Hi Geoff
CARockwell@aol.com wrote this to the mini-list recently. It's long, and not
exactly about Triumphs, but close enough? ;-)
Cheers
Jeff
"I am writing this because a private response to an earlier posting
requested
that I explain Colourtunes to the Mini list. The Colourtune ( spelling? )
is
a quartz window spark plug that lets you see into the combustion chamber
when the car is idling. If the combustion mixture is too rich, then the
flame
appears yellow. If the combustion mixture is too lean, then the flame
appears
blue. You peer into the window whilst the engine is idling.
After several years of dyno tuning British cars with a four gas
exhaust
analyser , I still found the Colourtune to be an invaluable tuning aid. On
an
A series engine the inner cylinders run different air fuel mixtures than
the
outer cylinders, so your air fuel mixture is a compromise. I found that the
engines usually ran best when the leanest cylinders were on the verge of
running blue and the richer cylinders were very yellow with the engine
fully
warm. It is easy to spot a misfiring cylinder because it shows no
combustion
flame. If you keep richening the mixture and the cylinders still runs blue,
then you may have a vacuum leak. You can diagnose many problems that occur
at
idle, or high speed idle at say, 3000 rpm.
The Colourtunes do not work to diagnose problems that occur while the
engine is under load, most notably because you have to be running alongside
the car peering into the little window, but also because there is
considerable risk that the quartz window material could blow out into your
face because of the high combustion pressures. That safety note being said,
I did run several cars on my dyno with the Colourtune installed, and I am
still
alive to talk about it. I also inhaled carbon monoxide fumes for eight
years
while tuning cars so my judgement may be suspect....
If you are thinking ahead of the game you may realize that you could
save time buying four Colourtunes as you could adjust the mixture whilst
looking at all four cylinders at the same time. Naturally I also tried this
because I could write all four off my taxes. The engine will not run right
with so many Colourtunes installed. Some engines ran okay with two
installed
at the same time, but four was too many, even for an eight cylinder Aston
Martin. Save your money and just buy one for your Mini :)"
>
> Geoff wrote:
>
> > Thanks for the info on Colr Tube to Bob, Jim and Michael. I will have to
> get one.
> >
> > Can you use more than one at a time, so you can compare adjacent
> cylinders?
> > Geof in CA 69tr6
> >
> > Bob Rochlin wrote:
> >
> > > Geof,
> > > Color Tune is, in essence, a viewing system which allows you to
> see the
> > > actual color of combustion in the car while its running. It looks
like
> a
> > > spark plug and is inserted into the plug hole and has an electrode
> attached so
> > > that the cylinder will fire, surrounding the electrode is a
transparent
> > > material which allows the viewing of the combustion chamber.
> > > I've found it to work well. I know other people have "issues"
with
> the
> > > color tune system, but I like it just for the pretty colors it
> generates. Far
> > > out...
> > > Bob Rochlin
> > > 72' TR 6
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