[Diy_efi] Rich detonation?

[Bernd Felsche]

On Monday 20 November 2006 15:23, Charles Woock wrote:
> The richer the mix the faster the burn.  The leaner the mix the
> slower the burn.  

How so? There is less probability of oxygen being available for
combustion of a part of the fuel when the mixture is richer than
stoichiometric.

OTOH, the ready availability of oxygen in a lean mixture means that
combustion is hotter and therefore tends more towards detonation.

The flame front will burn at about the same speed in both cases for
mixtures slightly either side of stoichiometric. Basically; if it
burns, it'll burn at the same rate. 

> It is all about ignition timing,

How can that be? You said it was related to the mixture.

> however the source of detonation

It's also about initial gas velocities, mixing, piston speeds,
cooling, internal and external EGR ratios, ...

> aside from improper timing is from poor quality fuel or fuel not
> suited for a specific compression ratio.  Poor fuel combined with
> hot spots in the combustion chamber results in pre-ignition.

Pre-ignition is NOT detonation.

-- 
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