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Re: Pete's 4ktq woes continued.

-----Original Message-----
From: PAT MARTIN <MARDKINS@classic.msn.com>
To: quattro@coimbra.ans.net <quattro@coimbra.ans.net>
Cc: Pete Kunzler <pck@gte.net>
Date: Monday, October 12, 1998 1:27 AM
Subject: Pete's 4ktq woes continued.

>While the engine was out we cleaned the top of the cylinders up with wd40
>lots of elbow grease.  We then reassembled it and put it back in.

    How much carbon did you remove, Pat? Enough to reduce the effective
chamber volume and drop the compression? Doing some rough calculations on an
MC engine shows 2mm of carbon on a 81 mm diameter piston has a volume of
10.2 cc. I don't know the chamber volume, but estimating it from the
compression ratio (8.4:1) and the bore and stroke shows a volume of 53cc.
Removing 2mm of carbon from the piston top would therefore reduce the
compression ratio by 20%!

>When we were trying to figure out if there was a major vacuum leak we took
>the crankcase ventilation hose and viola.  Pete started it right up with a
>plug on the intake side.  Ran like a charm except for a lot of crankcase
>gasses spewing from the hose.  This was not good, major blowby.

Major blowby usually indicates bad compression rings.


Fred Munro
'91 200q  260k km