alternate waste oil fuel

[JohnEd]

I read a long while ago that DD and Cummings would void your engine warranty if you added more than 10% DRAIN OIL to your fuel...by volume.  I gasped at the thought.  Then I reflected on how darn quick of Whit and down right smart those engineers that made all those big bucks and engines that went a million miles must really be.  I have heard little chatter on this subject on this board and I know that a 10% reduction in fuel costs are a matter of concern for "almost" every man and woman in this "room".

One article said that the "cut" fuel would have more than a 10% loss in power and you needed to be able to switch to the straight stuff for the hills only.  One method of mixing the drain oil was to simply add it during the fill.  That precluded your being able to "switch" fuels for hills.  The other method was to have a proportioning  valve that mixed the brew at the inlet to the fuel pump.  That seemed a partial failure as all the fuel passed by the pump isn't burned.  Some, or most, is returned to the tank after cooling the injectors.  So again we get mixed fuel in both tanks.  I pondered the question and concluded the answer was to have two return lines that switched with the source selector.

I didn't imagine all this, did I? 

Help!

John

[HB of CJ]

Nope....you got it right.  During normal power levels in my Cummins CB2, only about 25% of the fuel is burned by the mill....the other 75% is returned to the fuel tank where it came from, since right now my Crown only has one 100 gallon tank.  The circulating fuel lubricates and cools the pump and injectors as the engineers intended.  At full power, the top of a diesel mill can get quite hot.

If your coach has two or more fuel tanks, then the plumbing kinda takes on a life of its own, with all sorts of possiblities. (and goofs)  In my case, the planned electric transfer switch must do several things wired up thru relays such as powering the dedicated individual tank transfer electric fuel pump as well as switching the "to" and "from" fuel lines of the proper (enlarged) diameter.

Some owners wire up such circuits soosss they can (if they have to) transfer the return flow to the tank of their choice.  Sometimes this is done sossss they can physically refuel the coach from only one fuel tank since they have already filled up the other by transfering fuel.  Some airplanes have this ability.  Very dangerous if you are flying if you goof up because they you may just bleed profusely then burn completely.

I do not have the mental ability to do that.  Somewhere along the line of time and space I will goof up and either overfill the wrong tank or worse yet, run a tank complety out of fuel which is a very bad thing with a Cummins engine since the repriming process is a real involved process.  The plan for me is to have one protected rocker switch commanding only one tank at a time for fuel coming and going from the mill.

I just do not know about burning 10% drain oil.  Such oil is very heavy and contains all sorts of stuff and air and water not desirable for an expensive fuel injection pump and injectors.  At the least, such a blend may place your fuel filtures at risk of either wearing out quickly or perhaps clogging trying to do their job.  And if they fail in their job, what will happen over time to your pump and injectors?

You would probably find that your fully warmed up diesel can, if it has too, burn all sorts of oils, including your formentioned drain oil.  In an emergency, I am sure my Cummins could burn all sorts of stuff like kerosine, heating oil, jet fuel and drain oil if properly blended.  I just do not know if I would want to do soosss on a routine basis.  Hopefully others can answer your question better than I. 

[tekebird]

I think you will find such blending of oils really only matters if you run 5 days a weeek 52 weeks a year.

[JohnEd]

Henry,

I did say "I gasped".  And, for all the same reasons as yourself.  Acids are in drain oil that, I thought, would make quick work or at least accelerated wear of a fuel pump. 

I never got where they filtered the stuff before putting it through the pump/fuel filters.

This wasn't presented as a "emergency" measure but as a routine way to conserve fuel/reduce costs.  I am not trying to sell it now and I am only "sorta sure" that I got it straight.

heating oil is diesel fuel and kerosene is diesel without the quart of motor oil (virgin) per ten gallons ratio.  Or so a trucker told me long ago.  JP 4 is diesel but JP5 is diesel with an oxygen releasing element that destroys a diesel engine.  According to an Air Force type.  I don't swear by any of that cause beer was involved.  Beer and fuel don't mix.  At least not well.

Being GREEN though and as cheap as that might imply, I would like to use my drain oil for something other than the trash heap of society or the premature expiration of my engine.

Thanks for your contributions, all of you,

John

[tekebird]

get a home or shop furnace that burns used oil.....generally when you take your oil to a recycling point it gets used for soemthing else so it's not like it is getting put down the storm drain

[TomC]

While this was a practice that was done regularly with big rig trucks, now with the strict emission laws, it is a completely banned practice with the new trucks (the ones with the catalyst/particulate traps).  With our older engines putting a gallon or three in the fuel tank and then topping it off shouldn't hurt-just will create more smoke.  Good Luck, TomC