Super Tigre Blue Head Schneurle .40
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I bought this engine used and finally got around to running it.
Powermaster 5/22 Rev Up wood 10x6 13,489 rich of peak (TNC Tach) That seems like a good number to me.:D David |
RE: Super Tigre Blue Head Schneurle .40
Very nice numbers dave, mainly because this st muffler is very much restritive .... hot engine
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RE: Super Tigre Blue Head Schneurle .40
Thanks. And, the carb seems somewhat oversized, too. In fact, it has the same .351" venturi as the carb on my .60 Blue Head. It's also loud as heck!
David |
RE: Super Tigre Blue Head Schneurle .40
ORIGINAL: stg61abc Very nice numbers dave, mainly because this st muffler is very much restritive .... hot engine so if it was less restrictive the numbers would have been higher? |
RE: Super Tigre Blue Head Schneurle .40
sure.... i bet this engine taps 14 / 14.5 K with the modern ST silent muffler...
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RE: Super Tigre Blue Head Schneurle .40
Hi Dave. Bout time you posted some stuff here. I was getting lonely. :)
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RE: Super Tigre Blue Head Schneurle .40
Howdy Jeff! I've got more to come... I recently bought a TNC tach which is an absolute pleasure to use, so I'll be taching a lot of oldies.
Hmm, I don't have a .40/.45 size ST quiet muffler. I do have one of those "Paw" types. I wonder if that would add any revs. David |
RE: Super Tigre Blue Head Schneurle .40
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Ok, I'll run it again with this muffler. So, you think I'll pick up a few hundred?
David |
RE: Super Tigre Blue Head Schneurle .40
hi Dave. I bet this muffler will improve the power of you ST 40. It has a bigger chamber than the other muffler that you used. Please test it and if possible post the numbers ok?
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RE: Super Tigre Blue Head Schneurle .40
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stg61abc, I ran the engine again with a new ST muffler.
Powermaster 5/22 GMA Rev Up 10x6 14,111 peak 6.33lbs static thrust 1.24hp Wow! I gained 622rpm. With an APC 10x6 it would probably rev a bit higher still (but, I don't have one). Thanks for the muffler suggestion! I wonder what it would do on a pipe?:D David |
RE: Super Tigre Blue Head Schneurle .40
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Hey Dave.
I've tested a GS 45 with an old no name tuned pipe and gained 500 RPM. It's very easy to test a pipe on that engine on the test bench, because you just have to take of the muffler and put a 15 cm long peace of silicone tube on. No need to buy a manifold for the test. Let the pipe go straight out from the engine and fix it, so it's possible to move it towards the engine when you tune it. The set up of the pipe is similar to the picture. I’ve bought a OS super silence muffler VERY cheap and removed all the stuff inside and enlarged the exit hole to 7,5 mm. The RPM’s are the same and the muffler is 35 grams lighter than the stock muffler (the muffler you have). Because of that I could take off 15 grams in the tail of the plane. A downside is that you will have to modify the exhaust screw holes on the engine. Good luck |
RE: Super Tigre Blue Head Schneurle .40
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Hi Dave, good to know that the silent muffler worked well for you. I love the sound produced by this muffler, really nice. I have this muffler in my ST GS 40 as an OEM part and is really nice. Super Tigre also made some years ago a series of tuned mufflers called "tiger paw" that were telescopics tuned mufflers in a header, but they were taken out from production.
Also a hot muffler from ST is the tuned muffler specially made for the quickie 500 engine version of their .40, called the ST G-500 ABC. The engine is out of production now, but the muffler is still for sale in some places at the USA a pic from my G 500 nice flying friend |
RE: Super Tigre Blue Head Schneurle .40
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ORIGINAL: rainedave stg61abc, I ran the engine again with a new ST muffler. Powermaster 5/22 GMA Rev Up 10x6 14,111 peak 6.33lbs static thrust 1.24hp Wow! I gained 622rpm. With an APC 10x6 it would probably rev a bit higher still (but, I don't have one). Thanks for the muffler suggestion! I wonder what it would do on a pipe?:D David I plan to run this same engine with a Macs 6.5cc muffled pipe and 10x6 and 11x5 props in the spring. I'll report back with some results... 15K on a 10x6!? or maybe 14K on an 11x5? Cheers, David. |
RE: Super Tigre Blue Head Schneurle .40
David, your Tsunami looks great.. and very fast. I'm sure that engine will scream on the pipe. Maybe try a 9x8 for even more speed?
David |
RE: Super Tigre Blue Head Schneurle .40
Thanks David. I'm fairly happy with how she turned out. As always, a few things that I wish I'd done differently but chalk it up to experience!
