New to diesel

CosmicDP said:
You are correct that diesel contains a small fraction of paraffin series aliphatic hydrocarbons with n<9, including n-octane although the majority of the aliphatics have between 10 and 19 carbon atoms in the chain. You are also correct that one would not want to significantly increase the number of lighter hydrocarbons such as octane because that would change the bulk chemical properties of the mixture and adversely affect it's performance as a fuel in diesel engines. That doesn't mean a small increase in octane content would not be beneficial for improving cold starting.

Consider the auto ignition temperatures, in other words the temperature at which combustion will occur in the absence of a spark. For number 2 diesel the auto ignition temperature is in the range of 254-285 degrees Celsius whereas the auto ignition temperature for n-octane is 220 degrees Celsius. It's interesting to note that this is lower than that of comparable light aliphatics except for heptane which is marginally lower.

This means the octane will auto ignite at a lower temperature than the majority component hydrocarbons in diesel. Once a non-negligible component of the mixture ignites, the resulting flame front will serve as a catalyst for the ignition of the remaining hydrocarbons rendering their higher auto ignition temperature irrelevant. The reason diesels are hard to start in the cold is because they rely on the auto ignition of the fuel. In principle, by slightly increasing the octane content of the diesel fuel, the engine would cold start easier because you would only have to auto ignite the octane and this exothermic reaction would in turn ignite the rest of the fuel. This is the same principle, although not as effective, as using ether to cold start an engine since diethyl ether auto ignites at 160 degrees Celsius.
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:eek:wned: i think i used it right this time.:hehe:
 
Uh, Cosmic, you used an improper contraction - "it's" instead of "its." :eek:wned:

EDIT: If using the term "owned" is frowned upon here, then why devote an emoticon to it?
 
thechoochlyman said:
Uh, Cosmic, you used an improper contraction - "it's" instead of "its." :eek:wned:

EDIT: If using the term "owned" is frowned upon here, then why devote an emoticon to it?
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First the diesel police, now the grammar police. A guy just can't catch a break around here.

pope_face_palm.jpg
 
The text in your avatar also seems to be violating spelling rules by not possessing "e"s on the ends of "Coal" and "Roll." :think:
 
I was refering to the multiple website links that were copied and pasted in his original post that was edited by him.
 
I figured a season caption of the CompD ship, such as yourself, would know all too well that it is never appropriate. LOL
 
TMONEYDIESEL said:
I was refering to the multiple website links that were copied and pasted in his original post that was edited by him.
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Those are called references. Generally when data is presented references are cited so that anybody can go to the original source to verify the data. Unless somebody has performed the measurements themselves the source of the data should be given. Data with no verifiable cited sources should not be trusted. That is standard in the presentation of information and those who have higher education are familiar with the concept of citing sources. The edit was to correct a grammatical error replacing it's with the correct its. Go ahead and copy and paste any part of that post into Google and you will find the content of my post was not lifted from anywhere. My post is not a repost from anywhere else.
 
Interesting that you would delete the references after using them to make a intelligent looking post.
 
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