From: emory!bangate.compaq.com!sravet X-Source: The Hotrod Mailing list Date: May 1994 Subject: Cylinder pressure sensors? X-Sequence: 8635 Sorry if this is a repost, I can't remember if I asked this here before. Does anyone make a pressure sensor rugged enough to live in the combustion chamber? I seem to remember someone mentioning that there was one that went on the spark plug or something... thanks --steve Steve Ravet sravet@bangate.compaq.com "Baby you're a genius when it comes to cooking up some chili sauce...." [Yes. Kistler, Valedyne, Piezo, Endevco all make piezoelectric pressure transducers. Kistler makes one built into a spark plug. Better grab hold of that wallet and get ready for a ride though. Several hundred bux a shot. Then you need the external charge amp which is more $$$. Kistler advertises in most of the hotrod magazines (Circle track and Stock Car Racing, for sure) and they all do in "Sensors" and "Measurement & Controls" magazines, the latter being the journal of the Instrument Society of America. If you can sit tight for a couple of years, these things will be OEM off-the-shelf items. This is going to be the next big increment in engine management sensor technology and several companies are on the verge of rolling out production engines with combustion chamber transducers. Incidentally, there was an interesting article in one of the SAE pubs within the last year or so about using the spark plug gap resistance to measure cylinder pressure. Might want to look that one up. JGD] From: John De Armond Subject: Re: Manifold Pressure sensor? Date: Tue, 12 Oct 1999 18:37:29 EDT Newsgroups: rec.aviation.homebuilt Mark Doble wrote: > > Anyone know where i can find a manifold pressure sensor for a lycoming > 320/360? I'm rolling my own engine monitoring system.... > > I have heard it referenced as a GM Map sensor? That's it. The MAP (Manifold Absolute Pressure) sensor. A solid state absolute pressure transducer. There are two versions. One version is for normally aspirated engines (P/N 16017460) and a 1 bar unit for turbocharged engines (P/N 16009886). Rumor has it that GM briefly made a 2 bar version for high performance engines but the part number I was given (P/N 16036394) has never been acknowledged by GM as valid. Numbers given are GM part numbers. The sensor should cost in the range of $15 at a car parts place. If you hold the sensor so the connections face you and the pressure port is at the bottom, the three electrical connections are: Top - ground, Middle - signal, Bottom - V+ (12 volts, as I recall). Output signal is 0-5 volts across the rated pressure span. John |