At 10:31 AM 26/06/97 -0400, you wrote:
>Brian Evans wrote:
>>
>> At 08:18 AM 26/06/97 -0400, you wrote:
>
>> >What kinds of things should I be looking at to cure hesitation coming
out of corners with my vintage TR4?
>>
>> What Kind of Carbs do you have?
>
>Well, you've asked me a question that may cause all kinds of flames -
>but that's OK - I've got a Nomex skin. We're using Strombergs. I thought
>
Strombergs being constant velocity carbs are alot like SU's including the
dashpot damper, no? If so, why not experiment with heavier oil in the
reservoir - the idea is to slow down the action of the piston when opening
the throttle so that the fuel mixture goes to less air. What happens is that
as the throttle plate opens, the pull of air into the engine increases,
increasing the signal at the fuel jet, so more fuel is pulled up into the
airstream. But, because of the slower response due to the dashpot damper
the piston doesn't rise to match, the mixture goes rich until the piston can
catch up, just like an accelerator pump.
Webers are the opposite of CV carbs in that tey use varying signal at a
static sized fuel jet to pull varying amounts of fuel into the airstream,
and use emulsion tubes to control the rate at which the change happens. CV
carbs use relatively constant air velocity to suck varying amounts of fuel
out of a fuel jet that varies in size as the needle goes up and down.
>
>There is a drawback that I may not be able to overcome -- they have a
>rather shallow float chamber below the throats, instead of a rather tall
>float chamber a la SU's. BUT, I haven't been able to figure out if I'm
>flooding or starving coming out of sudden corners.
With CV carbs, if it idles, then it's probably not rich coming off a closed
throttle condition. Which brings up a point - is it corners or throttle
transitions that it doesn't like? if you can run thru a steady state
throttle corner ok, then it's probably not float level or anything like that.
>
>The really puzzling thing is that steady state corners like carousells
>at Road America or Blackhawk do not cause the problem -- it just happens
>after short, sudden corners like 90 deg right handers.
>>
>
>> SU's are way tough to set up compared to Weber, in my opinion!
>
>Yeah. More black magic, I suppose.
>
>uncle jack from Iowa
>
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