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Re: does octane change your afr?

..... :o

that is some important information, and good to know. Dang'!

Re: does octane change your afr?

Quote:

Originally Posted by Joseph Davis

Quote:

Originally Posted by nitrogen

that ---- is confusing. here.
The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites.

No, that is Cetane rating, used for compression ignition engines aka DIESEL.

Spontaneous ignition in a low compression spark ignition engine ("high CR" spark ignition engines are very low compression compared to diesel) is not from adiabatic heating of charge upon compression - utter bullshit - but from pre-ignition/chamber hotspots which has nothing to do with octane ratings.

My ---- is not confusing, my ---- is correct. Ignore the noise.

http://auto.howstuffworks.com/question90.htm
This is where my facts came from. ::)

Re: does octane change your afr?

Looks like it's Joseph Vs. howstuffworks.com

Send em an email Mr. Davis

Re: does octane change your afr?

Quote:

Originally Posted by nitrogen

http://auto.howstuffworks.com/question90.htm
This is where my facts came from. ::)

Ah, so when you advance the ignition timing it raises your compression, resulting in detonation. Now who's rolling their eyes? ::)

You do realize that most lay-explainations rendered to laymen are gross oversimplifications, which lead to gross miscalculations and outright errors when laymen attempt to get technical? Cylinder pressures are not compression. Consult any basic ICE text.

Stop citing stuff you googled to look smart, and start learning about the complete system. Build the picture in your mind and BE smart.

I'll post a HMT recommended reading list today, tomorrow, next week, or whenever I feel like it. Mostly stuff MGB passed on to me. There might eventually be .pdf piracies of some of these works floating around on the bad interweb - it won't help the signal:noise ratio in the automotive community much, although it might get my ass welded to my spine by the SAE, various technical presses, et al. Most of the reading is engineer-speak, and you need to be solid with math, and ideally know basic engineering physics. First year college classes for the typical engineering-wannabe or math type will do. I'd guess there are ten people on HMT right now who could digest all of it, and only three who'd care to try... but most of you HMT guys are still teenagers, or alcoholic early twentysomethings. Who knows what the future holds?

Re: does octane change your afr?

I for one would be up to the reading. I do agree with you with the over simplifications out there. Things should be made simple, but no simpler. (wonder what smart guy said that)