Author Topic: Super Tigre .46 vs. O.S La .46?? (Read 5994 times)

frank mccune · « **on:** August 24, 2013, 05:25:33 AM »

Hi:

I have a ST .46 NIB that I have been saving for a rainy day and I have been getting great pressure to sell it to a mate. I have not used a ST .46 but I have seen them run and they are a sweet stunt engine!

My question is this, is the O.S La .46 engine as good as the ST .46 for Stunt use? I could sell my mate the ST to make him happy and purchase an O.S .46 for my own use. Would this be a good choice or should I keep the ST?

Oh yes one thing that I should mention. I am a huge fan of ST engines and I have never met one that I did not like!

Any suggestions?

Tia,

Frank

Steve Fitton · « **Reply #1 on:** August 24, 2013, 09:07:19 AM »

From what I see at our home field the ST-46 is much better than the LA-46

EddyR · « **Reply #2 on:** August 24, 2013, 01:47:43 PM »

I can see flames coming. I am watching this with interest.
Ed

Bill Little · « **Reply #3 on:** August 24, 2013, 01:59:10 PM »

I think most of the answers will be based mainly on personal opinion. In my case I feel that the ST is a slightly stronger engine, but the different run styles has me wondering.

BIG Bear
RNMM/AMM

RandySmith · « **Reply #4 on:** August 24, 2013, 02:38:04 PM »

I would go with the ST 46 no question.

Randy

steven yampolsky · « **Reply #5 on:** August 25, 2013, 08:55:27 PM »

LA's have a plain sleeve bearing. Unless you balance your props religiously, it will not last as long as ST. If you still crash on regular basis(more than once in two seasons), LA's are cheap to replace. It you want a sweet sounding stunt run, go for ST.

I've won at contests with LA but never with ST. That said, I've sold all my LA's when I went to serious PA's and RoJetts but kept one ST46 because I want to experience that sweet stunt sound that only three motors are capable of producing: ST46, ST60 and Fox35.

Flame suit on...

MarcusCordeiro · « **Reply #6 on:** August 26, 2013, 04:14:30 AM »

Maybe this thread should be moved to the debate zone...

I have one ST 46 T& L and it's a wonderful engine.
Got one LA too.
No way the LA matches the tiger in power..

Marcus

Air Ministry . · « **Reply #7 on:** August 27, 2013, 06:26:42 AM »

If you sold it , and it paid for FOUR LAs , he might be talking .

Wikk you swap tour Ferrarri for my NSX Honda ? check the prices .

Brett Buck · « **Reply #8 on:** August 28, 2013, 06:54:58 AM »

I don't want to get into an argument, but having spent a massive amount of time flying ST46s (stock), give me an LA any day. The very best ST46 on its best day might be a match (although you are still running 5+ inches of pitch) but those days are very rare.

Brett

ChrisSarnowski · « **Reply #9 on:** August 28, 2013, 08:47:55 AM »

How good of a friend is he? If you really like him and want to share the joy of running a Tigre 46 with him, then go ahead and sell to him.
If he is a wanker just annoying you about the engine, tell him to stuff it, the Tigre 46 is only for real men.

-Chris

James C. Johnson · « **Reply #10 on:** September 02, 2013, 07:52:44 AM »

You can add the McCoy 35-40s to the "sweet engine runs"... category. IMO, they run wonderfully but are strictly a sport type engine. A T&L 46 in the right hands is a formidable engine... The LA has no "grunt".... my first experiences with the LA 46 were not that good. I personally don't like engines that can't run different props... the APCs are ugly and hard to work with... they do run good and are cheap... I still wonder how the stunt guys back in the 60s and 70s could get a Fox 35 to fly a 45-48 oz stunter competitively. This little guy seems to like 35-38 oz planes... Wanting an LA 46 to be a ST 46 substitute is what I think a lot of people are looking for... life isn't that good.

