stunthanger.com
Engine basics => Engine set up tips => Topic started by: Paul Smith on January 01, 2010, 02:50:46 PM
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Is the particular Supertigre G51 the engine currently being recommended as a stunt engine?
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFV72&P=ML
I'm trolling for something to put in a Shark 45, Magnum, or Stiletto.
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I don't think so (that is the RC version).
The RC version has a different cylinder liner part number (or at least it use to) than the CL version. I don't have an RC version to make a real comparison of liners (timing for example).
Here is the link to the CL version.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFV87&P=0
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LXFV87 SuperTigre G-51 Dual BB Ringed Control Line w/Muffler
89.99 In Stock........TOWER HOBBIES
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http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFV87&P=0
OK, that's more like it. $10 less expensive and I don't need to make a venturi & NVA.
Amusing, Tower didn't bother to change the "tech notes" from the RC version. I'm not sure ST would bother to redo the timing for stunt. We're lucky to get a venturi. If they actually retimed it for stunt, they're one miracle shy of sainthood.
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Hi Paul,
It's my understanding that the sleeve for the U-control is different than the RC sleeve (timing).
LXFX44 SuperTigre Cylinder Sleeve G-51 Control Line
LXFX43 SuperTigre Cylinder Liner G-51 RC
Both sleeves are $20.99 from TOWER plus shipping etc.
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I really recommend getting a ST 51 C/L from Tom Lay. His rework is magic! Turns the ST 51 into possibly the best stunt engine you could have.
Floyd
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Yes, I have heard good things about Tom's engine rework. I actually had my ST51 done by Byron Barker of C.F. Slattery Co. (812)948dash9167 and it is a sweetheart. I have it in a 64 oz. plane and it is impressive. Nice 2-4 break with plenty of power. There are probably others, and don't forget Randy Smith of Aero Products.
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Greetings and a Happy New Year folks from S.W.France.
Just to add my two cents worth....... Don't expect the C/L version of the ST51 to behave as a true stunt engine.
I bought a C/L version , it just wouldn't give up on the dreaded 'run away' no matter what I tried.
I sent it to Tom Dixon and it came back transformed !! It's brilliant now.
Maybe some chaps will have success with the stock C/L engine , I didn't.
Byron [ Barker ] is a real 'gent' and a great engineer. He'll fix any engine and make it run just fine.
Robin [ ex-pat Brit in the Charente full of ex-pat Brits ]
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What's wrong with it that needs to be fixed?
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I think like a lot of engines, it just depends!
On things like tolerances --some guys get them ready to go right out of the box, others have runaways. In the past (maybe even now), the ring gap was insufficient. George Aldrich even claimed that a lot of them had "negative" gaps. Here is a copy of his reply to a post of mine in some long lost forum about a problem a buddy of mine was having with his Tigre 51 (Italian version):
"Everyone of the current ST's I've seen, clear up to the .91, have come with NEGATIVE ring end gap ! The
piston rises to the very top of the cyl. on all of these designs, and if you remove the ring from a new
engine, it will not fit in the cyl. at the top where it get hottest ! The ring ends will actually over-lap !
The end gap should be increased to about .003", and then a more normal run-in will have the engine
purring in about 30 min's. to an hour of slightly rich flying runs.
Above all, at least 20% lube, with 5% min. of castor for fuel."
By the way, I did check mine at the time and the gap was ok.
Also it may be the prop you use, or the fuel, or the ......
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My TWO CENTS.
The R/C 51 works very well. IF fact here in the NW most of the Tom Lay 51's that are being used...ARE the R/C Cylinder and piston. There called "Sweet Alice 51's". Tom can chime in with the details. I have TWO of them and Two T&L C/L 51 all work about the same. BUT it's the R/C ones that I like.
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Scott,
And why is that and what is the performance difference?.......TIA
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Thanks, that's what I was looking for.
So the ring gap needs to be "up to .003" at the top of the stroke. I'll look for that if I get a hold of one.
If it's tight, what's the best practice for opening it up. Other than outsourcing, that is.
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Thanks, that's what I was looking for.
So the ring gap needs to be "up to .003" at the top of the stroke. I'll look for that if I get a hold of one.
If it's tight, what's the best practice for opening it up. Other than outsourcing, that is.
Like I said, my ring turned out to be okay (this was back ~10 yrs or more). This might have been an old problem which doesn't exist today. So keep that in mind!
To really check, you need to take the ring off, and push it up the cylinder (use the piston as a pusher), to roughly where it would be at the top of the stroke. Then you try to measure the gap with a feeler gauge.
The downside is that you might distort the ring taking it off, or putting it back on. Simply buying a new one (I don't recall the name of the guy who is THE source for rings) might be the best idea.
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"The downside is that you might distort the ring taking it off, or putting it back on. Simply buying a new one (I don't recall the name of the guy who is THE source for rings) might be the best idea."
