Yair . . . does anybody on here remember when part of the mystique of Cats . . . apart from the fact that they started with a pilot (pony) motor was that they ran on "black fuel" instead of distillate? The stuff over here in Australia was much more volatile than distillate and for lighting fires was more like petrol (gasoline). I have forgotten the details but the stuff was sold under a different excise regime to other fuel and was slightly cheaper. When it was phased out and we had to run the nines on distillate we reckoned they lost a bit of grunt . . . it must have been in 1965 Cheers.
The only black fuel I remember NSFO (Navy Standard Fuel Oil) also known as Bunker C it was a grade 8 or 9 fuel oil it had a very high BTU content much more than distillate and had to be heated to flow. Large marine diesels used it and may still if the EPA hasn't outlawed it all together and smelled worse than gear 90
Scrub Puller - The diesel fuel grades were listed differently in Australia as compared to the U.S., so this can cause confusion. I think this came about because our fuels were produced using British terminology and grade identification. Diesel fuel in the U.S. had no set refining standard until 1931, up to which time, anything that looked black and oily was termed "diesel oil". In 1931, the diesel refining standard was set by the ASTM standard, D975. The U.S. used up to 5 different grades of diesel, which included Winter and Summer grades, or cold climate and hot climate grades. I believe the U.S also defined diesel fuels by sulphur (sulfur) levels. We in Australia only had one diesel grade for the entire country - "distillate" - although I understand the Australian refineries would blend diesel to match the areas where it was sold. For example, diesel going to the Australian Alpine region would be produced with lower levels of waxes to prevent gelling. The U.S. produced around 6 grades of "Fuel Oil" (or maybe up to 9 grades, if stinkycats numbers are any indication), which were used to power a lot of different type of engines. The lowest grade of fuel oil needed to be heated to be able to be pumped through an engine. It was usually used to fuel low speed marine engines. There was a second grade of "diesel" available here, called "No. 2 Fuel Oil". This was a less-refined grade of diesel-type fuel with a very dark appearance. This dark appearance was due to oily constituents that weren't removed in the refining process. The No. 2 Fuel Oil was only available in 44 Imp gallon (55 U.S. gall) drums. Cat made a big thing in the period up to the early 1970's about Cats being able to burn "lower-priced No. 2 Fuel Oil" very satisfactorily, because of the Cat precombustion chamber fuel system. This was designed to be a good selling point - but in reality, few people bothered with No. 2 Fuel Oil - because the pricing difference wasn't substantial enough to warrant it. Fuel filters had to be changed more frequently when using No. 2 Fuel Oil. The fact that No. 2 Fuel Oil was only available in drums was a PIA, too. Most contractors used bulk fuel by the late 1940's/early 1950's - and oil companies would supply you with a new 500 gallon or 1000 gallon, 4 wheel fuel trailer tanker for free, when you contracted to use their fuel brand, to encourage you to use bulk fuel. The companies didn't want to handle large numbers of drums if they could avoid it. Bulk diesel fuel was delivered free to your bulk fuel tanker trailer within about 80kms of a fuel depot. The brother and I tried some of the No. 2 Fuel Oil for a period in the D6C's. It was O.K., but the hassle of handling drums when we already used bulk fuel, was a complete PIA. The slightly lower cost hardly justified the use of it. By about the late 1960's, the No. 2 Fuel Oil was longer produced, as demand for it had dropped to a trickle. The era of old slow RPM engines with large injector orifices and the ability to burn unrefined diesel fuels was essentially over.
Yair . . . Gotcha OzDozer . . .you're a bloody enyclopaedia mate. It would have been No.2 Fuel oil we used in Cats and a blacker grade we rightly or wrongly called "crude oil" in the Bulldog and the single cylinder Fowlers. All our fuel was prepositioned in drum dumps and pumped into the thousand gallon tankers with horrible Coopers engined pumps. We worked in remote country and in a F600 or 190 Inter. that delivered the fuel we could be eight or ten hours from town . . . if they made it through the sand. Cheers.