Brett Buck · « **Reply #11 on:** September 02, 2013, 11:33:34 AM »

Quote from: James C. Johnson on September 02, 2013, 07:52:44 AM

You can add the McCoy 35-40s to the "sweet engine runs"... category. IMO, they run wonderfully but are strictly a sport type engine. A T&L 46 in the right hands is a formidable engine... The LA has no "grunt"....

That's a feature, not a bug. And if you actually measured the torque curve, I expect that the LA has about the same, or more, power at low revs. Everybody had the same impression of the 40FSR, yet it had 50% more torque at 8000 RPM. The issue is that the ST will stay at low revs, The FSR (and LA) won't. So you can't slap on larger and larger props and have it take off and nicely regulate itself at 5.2 second laps.

Quote

.. I still wonder how the stunt guys back in the 60s and 70s could get a Fox 35 to fly a 45-48 oz stunter competitively. This little guy seems to like 35-38 oz planes... Wanting an LA 46 to be a ST 46 substitute is what I think a lot of people are looking for... life isn't that good.

People were making the mistake of treating engines like the 46 LA (its older brothers the 40/45FSR, and then every schneurle engine available in the late 70's/early 80s) like ST46s and 60s for years. Myself included. The solution to the regulation problem is a tuned pipe that chokes off the power rise at the RPM you want and can adjust.

The ability to put a Fox in a 45 ounce airplane is a matter of perspective. I flew thousands of flights that way, you can definitely get through patterns in a reasonable range of conditions with it if everything is right. If you don't have an Aero-Tiger to compare it to, you don't know any better. Truth be told, ST46s in 55 ounce airplanes aren't a lot better - maybe some, but not transformational. No one even started getting a hint of how much better it can be until engines like the 40FSR and other schneurle engines, and it didn't get to be practical until you had a pipe to control it. The standard got raised, now, not too many people want to put Fox 35s in mid-40's airplanes any more.

Brett

Bill Little · « **Reply #12 on:** September 02, 2013, 11:50:18 AM »

Quote from: Brett Buck on September 02, 2013, 11:33:34 AM

(snip)

The standard got raised, now, not too many people want to put Fox 35s in mid-40's airplanes any more.

Brett

For "Serious Classic/Nos.30 Competition", I would DEFINITELY use an Aero Tiger .36 over a Fox .35 any day and twice on Sundays! There is just that much difference in the two engines. The power of the AT .36 is light years ahead of the Fox.

BIG Bear
RNMM/AMM

Jerry Reider · « **Reply #13 on:** September 14, 2013, 10:22:24 PM »

I've never had a Super Tigre .46 but I do have an O.S La .46 w/a Master Airscrew 12x4 prop on a Banshee using 10/20 fuel. The engine always runs sweet, almost never needs a needle adjustment, starts 1st or 2nd flip, runs consistent every flight, has good even pull through all stunts..... Best O.S that I have.

Brian Massey · « **Reply #14 on:** September 15, 2013, 01:16:34 PM »

My LA 46 is swinging a 12.25 X 4.2 Brian Eather prop (reworked from his 12.5 x 4.5) with ease. The setup: 10/22 GMA fuel; 2 head shims; stock nva and a Scott Dinger Muffler. It's set up on a 53oz Trophy Trainer. I launch around 9050 rpm and get 5.5 laps on 62.5 ft lines, and have great tension in the overheads.

I launched at 9000 once and got 5.7 laps (with a great 4/2 break) but was just a tad shy of tension on the overhead corners of the hourglass.

You can put me down in the LA camp.

Brian

Bill Little · « **Reply #15 on:** September 15, 2013, 02:42:47 PM »

Quote from: Brian Massey on September 15, 2013, 01:16:34 PM

My LA 46 is swinging a 12.25 X 4.2 Brian Eather prop (reworked from his 12.5 x 4.5) with ease. The setup: 10/22 GMA fuel; 2 head shims; stock nva and a Scott Dinger Muffler. It's set up on a 53oz Trophy Trainer. I launch around 9050 rpm and get 5.5 laps on 62.5 ft lines, and have great tension in the overheads.

