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Author Topic: Super Tigre 46  (Read 5194 times)

Offline Allan Perret

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Super Tigre 46
« on: May 17, 2009, 09:34:50 AM »
What is recommended fuel ? 
Getting ready to use one for the first time. 
I wasnt flying stunt back in the glory days of the Super Tigre's..
What are materials of piston / sleeve ??
Will be using on a profile around 46~48 oz. 
What are some good props to try, prefer wood ?
Allan Perret
AMA 302406
Slidell, Louisiana

Offline Ralph Wenzel (d)

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Re: Super Tigre 46
« Reply #1 on: May 17, 2009, 07:58:20 PM »
Fuel - - Powermaster 5-22 (50-50 Castor/synthetic) or 10-22 (on a hot day or at altitude)

Iron piston ring running in a chromed, steel liner. (New rings available from Frank Bowman - Even the other engine rebuilders use his rings!)

It'll be a good performer at that weight. Get a good (non-ST) muffler

Props - 12-6, 12-5, or these possibly trimmed to 11

Make sure the nose is solid! The G21/.46 doesn't shake like a Fox .35, but . . .

(Too many irons; not enough fire)

Ralph Wenzel
AMA 495785 League City, TX

Offline Brett Buck

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Re: Super Tigre 46
« Reply #2 on: May 17, 2009, 11:09:46 PM »
Fuel - - Powermaster 5-22 (50-50 Castor/synthetic) or 10-22 (on a hot day or at altitude)

Iron piston ring running in a chromed, steel liner. (New rings available from Frank Bowman - Even the other engine rebuilders use his rings!)

It'll be a good performer at that weight. Get a good (non-ST) muffler

Props - 12-6, 12-5, or these possibly trimmed to 11

Make sure the nose is solid! The G21/.46 doesn't shake like a Fox .35, but . . .



    For models of that weight (and all of mine were in that range (with about 625 sq inch or so)) I would suggest looking into 11 to 11.5" diameter, and maybe 5.5" of pitch to start with. I don't think you will have a lot of luck with anything below 5" of pitch, but the lower you can get without running out of "breathing room" on the engine the better. At this weight, there's no reason to run the larger diameters and you will get a strong run but soft break with this type of prop. A strong engine will turn a 13-6 or even a 13-5 well enough to be useful but the break you get will not be what you want on this size airplane. A lot of guys ran props like the 10-6 Tornado 3-blade back in the day, and that actually works surprisingly well on 48 oz airplanes. I was running a Bolly 11.25-6.5 3-blade depitched to about 5.5 at the end of the era. It was a lot less load than a Rev-Up 11.5-5.8=>6.3 2-blade, even when it was cleaned up.

   With the stock venturi, 5% will work. But it will be pretty feeble. Even at sea level I ran 10, and later 15%. With anything bigger than stock venturis, forget 5%. The last hurrah for the ST46 was David's 6th place at the 89(?) Team Trials, and that was with 20% Cool Power with a bunch of castor added. You definitely need a BLEND - not straight castor. Straight castor will glue the ring in the groove and lose compression.

   Break it in normally. After about 1/2 hour of break-in cycling, check the ring. To see if you have a good ring, check the compression forwards and backwards. If it's grossly different you will probably need a new ring. A good ring, properly seated, will have very good compression forwards and backwards. If it doesn't have good compression both ways, set it up on the test stand with a 10-4 Rev-Up or equivalent and run it, just short of peaked out, for about 5 minutes. Let it cool, and check again. If it still fails, you probably need a new ring. A good stock ring, properly broken-in, will look brownish and much darker than the gray piston. The ring fit is *everything* - nothing will fix it if it doesn't have a good ring, and if you have a good ring, there's nothing you need to do to the rest of it. NO modifications are necessary to anything else.

    Brett

Offline Greg L Bahrman

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Re: Super Tigre 46
« Reply #3 on: May 19, 2009, 09:44:39 PM »
<Iron piston ring running in a chromed, steel liner.>

I have never seen a stock ST46 with a chrome sleeve. Did the factory do this ???


Greg Bahrman, AMA 312522
Simi Valley, Ca.

Offline Ralph Wenzel (d)

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Re: Super Tigre 46
« Reply #4 on: May 19, 2009, 10:37:24 PM »
Yeah. The first G21/.46 engines all had chromed liners. I can still remember the bitchin' and moanin' (and accusations of false advertising) when they stopped chroming the sleeves in the late '70s (might have been early '80s . . .). ST maintained that it wasn't "false advertising" 'cause the crankshafts were still chromed.

(Too many irons; not enough fire)

Ralph Wenzel
AMA 495785 League City, TX

Offline Brett Buck

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Re: Super Tigre 46
« Reply #5 on: May 19, 2009, 11:10:08 PM »
<Iron piston ring running in a chromed, steel liner.>

I have never seen a stock ST46 with a chrome sleeve. Did the factory do this ???

