Slats!

My Feedback: (1)

Hi just getting back in the hobby I have an older (10yrs) Super Tiger 45-abc made in Italy that has never been run. The plane I am putting it in requires a slimepitts muffler and I am not sure if its worthwhile investing in a muffler for this engine or going out and buying an OS 55 instead. I am wondering the following

-Is there a huge power difference between these two engines (I cant find the specs on the older engine).
-Are these older engines good still or have things changed quite abit, eg are they now lighter, put out more power for the same size motor than the older engines.
-Or the Italian versions have great power and there is not really a heck of allot of difference keep it.


Thanks

beppeVRCS

I think it is not fare to compare a 45 and a 55 (unless the 55 is a real dog, or the 45 is a Rossi). Other than that, the ST GS 45 was a MUCH better engine than anything else in his class. It was 10-15% more powerful than the equivalent O.S. , for instance.
The Pitt Style muffler is quite a limitation, because:
1. The muffling action is poor,
2. The back pressure provided to the tank is limited
3. It does not enhances the engine performance

The only positive sides are the light weight and the scale appearance.

Please note that the ST muffler with a flat, round back plate acts like a mini-pipe, providing almost 1,000rpm more than the previous version of ST muffler. You'll lose all this if you use a Pitts style muffler.

Taking about money, you can find a lot of mufflers, Pitts Style, new and used, on E-Bay. I would buy one and use the ST 45, properly broken in...

Ciao
Beppe

Slats!

My Feedback: (1)

Thanks for the heads up on the muffler not sure if I want to loose power for looks.

DarZeelon

I can only agree, Beppe.

The ST .45 ABC can spin a Master Airscrew black 11x6 prop well in excess of 14K.


Even though the MA is a very light prop, considering these dimensions, the OS.46AX cannot even come close, on the same fuel (probably not on more potent fuel either).

And its carburettor is an excellent design, with three control ranges.

downunder

In your dreams maybe but 12K+ would be closer.

djlyon

Dar I have to agree with Down. I've used a ST45 quite a bit and 14K on a 11/6 would be very special. But I do agree the engine is a sweet running power house.

Denis

DarZeelon

Brian, Denis,


Not in my dreams, but in a test-stand on my lawn...

I will have to summon the owner of this engine, if proof is required...


The OS.46FX used to spin a Bolly 11.5x6 at 12,200 RPM and the MVVS .49 with the tuned muffler spun the same prop at 13,600 RPM.

I have seen another MVVS .49 exceed 14K with an MA 11x6 (which I have not used in the last 5 years), so this ST .45 seems impressive, but also quite reasonable.

Hobbsy

My Feedback: (102)

Dar, I think I have SuperTigre .45 ABC in my little box of ST, I think it is Dieselized at the moment but I can change that in about 2 minutes.

captinjohn

I would not break that engine in in COLD weather. Read your directions. It has to be run on the lean side right away to heat up for piston clearence. I would wait untill warm weather to run that engine. My ABC .51 screams to this day. Its 20 years old!!! Very good engine. Capt,n

DarZeelon

Quote:

ORIGINAL: Hobbsy

Dar, I think I have SuperTigre .45 ABC in my little box of ST, I think it is Dieselized at the moment but I can change that in about 2 minutes.

OK, Dave.


So, maybe you can slap the glow head back on temporarily, along with an MA 11x6 prop and 15% castor/synthetic fuel...

...So you can see what it can do and report back.


Make sure the muffler does not have the stack too close the the canister wall.

Hobbsy

My Feedback: (102)

Dar, here was my set up
Plug==Fox GoldPost idle bar
Prop==MA 11x6 black
SuperTigre .45 ABC
Fuel WildCat 5% with 18% 80/20 syn/castor blend
SuperTigre quiet Swing Muffler, I think I have one of the bullet shaped loud ones if thats what you used.
RPM===13,150

This thing has a fantastic idle at about 1,900


I have WildCat 15% 2/4 18% all synthetic and WildCat 15% Premium Extra with 18% 80/20 syn/castor blend. I am going to order some more Fox 5% with 20% castor, that is by far the best fuel I have used in two strokes. I even swapped out the carb for one with the skinny spraybar, it made little difference.

djlyon

That's a nice reasonable number in my experience with that engine although I have never run it with a MA prop.

Denis

JoeVen

My first model engine was an italian GS-45, the one with square head packed in a red box and represent a pretty good cost to power relation. Piston and cylinder are a little wear after almost 11 gallons of commercial fuel an a couple FAI home made mix, not to mention the abuse a beginer can put.

It pulled an ugly franken-trainer I learned to fly with, then a step up Carl Goldberg 72" Piper Cub and latter a SIG 51" Cougar.

Regards out of market mufflers I´m with bepppe

I changed the muffler to fit the Piper and the Cougar cowlings and it suffered from lost of power. The mufflers I tried were:

[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXR599]J'Tec In Cowl .45-.60 [/link] and [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFG76]Slimline Pitts SuperTigre .40-.45 Bolt Thru Motor[/link]

Enjoy an fly....

