This is interesting because several times before the recent failure I
had to pull the plugs and clean bits of junk out of the gaps,
particularly in the #6 cylinder. Also, I was getting frequent plug
fouling in #6. Now that I have the head off there are quite large
deposits of carbon and something else that breaks off easily. Maybe
some of this crap got caught between the valve and its seat, weakened
the metal and eventually led to the breakage.
Jim
______________________________ Reply Separator _________________________________
Subject: Re: Well, well...
Author: jcatford@rsvs.ulaval.ca (Jean-Guy Catford) at smtpcc
Date: 6/7/96 11:28 AM
This happened to me 3 times with different cars. Discussing with a
specialist, he told me that sometimes it is a carbon particle that is
responsible for interferring with the closure of the exhaust valve. The
hi-temp. of burned gases complete the job. The last time, I notice some oil
burning for few weeks prior to the breakage. The cause was a worn valve
guide and I easily imagine that in did not help!
J.G.Catford: 73 MGB-GT and 75 TR6
> So I get the head off using the Rope Trick and I'm cleaning the old
> gasket off of it last night and I notice this nifty chunk missing out
> of the exhaust valve in the #6 chamber. Doh! as Homer would say. My
> compression leak wasn't the head gasket after all and now I'm looking
> at a head job :-(.
>
> I was wondering, is this something that "just happens" like s**t
> happens, or could I have done something to bring this on? As
> background, I keep the valves well adjusted, I use high enough octane
> gas and I've never revved this engine over 4,500 rpm. Any comments?
>
> Thanks,
> Jim
> jims@autodesk.com
> '74 TR6 CF20076U
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