While I couldn't find anything on what the gauge reading should be for the PRV, I did find this. ""compression ratio": It's the total cylinder volume divided by the combustion space volume, and it's done using a burette and thin oil. It's a measure of the amount of squish and has little real-world value because of valve timing, etc. "Pressure ratio" is the more realistic measurement since it tells you something about the condition of your engine, particularly if the measurement is taken with the engine hot. For example, if the pressure gage reads 152 psi (gage reading) and the ambient atmospheric pressure is 14.7 psi (absolute, also equal to 29.92 Inches of mercury - phone your local weather station or airport for the real-time value), then the pressure ratio is (152+14.7)/14.7=11.3. This is NOT the "compression ratio": it's only an indication of how well the compression process is being carried out. The variation from one cylinder to the next reveals how the various pots are probably contributing to overall engine output. For any engine, it's a relative measure of wear/deterioration." >From this link found on Google: http://www.captain.norton.clara.net/cnn3sec12.html If I did my math correctly, I calculated the combustion space volume to be 28.986. Maybe you should also do a leak-down test. Hell, why not! Good luck, Greg -----Original Message----- From: cruznmd [mailto:racuti1@xxxxxxxxxxxx] Sent: Sunday, August 03, 2003 6:08 PM To: DMCForum@xxxxxxxxxxxxxxx Subject: [DMCForum] tone L.O.C. Some bright soul out there asked if I'd put a compression gauge on the car instead of just my thumb. So today, I purchased a gauge from Advance Auto and measured 3 cylinders before the rain drove me inside. The manual states that this engine runs at an 8.8:1 comression ratio but I don't know how many PSI or kPa that is. I measured cylinder 3 at 100 psi, cylinder 6 at 120 psi and cylinder 2 at 90 psi. Now I -already- know that that is insufficient to support self- sustaining combustion. So now I know why the car won't start. Now I need to know: a) What is compression -supposed- to be (in psi or kPa)? b) What are the possible causes of loss of compression? c) What could I do to get it back? I know some of b) but I want to hear as many answers as I can in case I'm skipping something. As usual, thanks. Rich Yahoo! Groups Sponsor ADVERTISEMENT <http://rd.yahoo.com/M=194081.3551198.4824677.1261774/D=egroupweb/S=170512 6215:HM/A=1663535/R=0/SIG=11ps6rfef/*http://www.ediets.com/start.cfm?code= 30504&media=atkins> click here <http://us.adserver.yahoo.com/l?M=194081.3551198.4824677.1261774/D=egroupm ail/S=:HM/A=1663535/rand=398289773> To unsubscribe from this group, send an email to: DMCForum-unsubscribe@xxxxxxxxxxxxxxx Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service <http://docs.yahoo.com/info/terms/> .
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