Edelbrock accelerator pump linkage

[451Mopar]

Not sure if this helps, but last time I looked (several years ago), Edelbrock listed 29 different metering rods, and I had the 6 metering rods from my old Carter strip kit.
The standard jet sizes go from 0.071" to 0.116" diameter on 0.003" diameter increments.
Of the 35 different metering rods I have in my list, the upper thick section diameters (Economy) run from 0.055" to 0.076" diameter, and the lower thin sections (power) run from 0.037" to 0.060". The differences in the thick and thin sections of the rods can vary from 0.000" (no change 0.055" x 0.055", Edelbrock #1436) to 0.038" (0.075" x 0.037" which is a difference in area of almost 311% or about 7 jet sizes (calculated in area not diameter), edelbrock #1458.)
If you sort the rods by step difference, about 1/2 of the rods seem to be more for some special tuning situations with either very little change from power to economy step difference 0.000" to about 0.010"), or a very large step difference (0.026" to 0.038".)
This leaves about 12 Edelbrock rods, and the rods I had from the strip kit, that seem to have a fairly normal step size difference of 0.012 to 0.024", which is about like a jet size difference of 2.4 to 4.7 or 48.4% to 128.2% change in area.
There is also the step-up spring kit of 10-springs for five different vacuum levels ranging from 3" of vacuum to 8" of vacuum.
Accelerator pump nozzles are normally 0.024", 0.033" or 0.039", but can be re-sized with a pin drill to different sizes if needed.
There are also different diameter needle and seat assemblies 0.110", and 0.120", but normally not an issue.

My Holley tune up parts kit is even more extensive with air bleeds, metering block restrictors, power valve, jets, vacuum secondary springs, accelerator pump cams, and the discharge nozzles.

 

[oldbee]

Not sure if this helps, but last time I looked (several years ago), Edelbrock listed 29 different metering rods, and I had the 6 metering rods from my old Carter strip kit.
The standard jet sizes go from 0.071" to 0.116" diameter on 0.003" diameter increments.
Of the 35 different metering rods I have in my list, the upper thick section diameters (Economy) run from 0.055" to 0.076" diameter, and the lower thin sections (power) run from 0.037" to 0.060". The differences in the thick and thin sections of the rods can vary from 0.000" (no change 0.055" x 0.055", Edelbrock #1436) to 0.038" (0.075" x 0.037" which is a difference in area of almost 311% or about 7 jet sizes (calculated in area not diameter), edelbrock #1458.)
If you sort the rods by step difference, about 1/2 of the rods seem to be more for some special tuning situations with either very little change from power to economy step difference 0.000" to about 0.010"), or a very large step difference (0.026" to 0.038".)
This leaves about 12 Edelbrock rods, and the rods I had from the strip kit, that seem to have a fairly normal step size difference of 0.012 to 0.024", which is about like a jet size difference of 2.4 to 4.7 or 48.4% to 128.2% change in area.
There is also the step-up spring kit of 10-springs for five different vacuum levels ranging from 3" of vacuum to 8" of vacuum.
Accelerator pump nozzles are normally 0.024", 0.033" or 0.039", but can be re-sized with a pin drill to different sizes if needed.
There are also different diameter needle and seat assemblies 0.110", and 0.120", but normally not an issue.

My Holley tune up parts kit is even more extensive with air bleeds, metering block restrictors, power valve, jets, vacuum secondary springs, accelerator pump cams, and the discharge nozzles.

451-you need to read more,lol. They also used some 3-step metering rods to add to the confusion.

 

[Garys1969RR]

A bog, as I understand it, is a flat spot or hesitation in the motor that occurs when transitioning from a closed or partly open throttle to a more fully open or wide open throttle position. If it does it at a steady open position, then something else is wrong. Describe exactly what the motor does when it "bogs." Good luck.............Whatever happened to:I asked a simple question, and I expect a simple answer! LOL

 

[Garys1969RR]

I'm going to 451s house when it's time to tune up my AFBs! Put some coffee on! LOL

 

[rumblefish360]

451-you need to read more,lol. They also used some 3-step metering rods to add to the confusion.

Those 3 steps are for the AVS carbs.
Very effective in creating excellent fuel curves and achieving emissions standards of the day.

TQ’s also have 3 step rods.

 

[451Mopar]

451-you need to read more,lol. They also used some 3-step metering rods to add to the confusion.

I know about the other AVS rods, jets, and raised caps, and the Thermoquad parts too.