I launched at 9000 once and got 5.7 laps (with a great 4/2 break) but was just a tad shy of tension on the overhead corners of the hourglass.

You can put me down in the LA camp.

Brian

Hi Brian,

I think you will find that most people who have run the ST .46 will tell you that you are not using enough pitch. 4.2 is just too little for how the engine is timed to run.

Bill

Balsa Butcher · « **Reply #16 on:** September 15, 2013, 07:37:17 PM »

Not a good choice for a ST-46 but a great choice for an LA-46.

Brian Massey · « **Reply #17 on:** September 16, 2013, 09:27:54 AM »

Quote from: Bill Little on September 15, 2013, 02:42:47 PM

Hi Brian,

I think you will find that most people who have run the ST .46 will tell you that you are not using enough pitch. 4.2 is just too little for how the engine is timed to run.

Bill

I've never owned an ST 46 so I can't say, but you may be right regarding it's pitch "sweet spot". But I can tell you first hand that at least my LA 46 loves the prop I have mounted. May be that the LA does not like as much load as the ST?
When I got my first LA I was told to run it at 8800rpm. While that was OK, I got much better results by pitching down and letting it spin a little faster. For a while I used a Zoar 11x4 with a launch RPM of 9600. That worked, but my lap times were 5.0-5.1. Too fast for my reflexes. This BE prop seems to let the engine hit a happy groove.

Brian

Bill Little · « **Reply #18 on:** September 16, 2013, 10:59:27 AM »

Quote from: Brian Massey on September 16, 2013, 09:27:54 AM

I've never owned an ST 46 so I can't say, but you may be right regarding it's pitch "sweet spot". But I can tell you first hand that at least my LA 46 loves the prop I have mounted. May be that the LA does not like as much load as the ST?
When I got my first LA I was told to run it at 8800rpm. While that was OK, I got much better results by pitching down and letting it spin a little faster. For a while I used a Zoar 11x4 with a launch RPM of 9600. That worked, but my lap times were 5.0-5.1. Too fast for my reflexes. This BE prop seems to let the engine hit a happy groove.

Brian

Hi Brian,

It is a matter of different engine types. The Super Tigre .46 is a strict 4-2 engine while the box stock OS .46LA seems to really work good in a wet 2 style run. It is making its power at a much higher rpm. A good prop for the LA is an APC 12.25X3.75. The Tigre, if run fast enough to fly a decent speed with that prop just has no "head room" to give any boost in maneuvers. It likes, and works best, with something like a 12X6 running in a 4 stroke. Just different designs of engines.

BIG Bear
RNMM/AMM

Brett Buck · « **Reply #19 on:** September 16, 2013, 11:05:50 AM »

Quote from: Brian Massey on September 16, 2013, 09:27:54 AM

I've never owned an ST 46 so I can't say, but you may be right regarding it's pitch "sweet spot". But I can tell you first hand that at least my LA 46 loves the prop I have mounted. May be that the LA does not like as much load as the ST?
When I got my first LA I was told to run it at 8800rpm. While that was OK, I got much better results by pitching down and letting it spin a little faster. For a while I used a Zoar 11x4 with a launch RPM of 9600. That worked, but my lap times were 5.0-5.1. Too fast for my reflexes. This BE prop seems to let the engine hit a happy groove.

   A 12-6 takes less HP than a 12-4, so arguably a 12-6 is less load. That's the problem with the 12-4 on the ST46, it doesn't have enough poop to run fast enough with a 12-4 (and still have an responsiveness left). The 12-6 puts can pull the airplane with much less shaft HP, so the ST still be happy.

