Hybrid Car – More Fun with Less Gas

noise of low speed diesel?

register ::  Login Password  :: Lost Password?
Posted by soundhaspriority on April 23, 2006, 1:17 am

How does the noise of a low speed diesel compare to a  DEK 3600 rpm "silent
enclosed aircooled"?  I ask for the comparison because I have one of these
silent units, rated for standby use. I'm considering buying a 1200 rpm one
lung -- suggestions? but these don't come with silent cabinets at any
reasonable cost.

BTW, I've had my DEK for about a year. While I can't provide hour figures,
it uses no significant lub, has no leaks, and the fit-finish is really first
class. After a couple minutes, the exhaust is almost invisible. If I hold my
palm to it, there is no deposit.

The DEK really is quiet, after I took the advice of one seller and attached
a 5' stainless flex tube to the exhaust. The manufacturer brags about extra
moly in the crank, VW valve seals, while apologizing for the
ever-so-slightly crudeness of appearance compared to, say, a Yamaha or
Honda. They don't powder-coat; it's ordinary, slightly soft paint. The fuel
tank shutoff is in an inconvenient position. But the internal layout, fit,
and internal parts finish is very, very good. And the Japanese don't make a
silent diesel that weights less than 400 lbs anyway.

The DEK was an eye-opener for me. It says, with respect to China, "Be
afraid. Be very afraid."  But at the current artificial exchange rate, the
damn thing cost me $10. It's so cheap, I bought another one recently for

But these are, of course, standby models. What could I get that would chug
along at 1200 rpm, or maybe 1800, without requiring the incredible effort
some of you guys put into baffling? Should I go water-cooled just for the

Posted by JoeSP on April 23, 2006, 1:09 pm

Just curious.  Are there no cheaper power options available for you?

Posted by Bruce in Alaska on April 23, 2006, 5:43 pm

snipped for brevity

Most of the low Rpm diesels, make more mechanical noise than exhaust
noise, when fitted with just about any decent baffeled muffler.
I own a 3Kw Fairbanks/Morse 45B that turns at 1200 Rpm with a 3:1
pully upspeed to a 3600Rpm Dayton Gensend. at 10 feet the exhaust noise
is a simple "Putt Putt putt" of very low order, and with the door closed
to the powerhouse, the mechanical noise is fairly well isolated.
I also have a 3.0DJA Onan Air Cooled that  makes about twice as much
noise, but at 30 feet, it isn't a big deal and inside the cabin it is
very hard to tell if it is even running. Again, the mechanical noise is
much more significant than the exhaust noise.  My twin 3.0MDJA Onan
water cooled gensets are very similar to the Fairbanks/Morse in
operating noise. Air cooling does make significantly more noise than
water cooling.

Bruce in alaska
add a <2> before @

This Thread
Bookmark this thread:
  • Subject
  • Author
  • Date
please rate this thread