ORIGINAL: gkamysz
Andy that's interesting to hear. Yes, I agree that single component fuel won't work unless we have crankcase oil. Yes, cetane rating of BioFUEL is high. But CN alone doesn't make for a good model fuel. We also need low autoignition temp. Biodiesel's AI temp is much higher than petroleum products.
Why is raising the CN by adding ether any different than cetane boosters? I have the same problems with ether in four stroke engines as I do with excessive cetane boosters.
The connecting rod big end is constantly trying to shear the oil because of the surface velocity which builds the wedge that oil lubrication relies on. The piston pin end has low surface velocities and the oil gets squeezed out.
Greg,
Recent work has produced BioFuel with much higher viscosity but still tests out as good fuel. Two test are used. One is to mix a quantity of 50/50 fuel and water and give a good shake. The water must settle out in ten minutes to a crystal clear colourless phase with no soapy middle layer. The other test is to add some fuel to methanol and shake. The oil must be totally soluble in the methanol giving you a crystal clear, colourless solution. All my recent batches pass these two tests with flying colours.
The low viscosity fuels are made from coconut and olive oil. The higher viscosity from corn, peanut, soy and canola. Don't know why this works out that way.
Postings on this can be seen here.
http://biodiesel.infopop.cc/eve/foru...771#5691026771
So, in the end, I may be able to run B100 fuel in a gas to diesel conversion after all.
On Norvels ONLY, adding just IGNITION IMPROVER always requires you to increase the compression to start. This is due to a cold cylinder. Using 40% ether ON NORVELS, for some reason, you DO NOT have to increase the CR to start. This characteristic works toward also not having to have a different CR for idle compared to full bore. Don't know why this is so, ON NORVELS ONLY. I suspect that it's the hard anodized cylinder. Anodizing is electrically insulating, maybe its also thermally insulating.
Biodiesel has a higher FLASH POINT than kerosene but much searching before and just now and I can't find any references to the AUTO IGNITION temperature of BioDiesel.
Meanwhile, I found a site that gives the best tutorial on diesel combustion and diesel engines I've ever seen.
http://www.biofuels.coop/pdfs/6_tech.pdf
Have given up on trying to make a bearing supported rod for small engines. So the Tanaka will be our test bed for a one component fuel.
Merugo,
From what I can make out, you are saying that as long as there is water in the pressure cooker, this will limit the temperature. So are you suggesting that oil, in place of the water be used and that this may allow the pressure cooker to work in making a better BioOil?