In article om,
Bret Ludwig wrote:
The snag with the DCOE Webers and similar designs is the poor
atomisation at low flow rates - ie low engine speeds. It can also be
near impossible to get smooth progression. The SU alters the venturie
size to keep relative airflow speed high to aid atomisation. The
downside of this is you can't make such a clear flow path at maximum
power. But for road cars it's a good compromise. Other ways of course
are twin choke designs with a small and large venturie - but these
aren't known for long reliable service life. Other thing with fixed
jet carb is there is no compensation for the inevitable wear - an SU
unless bodged or neglected can be adjusted as needed.
90% of carbs on the US road anymore, if not 95% are four barrel
Holleys with progressive operation, two small and two large. Most are
on 60s-80s V8s.
Interesting point was that just about the only US V-8 that ended up being
made in the UK was the Buick unit which became the Rover one - and gained
some 20 bhp when being fitted with SUs. Of course that wasn't the only
mod. But I'm not sure what the original carbs were.
But where people were converting 80s cars with TBI to
carb ten years ago, now we are seeing EFI on everything from old
Beetles to flathead Ford V8s.
IMHO the reason is injection no longer holds the same fears for home
mechanics who also now realise the considerable benefits.
You have to realize that at least in these parts the easy availablity of
credit and $100/hr shop charges have denuded the US roads of cars older
than ten or fifteen years.
Pretty rare here too. Certainly 15 year old ones.
Last time I was in England the numbers of old cars I saw vastly exceeded
what I have seen anywhere in the US, except for a couple of college
towns and parts of Los Angeles.
Heh heh - you saw all of England?
Of course, we are going to see a massive credit implosion.....but
that's another matter.
I hope it doesn't end up being as bad as some fear. It will hit the
poorest most - as usual. Many have been predicting a property crash here
in the UK too. But so far it hasn't happened.
--
*The early bird gets the worm, but the second mouse gets the cheese *
Dave Plowman
London SW
To e-mail, change noise into sound.