In article ,
dazed and confuzzed wrote:

You can also burn a mix in the summertime. My Dodge/Cummins likes a
70/30 mix of peanut oil (used)/diesel until the temp drops below 40 deg F.


then it's straight diesel/biodiesel.

Be careful what additives you use if using biodiesel in the winter. Some
meant for petrodiesel don't work well with biodiesel.

Dave Cannell wrote:

For burning cooking oil in your diesel engine try the following sites.

http://www.greasel.com
http://www.greascar.com
http://www.greasecar.com

I suspect anything that runs straight cooking oil will need duplicate fuel
systems so they can start and finish on diesel rather than cooking oil.
Bio-diesel is another story though, I think that can be run straight.

You can also burn a mix in the summertime. My Dodge/Cummins likes a
70/30 mix of peanut oil (used)/diesel until the temp drops below 40 deg
F. peanut oil? upscale Chinese restaurant? sweet.

hey, could this end up being some kind of a contest? "motor the length
of the Mississippi river on fuel from cat fish fries" ????
Maybe Capt. D's or Long John Silver's could sponsor a boat???
anybody got a boat named "Grease Fire"?

Max,
I am a marine engineer and worked on big motor ships much of my career.
The simple fact is that this would not be practical for anything less
than a megayacht with a large hired crew.

Any heavy fuel equipped ship not only has heating coils in the tank to
warn the fuel so it softens enough to be pumped out, but then also has
specialized fuel heaters that are used underway to heat the residual
(what is left over when everything they actually want is gone) fuel oil
(the current name for bunker oil) fuel to near 300F for either diesel
injection systems or atomizing burners in a stream generator (boiler).
In the engine spaces of a motor ship that runs heavy fuel is also a set
of crud catchers, strainers, filters and even centrifuges to get the
fuel clean enough to prevent damage to the injection equipment.

There is also a "burn time" issue with residual fuel oils. Back when
big engines (greater the 18'(.5m) bore were low speed engines they could
get away with it, but as they are now medium speed engines (this is
piston speed not crank speed) they are now haveing trouble there. The
story was that the low burn speed could cause conditions where the fuel
would squirt all the way across the bore to stick on the far side
without burning at all. New injection hardware has cured some of this,
but that new technology is also less crud tolerant.

Out here on the great lakes (where I last worked) they don't even bother
with trying to use heavy fuel in diesels, but a long run here is three days.

Matt Colie
Lifelong Waterman, Licensed Mariner and Perpetual Sailor

wrote:
Howdy group,
All the yachtsmen I know who run a diesel use only 'diesel fuel', which
is light and expensive. However, in the merchant navy we use bunker
fuel whenever we're going to be running the engine for a long time,
without varying RPM.

It's thicker than molasses at room temperature, but when suitably
heated, it runs enough to be used in a diesel engine. It also costs a
fraction of regular 'diesel fuel' (aka "Champagne"). The engine is
started with light diesel fuel until it's running hot enough, then the
fuel mixture is gradually changed over to bunker. If the ship comes to
manoeuvering conditions, then the mixture is switched back to light
fuel. They always go back to light fuel before shutting off the engine,
too, to 'clean' the insides for the next start-up.

Now I'm wondering why we don't do this in cruising yachts, where the
engine is running constantly for days, especially considering the fuel
prices of late. All one would need is a heated holding tank and a way
of adjusting the fuel mixture. Then again, I'm not a marine engineer.
Am I missing something?

Regards,
-Max

Re. biodiesel - there's 'biodiesel' and 'straight vegetable oil' (SVO).
biodiesel is an EPA-certified fuel that can run in an unmodified
diesel engine
http://www.biodiesel.org/resources/b...s/default.shtm. SVO
is the 'fish shack' fry oil that, when filtered, can be used in a
modified setup (heated tank, some extra fuel lines / switches).
Apparently one can brew his own biodiesel from SVO, but i imagine this
is a PITA.

Marine applications seem to be a great place for biodiesel: it's
limited availability is countered by the fact that a boat takes on a
larger amount of fuel less frequently, and that you can mix biodiesel
with petrodiesel in any proportion.

Thanks for all the responses. I asked some of the marine engineering
students at school, concurrently, and they replied more or less the
same thing: way too much trouble. Where you're burning LOTS of fuel on
long runs with a good maintenance schedule and a sizeable crew, it's
worth using bunker. Otherwise, it's way too much of a headache.

Looks like SVO or biodiesel would be a better alternative to straight
diesel.

-m