Fuel dilution

Gday
1hz toyota

Gday Pete
Ill go with your dilution s mine was less than yours. Thanks for the percentage number.
Murray

NAH...100 mil of 2 stroke will do sweet FA....chuck in a litre of it ...wont do any harm at all...PLUS...make sure it is mineral 2 stroke that is used in mowers,brushcutters,chainsaws etc...NOT OUTBOURD !!!..Anyhow ...if you have an old 1hz ...you probably should have been using 2 stroke anyway...just to give your injector pump some lubrication..at the rate of 4mil per litre. I have been using it in my diesel patrol now for more than 2 years...and I reckon it has saved me a pump rebuild already...after one at 100,000k due to wear from no lubrication because of the fuel nowadays

HTH.

Cheers Keith

Th counter the petrol I would also ADD air cooled mineral 2 stroke to the mix.
Up to a litre with that amount of petrol would be quite ok as it adds lubrication and also negates the octane effect of the petrol fuel trying to explode in a diesel.

Techedge
A CRD engine's high pressure pump ie, the actual injection pressure device, develops at least 10 times the pressure a conventional diesel develops in the injector lines. If chipped that pressure is/can be, 15 to 20 times higher.
The fact the pump is still a mechanical device and using a piston which is being displaced by a cam arrangement, those contact surfaces run at higher mechanical and sliding forces than the conventional diesel.
Having as much lubricity will definitely increase it's life.
The lubricity may also assist the life of injectors too.

A conventional diesel MAY suffer no appreciable ill effects, perhaps a shorter injector pump life judged over the normal life of a pump, BUT the CRD single sumps which supplies all fuel to all cylinders does work hard and if there isn't enough lube between the vital surfaces the metallic surfaces may/can suddenly be destroyed.
If there is scuffing of those parts, they then shed fine metallic particles which have only one way to go, THROUGH the common rail and it's pressure relief valve and also through highly precise injectors too.

Injectors of such fine tolerances do not take kindly to anything other than fuel going through them. Therefore they quickly deteriorate or suddenly fail.

If 2 stroke can provide the vital/essential lubricity, then it isn't such a bad idea to add a bit. Insurance is a nice thing to have, it is thought 2 stroke gives a degree of insurance.
If the pump and injectors last longer than one which doesn't have 2 stroke added, then it works. It is a long time in the test phase for 2 stroke use in normal CRD so a definitive result isn't readily at hand.

Hi Ross,

thanks for your explanation, much appreciated. Yes, it was my understanding that, even on a CRD, adding extra lubrication, in the form of an appropriate quantity of something like mineral two-stroke oil, could overcome the accidentally-added petrol's almost zero lubrication, such that the mixture was as least as "slippery" as straight diesel.

However, members "John", "Bushranger1" and "TourBoy" all say words to the effect: "but not on a CRD"!

So, I'm not sure we've really come to a consensus on CRD and petrol dilution solutions? But, back to practicality rather than theory, there are some questions, should someone dilute their diesel with "petrol" - and I appreciate that these are not trivial questions, nor easy to answer:

a. Is E10 (with the possibility of a small percentage of water being mixed in with the percentage of methanol in the petrol) worse, or just as bad? What about Opal fuel?

b. Is there a recommended lubricant that's better than (or as good as) mineral two-stroke oil? - ie. will a quantity of mineral/synthetic engine oil do much the same job? What about (say) cooking oils like canola? I ask this because, although it's less likely that dilution will occur at other than a service station close to "civilisation", I'm sure this could happen somewhere else like the fuel dump on the CSR near well 23.

c. As well as the very high pressure CRD pumps, some CRDs use fairly sophisticated injectors (ie. not all CRDs have the same injector technology) - will the "added oil fix" work for these injectors too?

Thanks, Peter GARGANO.

Fuel pressure in a CRD can be as high as 26,000lb and if you crack a joint when pressured and it hits you it can kill you.

The best thing to do if you put petrol in it is DONT START IT Get it towed and drain it fully before turning the motor over.

Have heard of bills of $9000 for running it for a short time with petrol in it.

Tom, thanks for the info.

WRT things to worry about your vehicle (apart from the largest risk, being the driver behind the wheel of the next vehicle) would surely be something as simple as a tyre exploding while you are pumping it up, or other more common things than your CRD injector-plumbing randomly exploding. Yes?

I'm not one who takes the FUD (Fear, Uncertainty and Doubt) factor too seriously - and that's precisely why I'm after more info/facts on the risks peculiar to this CRD fuel dilution issue.

Methanol has less calorific energy per volume than petrol, but if petrol AND methanol, ie, E10 is in diesel, the situation becomes worse from the corrosion and dissolved water aspect. Injectors don't like water.
You may get away with it initially, but unseen damage will almost certainly shorten the life of fuel systems components.

I agree Ross, but I made a mistake in saying E10 has Methanol (CH3-OH), it's actually Ethanol (C2H6-OH). My apologies.

The energy content of hydrocarbons primarily depends on how many hydrogen-carbon (H-C) bonds there are. Alcohols have an extra oxygen atom and therefore fewer H-C bonds. And it's also the -OH bond that allows alcohols to combine with water (H2O, or H-OH).

As you note, the calorific value of fuels is often measured per-unit-volume (as a fuel pumps delivers a certain volume, not a weight) but if it was purchased per kg then more people would buy LPG (primarily C3H8) because it has an even higher calorific value per kg than unleaded (primarily C8H18) or diesel (primarily C12H23), and of course Ethanol (C2H6-OH).

Peter GARGANO (BSc., Dip. Ed.)