aerobear

My Feedback: (4)

Don't give up. I have an identical setup that runs great so I am guessing you have some yet undiscovered problem. Mine had an APC 16x8 with OS F plug.
The Jett webpage claims 9600 rpm with the APC 16x8. I got slightly more than that. I don't remember what the rpm with the stock parts was but the Jett setup gave a healthy increase in power with very good behavior throughout the rpm range.

Have you tried a batch of fresh fuel?
Has the engine been run very lean? I saw one of these that had been run so lean the top of the cylinder liner had turned blue.
What tach are you using? The cheap hobby tachs we use can give unreliable readings if the lighting conditions are not optimal.

Sport_Pilot

I would consider an Enya #4, OS A5, or Fox #8.

NM2K

My Feedback: (14)

Don't blame yourself for being confused, Crispyspa. It seems as though the glow plug manufacturers have done their absolute best to confuse we
modelers as much as possible - and they have succeeded. Now that I think of it, this subject would make a great magazine article for some
knowledgeable modeler to write. Hint - hint!

As you may have guessed, there is no universal rating system for glow plugs, so making judgements based upon number/letter combinations is impossible. Even within the same brand of glow plug, in some cases.


Ed Cregger

NikolayTT

Anyway with this 15% nitro in the "blood", this ST is maybe not in the best "mood"...

crispyspa

The fuel is fresh, bought about a month ago, and the engine has been overheated to the point that I accidentally touched my forearm to the head and received a nice striped burn. The overheating happened before I got the bubbeless tank. The previous tank would be good if kept full, but once it got to about 3/4 full, the bubbles would create a very lean condition.
I should take the head off and check the condition, shouldn't I?

Tach is a hangar 9.

Should I get some lower nitro content?

Thanks for the tip.

Kweasel

My Feedback: (29)

Try placing your tank on a pad of latex foam 1/2" or thicker and use rubberbands to hold it down. The tank should feel very loosely mounted in order to be well isolated, use a drop of CA to keep the tank and foam in place. Your peak RPM numbers are fine. The jett muffler is no good for this application but their carb may run cleaner at part throttle. Dont worry about glow-plugs, the stock one is fine. The OS-F plug allowed the slow needle to leaned slightly but made it more difficult to hand start. A K&B idle bar plug is most forgiving of rich needle settings.

NikolayTT

Lets talk about the money... You have choosen ST because of good performance vs. price ratio, OK ?!
What ever you do with plugs, fuels, propellers ST is going to be a ST and more you spend on it with
other gadgets, worse gets the ratio Performance/Price. I found myself involved in this "game" with
some engines sometimes ago and then I took the "smarter" approach; it is maybe worth trying by
yourself. Here is the idea:
- You have got the RPMs with all those gadgets.
- Try then with Castor20%, Methanol80% what RPMs you'll get. Castor you can get very(!) cheap
from the local Chocolate Factory and Methanol from the local factory which makes Washing
Liquids. The price of this fuel is then maybe about 3x lower than any ready fuel.
- Post us the comparisson; that will help RCU readers (I wander should I buy ST too...)
- Go flying with different propellers (the Flight is the goal, isn't it?!) and see which one
propeller matches your plane and Style of flying ; the only good engine performance is
not everything.
- With money you save on Fuel, then you buy a better engine, for example Webra or MVVS
or OSMax, which on the same weight have bigger displacements and thus lot more power.
- to avoid the gum pilling in your engine from the Castor-only fuel, at each of the
flying days, use for the last flight fuel with 20% good Synthetic Oil fuel, for example
the Graupner's Aerosave Oil and then your engine will be clean and last almost forever
(till a crash on asfalt...). (In Europe the RC prices have weaking effect on the RC funs...)

Cheers,
Nick

NM2K

My Feedback: (14)

Nick, I truly wish that Aerosave oil, or its equivalent, was available here in the USA.

The varnish formed by castor oil is many times the result of overheating the engine. Castor oil has no reason to turn
into varnish if not overheated.

Many modelers tune their engine based upon performance at the beginning of the flight and forget that the engine is
going to go leaner and leaner as the flight goes on. The result is high temperatures half way through the flight that
causes castor oil to varnish. Varnishing is a good thing when compared to what happens to the engine when these
high temperatures are present with only American synthetic oils available to the engine.

