Graham McCann wrote:
> The vacuum actually retards the ignition under load, not advances it.
> Power comes from retarding the ignition. In many of the rubbernose
> series
> engines owners found that the engine would idle much smoother if the
> vacuum
> was disconnected. The problem is that the vacuum line comes from the
> inlet
> manifold, not the carby throat and thus is a much greater vacuum,
> especially at idle. I think this was done to ensure that the engine
> would
> clear unburnt fuel better and so pollute less. The SU carby was a
> very
> 'dirty' idler, hence the change to other carbies on the US
> specification
> cars. The vacuum unit spring has a much higher rating to cater for
> the
> greater vacuum.
I hooked up the vaccuum, it starts much much easier and idles much
smoother. I can also get it to idle smoothly at a lower rpm. When I got
the car, the idle was set at about 1200rpm and now I have it set to 800
rpm. The other thing is that it doesn't stumble off idle. Before, I
could get it to die by flooring it while idleing. Now, it won't do that.
>
>
> If you refit the hose and note the change in timing setting as you
> refit
> the hose you will find that it will wind on about 10 degrees of
> advance.
> This retards to the desired setting when you accelerate because the
> vacuum
> falls away under engine load but can mean that the car idles very
> roughly.
>
I haven't reset the timing yet, I'll do that tomorrow.
>
--
John Steczkowski
PSW Technologies, Inc.
512-343-6666
stecz@pswtech.com
http://www.pswtech.com/~stecz
http://www.pswtech.com O-
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