It depends on the kind of driving you do, Paul, and whether your head has
been fitted with hard exhaust valve seats. If lots of constant speed for
long periods of time and no hard seats, valve seat recession is entirely
possible.
Lawrie
British Sportscar Center
-----Original Message-----
From: Ptegler <ptegler@gouldfo.com>
To: mgs@autox.team.net <mgs@autox.team.net>
Date: Saturday, January 13, 2001 8:18 PM
Subject: oh NO! What's up!
>the 73BGT has been running a bit rough lately.
>OK cold weather broke for a day here in MD
>let's see what I can fix here.
>
>HHmmm .... Vacuum gauge at idle of
>850 is fluttering 3-5 Hg/in and down at 15 Hg/in
>At 1krpm steady at 18 Hg/in.
>
>Well... the spark plugs all look good.
>Nice clean light brown ash color. Hmmm....
>
>So I did a compression check....
>#4 cyl - 145 #3-140 #2- 120 #1-10 What!??
>repeated tests with oil in cyls. ...not much change.
>...well at least it's not broken rings.
>But what's up with cyl #1?
>
>Popped the valve cover... check the clearances.
>ZERO clearance on three valves. What the ....?
>
>Readjusted them all to spec. all comps now at
>140+ lbs/sq in.
>
>All the power is back and she idles steady and
>rock solid at 750-800 rpm now. Exhaust pulses
>and sound very steady now.
>
>So the question is... didi/do I have a bad
>case of valve recession? Over just the last 5 k miles
>or so?
>
>Paul Tegler wizardz@toad.net http://www.teglerizer.com
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