N1EDM

My Feedback: (2)

I'm no expert, but I'm wondering if the blunt tip may be intentional to minimize turbulence as the fuel passes by the end of the needle?

Again, I'm not trying to pass this off as fact, just posing the question/possibility that this might be intentional. Or, it would seem to me that the sharpened point would be easier/cheaper to manufacture. Which needle was on the 600-series engine?

I agree with Tigrejohn - swap needles and experiment, provided that the tapers/threads are the same... let us know what you find. It might be interesting to see if either of the engines usese the same number of turns with either needle (or not), how well it transitions, or whether or not the needle is more or less sensitive with one of those needles.

Bob

BD Culver

I run 15% cool power and use #8 O.S plugs ever since I started flying. Works great

tigrejohn

My Feedback: (7)

One of the most recurring problems I read about in this forum is transition problems; i.e., rich in mid range. Drawing from my experiences with playing with glo engines since 1955, I feel that the spraybar design in the ST carbs is the source. The ST carb has a straight across spraybar (the same as most controlline motors) with the fuel exit at the bottom, 180 degrees to the wide open airflow, with both needles within the spraybar. Other designs use a stub spraybar with the low end needle going into the stub. Which is better? Read on.

A good number of years ago, an engine guru and damn good C/L stunt pilot (can't remember his name, age is a *****) set up a venturi to test with an air flow bench and a manometer to determine where was the best place to position the spraybar hole for best fuel delivery with suction and pressure fuel feed. He found that placing the hole at between 105 and 120 degrees to the airflow gave the best fuel delivery. A follow-up in motor testing, this position also gave the best power and RPM with the needle needing less turns open to achieve this in comparison to placing the hole at 90 or 180 degrees.

Now, with a fixed spraybar hole and a barrel that rotates almost 90 degrees, we have an airflow that changes in relation to the spraybar hole and goes thru this best position in mid-range (the transition). The carbs with the stub spraybar and exposed low-end needle don't experience this effect as these parts are round and their profile doesn't change in relation to the airflow.

We now have two options that I can see. 1. Change carbs. Or 2. Experiment with spraybar hole position. Haven't tried it myself yet as I just had cataracts corrected and haven't flown or played with my motors since last fall. But during this time, I had a brain fart and think that if the spraybar hole is rotated 30 degrees toward the back of the engine, this places the hole the at optimal fuel draw position at idle. Then as you bring up the RPM's, you move away from this point rather than going thru it. May be worth a try. I can't try it myself right now; have to left the eye heal.

rc34074

My Feedback: (5)

the tiger carbs tune fine if you give them the right muffler back pressure. I have run many G90s and 2300s and they all run fine with the right back pressure - eg no rich midrange. i have used 10% omega and the os "F" plug after breakin and these engines run GREAT!!. they are great sport engines.

when I land my mustangs after flying them they idle forever if I don't turn down the idle. I have run them at half throttle on the bench for several minutes and they repsond instantly to the throttle. no problem.

there is not a carb design problem on these engines. After running at least 15 or more of these tigers I am certain of that. so all these comments about the carbs being designed wrong are themselves wrong. anyone who wants to dispute that can come to my field here in Ohio and I will show them how these tigers run. mayber they can then learn how to tune a carb if they are willing to listen and learn.

please don't post these erroneous posts as I will keep repeating this message every time this is done. there is no slightest doubt that the tiger carb is a very good design.

Ed

Matagordababy

Gents,

I must say that I'm at a loss for words most of the time when I read this Forum. I'm no expect, believe it. I have however been running 2-Stroke Engines since my Dad bought me my first Fox .35 in 1962. It ran great for many, many flights until finally destroyed by the idiot behind the U/C Handle. That would be me.

Anyway, as a proud owner and operator of some pretty cool Engines (2 Stroke, 4 Stroke, Radials, and Jets), I still MUST say that my Tigre's are bulletproof. They run first time, every time. They are not finicky. My Tigre's are mostly "Big" ones - 2000, 2300, 3000, 3250, and an ST-6000 for which I have yet to select a plane.

Please understand that I am not trying to spread hate and discontent - rather, I must simply cast my heartfelt vote that although there are much, much, MUCH "cooler" Engines (quite a few of which I own), when it comes to dependable, kiss my butt I've got to run Flat Out Power, I turn every single time to a SUPER TIGRE.

If I'm wrong, I'll deal with it. Balsa is EASY to repair!

