Metering Plates, six pack
There is fair amount of confusion with figuring out the equivalents for metering plates.
Wish I had a staightforward answer but I don't.
See this thread.
Secondary metering plate vs Secondary Metering Block?
In that thread you will also find the original picture mark up by GNTKLR (Mike) was corrected in Tuner's post that follows.
In the metering plate, that isn't an 'emulsion' feature, like the air bleed well acts in a primary metering block, it is an acceleration enrichment feature. When the secondary initially opens, the well adjacent to the main flow path that joins the main where you circled in red acts as a source of acceleration enrichment. The fuel standing in that well when the secondary is closed is downstream of the restriction of the main jet and readily enters the flow when the main nozzle starts through orifices larger than the main jet.
A metering block has similar acceleration enrichment when fuel in the air well is pushed into the main well by pressure from the main air bleed, however the restriction of the small .028" E-bleeds slows the movement of fuel from the air well to the main well, compared to the open orifices in the secondary plate.
Some metering plates, such as original on 3-bbl carbs do not have the partition with the orifice (circled in rid) entering the main flow path below float level, just a single large well.
There is fair amount of confusion with figuring out the equivalents for metering plates.
Wish I had a staightforward answer but I don't.
See this thread.
Secondary metering plate vs Secondary Metering Block?
In that thread you will also find the original picture mark up by GNTKLR (Mike) was corrected in Tuner's post that follows.
In the metering plate, that isn't an 'emulsion' feature, like the air bleed well acts in a primary metering block, it is an acceleration enrichment feature. When the secondary initially opens, the well adjacent to the main flow path that joins the main where you circled in red acts as a source of acceleration enrichment. The fuel standing in that well when the secondary is closed is downstream of the restriction of the main jet and readily enters the flow when the main nozzle starts through orifices larger than the main jet.
A metering block has similar acceleration enrichment when fuel in the air well is pushed into the main well by pressure from the main air bleed, however the restriction of the small .028" E-bleeds slows the movement of fuel from the air well to the main well, compared to the open orifices in the secondary plate.
Some metering plates, such as original on 3-bbl carbs do not have the partition with the orifice (circled in rid) entering the main flow path below float level, just a single large well.