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Engine basics => Engine set up tips => Topic started by: Avaiojet on October 04, 2015, 05:52:53 PM
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I doug deep through the "tongue muffler" Threads.
I still couldn't find what I was looking for?
Seems on profile mounted engines the tongue muffler is mounted so the holes are towards the outside. Some photos show this. My Pathfinder profile is set up this way.
Inverted engines, what photos I could find, show the holes towards the bottom.
I could not find a photo of an upright mounted engine with a tongue muffler?
For an engine mounted upright using a tongue muffler, which way are the holes? Are they normally pointing up or are they pointing down?
Thanks in advance.
Charles
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Charles,
Put them so they spray oil away from the wing. That's one of the reasons I don't like them....... n1
Jerry
PS: Did you understand what I meant? You don't want it spraying directly on the LE. (at least I don't)
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For an engine mounted upright using a tongue muffler, which way are the holes? Are they normally pointing up or are they pointing down?
Depends on how much you like the guys who are launching for you! Lol
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If the engine is mounted upright the exhaust is either on the top of the muffler or the bottom.
I'm not all that sure if there's that much of a difference once the prop gets going?
It looks nicer if you cannot see the holes, but probably less overspray if the holes are on top or less spent fuel on the forward fuselage area.
Not sure about that either.
A photo or two would be nice.
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I had the holes on top on my Dragon which you can barely see in the picture. I turned it over after some complained of it throwing exhaust oil in there face. It really makes no differnce as far as I can see but may be just a bit quieter on the ground with the holes down.
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Jim,
Great looking Dragon, clean and simple, very pleasing to the eye.
Nicely detailed and even elevator hinge work. It's the little things that make a difference.
I will have an all yellow airplane one day. Well, maybe with a bit of blue trim.
Please, what is the engine and what is the prop?
Charles
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........... may be just a bit quieter on the ground with the holes down.
Good point Jim, diffusers are louder than expansion mufflers.
I have always wondered why tongue mufflers don't have drilled ends with holes facing outwards?
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I have always wondered why tongue mufflers don't have drilled ends with holes facing outwards?
Some have been made that do just that. It does not make much difference. What does make a difference in noise and power reduction is the total area of the holes in that tongue muffler.
Keith
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Charles; The engine is a Larry Foster modified Fox 35, and the prop is an APC 10-5. It really is a fine flying plane if kept light.
I believe it was Bob Paul that made mufflers for the Super TIgre 46 that had really cool looking holes in the end of the muffler. Not sure how quiet they were but they sure looked neat.
One thing I learned is that those holes can get plugged up with carbon and it will make you scratch your head as to why your plane is now using way less fuel, not near as loud, and quits everytime you level off after the outside loops. Should have known when Elwyn was taking pictures and told me how quiet my Fox was. Ding ding ding. That was in my original Nobler.
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The only plane that I have with an upright engine mount is a Smoothie, and after 150 flights with the tongue muffler holes pointed down, the outboard flap became oil soaked and had to be replaced. After that, I reversed the muffler, now the only adversed affects are a few guys that launch my plane complain about the exhaust in their face. Seems like a good trade off if you ask me.
Don
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I know Don; Doesn't everybody know that a good castor bath is good for your complection? Sheesh!
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Charles
I just made the tongue muffler for the Greenhead 35 in time for the Fly-A-Thon and it worked OK. I had the same questions you did and chose keeping the exhaust off the launcher and plane as the priority. Guessed that the exhaust exiting up or down (or inboard/outboard on a profile) wouldn't matter in terms of noise and had the gasses exhaust out the edge via a single hole. The plane came in a lot less oily than normal, and was definitely quieter.
Ara
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3:00 and I have to walk my wife's dog. Can you believe it?
Just viewed this Thread agan, it's been a while.
Thanks for the replies.
Don, last thing I need to do is replace an outboard flap. Spent fuel in a face could be a good thing. LL~
Jim, you mentioned the APC 10-5. I think I'll give that a try on my FOX 35. Thanks for that tip.
Ara, Wow! What a great muffler, it's well made and it's going no place. I believe I see tooling there. I don't have the means/equipment to produce a quality muffler of that standard.
Scott B. Riese makes really nice tongue mufflers, and this reminds me, I have to measure a model for one.
Scott makes them look like chrome! My Flite Streak would look terrible without his muffler. Makes the whole model!! Same with the Mig-3, another Scott B. Riese muffler.
Thanks for the replies.
Charles
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I doug deep through the "tongue muffler" Threads.
Charles
I hope 'Doug' didn't mind! ;D
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I hope 'Doug' didn't mind! ;D
Chris,
You told me it was spelled that way.
I believe I will point the holes up away from the fuselage on the P-40.
Charles