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Old 04-26-2012, 12:09 PM   #114 (permalink)
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You've got to be kidding.
Originally Posted by asimmons04 View Post
EFI engines actually probably handle SLIGHT mixtures even better due to the fact they can sense knock, rich/lean mixtures in exhaust, and can adjust fuel input, as well as ignition timing and in newer cars even intake/exhaust valve timing.
Do you know the difference between octane and cetane? Why don't you go look that up.
Originally Posted by asimmons04 View Post
NOW, I know you guys dont know me but I'm going to put your mind at ease before I go into some detail. I have a degree in automotive machining. My knowledge, what little I have, seems to fill a hole in the wealth of information you guys have. Your all actually right.
Could have fooled me.
Originally Posted by asimmons04 View Post
Diesel actually, if you wanted to compare apples to apples, has MORE detonation resistance, which in gas, is rated by Octane level. So yes, it would in theory RAISE your octane level. If diesel had a "low octane" rating, per say, they would not be able to run 14:1 or higher compression. YES, Diesel engines are compression ignition engines. But the fuel allows for it, producing more torque when its all said and done... What do you do when you build a race engine with 12:1 compression? You need a fuel that will NOT burst into flames too soon at that pressure, so you go HIGHER burn resistance, be it race gas (110 octane?) or Methane, or...Ethanol based fuel. E85 actually is about 110 Octane... but only a car designed to be able to adjust valve timing, and advance ignition timing far enough, can actually run it (flex fuel cars) which brings me to your diesel theory...
Do you have any idea how a compression ignition engine works? Diesel engines only inject fuel directly into the combustion chamber at TDC after the compression stroke precisely because the fuel has a low octane. Diesel has an octane number of ~20 depending on where you buy it. It is very prone detonation. Don't believe me? Look it up.
Originally Posted by asimmons04 View Post
ANYWAYS I am just adding to what you guys have already stated. Your all pretty awesome. And any google search telling you Diesel is more prone to detonation is an idiot. Pour gas on something, and throw a match. Do the same with diesel. See the difference. LOL I could get into the actual specifics of how diesel actually has a higher burn resistance "octane", but thats not as fun as burning stuff.
Detonation due to compression and flammability are 2 very different things. I'm surprised you don't know that.
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