[Diy_efi] Re: davy lamps and
phil at injec.com
Tue Jun 28 10:43:51 CDT 2005
On first glance it appears that the temperature of
the metal and it's ability to cool a local zone below
the ignition temp that would "prevent " the escape
of the ignition source to the atmosphere.
The dead zone in an IC engine can be more than 1 mm
thick under some operating conditions.
Still it seems that having a combustible mixture of
methane in the air you're breathing can't possibly be
good for you even if it doesn't ignite.
In the same light the flame traversing the small holes
in the plug would be moving quickly enough not to be
quenched completely. Although I would recommend
that they don't make the plugs out of metal.
If the TMFB is 90% at 5 to 8 degrees ATDC with a bore
diameter of 84 mm and a central plug that give an approx.
propagation time of say
6000 rpm = 10 mS per rev or 36 degrees of crank in approx. 1 mS.
42 mm in 1 mS or 42 M/S or 151 kMHr (95 mph if you wish)
As for pressure gradients, not sure what you mean.
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