   Yes. I have had some differences of opinion with various people over which where chrome and which weren't, but early on they all were, and at the end none were. Where it stopped is the point of debate - I agree with Ralph, it was sometime in the 70's, but when, who knows. There were a tremendous number of variations but they were all pretty good as long as you have a good ring. There were fewer variations than the ST35, I never saw two of those that were the same.

     If I had a stuffer crank engine, based on information from EricV, I would cut off the stuffer band before it breaks on its own. Other than that, everything else is fine straight out of the box.
   
    Brett

Offline RandySmith

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Re: Super Tigre 46
« Reply #6 on: May 25, 2009, 11:57:56 AM »
What is recommended fuel ? 
Getting ready to use one for the first time. 
I wasnt flying stunt back in the glory days of the Super Tigre's..
What are materials of piston / sleeve ??
Will be using on a profile around 46~48 oz. 
What are some good props to try, prefer wood ?

Hi Alan

You will find that a huge number of props work with the ST 46, depending on what is needed for your particular setup.
We used Rev-up 12 x 5 at full span or cut to 11.5, This was before Bolly props,and as Brett mentioned Bolly has many props that worked well.
 Many other props work well too, The BYO 12 x 5, Top Flight 12 x 5, Rev-Up 11 x 6 EW, this will depend on what plane, how much weight, size, etc
In what is out there today to buy, The BYO 11x6 11 x 5  12x 5  ... 12x6  Zinger pro series  12 x 5, Eric Rule has some very good wood props that may work also, I know some are using the Power point TF props on 46s. So you have a lot to choose from.

I always used 50-50 oil with about 23% total in mine.  The ST 46 will pull as 46 to 48 ounce profile with little effort, as it is a very  strong motor.
The engine ,if new needs to be broken in very slow and carefully, As Brett stated The early ones, without muffler lugs were chromed, Every St 46 I had seen with muffler lugs did not have a chrome liner stock. Also the early chromed liner were much thinner than the later motors.
The chrome liners take more running time for ring breakin than the newer ones do, The rings are the key to any motor that uses them as Brett stated. The BIG problem with ST 46 rings were, many had zero gap when sent.
 These would heat up as soon as you run them, the gaps would touch and the ring would start to wear flat on part of it from the heat.
 If you were not very careful ,one run like this would ruin the ring were it would never seal right.
Even many of the replacement rings ST sent would have no gap, replacing the ring without measure and setup would result in the same results.
I have setup 100s of ST 46s and I always used .003 to .004 initial gap on chrome motors and .002 to .003 on Steel ones that were not chromed.
If the sleeve was honed with a coarse cross hatch (the swirling scratches cut into the sleeve in 2 spiraling directions) you could set the gap at .001, as the ring would wear and open up much more quickly.
When you got a great ring seal it lasted for a while, as long as you didn't get a lean run.
Other things that would benefit the ST 46 and make it a better motor was to replace the venturie with a true venturie or block off 3/4 of the groove cut into the fuel feed part of the ST venturie.
This helps with stopping the surging at the end of the tank.
 Also the stock ST 46 venturie was pretty small, as the ones came with .150 to .157 diameter, We used 160 to 175 diameter holes in them, however the stock small one will work in the small plane you are talking about flying. There are many other things that will improve the ST 46 but that is another thread.

Regards
Randy

Offline Allan Perret

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Re: Super Tigre 46
« Reply #7 on: May 25, 2009, 01:27:25 PM »
Brett and Randy:
Guess I should have told you guys the rest of the story.  I am building Don Hutchinson's profile Stearman.  Its a 40 size bird,  36" span, 530" area.  Plans also show 11" prop.   But being scale it has the short nose of the full scale bird with the big radial.  Plan calls for 3.5oz of nose weight to get the CG right.  So instead of a 40 and 3.5oz of lead,  I have this Tigre 46 laying around (came with a used model I bought 10 years ago) doing nothing.  I figure I'll put the Tigre 46 on it and have a reserve of power.  That would allow me to run it in a steady 4 cycle for a more realistic sound.  I realized it might be overpowered but figure if necessary I could tame it with smaller venturi.  Like I said I'm not familiar with the run of the Tigre's and didn't realize when I made the decision to use it that the 46 has the power more like a 60 than a 40, at least that's what it sounds like you guys are saying.   It  will have the extra drag associated with biplanes,  and in my case I am adding a dummy scale radial engine, which will be additional drag.  Wont be that big of a deal if it doesnt work out because I am setting up the front with aluminun motor plates which will make it easy to swap out motors.  I also have Fox Silver 40  and Saito 40 as back ups..     
Allan Perret
AMA 302406
Slidell, Louisiana

