Started logging fuel pressure
I know there's some recommondations in the old MP Tech Tips about running a mechanical pump with an electric pump but I don't have any experience with it.
One rule of thumb is 1 lb per hour of fuel is needed for Hp/2
Even not knowing the Hp your engine is producing, there were several mechanical pumps that should be able to supply the volume needed at 4.5 psi.
Here's Holley's chart for the "Keith Dorton" 110 Mechanical pump.
Free flow is 0 psi in the outlet tube.
4.5 psi is a somewhat restricted outlet and seems to be a common reference pressure.
I've seen cut off pressure listed as low as 6 psi an das high as 8.5 psi. I did not send this pump to Ryan Brown for testing, but my experience with it has been pretty much no issues with it over powering the bowl inlets beyond the usual with Holleys that sit.
Where I'm going with this is that lower pressure on the outlet side of the pump will result in more fuel into the bowl.
The question is whether the lack pressure at 5000 rpm is due to inneffective delivery or some restriction before the gage.
Electric pump delivery is similar.
I think it is worth looking at an experiment @Cudafever did at @PRH suggestion. I contributed pump flow charts and diagrams.
Holley/Demon Carb stumble
His first test is post 488
I know there's some recommondations in the old MP Tech Tips about running a mechanical pump with an electric pump but I don't have any experience with it.
One rule of thumb is 1 lb per hour of fuel is needed for Hp/2
Even not knowing the Hp your engine is producing, there were several mechanical pumps that should be able to supply the volume needed at 4.5 psi.
Here's Holley's chart for the "Keith Dorton" 110 Mechanical pump.
Free flow is 0 psi in the outlet tube.
4.5 psi is a somewhat restricted outlet and seems to be a common reference pressure.
I've seen cut off pressure listed as low as 6 psi an das high as 8.5 psi. I did not send this pump to Ryan Brown for testing, but my experience with it has been pretty much no issues with it over powering the bowl inlets beyond the usual with Holleys that sit.
Where I'm going with this is that lower pressure on the outlet side of the pump will result in more fuel into the bowl.
The question is whether the lack pressure at 5000 rpm is due to inneffective delivery or some restriction before the gage.
Electric pump delivery is similar.
I think it is worth looking at an experiment @Cudafever did at @PRH suggestion. I contributed pump flow charts and diagrams.
Holley/Demon Carb stumble
His first test is post 488