Absolutely a fine idea. Frank Bowman is the Ring Man...and he has a "forum" down in the Vendors section. You can contact him easily...but I would go for email, not a post or a PM. y1 Steve
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Maybe it would suffice to just take the head off and see if there is any gap at all.
Maybe you could carefully probe the "gap" with a sharp #11 blade to see if a gap exists.
This might determine whether further disassembly is warrented.
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Maybe it would suffice to just take the head off and see if there is any gap at all.
Maybe you could carefully probe the "gap" with a sharp #11 blade to see if a gap exists.
This might determine whether further disassembly is warrented.
No you can't do that, please do not even try, you will not get the results you seek
If you want to check the gap you will need to remove the piston sleeve
Regards
Randy
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Right, I realized that idea would only work if the ring is at the top of the piston.
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Paul, if you can let Randy,Tom Lay or someone equally good go through your engine before you run it. You won't be sorry. I sent a N.I.B. ST.51 to Tom and he found a broken ring!!!!!!! n1 The engine has run great since i got it back. Never been sorry i sent it to him. Love the Shark and your sharing the build with us. Ron. y1
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We use a local chop with a good record in blessing SuperTigres.
They have granted my future engine an audience.
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Paul, I have a current ST51 slightly modified by one of the better ST rework guys and it pulled a 67 oz Score very well. Several ST51s are in Sharks that have flown recently at VHS. You would have about $185 in a ST51 modified by Tom Lay, regarded by many as the best ST person. That would be a fine engine. However, since you apparently don't already HAVE an engine for your largish model, consider the new Enya 61CXS Pro, a modern stunt-specific engine with traditional side exhaust and ported for lower RPMs. The price is very close to what you would have in the ST51. (This is NOT the Enya clone of the old ST60. It is a new engine.) I replaced the ST51 with the 61CXS in the Score, and Wow! Randy Smith now sells the Enyas, as well as the light tube muffler for it. The Mejzlik carbon 12.5-5.2 3-blade works well. Randy sells those too. The Enya is going into the Shark 45 I am building now. (Eric Rule's kit)
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I looked at the Aero Products price list here on Stunt Hanger and found the prices for similarly set up ST 51 and Enya 61.
ST 51: $159.95
Enya 61: $199.95
40 bucks wouldn't be a deal-breaker if I needed/wanted at 61. But the plane was designed for a K&B 45 and it won Lew MacFarland a lot of championships with one. Granted, that was in the pre-muffler days, so there needs to be some compensation for the weight, power loss and extra fuel load imposed by the muffler. I'm betting that stepping up to a ball bearing 51 will be enough.
Tower's price on the 51 is $89.95, so I have $110 left to get it blessed a witch doctor with some strong mojo before exceed the price of a RTF Enya 61.
Question? Is the Enya and/or it's parts available from any regular shops or distributors?
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Hi Paul,
You can sure fly a Shark 45 with an ST G51 or even a modern .40. What people are trying to tell you is that the ST G51 sucks out of the box, it needs to be reworked and there are some better options for you to consider.
If you talk to any expert he will tell you that an Enya 61CX, Saito 72, PA-75 or a Stalker 80 would not be too much power for your Shark 45.
Today we have learn how to use the power of an engine and the limit is weight and money, never power.
Martin
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I received my new SuperTigre G51 last week. I've already started fitting it into the Shark 45. Thanks for all the suggestions. I considered 'em all, but couldn't comply with all on the same project.
Here are some of my unsuccessful candidates:
K&B 40 R/C and Merco 49 R/C. Weights (less muffler in all cases) 11.4 ounces and 12.9. Both engines are healthy on the test stand, but would need CL modification and are heavy and without parts backing. Back into the engine drawer for maybe a Nostalgia Carrier job in the future.
ST V51, rehabbed by Frank Bowman and CLized by Big Art. 12.7 ounces. Healthy on the test stand, but ear marked for a long term Magmum knockoff project.
ST G21/46. A strong contender. 8.7 ounces and can be maintained with rings and bearings. Not accepted because the plane seems to be at the limit of bigness for this size engine.
K&B 45 CL. 8.6 ounces. This was Lew McFarland's engine, but I only have one and there are no parts. IT worked for Lew in the pre-muffler days when you could run nitro and swap out an engine for $16.95.
The winner - ST G51, 10.6 ounces. A modern engine with spare parts and whole spare engines for $89.95. A 2-ounce hit vs the original, but only 0.03" wider.
The factory muffler is a real high water mark in aircraft mufflers. 5.6 ounces. If I as into firearms, it would make a good silencer for an M16 or a 45 automatic. My 1975 5 HP Sears Eager One is almost due for a new muffler. This one is only a little over size.
The round muffler adapter might make tongue-style muffler if plugged with a perforated stopper. Not a joke.