   The faster it is spinning, the less efficient the prop, so the more HP is required from the engine to get sufficient HP into the airframe. We are talking 8700 RPM or so with a 12-6 inflight, VS, ~11,000 with the 12-4. All else being equal (which is isn't since they are the same type prop), that would be almost twice the parasitic drag.

   Brett

Phil Bare · « **Reply #20 on:** September 16, 2013, 12:05:40 PM »

A 12-6 takes less HP than a 12-4, so arguably a 12-6 is less load

You are joking, Right, Brett, right?
.

That's the problem with the 12-4 on the ST46, it doesn't have enough poop to run fast enough with a 12-4 (and still have an responsiveness left). The 12-6 puts can pull the airplane with much less shaft HP, so the ST still be happy.

The faster it is spinning, the less efficient the prop, so the more HP is required from the engine to get sufficient HP into the airframe. We are talking 8700 RPM or so with a 12-6 inflight, VS, ~11,000 with the 12-4. All else being equal (which is isn't since they are the same type prop), that would be almost twice the parasitic drag.

Brett
[/quote]

Brett Buck · « **Reply #21 on:** September 16, 2013, 12:27:53 PM »

Quote from: Phil Bare on September 16, 2013, 12:05:40 PM

A 12-6 takes less HP than a 12-4, so arguably a 12-6 is less load
You are joking, Right, Brett, right?

No, I am not. Look up the definition of horsepower as applied to propellors, and how it changes with RPM.

A 12-6 is more load *on the ground*. It is not more load *in the air* where you care about it.

Brett

Phil Bare · « **Reply #22 on:** September 16, 2013, 05:32:40 PM »

Brett, 6" of pitch is 6" of pitch on the ground or in the air, just as 4" of pitch is 4" of pitch on the ground or in the air.
It takes more power to spin 6" of pitch at 10,000 RPM than it does to spin 4" of pitch at 10.000 RPM on the ground or in the air.
If you look at reviews of the ST .46, you will find that its peak HP output comes right at 13,000 RPM.
Put the same 4" pitch prop on the ST as used on the LA and lean it out and see what happens.

It is pretty worthless to compare an engine running in 4-2 mode with an engine running in a wet 2 mode. Run them both the same and then some valid information might be had.

Phil.

Brett Buck · « **Reply #23 on:** September 16, 2013, 11:16:34 PM »

Quote from: Phil Bare on September 16, 2013, 05:32:40 PM

Brett, 6" of pitch is 6" of pitch on the ground or in the air, just as 4" of pitch is 4" of pitch on the ground or in the air.
It takes more power to spin 6" of pitch at 10,000 RPM than it does to spin 4" of pitch at 10.000 RPM on the ground or in the air.
If you look at reviews of the ST .46, you will find that its peak HP output comes right at 13,000 RPM.
Put the same 4" pitch prop on the ST as used on the LA and lean it out and see what happens.

You miss the point completely - to fly the airplane, you don't spin them both at the same speed. Presuming you shoot for the same level flight speed, you have to spin the 4" of pitch much faster. We even know how fast - it's about 8800-9000 for 6" of pitch, and it's about 11,200-11,500 for 4". That's from in-flight RPM measurements, it is not speculation, we know. Check the HP at 8800 and the HP at 11,200.

And of course the ST might be able to swing a 12-4 at the necessary 11,200 RPM to get the right level flight speed. It will be absolutely gutted out and have absolutely nothing left for the maneuvers. I know, it is not speculation, we know since it has been tried before.

Take the LA, same prop, same RPM, same level flight speed - no problem, plenty of headroom. LA>ST, QED.

Brett

Phil Bare · « **Reply #24 on:** September 17, 2013, 05:40:09 AM »

Brett, in engines with no throttle control, there is no such thing as 'headroom'. The mixture is set on the ground for a given launch RPM and that is where it stays.
The ST.46 peak HP comes at 13,000 so turning 4" of pitch at 11,000 means that it has some 'headroom' as you like to call it.
No throttle control means that you are stuck with what ever the needle setting made on the ground yields.
Run both engines in the same mode with the same props and see what real world results might be.