The ST G2300 is just a large glow engine that was designed for sport/scale applications. It serves that function well too. I
would not spend a lot of money on it trying to turn it into something special. If I really needed something special in this
displacement class, I would be tempted to purchase the OS 1.40RX. Instead, when I needed another engine in this class, I
did purchase an OS 1.60FX. Nothing special, but more powerful, easier on fuel and in an attractive package.


Ed Cregger

NikolayTT

Hi Ed,

I hope I can help with at least the Link of FUCHS, who makes Aerosave and Aerosynth:
http://www.fuchs.com/index.php
It has offices in USA and maybe would be even cheaper to get Aero Save and AeroSynth from them
even if Graupner or TowerHobbies do not carry them.
Here are also the locations of FUCHS in USA:
http://www.fuchs.com/fuchs_in_americas.php
Please NOTE: - I mixed Aerosave with Castor (3:1) and the results were DISASTER - hell of detonations !!!
Then Pe Reivers exlained that FUCHS warned about this and then Fuchs reccomends AeroSynth to be
mixed with Castor if one want to do that. Still Aerosave is for me about 6x more expensive than castor
and I use it only for last flight & conservation of the engine. Yes, I agree fully for the castor varnish
but you know sometimes with too much experiments with propellers (small ones and high RPM) the
things go easily out of control. Thus the "wash" of the last flight makes to me good sense and then
I do not care if I am going to fly next day or ... next year... Aerosave seems real safe ...

Cheers,
Nick

PS. It might turn out that Aerosave and AeroSynth are distributed only by Graupner.
I wander what is the case in USA; why do you say that they are not available ??
Still one can order directly rom Graupner or even better from www.lindinger.at;
have you tried any of those ?

crispyspa

OK, I took the head off and look what I found:

NM2K

My Feedback: (14)

Thanks, Nikolay. I'll try to catch up on doing my homework. I haven't checked for US availability of those products for a while, now that I think of it.


Ed Cregger

NikolayTT

Hi crispyspa,

What a horrrror movie .... Uuuups ?!?
This is a well fried engine ... It looks you better
forget using Nitro as soon as possible ...

Cheers,
Nikolay

crispyspa

You mean lower the nitro content for that engine or stay away from nitro engines all together?

I think it might have been a combination of aerated fuel and a manufacturer defect, leaning on the defect side.
If you look at the copper head gasket, there is a burn mark that goes from inside to outside. That to me indicates a bad mating surface between the steel cylinder and the aluminum head....almost as if the sleeve isn't flat on top. You can see what I'm talking about in the second pic.

Anywho, I sent in the engine today, we'll see what happens.

aerobear

My Feedback: (4)

Hei Nikolay, this is incorrect information. His engine may be fried but nitro did not do it. This engine is not like the other larger Super Tigre engines or the big Moki/Mark engines. This engine loves nitro. I have 3 of these, 2 Italian and one Chinese. All have run 20-30% nitro for many gallons with no problems including contests where reliability is the most important thing. I have run as much as 50% just for fun. This engine increases rpm with every increase in nitro, the idle gets better, midrange cleaner, acceleration better. The OS160FX does not increase rpm much above 15% nitro for contrast.

I am not recommending that everyone run high nitro.

Ithink more nitro will make it less likely the user will fry the engine. Why? Because more nitro makes the correct needle setting more broad, making it easier for inexperienced users to set the needle.

aerobear

My Feedback: (4)

Nikolay

I know you must pay outrageous prices for nitro in your part of the world. Here is a setup that may work well for strong performance with lower nitro. The spark ignition makes the engine
behave like it has more nitro than it really does. CDI ignitions are cheap now.

Edit: This engine uses regular glow fuel, not gasoline.

crispyspa

aerobear, I have a question about that pic.

If you are running a perry pump, why do you have a line running to the fuel supply hose from the muffler? Wouldn't that inject air into the fuel supply line?

EDIT: nevermind, the two hoses cross behind the spark boot making it look odd.

NikolayTT

One seem stupid thing the manufacturer has done is (what was already mentioned by some other guys)
that there are only four(4) bolts to tight the head of the engine. Surely one can maybe do it even with three(3)
but that is real tricky to do it right. Seems you have not got the head well pressurised; let see what the
dealer will tell indeed; please post it.

NikolayTT

Aerobear,

Nitro is not that super-expensive here but anyway heats the engine too much if it is more than 15% whatever the
engine type is; of course in the Finnish winter more nitro makes it "warmer".
The Big Problem with Nitro for me is that it "Eats" the construction of the airplane unless the whole model is done
by fiber-glass but that is not the usual case. Even if you have resonance pipe,the spill of fueloutfrom the carb
will go over the model and "wear-it-off", not to talk when there isn't a pipe which take the exhaust away from the
model.