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Hey Paul:
I am sure you will be happy with the ST51. Do yourself a favor and throw the ridiculous stock muffler in the recycle bin and get the excellent tube muffler from Randy Smith, about $35 and worth it. I did. Then, send the motor to Tom Lay with $85 for him to work his magic. I think he did all the ST51's seen at VSC. He replaces the bearings, ring, NVA and venturi plus does some internal work. Don't know how these rework guys do this so cheap. I would have gone for the Enya (actually I did) but this one will make you smile too. Tom's replacement NVA is at a more "conventional" height and makes tank placement easier.
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Paul, Scott Dinger makes a tube muffler designed by Tom Lay for the ST.51. Tom once told me not to use a tongue muffler, doesn't remove enough heat from the exhaust. Ron.
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How does one reach Tom Lay?
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Here you go Dick, thelayster@aol.com y1 Ron.
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Paul, Scott Dinger makes a tube muffler designed by Tom Lay for the ST.51. Tom once told me not to use a tongue muffler, doesn't remove enough heat from the exhaust. Ron.
I would never doubt Tom Lay, but he might have been talking about his engines. My stock ST 51 (except for Bowman ring) won't run with a tube muffler hardly at all, it will flame out most of the time on launch. A tongue muffler and all synthetic 10% fixed it.
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Bob, i think you are right. I should have been more specific. '' Ron.
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Bob, i think you are right. I should have been more specific. '' Ron.
No No, if anything I've got a weird engine.. Many have told me they have ST 51's that ran great right out of the box.. This engine is partially responsible for me having thin hair and moving to 4 strokes.. If I could afford it I would send it to Tom...
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$85.00 for reworking that 51 by Masta' Tom sounds interesting however...My jury is still out if he couldn't HOG some of that ALMOST 11.0Z...while my old Bob Wilder ST-46 weighs in a teenzee' tad over 8 ounces?
Would this 51 at a whopping 11 ounces be much better than a teenieweenie ST-46 in the power to weight dept.
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Shultzie,
You definitely need the 11 ounce engine in the nose of a shark to balance it. I don't think an 8 ounce engine could come close to balancing it. My shark has a G21 .51 in it and it only weighs 61 ounces and needs every bit of that engine and the weight of a 6 ounce tank to get it balanced. Also, I think the shark would be the easiest classic plane to update for modern performance. Put a PA .61 in it, extend the stab/elevator to 26" stick on a pipe tunnel and wa-la, an updated shark. I would call it the Great White Shark, and yes I would paint it gray on top and white on the bottom.
Jim Pollock, flying a shark since 2002. H^^
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G21/51?
Is that a one of a kind custom job?
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Who is that handsome dude holding the trophy and plane? LL~ LL~ LL~As you can see I am kidding as you haven't changed that much. Always scares me when I see someone on 70 foot lines on our old circle in Topeka KS. Mine were 65 foot eyelet to eyelet. People were still backing up from the edge of the circle. Hate to see pretty planes busted up because some one doesn't know how to measure a circle. By the way I guess we do not have a circle in Topeka anymore as the construction shack is in the middle of it. They are building a childrens museum there. Have not seen the new site yet. Off topic I guess, so forgive me.
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Who is that handsome dude holding the trophy and plane? LL~ LL~ LL~As you can see I am kidding as you haven't changed that much. Always scares me when I see someone on 70 foot lines on our old circle in Topeka KS. Mine were 65 foot eyelet to eyelet. People were still backing up from the edge of the circle. Hate to see pretty planes busted up because some one doesn't know how to measure a circle. By the way I guess we do not have a circle in Topeka anymore as the construction shack is in the middle of it. They are building a childrens museum there. Have not seen the new site yet. Off topic I guess, so forgive me.
LL~ LL~
Yes..
I guess we both spin-driffed off the topic...and yes, that was me, as a nieve child with my love for Sharks. I Hopefully I can delete that bunch of drivel. You know how impossible it is to try and convince every newbee Shark builder alive that every Shark has to weigh over 60 ounces and contain at least a 60 size engine or more up front in order to fly a decent pattern.
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I'm certainly going to test that theory. The builder in the picture above has already employed one of my lightening-up plans. The canopy and dorsal fin are skinnied down quite a bit verses the kit.
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"Not only was the fuselage of that old Shark a tad "skinnier (thanks to the K&B narrower crankcase) than Lew's but also check out the extra added length that I added to the nose.
Plus that model was made from select contest wood...and NO PRIMER just a tad of primer on the balsa surfaces.
(Remember that WHITE in bright sun light hides a ton of flaws...except that model looked so shabby when you held it up to the sunlight where you could see the blotchy ness of my thinned Aerogloss finish. (Never received many appearance point as I can clearly remember.
Another PLUS in a way but also a huge MINUS...was that tweaked K&B 45 was not a heavy fuel guzzler and because of that I was always BEGGIN for power to pull that Skinny old Shark that ended its life when I flew it into a crowd control barrier at a contest at Boeing Field the next week end after this photo was taken.