actual hands on experience.
Fred

AMB

I have 2 STs a 40 and 91, the 40 came with the "economy muffler" a conventional looking one rather than than that big thing on a stack that swivels , both by the way are converted to diesel with Davis heads and are among my best running engines
As far as power goes a ABC or ABN engine will turn faster than a ring cube for cube 500 to 1000 at least. however for sport use you do not need that last bit of revs, also when needed
a ring is a lot cheaper than a piston and liner put on the ring remove the glaze on the cylinder thats it, most use a steel or iron liner so the are a little heavier - martin

Jezmo

How's it going Martin? I'm competing quite nicely here in Texas with a SuperTigre G40 ring in Club 40 pylon racing. Some of the other guys wanted to see what it was taching two weeks ago and the number was 200 rpm's higher than the highest turning ABC. One particular ABC was 500 rpm's less than my old ringer. ABC engines do generally turn more than an identical ring version but the difference tends to be very minimal in sport engines. Race engines are another story and most of them are using AAC instead of ABC. (They don't last long either, I have some. By last long, I mean hold peak power. Think Jett and Nelson.)

Andy McC

I prefer it to my OS 46fx. It does take a little while to run in but will last a long time. It’s also happy to turn larger props than the OS and as such can be quieter. I use only 5% nitro in it and never have a problem (I use 10% in my OS engines). It can sound rich in the mid range but I have never had a dead stick in over 2 years. If you liked the G90 you’ll like this just as much.

bigedmustafa

My Feedback: (2)

My experiences with Super Tigre engines have only been positive so far. I have an old Bull Ring 46 Italian-made Super Tigre on my current trainer, a Hangar 9 Solo Star ARF. It was a bit sensitive on the idle setting, but since getting dialed in has been very reliable and very, very good on fuel consumption. I bought this engine at our club auction last fall, it was attached to a crashed Sig Four Star .40. It's currently turning an 11x5 Nexstar prop at 11,800 rpms with 10% Wildcat fuel and an O.S. A3 glow plug.

I have a new Super Tiger G-61 ringed engine on my Sig King Kobra that broke in surprisingly quickly and has been both very powerful and very reliable. It's spinning a MA Scimitar 11x7 prop at 13,300 rpms with the original Super Tigre plug and 10% Wildcat fuel.

I haven't found Super Tigre engines to be either unreliable or particularly hard to tune so far. That having been said, if I were going to recommend an engine with good power that was extremely easy to tune and dead-solid reliable at a great price, I'd recommend the Thunder Tiger GP-42. The TT GP-42 may be the perfect engine for a .40-size glow trainer.

This is always a difficult choice because there is a huge variety of engines in the .46 2-stroke market segment and they're literally all great engines. Even the brands that aren't mentioned much like MECOA, Fox, K&B, Aviastar, JBA, and SK make terrific and affordable 2-strokes in this size range.

mike109

G'day I have used several older ST G20 and G15 engines and they were great. I have more recently had a couple of GS45s and they were great. Plenty of power on 10% fuel and no problems (apart from crash damage). And quite recently I had an older S40 which ran well, ran in easily but I did not keep it long as I sold it with the model it was in.

But ... I have had more than 40 years using small engines and tuning them, repairing them and generally sorting them out. I don't consider myself an expert but I am a pretty good beginner.

Recently I suggested a relative newbie buy a ST51. Initially all was well but then I was being told it was no good and hard to tune etc etc. It took me about 5 minutes to have it singing again. A few weeks later I was hearing the same song again. This time an Expert (and he really is) sorted it out in a couple of minutes.

The problem seems to be that inexperienced users are too easily able to get the G51 running badly. Why? I really don't know.

You said you want it for a trainer. There is no better engine for a trainer than the OS LA 40 or 46. I have had good luck with the old Magnum GP 40 too and also the old OS FP40. The LA engines are the easiest handling engines I have ever come ac
across. They are not especially powerful but they are powerful enough for most trainers. They will tolerate bad tuning and they survive being banged into the ground better than the more expensive ball raced motors. I used one for about two years in a series of trainers and never once did I need to reach for the electric starter. Just prime and swing the prop and away she went.

So

If I were buying an engine for a trainer the LA is what I would buy. My latest trainee is using (and crashing) one now. He originally had an AX46 - also a very nice motor but he managed to destroy the crank case and the bearings and the cost of parts was about the same as a new LA. The AX can wait until he is a bit more expert in his landings. With the LA he is independent and does not need me constantly helping with the engine. It just works.

Of course if the engine were for me ... then I would look hard at the G51. But then I would probably buy another Saito anyway. I just like the sound and the way they work.

buzzingb

My Feedback: (2)

I now own 2 Super Tiger 51 engines. They are good engies but the Thunder Tiger 46 with Tower muffler will out perform them on power. However, I have just slung a rod out of a Thunder Tiger 46 that I have been useing on a Patriot for a few years. It was swinging a 10X6 at 15,500 to fly. The Super Tiger 51 can't come close to this.

