I was wondering if Diesel fuel has an octane rating. I was daydreaming and I thought that if someone had a 14:1 compression race motor and they wanted to run it on the street, would it be possible to run a second fuel tank with diesel. Even though the compression is low by diesel standards I figure the spark plug would take care of that. I'm sure I am not the first person to think of this, so tell me why it wouldn't work.
I believe I've seen a '40 something' rating on the pumps...but as Dwayne pointed out, that's probably 'cetane'. o No: I think most diesels run 22:1 or so. At 14:1 - Alcohol might be a more attractive alternative fuel...or propane/CNG.
Turbo diesels run as low as 18:1, but without the proper diesel fuel control it will either not work or it will blow itself into little pieces. Do a bit of checking on how a diesel injection pump works.
I read up on diesel engines at www.howstuffworks.com and I figure the extra oil in the fuel would clog the spark plug and prevent it from running very long.
You are correct in saying it is cetane rating. If my memory serves correct, it has something to do with the eveness of the burn. If you are look at an alternative fuel, Diesel would not be it in a spark burn engine. It uses the engine compression to ignite the air/fuel charge. A diesel engine is in fact more like an air pump than what a gas engine is. As far as the other alternatives, alcohol requires more fuel for the same amount of power. That is why you see special built carbs for alcohol drag cars, plus it is very hard on any parts that are rubber. And propane also has its very different intake/induction system. Not saying that it cannot be done, but I think that you have to research the gas/propane combination pretty hard.
Being in the diesel fuel injection and engine business for over 22 years, and 32 years wrenching, I can prolly answer some questions... US cetane # is mandatory 40, Europe uses 50-52 US quality of diesel fuel sucks... I'm building 4 Stanadyne injection pumps now to run on 100% bio-diesel We also build special pumps for JP4 and Jet-A Jim
I think cetane has to do with volatility, almost the opposite of octane. Apparantly, US fuel has a low volatility of about 40 which means it has poor cold start qualities and doesn't burn as cleanly as the European diesel. I'm still trying to figure out why diesels only make power at super low rpm and don't seem to rev up very high.
I believe it has to do with how slowly the fuel burns. The fuel won't burn fast enough to turn the motor any faster.