I'm looking forward to running that 25+ year old ST! I've never run it on a pipe! I should have some figures sometime in March-April. The Tsunami is almost finished. I completed the radio installation today so I'll be able to finish up the linkages. More on that in my thread. Cheers, David. |
RE: Super Tigre Blue Head Schneurle .40
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Ran it again today with a Mac's muffled pipe:
Powermaster 5/22 GMA APC 10x6 14,972 peak 6.99lbs static thrust 1.26hp 73.9mph I could cut another 1/2" off the header, go up to 15% nitro and break 15,000, but this is an old engine and I don't want to push it. Parts are hard to come by. David |
RE: Super Tigre Blue Head Schneurle .40
Dave sweet setup. Iam considering something similar on my MVVS 40. Just need to decide what airframe, (like i'm in a hurry) http://www.rcuniverse.com/forum/js/f.../msn/75_75.gif
Ijust need to get the header for it and Iwill make a tuned pipe. |
RE: Super Tigre Blue Head Schneurle .40
jeffie,
Tell us about makingyour ownpipe. Ihavemadesome pipes in the past but they weren't for smoking model engines. http://www.rcuniverse.com/forum/js/f.../msn/47_47.gif Terry in LP |
RE: Super Tigre Blue Head Schneurle .40
rainedave, Impressive numbers there. Terry in LP</p> |
RE: Super Tigre Blue Head Schneurle .40
ORIGINAL: anuthabubba jeffie, Tell us about makingyour ownpipe. Ihavemadesome pipes in the past but they weren't for smoking model engines. http://www.rcuniverse.com/forum/js/f.../msn/47_47.gif Terry in LP David |
RE: Super Tigre Blue Head Schneurle .40
Outstanding figures David!
15K it is! From the stock muffler at ~13.5K gaining almost 1.5K on a pipe is impressive! I'm glad I didn't decide to retrofit the Tsunami for a YS 45. Although speed is fun I'm also curious about how she'll stand up to higher loading - an 11x5. I think I'm going to do the final push on the Tsunami this week and get her ready for takeoff. Beforehand, some testing of the bluehead will be required. It'd be nice to have an APC 9x8, 10x6 and 11x5 on hand. What's the length of your header at present? I'll cut mine 1/2" longer to try out the 11x5 for a starters. BTW, do you have the conversion formulas for thrust, hp and pitch speed or does the Fromeco do all that for you? Iguess pitch speed is easy to convert from RPM. David. |
RE: Super Tigre Blue Head Schneurle .40
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Thanks Terry and David.
I'll dig through my props for an 11x5. I know I have an APC 9x7 and 9x8. I used the 10x6 since it's easy to compare to existing data for other forties. The header is 4 7/8" long measured the way shown on the Mac's site (see image below). Here is the info from their site: <table border="4"> <tbody> <tr align="center"> <td align="left">ST S 40</td> <td>Zinger 10 X 6</td> <td>7.5mp</td> <td>13,550</td> <td>14,850</td> <td>4.75"</td> </tr> </tbody></table> The first number is open exhaust, the second with the header at 4 3/4" length. What's interesting is that Zingers are a lighter load than APC's, yet I still bettered their figure! You need to download Pe's spreadsheet for calculations. It's excellent: http://mvvs.nl/prop-power-calculator.xls And, you can use Open Office Calc to run the file.http://www.rcuniverse.com/forum/js/f...sn/biggrin.gif David |
RE: Super Tigre Blue Head Schneurle .40
Excellent stuff David - thanks. I'll be using that spreadsheet soon. A Matlab program of it would be even cooler. One could make it an executable which then could run in the absence of Matlab on the local machine. It's been at least 10 years since Itouched the stuff though.
It seems to me that every time an engine is tested with various props, the APC's always deliver. They must be seriously efficient despite their weight. More importantly though, at almost 7 lbs of static thrust in a 5 lb plane, the rocket could practically take off right out of my hand pointed straight up. Ever try that with a pattern design? I haven't... yet. http://www.rcuniverse.com/forum/js/f...sn/biggrin.gif David. |
RE: Super Tigre Blue Head Schneurle .40
rainedave said,
"What's interesting is that Zingers are a lighter load than APCs, yet I still bettered their figure!" That's 'cause they have a better shape for moving air. Or at least moving through air. A 'normally shaped' prop, like most wooden model props & even mostmetal full scale props, are only really efficientforabout half of each blade's length. <h3><span class="mw-headline">Aircraft propellers (airscrews)</span></h3> A propeller's efficiency is determined by</p><dl> <dd>http://www.newworldencyclopedia.org/...fad43ec0f2.png. </dd></dl> A well-designed propeller typically has an efficiency of around 80 percent when operating in the best regime.</p> Changes to a propeller's efficiency are produced by a number of factors, notably adjustments to the helix angle , the angle between the resultant relative velocity and the blade rotation direction, and to blade pitch (where θ = Φ + α ). Very small pitch and helix angles give a good performance against resistance but provide little thrust, while larger angles have the opposite effect. The best helix angle is when the blade is acting as a wing, producing much more lift than drag. However, due to the shape of the propeller, only part of the blade can actually be operating at peak efficiency. The outer part of the blade produces the most thrust and so the blade is positioned at a pitch that gives optimum angle to that portion. Since a large portion of the blade is therefore at an inefficient angle, the inboard ends of the blade are hidden by a streamlined spinner to reduce the resistance torque that would otherwise be created. Another method used is to have a curved pitch propeller, in which the individual blades are actually airfoils of varying camber and angle of attack across the span. This is achieved by twisting the airfoil across its major neutral axis(span length). It is usually set with the inner airfoil section of the blade in the direction of travel; that is, axial speed, or U (here freestream velocity), and the outer edges at right angles to it. Do the last three sentencesbring to mind the shape of a particular brand of model airplane propellor? Terry in LP edit: to fix the symbols that were made into emoticons!</p><h3></h3> |
RE: Super Tigre Blue Head Schneurle .40
OK, most of that went over my head, but I have a question: what's the difference between helical pitch and "twisting" of the airfoil? I always thought a prop with constant or helical pitch had blades that are twisted.
David |
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