Matagordababy

qldviking

Hi again I too have run Tigres for years, and while I had a spot of bother with the last .91 , once I got it dialed in, like the rest, they all been reliabvle fuel up. glow drive then flip and run motors. My question now is, I have recently bought a ST4500 which I will be mounting on an Edge540, what size prop should I be looking at? I will be running it on the same mix as my other big ST motors that is 5% nitro, 15%cp oil cheers Johnno

tigrejohn

My Feedback: (7)

Perhaps you would so kind to tell us how to determine and set the right muffler pressure, it would be a help to others. Perhaps I should have been more succinct and further elaborate. There are people who know how to set both needles correctly, there are some who don't. There is also the situation of manufacturing tolerances and their stack-up which can lead to a horribly running engine if they are skewed to one side. I was presenting a simple fix to provide more latitude in mixture control. And now you add muffler pressure.

The point I was trying to get across was that there is a situation with the positioning of the spray bar hole which could lead to a rich mid-range if the needles were not set to an optimal point. Good engine people know how to circumvent this condition and get the right needle settings. Then there are those that are close and complain. My effort was to possibly provide some insight as to why some people have problems and give them a possible no cost fix that would give them more latitude with their needle settings and have a good running engine. If you have a good running engine, why change it? And if somebody has something has something detrimental to say about an engine and its design, why suggest that you are going to "Flame" them?

This probably does not apply here but a situation that I have run across a couple of times in my tenure is in the design of an engine; the manufacturer has not considered all usage situations that the engine will be put to and has been burnt. A beautiful case is the (unfortunately) SuperTigre G21.35 in the early Seventies. Per their testing, this engine was more powerful than the Fox, K&B, Johnson, & etc. Then they began shipping them into the USA and initially they were dogs. It took a number of accusations back and forth, each blaming the other for the problem that apparently was only being experienced in the USA. But then it came to light that their test lab had made an oops. Their testing had been done with 0% nitro fuel (very common in Europe and other areas) and testing with 15% or 25% was not done because they couldn't get it. Result: they were shipped all over the world set to run on 0%. Adding one or two head gaskets to handle the fuel more commonly used here turned them into screamers. Of course, at that time, there were also the people who knew what to do and those who didn't. Of those that did, some were helpful with suggestions and the head gasket fix. Others were naysayers and wanted to keep their fixes a secret. That's life, then and now.

FLYINGFOOL*2007

OK FELLOW FLYERS, I CURRENTLY HAVE THE 3250 ON MY GIANT SUPER SPORTSTER AND WOULD NOT HAVE IT ANY OTHER WAY! THE ENGINE IS A FINE RUNNING SOB! I AM RUNNING A PERRY CARB. AND PUMP, IT WILL IDLE TILL THE COW'S COME HOME THEN THROTTLE UP AND RUN THEM OFF AGIN! I ALSO HAD THE 2300 ON MY TWIST 150 AND HAD THE SAME RESULTS. WE ARE CURRENTLY INSTALLING A 2300 ON MY COUSINS FUNTANA 100, WE HAVE BENCH RUN THE ENGINE AND HAD ABSOLUTLT NO PROB'S ADJUSTING THE ENGINE. MY BROTHER (A MEMBER) IS RUNNING A 3000 ON SOME SORT OF GIANT TRAINER THAT I HAVE NO DEATAILS ON OTHER THAN IT IS BIG AND HEAVY, THIS WILL BE THE FIRST FLIGHT WITH THE 3000 AS IT HAD THE 2300 ON IT FIRST AND IT FLEW WELL BUT NEEDED MORE, HE HAS DECIDED THAT THE PLANE WILL BE A TEST PLATFORM FOR HIS LARGER ENGINES IE:ST 6000! PROVIDED WE CAN FIND PROPER MUFFLERS FOR THE DARN THING, IN SHORT GENT'S, I (WE) CAN NOT GIVE ANY THING BUT TWO THUMB'S UP FOR TIGRE'S. I HAVE RUN ALL SIZES OF THEM AND WILL ALLWAYS RUN THEM, SOME ARE A LITTLE TOUGH TO TUNE IN BUT I HAVE FOUND THROUGH THE YEARS THAT SOME ENGINES ARE A LITTLE TOUGHER THAN OTHERS TO GET JUST RIGHT NO MATTER WHO MAKES THEM! JUST KEEP YOUR HEAD OUT OF YOUR A.. AND YOUR FINGERS OUT OF THE PROP. AND ALL WILL BE WELL!

