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kevthehover
6-Oct-09, 10:25 AM
Hi,

Can anyone suggest a silencer baffle for the 35Hp Briggs & Stratton engine apart from the B&S baffle itself a Micro engine silencer is to big to fit into the Osprey 1 so im looking for something i can hide away any suggestions would be appreciated. I currently have this set up in the pic but it restricts the airflow any ideas?
4157


Kindest regards

Kev

Keith Oakley
6-Oct-09, 12:15 PM
The Citroen C1 car silencer will reduce the engine noise level to an excellent 68dba at 25metres - way below your fan noise. It's mostly stainless steel and has entry and exit at same end. However its too big to fit inside the lift air box but it will fit very neatly along the outside back wall of the airbox, under the rudders. You don't really want a big silencer inside the airbox anyway, the air turbulence it will cause will reduce your lift airflow.
Keith

kevthehover
6-Oct-09, 04:05 PM
Thanks Kieth all ordered and i shall have it in by the weekend hope this stop all the noise going to pipe the outlet through the plenium hope that will be ok?

Thank you

Kev

Keith Oakley
6-Oct-09, 05:37 PM
Opinions vary on piping the exhaust into the plenum. Over the years I have personally seen several fires and small explosions under the craft as a result. You don't need to pipe this particular exhaust into the plenum just to reduce noise. I've measured this exhaust outlet considerably below the fan (around 10dba) so piping it into the plenum won't make any difference to the overall noise in your case. When you get the exhaust you'll see that if you mount the oval silencer 'vertically' the in and out pipes will fairly easily fit with one going through the hull back wall and the other exhausting to air. You need to check the regs about wether the silencer can overhang the hull though- the Osprey1 has a vertical back wall whereas my F35 has a sloping wall which means the silencer can be within the hull perimeter (just)
Keith