Re: Compression results question

["Fred Munro" <munrof@isys.ca>]

    Whoops, just answered my own question. As I sat at the keyboard
pondering it (after hitting "send", of course), I was struck by a terrible
thought - no, surely it couldn't be the Bentley's infallible Imperial/Metric
conversion. A quick trip to the basement, a few keystrokes on a calculator,
and voila - the upper "new" compression limit on the MC engine is 12 bar or
176 psig, not 12 bar or 144 psig as reported in Bentley.
    Not bad compression for 260k km!

    Sorry for the WOB!

Fred Munro
'91 200q  260k km (within spec after all!)
-----Original Message-----
From: Fred Munro <munrof@isys.ca>
To: quattrolist <quattro@coimbra.ans.net>
Date: Tuesday, October 06, 1998 9:19 PM
Subject: Compression results question


>    I have just replaced the plugs on my '91 200q and took the opportunity
>to do a compression test. The engine is a dual knock sensor MC with 260k km
>on it. The compression test was done with the engine warm (not hot), wide
>open throttle, and 10 compression cycles per test.
>
>    The results are as follows:
>
>        #1        165 psig
>        #2        171 psig
>        #3        169 psig
>        #4        171 psig
>        #5        167 psig
>
>    At first glance, this appears great!  However, Mr. Bentley states that
>the "new" range for my MC engine is 123-144 psig. The "new" range for the
>10:1 compression NF engine is 160-170 psig.
>
>    Hmmm. The question is - is Mr. Bentley in error? Or have I (very
evenly,
>mind you!) carboned up the combustion chambers to the point where I am
>running 10:1 compression? Do I have a very rare turbocharged NF engine?
 an
>NF/MC, perhaps?).
>
>    Any ideas?
>
>    TIA
>
>    Fred Munro
>    '91 200q  260k km (on steroids)
>