PROPS: 2300 = 16X8 3000 = 18X8 3250 = 20X8 MASTER AIRSCREW.


FLY IT LIKE IT AIN'T YOUR'S!

FLYINGFOOL*2007

QUICK QUESTION,
I AM HEARING BAD THINGS ABOUT DUBRO'S QUICK FILL FUEL VALVE, I AM USING ONE NOW WITH GLOW FUEL AND HAVE HAD NO PROB'S, IS ANYONE HEARING OF OR HAVING ANY TROUBLE WITH IT THAT YOU KNOW OF? IE: AIR LEAK'S?
THANK'S


FLY IT LIKE IT AIN'T YOURS!

pc55bomber

Hi
I have been using Dubro filler valves (glow fuel and gas) for a number of years without any issues.
They are very good quality and they have a rebuild kit that replaces everything inside the valve, not that I have rebuilt one yet.
I have found that twisting/spinning the fueling probe when inserting and removing ensures a good seal and tehy don't leak.
Hope this helps.

Also, I run tigres, stock standard carbys and they are THE BEST especially the big ones.

Cheers
Paul

Matagordababy

Good question, but one I cannot answer sorry to say as I haven't played with an ST-4500 (yet).

In general terms, I tend to overpower and overprop. at least from original specs. I push the outside of the prop envelope and if the engine will swing it (you might consider using a hand held tach to ensure the engine is coming up to speed with the selected prop) and I have enough ground clearance, I'm happy. A 10" pitch seems a good all around prop for most applications, barring extremely dirty machines requiring more tractor than speed, or a speed devil that only comes alive long after it's flying.

The closest I can come to an answer is the set of instructions I received with my ST-3000 called for a max 20x8 prop. It runs fine, but does not produce enough power or speed for my tastes. Mine is happiest with a 20x10. The RPM's do not fall off, and the difference in thrust or power is amazing.

Super Tigre calls for a max of 22x8 prop for your G-4500. If you have the luxury, fly your ship with the 22x8, then with a 22x10. Without a doubt, one or the other will prove best for your purposes.

qldviking

Hi again I too run a 20 x 10 mejzlik c/f on my ST3000, and been told a 22 x 10 max fo9r the 4500, which seems to me to be quite under propped [:-] I guess a bit of trial and error is called for again what revsd should I be looking for with the ST4500?

Matagordababy

The only additional specs I can locate for the 4500 is Max BHP is at 8,000 RPM's, so in other words a slow turning Torquer, virtually the same as the 3000 which reaches Max BHP at 7,900 RPM's.

Swinging a big prop, Tq is the big factor. The 3000 reaches Max Tq at 5,000 RPM's so a reasonable assumption would be that the 4500 does also as it is a 50% scale up of the 3000.

Just guessing here, but look for 5,000 RPM's as a baseline for Max Tq.

I too think that a 22x10 seems small for the 4500, but only a bit of trial and error will tell. Maybe someone else out there has experience with this engine and prop selections and will throw in their two cents.

Matagordababy


If I'm wrong, I'll deal with it. Balsa is EASY to repair!

FLYINGFOOL*2007

I HAVE HAD THE SAME RESULT'S FOR YEAR'S, DON'T KNOW WHERE THEY GET THERE INFO. I HAVE YET TO REPLACE OR REBUILD ONE ( UNLESS I TORE IT UP TRYING A WORM BURNER! [:@]) CONCRET AND HIGH SPEED DON'T MIX IN MY WORLD OF FLYING. GRAVITY SUCK'S!
KEEPUM FLYING.

FLY IT LIKE IT AINT YOURS!

thisoldman

My Feedback: (29)

run tigres also here.. have 3 62's one blue head 60 with perry pump, one brand new in box from italy s61. have not had time to run it yet. one 3250 and on twin inline tigre 60 or 120 total. that is runing on gas and does great. Have not had any problems with any of them and will buy more of them. the price is great. also have saito 4 cly engines and g38 gas engines. all run great.

FLYINGFOOL*2007

SAITO IS AN AWSOME 4 STROKE! I HAVE SEVERAL. DID I READ RIGHT? YOU ARE RUNNING A ST 6000 ON GAS?[:-]

FLY IT LIKE IT AINT YOUR'S![>:]

FLYINGFOOL*2007

SOME TIMES MY BRAIN LEAVES ME.

