Performance difference different Diesel fuels?
 

Hi All:

Is there any reference that would compare the power outputs of various Diesel fuel blends? If so, we’re may I find them?

Tia,

Franchi

Not that I've ever seen. Diesels don't respond that way. Your classic 2.5cc diesel will run best on what's called "Olly Brew". (eg PAW. Super Tigre, MVVS, OT, CS etc. )

The name comes from the Oliver Tiger, but it gives good results across all similar Twin Bearing diesels.

It consists of: 20% Castor Oil, 30% Di-Ethyl Ether, and 50% Kerosene. A variation for plain bearing engines might be 25% Castor, 30% Ether, and 45% Kerosene. The rule of thumb is that if you increase or decrease the oil you make up the difference with the Kero.

The Oliver Family expressed the volume of Ignition Improver that needed to be added as a ratio compared with the volume of mixed fuel. For example 15ml of Diesel Ignition Improver (DII) per Lire of fuel. This is a reflection of the practice of mixing a base fuel first, and adding the DII to suit the day. The volume of DII also depends on the quality (Cetane value) of the Kerosene. In Australia, we have good quality Kerosene, and I find that 14 to 15 ml of Amsoil Cetane Improver in 1 Litre of mixed Olly Brew works just fine for sports flying. I have access to Iso-Propyl Nitrate (IPN) and have found that it's not superior to the Amsoil. Amyl Nitrate (in the form of Poppers) is also again legally available but doesn't seem to have any advantage. Same with 2-EHN.

Hello Gaz:

Thanks for the reply!

A friend suggested that I do this test but I could not justify the time that would be needed.

Franchi

I think posting your rpm figures for a few props will give others a chance to compare notes? I got an engine from a friend that came with an rpm figure for a given fuel and prop. I mixed my own fuel to my own specs and got identical rpm initially, and better afterward with some engine modifications. So either fuel composition is not dramatically different or power doesn’t vary much from one fuel to another. Diesel fuel is definitely a different animal compared to glow fuel.