Duane-RCU

My Feedback: (5)

Is it the 6 bolt head or the 4 bolt head? I have an old 6 bolt that runs much harder than my 4 bolt .45GS AND the older one also unloads better in the air, this also has an "S" on the side of it. I could only get the GS close by opening up the carb, working on the head a little, and using a Jett muffler on it. I'm using them for speed , so I couldn't tell what they would spin an 11" prop at.

DarZeelon

Quote:

ORIGINAL: Hobbsy

Dar, here was my set up
Plug==Fox GoldPost idle bar
Prop==MA 11x6 black
SuperTigre .45 ABC
Fuel WildCat 5% with 18% 80/20 syn/castor blend
SuperTigre quiet Swing Muffler, I think I have one of the bullet shaped loud ones if thats what you used.
RPM===13,150

Dave,


The setup my friend had differed in the fuel, being rather like you Wildcat Premium Extra and in using the original ST glow-plug, without an idle bar...

The number we repeatedly witnessed had us going into a phosphorescently lit room in my home, to verify the accuracy of the cheapie [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXPT31&P=ML]Tower tachometer[/link] we were using... and the number was the same when taken from the front, as well as from the rear.

It also idled pretty low...

Although most two-stoke engines will only increase RPM by 200-300; going from 5% to 15% nitro, that reading was correct.


Perhaps the exact setup of the muffler and its stack coincided with one of its tuning ranges of the air column inside it... a Helmholz resonator, if you will, that was aiding the engine in getting a measurable performance increase.

downunder

I've also got both those engines although the S45 (round head, 6 bolt and ringed) is brand new. But the timing of the S45 is quite radically different to the GS45 so I'm not at all surprised it goes harder.

Duane-RCU

My Feedback: (5)

Strange, my S45 is ABC. I wish I could find a new piston/cylinder for it, mine is getting a little worn. Missed one on ebay last year...

Harry Lagman

Two things I've noticed that relate to this thread:

1) The MA 11 x 6 is a toothpick - it's a very light loading prop that is more like an APC 11 x 4 in terms of load.

2) The ST .45 is less powerful than typical .46/.47s like the GMS, TT and OS AX.

Most average .46s will pull well into the 13K-14K rpm zone with an MA 11 x 6. Put an APC 11 x 6 on it and see what the real world numbers are. Most .46s won't exceed 12K with the APC 11 x 6.

Lille-bror

I agree. Though I think it’s a good and reliable engine.

Hobbsy

My Feedback: (102)

Dar, the most I could coax out of it on the 15%/18% all synthetic was 13,550. One thing we didn't get ironed out was which muffler was used in your run. Was it the old bullet shaped, very loud muffler or the newer Swing Muffler. My engine was bought used and has no pinch at the top but seems to have excellent compression when flipping but that could change on a warm cylinder.

The MA 11x6 is anything but a tooth pick so don't buy into that BS. APC numbers are not real world numbers, they're just numbers for an APC prop and that's all. There are Graupner numbers, PowerPoint numbers, Bolly numbers, MA K numbers, Classic numbers, all props and numbers that will fly planes quite well.

NM2K

My Feedback: (14)

-


Responding to your signature suggestion - what a waste of a Les Paul and a Marshall amp.

Back on topic.

An 11x6 is too much prop for an ABC .45 that is designed to rev up. A 10x6 is more appropriate.

An idle bar plug in most Schneurle ported engines will cost you an rpm drop of 100 to 200 rpm on the top end.


Ed Cregger

downunder

That got me curious so I decided to find out the difference between the APC and Master 11x6 props. The MA prop was just the standard square tipped type. Venerable ST GS45 with a Taipan 4 stroke plug and 75/25 all castor fuel.
APC...12,200
MA....12,100

So, within the limits of my tacho, the MA has fractionally more load than the APC.

Hobbsy

My Feedback: (102)

The MA 11x6 is anything but a tooth pick so don't buy into that BS.

DU, I attempted to say that very thing but no so eloquently.

DarZeelon

The 'late model' Series II/III Master Airscrew props, specifically the 11x6 size, impose a rather small load on an engine.


The older MA style (visually similar to their current four-stroke props, but without the white painted tips) that preceded them was a rather heavy burden.

It has been stated elsewhere in this forum, that the RPM difference on the 11x6 size, between the newer MA black props and APC is ~1,200... The APC is spun much more slowly.


The number I saw the ST .45 ABC produce was on a Series II MA prop.

Harry Lagman

I did the same thing...

GMS .47 with ...
APC 11 x 6 - 12,000 rpm
MA 11 x 6 - 13,800 rpm

OS AX .46 with...
APC 11 x 6 - 12,300 rpm
MA 11 x 6 - 14,100 rpm

TT .46 pro with...
APC 11 x 6 - 12,200 rpm
MA 11 x 6 - 13,900 rpm

ASP .46 with...
APC 11 x 6 - 11,800 rpm
MA 11 x 6 - 13,500 rpm

Wrong answer! The MA 11 x 6 is a toothpick!