MY BROTHER WOULD SURE LIKE TO HEAR ABOUT YOUR ST 6000 AS HE HAS YET TO FIND THE MUFFLERS FOR HIS, WHAT DID YOU DO FOR YOURS? WE ARE THINKING ABOUT A PITTS STRAIGHT OUT OF THE FRONT HEAD AND A PITTS WRAP AROUND ON THE REAR HEAD. WE WOULD BE VERY INTERESTED IN KNOWING WHAT YOU HAVE.

THANK'S

FLY IT LIKE IT AINT YOUR'S! [>:]

TALK TO MATAGORDABABY.

rc34074

My Feedback: (5)

tigrejohn-

I adjust the area of the muffler outlet tubes to be about the same as the original super tiger muffler.

I have posted this many times in this forum and others. if you want to understand how to set the tiger carbs I and others have posted details descriptions of how to tune their carbs in this forum. the basic idea is the same as the procedure super tiger says to use. it works very well. use a fox r/c long plug during breakin and then switch to an OS "F" plug when its run a couple hours. you will need to gradually lean the carb as the engine breaks in and the ring seats better against the cylinder walls- this gives the engine better fuel draw and it lets you tune the low end very nicely.

Ed

Hobbsy

My Feedback: (102)

Ed, I have this little joke I quote now and then, I have about 8, maybe 10 extra ST carbs I've had passed on to me over the years because the oroginal owners claim they are faulty. In every case riding in a US Mail truck fixed them and they worked fine after a little needle tweakin.

thisoldman

My Feedback: (29)

yes my st6000 runs on gas. converted it over with electronict ign. Had twin ign's at one time. now run with one ign made for twin. less weight and battery's. Going to put this engine in a tf p51 and see how it does. shoud have some gitup and go. I love st engines. I keep buying them because of the price and the big ones convert to gas. some of the guys around here are runing gas on there st61 with glow plug and runs great.
I used copper fittings that i made to come off the exhause and these are going to hook to scale exhaust on the mustang.

FLYINGFOOL*2007

PLEASE TELL ME MORE, I AM VERY INTERESTED IN THIS GAS CONVERSION, WHERE WOULD I FIND THE NESSARY EQ. TO DO THE CONVERSION. HOW DOES IT COMPARE IN POWER? GLOW FUEL IS AS YOU KNOW VERY EXPENSIVE WHEN YOU BURN IT IN A BIG ENGINE! ALSO WOULD LOVE TO SEE YOUR MUSTANG WHEN FINESHED! WHAT PROP ARE YOU RUNNING ON THAT MONSTER?
I WILL POST SOME PICTURES OF OUR PLANES AS SOON AS MY DAUGHTER TEACHES ME HOW!


FLY IT LIKE IT AINT YOUR'S!

thisoldman

My Feedback: (29)

I bought my ign system from a guy in conn. He advertizes on ebay alot.. 75 dollars for single cyl and 95 for the two cyl that i have.. Have bought several from him. Will try and find his address and post later for you. Had to put two magnets 180 degrees apart on the hub and time it out. Works great. I have a four bladed prop that is 25-7 monster prop. Will post some pictures as soon as i can.
The ign system comes with the plugs and magnets, pickups and everthing you need to convert it over. can take the plugs out and put glow plugs back in and its ready to run on nitro again. But to darn expensive to run it on nito.. It likes its fuel on nitro.. On gas can run twice as long.

FLYINGFOOL*2007

[:-] DO YOU HAVE TO CHANGE THE CARB. ? I SURE HOPE YOU CAN GET THE ADDRESS! I SURE WOULD LIKE TO RUN MY 2350 ON GAS! WOW TALK ABOUT SAVING $$$$$$$.
BY ALL MEAN'S CONTINUE! I MIGHT BE ABLE TO GET THAT FOCKER DR 1 THAT I WANT!

FLY IT LIKE IT AINT YOUR'S!

thisoldman

My Feedback: (29)

i have not changed the carb. on my 3250 im looking for adapter so i can change it over to a walbro. want to try that and see how much difference it makes. might even try it on the st6000. They are great engines and on gas they really cut down the cost of operation. here is the address and phone number of the person selling electronict ign's.
Syssa Aircraft Performance
145 Harbor Pond Drive
Meriden, CT, USA 06450

http://www.syssaaircraft.com/

+01 (860) 538 2937
He will help you out.. tell him al ryan in florida recommended him..

sodbuster 1

Anywhere to get discontinued ST engine specs?

did the older 56's make much more power than the 51's?