As for the ignition, look a good idea but how the RPMs are different, meaning, could you please post what is
the best with ignition versus what is the best without ignition and tell the nitro content ?

Also, to implement the whole thing needs too much time and effort which I guess this ST engine does not
really deserve; I would buy better engine and keep the thngs as simple as possible. Anyway, congratulations
for the effort, you seems to be a ST-fun. I am too, still keep as Holly my original Italian 2.5cc and 7.5cc ones
while those Chinese versions seems to have lowered the performance.

And also, please post the scheme of the fueling connections.

aerobear

My Feedback: (4)

Idisagree that nitro heats the engine too much. Some heating yes. Lean setting frys the engine, not nitro. Ihave run many engines on high nitro without damage. The OS 160 only needs 15% or less. More nitro does not help that engine.

Yes, nitro can damage some types of paint. There are paints that are not damaged by nitro. Gasoline engines make some people happy. I like those too.

With 20% fuel this OS160 gained ~250 rpm with spark ignition and lower smoother idle. I prefer to keep the rpm instead of lower nitro. This will get 15% when the 20% fuel is gone. Another flier here reduced nitro from ~20% to 5% with the same rpm on the ST. I think each setup will be a little different.

"....Also, to implement the whole thing needs too much time and effort....."
This can only be determined by each individual. Many engines have hidden potential. Even the nice OS 160 gives good rewards for what I consider a reasonable effort.This modified one matches the YS DZ power with less nitro. It runs better than it did on the standard setup. Notice it has a ST 2300 carb! Actually only the outide is ST. The inside of the carb has Webra MC parts. This same setup works great on the ST. You can buy the whole Webra carb if you want to spend $€$€.

I was not satisfied with the Perry pump on normal carbs. Only the MC carb works with the pump the way Ilike for F3A type flying. There are no needle valves. Two servos work the carb with radio mixing.

My Chinese ST runs just like the Italian ones. I don't like the Chinese carb or Italian carb. The carb design makes production easy but not great running.

Lets not make crispyspa discouraged. His carb and pipe can work once he gets his engine back.

crispyspa

I just got off the phone with Hobby Services.....The engine has been replaced with a new one. It was authorized on Monday, so I should get it tomorrow.

NikolayTT

Seems your dealer admitted manufacturing problem. Cheers !!! You got a good dealer too !

Then it seems right to suggest that you do not spend more money&time on trying to

improve ST beyond its average quality and then buy a better engine  for better

performance, if/when needed. Still I think ST is a good one for daily and low-cost fun.

NM2K

My Feedback: (14)

[quote]ORIGINAL: aerobear:

"Only the MC carb works with the pump the way Ilike for F3A type flying."/quote]


If you wouldn't mind, what does MC stand for? I'm out of the loop in current pattern vernacular. TIA


Ed Cregger

aerobear

My Feedback: (4)

MC is short for mixture control. There are no needle valves. Two servos are used to operate the carb. One for air and one for fuel. The two servos are coordinated through radio programming. A number of radios have a special built in mix just for this. My old 8UAP has a 5 point mix and works fine. Newer radios have more points. At each point the mixture can be adjusted. It takes some experimenting the first time to get the hang of it. Decent quality servos are needed with zero linkage slop. Use ball links at both the carb and servo ends of the pushrod.

The carb is handy since different pipe/prop/fuel/pump combos may like different mixture curves.

Webra makes one. OS had one but killed it off when they introduced the fuel injected engines. The pictures below show a Webra. I grafted the metering valve ($18) into a Tigre carb rather than buy another complete Webra carb.

Here is an article giving an overview.
http://www.centralhobbies.com/Engine...a/webrtxt.html

Crispyspa won't need this. His Jett carb and mini pipe suits his situation well as long as he stays within the tuning range of the Jett pipe. I ran my Jett equipped 2300 the other day. 9600 rpm with 15% cool power. APC 16x8 OS F plug. Very simple and easy to tune.

NM2K

My Feedback: (14)

Thanks for the explanation and pics. Much appreciated.


Ed Cregger

NikolayTT

Hi Guys,

Here is the link to Webra-case, quite professional and worth reading indeed:

http://h1069662.hobbyshopnow.com/pro...e=1252-ART.xml

Well, you might want to check the specs of that engine; the price too...

Cheers, Nikolay