Phil

Brett Buck · « **Reply #25 on:** September 17, 2013, 09:40:10 AM »

Quote from: Phil Bare on September 17, 2013, 05:40:09 AM

Brett, in engines with no throttle control, there is no such thing as 'headroom'.

Oh dear Lord, how do I get into these arguments?

I thought you were a self-professed engine expert and a Fox supporter - ever hear of a 4-2 break? You do know the phase transition is not necessary for a regulating response, right? In other words, you know that it will regulate in a 2-stroke, or in a 4-stroke, without switching, do you not? Load makes the even a rich 2-stroke fire more cleanly.

Go fly some stunt planes with the engine peaked out, with the right pitch to get the right level flight speed (like maybe a 12-3.5 on ST46), then get back to me. OR, if you don't like listening to me, at least pay attention to what Bill said, which was a more concise version of the same thing.

These are not theories, I and many other people have tried all these combinations in real life.

Brett

Phil Bare · « **Reply #26 on:** September 17, 2013, 03:50:43 PM »

Bret, you get into these discussions by saying uninformed nonsense such as this.
< A 12-6 takes less HP than a 12-4, so arguably a 12-6 is less load. That's the problem with the 12-4 on the ST46, it doesn't have enough poop to run fast enough with a 12-4 (and still have an responsiveness left). The 12-6 puts can pull the airplane with much less shaft HP, so the ST still be happy.

The faster it is spinning, the less efficient the prop, so the more HP is required from the engine to get sufficient HP into the airframe. We are talking 8700 RPM or so with a 12-6 inflight, VS, ~11,000 with the 12-4. All else being equal (which is isn't since they are the same type prop), that would be almost twice the parasitic drag. >

Even the most casual aviation enthusiast knows that as you increase pitch, you increase load on the engine. That is just a fundamental fact of life . Don't believe it, get in any airplane with a controllable pitch prop on it and start cranking the pitch up and watch the manifold pressure go up along with the CHT and EGT..

I never professed to be an expert, but I sure do know that it takes more HP to spin a 6" pitch at a given RPM than it takes to spin a 4" pitch at the same RPM.

As for a 4-2 break, the engine has to be loaded and slowed down enough in order for the ignition to be capable of burning the too rich charge.

As for a 'wet two', the mixture isn't as far off as in a 4-2 mode so the change is very limited.
The only 'add' to be had from the break is an increase in torque due to the engine being slowed down enough to allow ignition on every revolution.

Phil

Brian Massey · « **Reply #27 on:** September 17, 2013, 10:33:43 PM »

Quote from: Bill Little on September 16, 2013, 10:59:27 AM

Hi Brian,

A good prop for the LA is an APC 12.25X3.75.
BIG Bear
RNMM/AMM

I tried that prop, and wasn't that happy with the results. I've done a lot of experimenting since then, and maybe should go back and try it again knowing what I've learned since then.

Brian

Balsa Butcher · « **Reply #28 on:** September 17, 2013, 10:37:24 PM »

Gotta go with Brian on this one - that prop did not work for me either. I think that prop presents sort of a "some swear by it, some swear at it" situation.

Steve Fitton · « **Reply #29 on:** September 18, 2013, 05:46:26 AM »

regarding the APC 12.25x3.75, I had best results running it cut down slightly, around 11.75". I learned that from the Moons when they posted their LA-46 setup.

Timothy Payne · « **Reply #30 on:** September 18, 2013, 07:14:04 PM »

Stick with the Super Tigre man. They're great engines! (What's all this about flame spitting stunt motors? - Should've seen my 35X on Tuesday after ingesting a little rain water in my back yard! This is England you know; after retightening the headbolts it ran backwards, blew the prop off a few times before spitting flames out of both ports:-\).

