pressure measurements with piezoelectric transducer

[SRavet at bangate.compaq.com]

Jerry Wills <jwills at ISI.EDU> Wrote:
| 
| 	 I was rereading SAE 820749, a valve events paper. 
| For the P-V (Pressure/Volume) measurements a piezo trans-
| ducer was mounted in the combustion chamber, I suspect in the
| head somewhere. I have an aircooled motorcycle, that I could
| bore a hole in the head, without worry of leaks.
| 
| Pressure info would be as good, or better than a dyno, to tune
| and check mods to an EFI, as well as the motor, wouldn't it?

I think so.  Instead of listening for knock, or having a static ignition 
advance table, it seems like the best method of controlling ignition timing 
would be to measure cylinder pressure and maximize the area under the 
pressure-volume curve.

John DeArmond, beloved former moderator of the hotrod list, once predicted 
that measuring cylinder pressure would be the next "great leap" in engine 
management.

| 
| Are the transducers prohibitively expense, short lived, weird
| calibration. What are the problems in dealing with these, or
| are like lambda sensors, for us DIY'ers?

The only ones I've seen are from Kistler.  They have pressure sensors built 
into a spark plug, and ones the mount right in the head.  I don't know how 
much they cost, but I think they are very expensive.  I'm sure someone else 
here knows about them...

| 
| 			Jerry Wills 
| I'll have enough POWER when I can spin the tires at the end of the 
straight!
| 89 FJ DERSLYR,           DoD#500 KotF(Flag)       Mark Donahue, about 
917's
| USC/Information Sciences Institute  (USC/ISI)  SoCal (310) 822-1511 x 236
| 90's cowboys, ride iron horses, and punch Deer!!!
| You done violated Physics, BOY!    Assume the position..... (Rider 5/92)
| 


Steve Ravet
sravet at bangate.compaq.com
Baby you're a genius when it comes to cooking up some chili sauce...