Propogation rate vs. octane.

I asked this same question in the early '70s--when Amoco introduced unleaded. I was told premium burns 'longer,' and low-life is 'flash, it's gone.'
 
Higher octane gives a slower burn,therefor you get a more complete burn as the piston is going back down.


At least thats what i read somewhere along time ago.
 
I thought I would just add this : detonation occurs, when the flame front travels at such a speed that the pressure on the remaining gas in the chamber gets high enough that it will ignite without a spark, causing a reverse wave and thus the knock you hear. The higher the octane the slower the flame front travels and thus allowing for more time for the remaining fuel to burn up. The higher octane also has an effect on how fast (pressure/temp rise) it will take to ignite a fuel mixture out of itself.
 
Higher octane gives a slower burn,therefor you get a more complete burn as the piston is going back down.


At least thats what i read somewhere along time ago.

Yes, a slower cooler burn.:thumbs:

Isn't that why you can bump the timming up with high octane because of the slower burn rate vs pump gas which just goes BOOOOOM all at once.

Yea, that about covers it.:wink:

Cool so i was right :D and everybody said i have been sniffing too much VP110:lol:

Darrow got to enhale his fare share of VP110,wonder if ever got that smell out of his car :ill:
 
Higher octane gives a slower burn,therefor you get a more complete burn as the piston is going back down.


At least thats what i read somewhere along time ago.

Yes, a slower cooler burn.:thumbs:

Isn't that why you can bump the timming up with high octane because of the slower burn rate vs pump gas which just goes BOOOOOM all at once.

Yea, that about covers it.:wink:

Cool so i was right :D and everybody said i have been sniffing too much VP110:lol:

Darrow got to enhale his fare share of VP110,wonder if ever got that smell out of his car :ill:

Saw Darrow today (along with Bird and Rich ) he still didn't look quite right.:friends:
 
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