3500w propane generator

 3500W PROPANE GENERATOR
* 3,500W surge, 2,800W rated
* 6.5 HP OHV engine
* Automatic fuel shut-off safety valve
* Produces 27.5A @ 120V
* 2 AC 120V outlets
* 1 AC 120V/240 twist lock outlet
* 1 12V outlet
* Runs 20 hrs @ 1/2 load on 5 gal/20 lbs. of fuel
* Propane fuel hose included
* Operating noise 68 dB
* Propane fuel provides cleaner emissions
and longer run time
Wt. 105.6 lbs.
8190365 SPECIAL  $599.99

Princess Auto has this generator.  The propane seems good, Price not
bad,
Same one as advertised here;

http://www.heartlandamerica.com/browse/item.asp?product500watt-propane-generator&PINS714&GUID=&DL=IVU4#

for back-up home power.

Propane, winter starting?

anybody using one?

opinions,

Thanks............Rob

 

Never used one but propane prices have gone way up around here -- still
cheaper than gas though.

Along the same lines, have any of you ever build a custom exaust for one
of these?  Or similar generators?  The 68 DB is pretty dang loud.  My
buddy has a pipe bender and I always wondered just how much you could
gain by fitting like a car muffler and longer exaust onto a generator
like this one.

Or is it really the sound of the engine itself that makes most of the
noise?

 
I once attached a muffler for a 2.2 Plymouth Reliant to the stock tubular
muffler on a 5 HP Briggs and it quieted most of the noise of the engine with
the exception of the valve noise which really wasn't that bad.

 The more muffler, the more back pressure, less fuel economy. I think
the idea is to get a tuned pipe like an organ pipe... 1/4 wavelength
open at one end.... the 'bang' propagates down the pipe at the speed
of sound... 1120 ft/sec and you want a low pressure antinode at the
exhaust port when the valve opens to suck out the exhaust. 3600 rpm is
60 rps and 30 'bangs per sec', 33ms per bang. So over 33ft wavelength,
1/4 wavelength would be about 8 or 9 ft. I'd make it slide like a
trombone so you could tune it to min fuel flow at running speed. Might
have a distinctive resonance at the tuned point.

 

   Not necessarily true.  Back pressure depends on the internal design of the
muffler.  Everything else being equal, if you simply scale a muffler up, it will
allow more flow and will have LESS backpressure compared to a smaller version of
the same muffler.


Vaughn