Sure any addition in the flow path could cause a pressure drop, but Chrylser wanted the higher pressure with the Carter carbs starting somewhere in the early 60s. Mopar and Carter documentation state that. In addition, the test procedure in the service manual is to measure the pressure at carb inlet, not pump outlet.
That is after the vapor separator. The Needle valves and floats on the AFB and early AVS are different then what Edelbrock uses. The float could handle the added pressure/force. It was calibrated that way.
The orifice is designed to flow vapor, not liquid. Mostly about preventing vapor lock after a stop. Open it too much and start moving liquid defeats the purpose of having sufficient volume flow at high speed.
If the pump is putting out too much pressure for your combo, you could take it apart and put in a softer spring. It can be removed from the pullup rod.
really? and how does a mechanical fuel injection regulate itself? i'm not with you on this.
What don't you follow or agree with? You want to regulate pressure with the vapor separator, fine. He may not even have one installed, but either way that is a lot of trial and error to set it, and then have all sort of variables like temp, and altitude effect the set point?
My only point is Carter can handle the higher pressure. Look at the float, needle and seat orifice used as compared to edelbrock and you can calculate a basic force on the float. Same relationship as Master Cylinder size other then the counter force of the float(buoyancy).
The pump is a positive displacement diaphragm pump. With sufficient head to flow the velocity and mass needed. Reduction of volume to reduce pressure because the pump is built wrong with the spring is not what you want. The chamber volume is constant on these pump.6903/4862
I am not sure how these latest pumps are pushing 18 plus psi. Would love to take one like that apart and measure the spring and see how they assembled the diaphragm and plates. I have had no issues with the older ones or the rebuild kits to fix them.
