stunthanger.com
Speed,Combat,Scale,Racing => Combat => Topic started by: dave siegler on October 09, 2017, 02:48:59 PM
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I know this is sore subject.
Our local club field requires use of a reasonable muffler on most days.
I can get a lot more practice and test time if I use a muffler. This will be on a Speed limit, fast sized foamie, with a 25 or and F2d With a a 25.
No landing gear or place to put it.
I know I will have to add tail weight.
How Do I protect the muffler from tearing up the airplane every landing?
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Use a tongue muffler and land inverted.
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I was going to say flip the motor over to the inboard side - muffler up.
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Use a K&B Green Head .35 or .19.
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Use a K&B Green Head .35 or .19.
Hey Bobsrc, a K&B Greenhead .23. .29 or .32 would also work nicely (the .09 is a little too small for this application). D>K H^^
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Here is what I did to my Sweet Sweep so I could fly by my self using a muffled engine.
The aluminum is long enough to clear the prop and matching piece top side under engine lugs.
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Typical combat plane with short nose and 25 engine does not relate well with a factory standard muffler
But maybe training with RST type slow combat plane where a 2020 OS muffler fits...do not know form OP question
Tongue is good compromise... combat engine max air flow...open all the holes a lot I would think
Simple music wire skid to keep Chip muffler out of the grass should not add too much nose weight
Just random thoughts
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Dave ,
Now that Autumn rains have started and flying circles are much softer than mid- summer a tongue muffler works well on a F2D plane . Keep the grass a bit long and your props and muffler will thank you .
Brad LaPointe
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I made an adaptor to allow the tongue muffler to be parallel to the cylinder.
Crude but effective.
Made from alum. angle stock.
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Howard, that looks great,
I see the aluminum angle.
what does the underside look like?
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Dave
Simple angle
Friend of mine welded it for me
Maybe could be JB welded
Design could be improved but was a first start.
Howard
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On the OS engines the stock 2030 muffler works pretty well. I've done it just moving the pushrod down a notch and adding a wrap of plumbing solder around the end of the boom. That probably wouldn't work on and F2D. The OS engines actually seem to run better with the muffler but the weigh is a bit much for competition against flyers not using a muffler.
A friend of mine adapted it by cutting off the muffler mount and refitting it so it pressed into the muffler. He used a couple of small coil springs wrapped around the muffler with grooves in the fins and sealed it in place with hi temp silicone glue. That tucks the muffler up near the wing and doesn't trip the plane up on landings.
The appropriate Macs tuned mufflers work too. If somebody asked nice they could probably bend a few to make the barrel parallel to the shaft.
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I weighed the muffler and adapter unit and it came in at:
.5 oz. or
14 gm.
Howard
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I know this is sore subject.
Our local club field requires use of a reasonable muffler on most days.
I can get a lot more practice and test time if I use a muffler. This will be on a Speed limit, fast sized foamie, with a 25 or and F2d With a a 25.
No landing gear or place to put it.
I know I will have to add tail weight.
Dave,
I had a short tongue muffler made for Os Fp25, by Byron Barker. Never had a problem with it on landing in the grass. Byron is gone now, so I talked to Jim Lee last summer. He said he can make them for me for my FP40s that I am using now.
Mike Stinson
How Do I protect the muffler from tearing up the airplane every landing?
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Here is what I did to my Sweet Sweep so I could fly by my self using a muffled engine.
The aluminum is long enough to clear the prop and matching piece top side under engine lugs.
This is a good solution. The wheel will slow the plane down & allow it to comply with the speed limit while carrying more horsepower.