Dave.........
Interesting observation! I used to gauge the accuracy of mixture color by
the tailpipe, too, but I find this isn't as accurate with unleaded. All my
cars have a black tailpipe inside now. It is, however, a dry, thin
coloration rather than the soft, sooty residue usually found as a result of
a rich mixture - which still can exist when the mixture is too rich.
And, yes, Colortunes work just fine with unleaded petrol.
Lawrie
British Sportscar Center
----- Original Message -----
From: David Hill <Davhill@btinternet.com>
To: MG Nuts <mgs@autox.team.net>
Cc: <triumphs@autox.team.net>
Sent: Friday, March 10, 2000 4:22 PM
Subject: Tailpipe Colour
> Hi All,
>
> I've been researching on behalf of all of us-in the UK at least.
> I noticed, after changing to unleaded fuel + Valvemaster Plus, that the
> tailpipe colour on both my classics is black.
> It used to be that tailpipe colour could be used to gauge mixture, i.e
> white=weak, light grey=right, black=rich. Looking at moderns using
unleaded,
> they also had black pipes.
> So, I asked Shell-they hadn't tested this aspect and weren't prepared to
> comment. Then, I asked BP-their expert was unavailable on three occasions.
> So...I asked Castrol. The tech dept. said that the tailpipe colour was due
> to lead halides in the exhaust gases and that these are no longer present,
> hence no colour. Sounds reasonable to me but, looking at the plugs in my
> BGT, they were still whitish-brown at a mixture something like right. I'm
> puzzled as to where that colouration comes from.
> Also, do you in the US get a god result from your Colourtunes, or does
> unleaded affect the flame colour?
>
> Any ideas, comments?
>
> Dave Hill
> Yrok, UK
> Can I Telework for you? See what I do, at...
> http://www.angelfire.com/biz4/davtel/index.html
> Troubled by a phobia? Know someone who has one? Go to...
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>
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