I know that it is better to run rich than lean. And it is best to run stoich. Can someone tell me why? What happens in my engine when I go rich/lean? What kinds of things could cause me to go rich/lean?

 

you have more fuel to air when you are running rich. I believe you detonate when you run too lean.

 

its safer fro your car to run eich and if you run on the lean side you will produce more power.

 

yes, i know what running rich is. and i know what running lean is. and i know that it is better to run rich than it is to run lean. does anyone out there know what really happens when you run lean or rich. why does my engine run hotter when i run lean? why is running lean bad? what could i damage if i run too lean? what could i damage if i run too rich?

i don't want some ricer who pays people to put mods on their car to answer. i want a truthful, provable scientific argument that demonstrates what happens in my engine when it runs rich & lean.

is there anyone out there who knows?

 

when youre running rich, you are getting more than enough fuel to the combustion chambers...therefore not geting the most out of your engine....when you run lean,you are not getting enough fuel to youre combustion chambers...this causes heat and you will detonate....

 

why does not getting enough fuel into my cylinders cause heat?

 

Detonation happens when too much heat and pressure in the combustion chamber cause the air/fuel mixture to ignite before the ignition timing determines that the spark plug should fire. Common causes for this diesal effect can occur from the heat of compression, or from a spark plug that is too hot. This causes many flame fronts inside the combustion chamber, instead of a single flame kernel centered at the spark plug. The flame fronts collide with explosive force and produces a rapid rise in cylinder pressure accompanied by a sharp metallic pinging or knocking noise. These hammer-like shock waves created by detonation subject the head gasket, piston, rings, spark plug and rod bearings to extreme overloading.

Just as an expample, this is a good explaination of detonation. Can someone, anyone, give me a good explaination of what happens when you run rich/lean?

 

if you run leaner, more air is present during combustion, thus it will be a hotter, more powerful detonation... remember that heat kills... a richer mixture will yield lower engine temperatures... so it's either you run hot and clean (lean) or cool and dirty (rich)... a place inbetween (A/F ~13.7 or so) is ideal...

 

When you are lighting a fire and you blow on it- the coals get hotter (glow more)- more oxygen means higher temps- Oxy/acetylene torch- add O2 get hotter flame- the same applies to your engine.

 

http://www.personal.utulsa.edu/~kenn...n/chapter6.pdf

 

thank you very much. now i get it. i feel kinda dumb for not getting it before. oh, and thanks for that pdf file. i loved reading that.

 

As a side note, the added fuel in the air has a slight effect over the intake charge by cooling it. (think of it as a very uneffective water injection)

 

No problem. I was going to try to summarize it but I didn't want to leave out any details. That's definiely one of the best write up's I've seen on the development and workings of the internal comustion engine.