Hi Dave, i have one of these. Is a great engine. The 23 likes small load props, for RC the ticket is a 9X4 and for fast ships(smaller) an 8X6 will go fine. Idle is superb. Fuel must be all castor oil. If you use nitro maintain the limit to 5%. Power is great and also the fuel consuption is high for a small engine, but at least is very powerful. The compression ratios is high and tends to distort plug elements easily. a 9X6 prop overheat it in my using and run erratically. The carb is firts class, maybe a little sensitive to set, but once dialed is done. Great small engine friend. In a past trainer i used an old TF 10X3.5 Nylon, also with great results, and in a small pattern bird the 9X4. First class starter with one or two flips and also a fierce finger "biter" heheheheh..... Hope that this help you
cheers

Thanks stg61abc!

I just ran mine on Powermaster 5/22 GMA fuel with the following props:

APC 8x5:
13,489
2.19 lbs. static thrust
0.31hp

APC 9x4:
12,768
2.55 lbs. static thrust
0.35hp

Do those numbers sound low or about right? They are a bit rich of peak.

David

Dave, your numbers are very good! i obtained lowers numbers because i dont use nitro in my fuel (80/20). The last measurement i made was 12.200 with a wooden prop, so your numbers are very nice. Dont forget that this muffler is very restrictive. this motor will last you "forever"if you use a nice fuel like this you are using (all castor)
nice flying


AHHH Dave, if you are using the APC props they are superb, but be careful to round its tips. Some time ago i cut my righ hand deeply with one of these

I have a G21-46 and can't run it... the muffler that came with it was a flow-through and won't meet local noise standards. I know that I could get a strap-on, but I was wondering...

Did the G21 actually come with a closed-end muffler like you show with your G20-23? I wonder if the muffler that I got with this (used) engine is not the Original Equipment muffler?

Bob

Bob, if your engine's bolt holes are 38mm center to center then PM me.

David

The first time I answered your question it was for a Zenoah G23. Then I saw that wasn't what you asked for and wrote the second reply, which you have read.

Okay, now for the G20/23 .23 CID glow engine. It just so happens that I used to fly one on several models. It was a really sweet engine for its day, which was the early Seventies onward.

I used a 9x4 to a 10x4, depending on the model, of course. Just pay attention to the load of the prop versus the amount of nitro in the fuel. This sweet little engine was meant to run well on 0 to 5% nitromethane.


Ed Cregger

N1edm,
I am not stg61abc but I can give you some ST g21-46 muffler info. I have the g21 46 engine. I bought a muffler for it a couple of years ago. That muffler is Tower Hobbbies # lxfv94. It is an O.S. style muffler and does a good job noise wise.
Tower Hobbies also has a muffler for the g21-46 that is Tower Hobbies # lxfv92. It is a 2 piece barrel muffler that will fit your engine.
Tower is currently out of stock of the muffler I have # lxfv94.
Their ad for the 2 piece barrel muffler says it increases the power and is quiet but I believe it is heavier than # lxfv94.
Capt Buford

Thanks for your offer, Rainedave, I got your PM, but it doesn't look like it'll work...

As you can see, my engine is a bit dated... no mounting bosses for a muffler. I guess I'm stuck with the old wrap-around. Maybe some of you ST Historians can tell me if this is the correct muffler for this engine (mufflers were an option when this engine was made). I also wonder what would happen if I plugged the nose end of it so that I could stick this on a vintage aircraft sometime.

Thanks again for your offer,

Bob

muffler extentions tend to quiet mufflers down alot. I run plastic hose about 8" on a couple of planes to divert oil toward the ground and it quiets the muffler alot.

Bob, that's a very nice muffler. Considerable time probably went into turning it's rear sections. I don't know how the front piece is attached, bit if you could turn a new cap to replace it then you'd have a good, authentic looking muffler. Some of the old mufflers, like the Kavan, I think, actually came with both a flow-through and a sealed front cap that could be interchanged. At any rate, you don't see those mufflers too often, so don't alter it too much (no JB Weld, please).

David

Hi

As a supertigre .25ci 4cc pre 1993 owner can I join and what would be my number

I haven't read all the thread as 45 pages is too much
Saw there that there is .20ci and .23 cu Super Tigre and they look exactly the same as my old engine.
I bought it Paris from LHS AOL for a good price .Said sell me a good engine cheap and they came up with that one and a Rossi 25
The Rossi cost more so ST won . ST .25 had twin ball race . I suspect was sitting the shop a few years as it was older design but was super cheap price probably to clear . Any idea when they stopped making the ST.25

Alway ran it on zero nitro 15% sythetic on 8*6 through to 9*6 until 2008 when I dropped to 10% EDL. Was generaly superiour to my OS FX 25 which I got later on but OS could 3D better .However OS didn't like zero nitro and OS more prone to flame out with low nitro.

I am possibly looking at the idea to get next year a big ST 3000 30cc and then I might possibly later on convert it to Davis diesel. Might also look to get a ST 4500 45cc but it seems very heavy compared to modern equivalents so its on the back boiler maybe start looking around in late 2009.Are spoares still availble for the ST 3000.. 30cc

I already have a MVVS 26cc so not really interested to look at 20cc to 26cc

Really with no nitro and 10% sythetic oil the running costs of the bigger glows are OK and engines are often lighter than same size gasser and often supply 20% more power and often cheaper compared to the higher capital costs of a good powerful gasser that can nearly match glow engines power .Pity ST stopped making the bigger glows

Blasaeater

The good part is that there are probably tons of NIB or near NIB large Super Tigres floating around in various places.