BlackB12

My Feedback: (9)

Go for it. I have a G51 I got second hand that was seized up. After cleaning it ran great and since then I've put about 10 gallons through it with zero problems. Mine seems to transition OK, not great, but OK. I've even had mine on my Mojo profile plane. On 15% nitro, it was stronger than an O.S. 46FX that I later put on the Mojo. For a trainer this is a non issue though as it will really be better suited to trainer flying styles. The midrange on mine was muddy compared to an OS but it never quit. I now have it on a 40 size telemaster and it will go vertical for a little bit (not unlimited) and that weighs over 6 pounds. Still strong. I've run it with several supertigre mufflers and now have the giant "silent muffler" and it did need a slight change to the low speed needle. My trick is to set the low speed needle as lean as you can once broken in and it really cleans up the midrange.

Hobbsy

My Feedback: (102)

I have two .51s, one is about 17 years old and has many hours as both a Diesel and as a glow engine, the new one is barely broken in but was no-brainer to break in and set up

Jezmo

Put a Tower muffler on it. (requires some mods to the holes in the engine to get it to line up) That really wakes it up and if you want see how fast it can turn put a an Ultrathrust or Jettstream muffler on it and it will surprise you. The mufflers that come with the 51 are designed for 40 size engines and are choking the 51 down pretty bad. Opening up the exhaust with the Tower muffler and changing the spray bar to a 60/90 version will make unbelieveable power. Even more can be gained by raising the exhaust port to 170 deg. if you run the Jettstream muffler or a tuned pipe. It has tremendous potential for a cheapy.

stg61abc

Great Engine. Very powerful and very durable. Run perfec without nitro, in fact run better without!
Among the many options available today, is a very good choice. If treated decently will give you years of nice service.

turbo.gst

My Feedback: (8)

I really like the ST.51 They run well on low nitro. With care, it will last a very long time. Many of my ST's are over 20 years old. After the trainer, you will enjoy the 51 on 40 sized planes.

turbo

buzzingb

My Feedback: (2)

Jezmo, what kind or rpms are you talking there. If the rpms are enough I may give your suggestions a try. I want to mount a 51 on my Patriot now but 14,000 with a 10X6 isn't going to pull the Patriot fast enough. If I could get the ST51 up to the 15,500 mark on that same prop I would be happy. Also what did you do to the Tower muffler to get it to mount to the 51? I have my old Tower muffler from the Thunder Tiger that I wouldn't mind modifying if only it will make the 51 powerful enough. Any RPM figures would be appreciated.

Jezmo

buzz, I will look up my notes but I can't get to them until this weekend. If memory serves me right it was well over 15,000 with the Jetstream and even higher than that on a pipe after I raised the exhaust and put the cut down spray bar from the 90 in it.

On making the Tower muffler fit all you do is enlarge the mounting holes in the engine case. When I get off work this evening I will measure what size I drill them to. The stock screws that come with the Tower muffler are what I use and you can always go back to the stock ST muffler because I'm not enlarging the holes that much.

I'll post sizes and pics of it on my G51 this evening.

Jezmo

Hi buzz,
I won't be able to get to my main information on ST 51 rpm's running on glow until this weekend. I do have my notes from gasoline test runs done with the Eagle Tree data aquisition unit. It turns a 10X7 APC 15,100 on the Jettstream and 14,500 on the Tower which is still on it. Those numbers are running on gasoline with spark ignition.

The drill bit size I'm using to get the Tower muffler on it is a #22. I drill from the side away from the exhaust opening which I have facing down to keep any shavings from going in and afterwards the Tower bolts right up. Just to make sure we are on the same page I am drilling the engine case not the muffler.

t1954r

I have 3 .51 engines, they do require a good break-in but I have no problems with any of them. I think they have a good deal more power than any .46 I have ran.

misterpanda

THANKS TO ALL for your great replies and comments. Now to make a decision... hhhmmmm...
Misterpanda

buzzingb

My Feedback: (2)

I hope I didn't sound negative about the 51, because I like it and the way it is designed. With the ring and iron liner it should hold up for a lifetime. I just need high rpms right now for my Partiot. I am currently flying the 51 on an Ultra Stick and it is great.

XJet

Any good quality 2-stroke should last almost a lifetime.

My oldest TT46Pro is now well past the 400 hour mark and going strong. Not bad for a motor that cost $70.

Use a good quality fuel, treat them right, change the bearings every 150 hours or so and they'll last a *very* long time even if they're not ringed. I'd wager that an ST51 will need a new ring long before it hits 400 hours.