[Diy_efi] Peak cylinder pressure timing

[Hugh Keir]

Brian,

This should take you to a Daimler Benz 1983 patent

http://l2.espacenet.com/espacenet/bnsviewer?CY=gb&LG=en&DB=EPD&PN=DE3130238I
D=DE+++3130238A1+I+
 or the above line is too long,
http://l2.espacenet.com/espacenet/viewer?PN=DE3130238&CY=gb&LG=en&DB=EPD

1938 patent
http://w3p.espacenet.com/espacenet/viewer?PN=DE656168&CY=gb&LG=en&DB=EPD

Click drawing

1972 Patent
http://w3p.espacenet.com/espacenet/bnsviewer?CY=gb&LG=en&DB=EPD&PN=CA908745&
ID=CA++++908745A1+I+

Click drawing and look at figure 3 bottom of the page

All of the above links are long and may loose some of their length with the
word wrap, so add the characters on the wrapped line back in.

There are loads more like the above, although the first one is more like
what I had in mind.

Hugh

----- Original Message -----
From: "Brian Michalk" <michalk at awpi.com>
To: "List for general do-it-yourself EFI talk" <diy_efi at diy-efi.org>
Sent: Tuesday, March 04, 2003 9:12 PM
Subject: RE: [Diy_efi] Peak cylinder pressure timing


> I am very interested.
> What do you mean by the top of the housing?  Is the crystal inside the
> combustion chamber?
> Do you have any references?
>
> > -----Original Message-----
> > From: diy_efi-bounces at diy-efi.org [mailto:diy_efi-bounces at diy-efi.org]On
> > Behalf Of Hugh Keir
> > Sent: Tuesday, March 04, 2003 2:27 PM
> > To: List for general do-it-yourself EFI talk
> > Subject: [Diy_efi] Peak cylinder pressure timing
> >
> >
> > There are a number of patents, some going back over 20 years covering
the
> > use of piezo crystals that use the spark plug ceramic as a piston to
> > compress the piezo crystal against the top of the spark plug housing and
> > allow you to read the cylinder pressure.
> >
> > There do not appear to be any systems in the marketplace that
> > take advantage
> > of this system for peak cylinder pressure readout.
> >
> > Optrand and Kistler make some more advanced systems that are US$3000 per
> > spark plug - hardly suitable for the hobbyist.
> >
> > Having spoken to a piezo manufacturer, it appears that there are
crystals
> > that will give a good response and should stand the heat found at
> > the top of
> > the spark plug housing. Does anyone have any thoughts on why this is not
> > do-able for the timing of peak cylinder pressure.
> >
> > 8000 RPM = 48,000 degrees crank rotation per second which should
> > be readable
> > to something close to 1 degree with a decent processor clock speed and a
> > simple bit of averaging, compare it to the crank trigger and display the
> > figure.
> >
> > Stands back and waits to be shot down!
> >
> > Hugh
> >
> >
> >
> > _______________________________________________
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> >
>
>
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