I used to groan whenever I saw a relative newbie break out a model with one of those engines on the nose. Nope, the engines were fine, but they were quite different in operation and fuel requiresments than what the average newbie was used to dealing with.

Of course, no one listened to the gray beards at the field that knew how to run them, so we just sat back and waited until they became discourage and waited for the engines to be sold cheaply. I had quite a collection of those "junk" Super Tigre, ASP and Fox engines over the years. Then I got cheap and switched to gas engines, having sold off the previously mentioned engines to finance several BME, Brison and RCS engines. Not sorry I did. I hate cleaning up glow goop from models.


Ed Cregger

Hi Rainedave,

I'll try to turn a nosecone and fasten it without damaging the existing muffler... I hate doing things like that to vintage pieces...

I was just hoping that perhaps an existing muffler might be out there that would solve that problem for me.

I hope that you all had a nice Thanksgiving. I'm still stuffed,

Bob

I would try running the engine as is at the field. See if someone complains. You might not have to do a thing. Remember, you can't judge how loud your model is if you are running it over your driveway at home. That makes everything sound much louder than how it will sound at the field.

I used to fly my CGM Cub powered with an Enya 80-4C four-stroke engine without a muffler because it didn't come with one. Just a plain old header pipe with no means of attaching a muffler. No one said a word about it, so I asked one day if anyone thought that the engine was too loud. The Cub was airborne when I asked the question. Everyone said to keep it like it is, that it was pleasant to listen too. Later issues of this engine did come with a muffler, but I never did pay the $60 that MRC wanted for the new header pipe with muffler. Folks were mystified about not having muffler pressure and what did I do with the vent line. Heck, this is how we used to fly all of the time before mufflers came out. I'd show them the vent line hanging slightly below the bottom of the fuselage and they couldn't believe that the carb would work that way, but they did see it working.


Ed Cregger

Hi Ed,

I ran it at my field and used my noise meter on it.. I was at 97-98db. I might be able to shave a couple db by going from a 10x6 to a 11x5 prop, not sure. Our field rule is 95db.

I'd like to get hold of some of those techniques that I hear that they use in the UK to get their noise levels into the 80's.

Sorry to get off topic about the noise.

Bob

I had one of the older G21/46 engines that had the rotating baffle plate. I bought it to copy Jim Kirkland's install on the Mustang-X.

While it was a reliable engine, mine never quite matched my K&B .40 and OS .40-H/P engines in power when swinging 10x6/7 props. It did shine when running an 11x6/7. I equipped mine with an open front Semco muffler. Remember those? They were anodized black on the bulk of the cylinder (thin steel). Back then everyone was running flow-thru mufflers in my area. For a flow-thru, it wasn't that loud. I have found that there is a correlation between power output and volume amplitude.


Ed Cregger

Bob, I found this photo on the web, so ST apparently sold that muffler with the front sealed.

David

If you notice the picture in your posting, Rainedave, you can see that the muffler is still the flow thru muffler, but with an insert.


Ed Cregger

Hi Ed and Dave,

Yup, I've never seen that picture before.. thanks!! I wonder if that insert is available somewhere... I'm going to check the Manufacturer's Direct Support forum to see if anyone has an old insert kicking around. I'd like to keep the motor stock, if possible.

Thanks! I'll let you know if I score over there...

Bob

Here ya go Bob

Hobbsy, your example appears to have a MAG II or III carb and muffler bolt ears. Do you have any tach readings for it?

Thanks,
David

Hi Hobbsy,

Yup, I have a couple of those Supertigres, a .46 and a .40. They aren't as powerful as some of their contemporaries, but they're still good for sport models...

I wish my G21-46 had bosses on the side like those newer ones - it'd be easier to fit a muffler to it. As I noted before, my engine doesn't have the mounting bosses for the muffler, they were an option when this engine was built.. I think that it was circa early to mid 70's. if you look over the photos in the earlier post, you can see that the intake for the exhaust has been routed out to accept the exhaust stack from the engine, to keep it positioned properly.

Bob

Dave, I sure don't, that engine spent time on a USAircore Colt 40 and a KnightHawk, I'll have to tach it. It came with a butterfly on the exhaust that was linked to the carb, the carb needle is a Harry Higley as the engine came without a needle. My brother in Aurora, Colo. found the engine in the truck of a 1963 Ford Falcon Sprint he bought and still owns.

Hi Hobbsy,

I took a closer look at that engine in your post.. I had looked too quickly before. I was wrong about the engine that I thought it was.

Are those muffler lugs/ears an add-on, or are they cast into the cylinder head?

Thanks,

Bob

need some help here.
have two ST .45's made in Italy.
However they look very different and trying to find out other than appearances what the difference is in these engines.
the pic shows one of them.The top of the head is dished in towards the glow plug. The carb slides into a sleeve in the body of the engine.Inside the carb it looks like there is a sleeve to rstrict air flow.
The other engine has a square head and the carb bolts to the engine.
If I can dig up a pic of it I will edit the post with it