Timing - again, ceramic

[jac at wave.sheridan.wy.us]

RE: ceramic surfaces

The ceramic coating keeps more of the heat in the gasses 
through the expansion cycle and more energy is extracted 
from it.

The knock and dentonation improvement is also the result 
of the insulating properties of the ceramic.  During the 
expansion cycle the surface of the insulation will be 
hotter than bare iron or aluminum would be in similar 
conditions.  There is less condensation of fuel and 
combustion products on the head and piston, therefor less 
carbon buildup and hot spots to cause problems during the 
compression cycle.

The timing can be retarded because the insulated surfaces 
cause less heat to be absorbed by the head and piston 
surfaces.  The flame front travels faster and probably 
initiates with greater precision.


---------------Original Message---------------
Remember the Reichstag

----------
> From: talltom <talltom at teleport.com>
> To: diy_efi at coulomb.eng.ohio-state.edu
> Subject: Timing - again
> Date: Saturday, September 14, 1996 12:30 PM
> 
> 
ve 
> maintained that some combustion chambers aren't inclined 
to knock and are
> best timed 
> by power. My expierience with these(Fiat and some fe 
series Fords come to
mind) 
> suggests that power goes down significantly before 
knock, and frequently
is
> accompanied by surging. While it doesn't show to a great 
extent, the
latest 

Some one will definitely correct me, but as I understand 
it, you want to
light the
fire before top dead center just enuff to make the maxium 
pressure thru out
the
entire power stroke.  Too early and some of the pressure 
slows the piston
down
on the compression stroke. Too too early and knock - drive 
the piston
backwards.

Vizard and other current writers says ceramic coating 
pistons, valves and 
chambers greatly reduces knock and ping.  Micro Coats of 
Santa Rosa, a 
leading coater says works great RETARD timing 3 to 4 
degrees after coating
to make optium power (10% increases not unrealistic).  WTF 
- if optium
power
is just before destruction limit, and ceramics move that 
up the advance,
why
do you make better power at less advance?  Maybe better 
combustion, flame
front propagation, etc cause the pressure to build faster. 
 Nah - just
f___ng 
magic.


----------End of Original Message----------

-------------------------------------
jac at wave.sheridan.wy.us
 09/15/96 23:09:21