Offline Balsa Butcher

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Re: Super Tigre 46
« Reply #8 on: May 25, 2009, 01:42:08 PM »
One thing to consider is that the ST-46 is not much heavier than a 40FP type engine.  They do use more fuel than though.  I don't know how big  tank you can fit on that airplane but it might be a consideration if you plan to fly the pattern.  8)
Pete Cunha
Sacramento CA.
AMA 57499

Offline Allan Perret

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Re: Super Tigre 46
« Reply #9 on: May 25, 2009, 02:55:20 PM »
One thing to consider is that the ST-46 is not much heavier than a 40FP type engine.  They do use more fuel than though.  I don't know how big  tank you can fit on that airplane but it might be a consideration if you plan to fly the pattern.  8)

Definitely plan to fly the pattern.  Tank is custom, it fits in a window thru the fuse between the bearers, sticks out a little on both sides.   Would be easy to make it bigger if necessary.  If I use smaller than normal venturi,  fuel consumption should be less than what most are  accustom to.
I could always use a stock muffler if I need the weight.
Allan Perret
AMA 302406
Slidell, Louisiana

Offline RandySmith

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Re: Super Tigre 46
« Reply #10 on: May 25, 2009, 02:59:19 PM »
Hi Allan

The ST 46 is not as powerful as a 60, but is a good motor, You will not have a problem with being over powered with a Bi plane, you can alway use more power for Bi planes. They have much drag, the 46 is a good choice for you, weight is not an issue and you can use a tube type muffler, I don't think fuel tank size will be either

Randy

Offline Brett Buck

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Re: Super Tigre 46
« Reply #11 on: May 25, 2009, 09:06:41 PM »
Like I said I'm not familiar with the run of the Tigre's and didn't realize when I made the decision to use it that the 46 has the power more like a 60 than a 40, at least that's what it sounds like you guys are saying. 

   I don't think that was what I was saying!  If I did, then disregard. The 46 is a nice mild stunt engine but not in the league with most stunt 60's like the PA or RO-Jett even on a header muffler. I think an AeroTiger 36 is a more effective stunt engine than an ST46. The ST is *no match* for any common 40 like the VF. It had decent power for the day, but that day was 35 years ago.

    Knowing your plans, the system discussed above should work out just fine.

    Brett

Offline Allan Perret

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Re: Super Tigre 46
« Reply #12 on: May 25, 2009, 10:13:49 PM »
   I don't think that was what I was saying!  If I did, then disregard. The 46 is a nice mild stunt engine but not in the league with most stunt 60's like the PA or RO-Jett even on a header muffler. I think an AeroTiger 36 is a more effective stunt engine than an ST46. The ST is *no match* for any common 40 like the VF. It had decent power for the day, but that day was 35 years ago.

    Knowing your plans, the system discussed above should work out just fine.

    Brett

No you didn't say it, that was just the impression I got from the range of props you suggested the 46 would handle.  I wasnt making a comparison to the modern 60's.  Just seemed like on a power scale from 40 to 60 of the older cross flow engines,  the 46 was closer to the 60 side of the range.  In any case I feel comfortable now that the two gurus have blessed my application.  Thanks for the help.   
Allan Perret
AMA 302406
Slidell, Louisiana

Offline Paul Smith

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Re: Super Tigre 46
« Reply #13 on: December 24, 2021, 12:58:21 PM »
What is the bore and stroke of a G21/46?

I have received an engine with the number ground off.

I know that the nominal bore & stroke of a G21/40 is .8032" x .7874.  But I can't find reference to the 46.

Research has found that when ST did the 29, 35, and 40, they increased BOTH the bore & stroke with each step, thereby keeping the ratio the same.
« Last Edit: December 24, 2021, 01:48:32 PM by Paul Smith »
Paul Smith

Offline Air Ministry .

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Re: Super Tigre 46
« Reply #14 on: December 24, 2021, 02:48:01 PM »
22x 20 Nom. could be 19.8 .  for the 46 .

20.5 x 20 for the .40 .

23 x 20 for the .51 .  >:D

Bottom ends the same . rod n crank . real early dual ring and first one ring had differant bits to later ones .





Riginly theysaid 20 stroke , thisisa rearly 20 stroke , thin wall sleeve , parrallel bypass case one, below .Series 1 & 2 ,



Alloffthe bulged bypass are thicker sleeve 19.8 stroke , perhaps ,
« Last Edit: December 24, 2021, 03:12:34 PM by Air Ministry . »

Offline Paul Smith

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Re: Super Tigre 46
« Reply #15 on: December 25, 2021, 09:30:41 AM »
Thank you for the data sheets.

The item seller's description was very hazy.  A previous user had for some reason (maybe sneaking a 46 in as a 40) ground off some of the markings.
I expected a G21, but actually got a G46. 
I was able to measure the stroke without tearing down the engine and it's .786" which confirms that it's a G46.  The G46 is the only engine with this stroke.

Now I have an engine for a small Old Time Class II Carrier model if I chose to build one.
Paul Smith


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