Maybe that is why I am converting some of the cars to EFI, way easier to make tuning changes on a laptop

 

[451Mopar]

I'm going to 451s house when it's time to tune up my AFBs! Put some coffee on! LOL

Let me know, it's still a slow process without a chassis dyno and wideband 02 sensor. I usually keep the tuning parts in the car trailer, but I was leaning out the Carter carb on the Jensen.
The Carb Shop in Denver is a good place to get a car tuned on their chassis dyno.
Jon took his '68 Baracuda 340 with a 830 cfm pro-series carb to them to get it tuned. The car came from CA, and was way too rich at this altitude.
http://www.thecarburetorshopdenver.com/#

 

[dvw]

Have you looked into the carb and seen how the pump shot looks? Worn plunger rubber, non seated outlet check valve, restricted squirter, pump plunger too high? These can all cause issues. Are the floats correct? Are the air bleeds clean? Are the idle feed retrictions clean? Does the carb have base calibration or has it been messed with? Does it have enough initial timing? Start with the basics first.
Dougt

 

[Bee1971]

Slight bog at wot is what I read in initial post ?

That was easy to get rid of on the factory Carter AVS Carbs and now the newer Edelbrock AVS

You just adjusted the air door spring

Problem with the Edelbrock 750 Performer 1407/1411 carbs is they have a weighted air door , non adjustable

Are you getting the bog off the line or just cruising down the highway stabbing the gas pedal wide open

Edelbrock 1407/1411 750 are notorious for off idle lean conditions that feel like a bog but are actually flat spot lean

 

[junkpile]

Slight bog at wot is what I read in initial post ?

That was easy to get rid of on the factory Carter AVS Carbs and now the newer Edelbrock AVS

You just adjusted the air door spring

Problem with the Edelbrock 750 Performer 1407/1411 carbs is they have a weighted air door , non adjustable

Are you getting the bog off the line or just cruising down the highway stabbing the gas pedal wide open

Edelbrock 1407/1411 750 are notorious for off idle lean conditions that feel like a bog but are actually flat spot lean

the bog is always off the line, when crusin if i stab it, it takes off like its supposed to.

 

[Bee1971]

I see you have two threads running

Looks like you have a multitude of fuel issues

A 1407 / 1411 Edelbrock 750 is notorious for a off idle hesitation issue

However in another post your talking fuel pressure/pump issues while cruising and wide open

Did you ever verify fuel pressure and your fuel pump rod not worn ? Pull your old fuel pump off and pull the fuel pump rod out through hex plug hole under the fuel pump - Get this fixed first , or verify proper fuel pressure

Then we can talk for months about the 1407/1411 Edelbrock carb issues

 

[oldbee]

I see you have two threads running

Looks like you have a multitude of fuel issues

A 1407 / 1411 Edelbrock 750 is notorious for a off idle hesitation issue

However in another post your talking fuel pressure/pump issues while cruising and wide open

Did you ever verify fuel pressure and your fuel pump rod not worn ? Pull your old fuel pump off and pull the fuel pump rod out through hex plug hole under the fuel pump - Get this fixed first , or verify proper fuel pressure

Then we can talk for months about the 1407/1411 Edelbrock carb issues

Boy, it sure sounds like a problem with acc.pump. Fuel pump/rod shouldn’t cause that problem. Remember KK’s post on other post. Your problem is “now”, not later. Bump timing a little?

 

[1967coronet]

I seen dvw mentioned the pump rubber cup. That made me think about the difference in the blue plunger and red ones.
the blue ones seem to loose their shape or well wall contact way sooner than the red ones. May be that any ethanol in the fuel makes that happen , not sure, but from my own use the red plunger rubber is the one I want.

 

[Dragon Slayer]

If your issue is truly a delay in the accel pump shot, making sure height is adjusted correctly, that the fuel inlet check valve does not leak back into bowl, making sure the check needle under the jet housing doesn't allow fuel to leak back to the chamber. Also good seal with the pump seal, which also means make sure the cylinder walls are not damaged or enlarged.

Lastly, the way to get a faster shot is to increase the spring tension on the accelerator pump. Moving linkage has nothing to do with how fast the shot is. It controls duration of the shot, along with the spring. Many stock springs are weaker and when the arm starts moving the first thing that happens is the spring collapses and shaft of the pump which can move into the head does. All while the actual head of the pump does not move until the rod bottoms and physically moves it. Once the shot is completed (arm no longer moves) that compressed spring releases and continues to push the piston down giving some extra duration of shot until the high speed circuit has sufficient air flow to provide the necessary fuel/air mixture at the right ration.