Quote:
Originally Posted by vteco
I have a 6 hp listeroid diesel one lung generator...objectionable to run in close quarters.
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As these engines are
fixed rpm; Quarter Wave and
Helmholtz Resonators are an effective means of making them less objectionable.
They work on both the exhaust and the intake:
- NB that as there is no exhaust flow in a Quarter Wave Generator they stay cool enough to use an adjustable O-ring sealed piston in the pipe.
- Helmholtz Resonators are OEM in the intakes of a good number of cars.
- NB that more than one Resonator is practicle.
- Rounding the corners of the T-junction for a QWR will increase the effective frequency range.
But as there is a LOT of noise from the many cooling fins of an aircooled engine a Helmholtz designed enclosure seems best:
Then there's always the old trick of exhausting 2 or 3 inches below the waterline on a boat.
(For ultimate efficiency: )
- You want a Tuned Length Exhaust that 'empties' into a Pressure Wave Termination Box (David Vizard), before any muffling.
- Similar for the intake, but also with properly designed Bell Mouths wherever there's a major change in tract volume like the filter box.
- There are calculators online for the tuned length and I've started various threads here on the other stuff mentioned.
- NB the surprising difference Bell Mouths make to intake efficiency once the throttle valve is close to fully open.
There's also all that 'wast' heat one could put to good use on a boat.