[DML] Re: Carburete a DeLorean at DCS'12?

["content22207" <brobertson@xxxxxxxxxxxx>]

Also FYI:

Speaking for the Autolite/Motorcraft 2100 only:

Unless the carburetor itself physically changes (gets dropped & cracked, stagnant fuel turns to varnish inside, jets are purposefully unscrewed and swapped out for different sizes, etc) it will "hold its tune" into perpetuity. Not counting the accelerator pump and the full throttle enrichment valve -- which has been disabled on my carb and Byrne Heninger's -- there are only two moving parts in the entire metering circuit: the throttle plates themselves. All metering is accomplished by air flow alone, and the amount of fuel that leaves the bowl through the jets in response to that air flow.

Bill Robertson
#5939

--- In dmcnews@xxxxxxxxxxxxxxx, "jtrealtywebspannet" <jtrealty@...> wrote:
>
> It is very difficult to mechanically tune a carburetor to the fuel curve accurately over all operating conditions and loads. You can get it very close at some points in the curve but you cannot get it close enough over the whole curve. A carburetor cannot "adjust on the fly" by itself. If it had some kind of adjustable component like the Lambda system on the mechanical K-Jet it could be more accurate. Remember, the K-Jet is a mechanical fuel injection system with an electronic control (Lambda) grafted over it to add just enough fuel to get the mixture right. The carburetor was just too finicky to hold it's tune. That is why it lost out to fuel injection. Eventually fuel injection systems became purely electronic. Now we see them moving to direct injection like on a diesel. Changing a jet just moves the whole curve up  or down. A carburetor has no ability to compensate for temperature or air density. Unless it has some kind of metering jet hooked up to the manifold vacuum it can't sense load either.
> David Teitelbaum
> 
> --- In dmcnews@xxxxxxxxxxxxxxx, Marc Levy <malevy_nj@> wrote:
> >
> > Sorry Bill, I don't trust "turning a screw" to achieve proper AFR in all running conditions and fuel types..  Heck, I don't trust it to achieve proper AFR in *ANY* condition! 
> > 
> > I don't think anyone else should either, especially if they are still running a catalytic converter.
> > 
> > http://en.wikipedia.org/wiki/Air%E2%80%93fuel_ratio
> > 
> > But, here I am..  Sucker for toll bait AGAIN!  Shame on me.
> > 
> > 
> > --- On Wed, 4/11/12, content22207 <brobertson@> wrote:
> > 
> > > I can jet a carburetor as rich or as
> > > lean as an owner wants. I can jet it so lean the engine
> > > predetonates (I've done it to my own car while experimenting
> > > with jet sizes). It's the same effect as turning the CO
> > > screw on K-Jet too far in either direction.
> > > 
> > > Bill Robertson
> > > #5939
> >
>




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