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  • August 22, 2017, 10:02:20 PM

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Author Topic: The sound of 4 strokes.  (Read 407 times)

Online Dennis Toth

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The sound of 4 strokes.
« on: July 17, 2017, 08:34:57 PM »
Guys,
Several years ago I flew small and medium size 4 Strokes. I kinda liked the engineer run and won several contests with them. One thing that always bugged me was the sound note of the 4 Strokes. They always sounded flat. Has anyone worked with mufflers designs to get a different sound from them?

Best,   Dennis


Online Dennis Toth

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Re: The sound of 4 strokes.
« Reply #1 on: July 26, 2017, 05:39:01 PM »
So everyone is happy with the sound? I've heard it described as a Pig farting into a barrel. I did see some information on changing the exhaust note by using a disc type diffuser, this might be a lot of work but maybe some creative muffler internals would work.

Best,        DennisT

Offline Chris Wilson

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Re: The sound of 4 strokes.
« Reply #2 on: July 26, 2017, 05:43:12 PM »
Bolt another cylinder on at 45 degrees for that American sound!
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Online Dane Martin

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Re: The sound of 4 strokes.
« Reply #3 on: July 26, 2017, 06:48:16 PM »
So everyone is happy with the sound? I've heard it described as a Pig farting into a barrel. I did see some information on changing the exhaust note by using a disc type diffuser, this might be a lot of work but maybe some creative muffler internals would work.

Best,        DennisT

I grew up on a feed lot in bakersfield. I like pigs. Lol

Offline Chris Wilson

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Re: The sound of 4 strokes.
« Reply #4 on: July 27, 2017, 07:39:09 PM »
Seriously here, what is with an engine that has the exhaust length about the same as the intake?
Run a decent length pipe and put a muffler at least 6X the engine capacity on it and see how that goes.
And try and pick up the bass notes with an absorption type muffler.
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Online Dennis Toth

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Re: The sound of 4 strokes.
« Reply #5 on: July 28, 2017, 04:51:53 PM »
Chris,
Interesting idea, so are you suggesting that we us a longer exhaust pipe and something like a glass pack muffler?

Best,     DennisT

Offline Chris Wilson

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Re: The sound of 4 strokes.
« Reply #6 on: July 28, 2017, 05:35:51 PM »
Chris,
Interesting idea, so are you suggesting that we us a longer exhaust pipe and something like a glass pack muffler?

Best,     DennisT
Yes to all except the glass pack as it will get oil soaked eventually.
An interesting idea is to use perforated pipe, glass wrap that section and jam open ended tubing over that.
That way you can simply slide the tubing off to replace the glass packing.
Hope that makes sense.

P.S. thinking about this again, perhaps a simple perforated tube wrapped with glass tape exhaust wrap just wired on may work well enough. All you need would offcuts of alloy pipe and a few inches of tape to test it out.
« Last Edit: July 28, 2017, 08:35:29 PM by Chris Wilson »
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Online Dennis Toth

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Re: The sound of 4 strokes.
« Reply #7 on: July 30, 2017, 07:29:01 PM »
Ok, do you think we could use a tube within a tube (a small one inside a larger one) that would allow a sliding length to tune the note? I'm wondering if the inner tube can be perforated with the end closed then slide the length to get the desired note?

Best,    DennisT

Offline Chris Wilson

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Re: The sound of 4 strokes.
« Reply #8 on: July 30, 2017, 09:37:44 PM »
Ok, do you think we could use a tube within a tube (a small one inside a larger one) that would allow a sliding length to tune the note? I'm wondering if the inner tube can be perforated with the end closed then slide the length to get the desired note?

Best,    DennisT
Like a trombone?
Give it a go!
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Offline Jim Carter

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Re: The sound of 4 strokes.
« Reply #9 on: July 31, 2017, 10:18:29 AM »
I grew up on a feed lot in bakersfield. I like pigs. Lol
:) I like'm too .... boiled, fried, baked, roasted ......  LL~ LL~ LL~

Offline Steve Helmick

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Re: The sound of 4 strokes.
« Reply #10 on: August 11, 2017, 10:29:53 PM »
"Pig farting in a barrel" is a perfect description. Try a megaphone and see how that sounds? I've read of folks running without the muffler, only using the tube between the pig and barrel. They said it didn't sound much louder, but then there's no muffler pressure to the tank, which some said was important.  D>K Steve

 
In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.

In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

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Offline Steve Helmick

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Re: The sound of 4 strokes.
« Reply #11 on: August 11, 2017, 10:33:54 PM »
:) I like'm too .... boiled, fried, baked, roasted ......  LL~ LL~ LL~

SMOKED!!!  y1 Steve
In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.

In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

"Be polite, be professional, but have a plan to kill everybody you meet." General Mattis.


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