Re: Importance of float level

Graham Motzing /
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hmm, i'm not exactly sure that i'm doing the math correctly but i'm pretty sure the original assertion here is wrong.

the pressure differential that you are overcoming with suction at the emulsion tube or jet is going to be based on the mass of the fluid at a given height, like a water column.

so, gas being sucked up say 2 cm in a large carb vs. being sucked up 1 cm in a small carb is going need 2 cm or 1 cm 'water column' which in this case is gasoline.

it doesn't matter if the float bowl is overall 5 cm deep or 3 cm deep (for the respective examples) if the float height causes the fuel level to be at 2.2 cm vs 2 cm it will be off by the same amount of pressure as the float height being 1.2 cm vs 1cm, the pressure differential will be equal to .2 cm x the specific gravity of fuel in either case.

now, how sensitive to the precise 'fluid column' pressure the carb is relative to the venturii and other dimensions, i think generalizing that is going to be tough. I have noticed big differences between different carbs regarding how sensitive they are to float height. I recently was tuning a VM28 on a big air cooled 2 stroke and that thing was ultra picky, where as something like a 14 SHA doesn't seem to care at all. I'm sure it has a lot to do with the strength of the vacuum signal relative to the sizing of the jets. If you have a big carb with low vacuum signal and large jets the fuel pressure differential across the jet is low and the relative impact of the fluid column pressure is high in altering the mass flow rate through the jet. If you have a small carb with a strong vacuum signal like a SHA (which also has some wacky emulsion tube tech) and a small jet with high pressure differential, the fluid column pressure will have a relatively small effect.

also,

don't talk shit on engineers, pretty much the entire modern world functions because engineers figured that shit out. this dude isn't any more an engineer than dr. phil is a doctor.(edited)

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Subject Written By Posted
  Importance of float levelTopic by: Michael Forrest Michael Forrest 08/28/19 11:16AM
  Re: Importance of float levelRe: live ɘvil live ɘvil 08/28/19 11:44AM
  Re: Importance of float levelRe: Michael Forrest Michael Forrest 08/28/19 11:46AM
  Re: Importance of float levelRe: jayson sumpter jayson sumpter 08/28/19 12:00PM
  Re: Importance of float levelRe: live ɘvil live ɘvil 08/28/19 11:52AM
  Re: Importance of float levelRe: Michael Forrest Michael Forrest 08/28/19 11:58AM
  Re: Importance of float levelRe: Rocco Taco Rocco Taco 08/28/19 12:15PM
  Re: Importance of float levelRe: Michael Forrest Michael Forrest 08/28/19 12:26PM
  Re: Importance of float levelRe: live ɘvil live ɘvil 08/28/19 12:34PM
  Re: Importance of float levelRe: Michael Forrest Michael Forrest 08/28/19 12:42PM
  Re: Importance of float levelRe: live ɘvil live ɘvil 08/28/19 01:37PM
  Re: Importance of float levelRe: Michael Forrest Michael Forrest 08/28/19 03:05PM
  Re: Importance of float levelRe: live ɘvil live ɘvil 08/28/19 03:34PM
  Re: Importance of float levelRe: Michael Forrest Michael Forrest 08/28/19 04:06PM
  Re: Importance of float levelRe: live ɘvil live ɘvil 08/28/19 04:12PM
  Re: Importance of float levelRe: Rocco Taco Rocco Taco 08/28/19 01:59PM
  Re: Importance of float levelRe: Michael Forrest Michael Forrest 08/28/19 03:15PM
  Re: Importance of float levelRe: live ɘvil live ɘvil 08/28/19 04:07PM
  Re: Importance of float levelRe: Braedan Cvetkovich Braedan Cvetkovich 08/28/19 04:50PM
  Re: Importance of float levelRe: ken gilbert ken gilbert 08/28/19 04:55PM
  Re: Importance of float levelRe: Rocco Taco Rocco Taco 08/28/19 05:13PM
  Re: Importance of float levelRe: live ɘvil live ɘvil 08/28/19 07:02PM
  Re: Importance of float levelRe: Michael Forrest Michael Forrest 08/28/19 09:15PM
  Re: Importance of float levelRe: live ɘvil live ɘvil 08/28/19 09:36PM
  Re: Importance of float levelRe: Rocco Taco Rocco Taco 08/28/19 09:51PM
  Re: Importance of float levelRe: K Olena K Olena 08/30/19 11:25AM
  Re: Importance of float levelRe: Michael Forrest Michael Forrest 08/30/19 11:38AM
  Re: Importance of float levelRe: Rocco Taco Rocco Taco 08/30/19 11:56AM
  Re: Importance of float levelRe: Rocco Taco Rocco Taco 08/30/19 11:57AM
  Re: Importance of float levelRe: Graham Motzing Graham Motzing 08/30/19 11:58AM
  Re: Importance of float levelRe: Graham Motzing Graham Motzing 08/30/19 12:27PM
  Re: Importance of float levelRe: Rocco Taco Rocco Taco 08/30/19 12:59PM
  Re: Importance of float levelRe: live ɘvil live ɘvil 08/30/19 01:53PM
  Re: Importance of float levelRe: Rebel Moby Rebel Moby 08/30/19 05:33PM
  Re: Importance of float levelRe: Overpriced Parts Overpriced Parts 08/30/19 07:28PM
  Re: Importance of float levelRe: baird co baird co 09/01/19 01:17PM
  Re: Importance of float levelRe: Norris Hall Norris Hall 09/02/19 10:25AM
  Re: Importance of float levelRe: Rebel Moby Rebel Moby 09/02/19 05:38PM
  Re: Importance of float levelRe: Rocco Taco Rocco Taco 09/02/19 08:03PM
  Re: Importance of float levelRe: Rebel Moby Rebel Moby 09/03/19 06:04PM
  Re: Importance of float levelRe: Norris Hall Norris Hall 09/02/19 06:57PM
  Re: Importance of float levelRe: Rebel Moby Rebel Moby 09/03/19 06:03PM
  Re: Importance of float levelRe: Norris Hall Norris Hall 09/02/19 06:59PM
  Re: Importance of float levelRe: Norris Hall Norris Hall 09/04/19 12:42AM
  Re: Importance of float levelRe: Rebel Moby Rebel Moby 09/04/19 06:05PM

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