22TDI Exhaust Questions

gone7
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22TDI Exhaust Questions

Post by gone7 » April 15th, 2012, 9:36 pm

Bryan,

On your recent 22TDI Explorer project it appears that you've run the engine exhaust into the fan bay. After using the craft in this way for some time now, is this a technique that you would recommend that others do as well? Since this would distribute exhaust around the perimeter of the craft I'm curious if there's been any issues with headaches and such? Do you feel that this technique helps to absorb additional exhaust noise?

Thanks,
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Guy Fichtelman
Sevtec Builder and Pilot since 2001.
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bphillip2
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Re: 22TDI Exhaust Questions

Post by bphillip2 » April 17th, 2012, 11:29 am

The muffler is in fact in the fan bay. I made heat shields for the muffler and piping. The mufflers I use are very compact and available in many alloys such as steel and various stainless materials.The volume of exhaust to air cushion air is perhaps 0.3%. I've never smelled exhaust while operating the craft, except in the shop. I can't imagine this being worse than driving in traffic. This is of course diesel, so no flammable vapor issues exist really. I don't think the gas engines would be an issue either unless you cranked for 10 minutes without it starting. The exhaust note is not discernible.

gone7
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Re: 22TDI Exhaust Questions

Post by gone7 » April 17th, 2012, 7:41 pm

bphillip2 wrote:The exhaust note is not discernible.
Thanks for the info Bryan! So, are you saying that you just can't hear any exhaust noise? I know you'd mentioned once about having a great muffler, but do you think running the exhaust into the fan bay has helped much with the sound factor?
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Guy Fichtelman
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bphillip2
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Re: 22TDI Exhaust Questions

Post by bphillip2 » April 17th, 2012, 10:01 pm

I'm sure it must attenuate it some what. But exhaust noise has never been an issue on craft I've built. I was just looking nice place to stick it.

gone7
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Re: 22TDI Exhaust Questions

Post by gone7 » April 17th, 2012, 11:10 pm

Alright Bryan, I was just curious.

Thanks for the quick reply!
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Guy Fichtelman
Sevtec Builder and Pilot since 2001.
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highlandhovercraft
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Re: 22TDI Exhaust Questions

Post by highlandhovercraft » April 18th, 2012, 11:49 pm

Not the diesel but here is a comparison between a good silencer/muffler and a pair of bad ones. The craft was my surveyor that I recently sold, engine was a 35hp Briggs & Stratton
http://www.youtube.com/watch?v=S82axBrY ... ufHSrB0%3D

sandy
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Re: 22TDI Exhaust Questions

Post by sandy » April 19th, 2012, 4:39 am

good stuff al will bear that in mind when the time comes

WerkSpace
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Re: 22TDI Exhaust Questions

Post by WerkSpace » April 19th, 2012, 7:38 am

highlandhovercraft wrote:Not the diesel but here is a comparison between a good silencer/muffler and a pair of bad ones. The craft was my surveyor that I recently sold, engine was a 35hp Briggs & Stratton
http://www.youtube.com/watch?v=S82axBrY ... ufHSrB0%3D
Thank you for that video. I recently bought a dB meter to put actual numbers to the muffler sound levels. I hope to achieve the same noise reduction as you have just demonstrated. Thanks again.

highlandhovercraft
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Re: 22TDI Exhaust Questions

Post by highlandhovercraft » April 19th, 2012, 7:53 am

The silencer I used was from a Honda Fireblade motor bike. It was the standard silencer as these are available on ebay cheap as they tend to get changed for noisier exhaust :shock:

WerkSpace
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Re: 22TDI Exhaust Questions

Post by WerkSpace » April 19th, 2012, 8:53 am

highlandhovercraft wrote:The silencer I used was from a Honda Fireblade motor bike. It was the standard silencer as these are available on ebay cheap as they tend to get changed for noisier exhaust :shock:
Thanks for the tip, I just bought one from eBay for $45 + $25 shipping. That's a pretty fair price and I'm sure many people will appreciate the quieter noise levels. The only thing left to do, is to find quieter props. The computer industry is making major progress with quiet cooling fans.

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