Finally got her to fire up and it ran sweet on my 10% nitro, 23% castor fuel.

A viable spare, pity the crankshaft bearings shot!

Tim

Jim Kraft · « **Reply #31 on:** September 22, 2013, 02:46:54 PM »

Tim, they run better with a loose bearing. If its really loose like you can move the prop back and forth at the tip a 1/4", run a 7/16" left hand tap through the bearing and it will tighten it back up and keep it from leaking out the front.

Works on 35 stunts anyway.

Brett Buck · « **Reply #32 on:** September 23, 2013, 11:03:03 AM »

Quote from: Phil Bare on September 17, 2013, 03:50:43 PM

Bret, you get into these discussions by saying uninformed nonsense such as this.

Hmmm, uninformed? You are a funny guy. Please tell us again how making the piston heavier increases torque.

Brett

Phil Bare · « **Reply #33 on:** September 23, 2013, 03:37:41 PM »

Brett, got that prop pitch thing sorted out yet?

< Please tell us again how making the piston heavier increases torque. >

I thought that you were supposed to be some sort of rocket scientist or something yet you have no clue about rotating and reciprocating mass and kinetic energy? No surprise there at all.

Oh, BTW, tell us again how to calculate the horse power of a rocket.
Heck, I'll even help you out.
One horse power is the energy that it takes to raise 33,000 lbs one foot in one minute.

Phil

Gerald Arana · « **Reply #34 on:** October 27, 2013, 11:34:40 AM »

What Brett said..................

I'll go with the LA 46, 762 Muffler, 11X4 Vess (Wood ), 6mm (LA 25) venture and an extra head shin. Oh and 10/22 fuel. Purrs like a kitten, does the whole pattern in less than 8 minutes (7:50, ask Brett) on 4 oz's of fuel.....

Anybody want to buy a St46 with an Adimisin muffler? All offers over $150 will be considered and Yes, I can send pictures. Just to lazy to add them here.

Brett Buck · « **Reply #35 on:** October 27, 2013, 12:43:11 PM »

Quote from: Phil Bare on September 23, 2013, 03:37:41 PM

I thought that you were supposed to be some sort of rocket scientist or something yet you have no clue about rotating and reciprocating mass and kinetic energy? No surprise there at all.

Right! Dumbest person on the planet, one of those silly ivory tower eggheads, not a real workin man!

Brett

Phil Bare · « **Reply #36 on:** October 27, 2013, 03:07:31 PM »

Quote from: Brett Buck on October 27, 2013, 12:43:11 PM

Right! Dumbest person on the planet, one of those silly ivory tower eggheads, not a real workin man!

Brett

Brett, I always considered my years spent in my career as a mechanical engineer to be real wok, sorry that you don't feel the same.

Phil

Dennis Moritz · « **Reply #37 on:** October 28, 2013, 12:01:15 AM »

In Philly we use 12.25x3.75 apc, sometimes cut down a quarter to half an inch. The weight, drag of the model, size of venturi, tank configuration, fuel, weird vibes, and so forth, all are factors in any installation. Even the clearances and wear of a specific engine. Lately I've been sliding .263 (there abouts) venturis into the spout. Power seems fine for Vector sized planes. Cuts way down on fuel usage. Much easier to stuff a 4.5 ounce tank max in a Vector. When I measured the stock venturi on one of my LA46s, I was shocked to find it at .290. Way large. It had been running fabulously on a 36 ounce Tanager for years. Setting was sloppy sloppy rich. A lean cough at the top of the loops and vertical eights. Nice on off power in the overhead eights. The engine sucked down a full 6 ounces to do the pattern. Not easy to get that capacity into a Vector. So far the smaller venturis seem tunable, runs pretty well.

Author Topic: Super Tigre .46 vs. O.S La .46?? (Read 5994 times)

steven yampolsky

ChrisSarnowski