Edelbrock 1407

[mvent]

Removed carb to put an insulator clean carb and check transition slot exposure. Couple of questions before putting it back together, any pros or cons to going higher or lower with float height dimension from stock 7/16” ? And also I’ve read that Herb Mc Candless at a seminar suggested leaving the weight out above the ball in squirter, makes sense to me, has anyone tried it with positive results?

 

[1967coronet]

I have never pulled the brass weight.
What problems are you having ?
Have you put vacuum gauge on and tuned it ? Springs , rods ect.

 

[mvent]

I have never pulled the brass weight.
What problems are you having ?
Have you put vacuum gauge on and tuned it ? Springs , rods ect.

Only issue I have is a very small hesitation right off idle when very slowly easing into the throttle, if I step into it more no hesitation.
I have used vacuum gauge, changed springs, changed pump hole position, advanced initial timing etc. One of the reasons for removing carb was to take a look at transfer slots which appeared to be more exposed than ideal.

 

[1967coronet]

Have you checked fuel pressure ?
Also just to toss this in....
Sometimes carbs get blamed for ignition advance springs and weights problems.
I know something like a little stumble will drive you nuts when all else is working.

 

[khryslerkid]

Get the orange accelerator pump if you're using the blue one. Todays gas will ruin the blue one. It's one of the main causes of hesitation off idle.

 

[Geoff 2]

What engine size, cam specs, timing at idle?

I would NOT change float height. For reasons known only to Edel, they went lower than the original AFB. Only reason I can think of is that less likely of misfire from cornering/sudden stop where fuel could slosh into the t/bores. Going to a smaller float setting [ raising the fuel level ] increases this possibility.

 

[YY1]

Just about the only modification I've had to do on any of these is to bend the accelerator pump arm to increase the shot.
...and that is after putting it in the max shot hole.
Every one I've tuned on every engine (even stock 318) has needed this to get rid of the slight, off idle hesitation.

 

[mvent]

G engine is 440, automatic,3.23 gear, initial timing 22* btdc.

 

[mvent]

Cam is unknown have 14-15 hg in park 10 in drive

 

[Geoff 2]

Well, there is your problem: 10" of vac in gear.....That leads to other problems. PCV is probably not working with 10", likely that it is vibrating/oscillating letting in more air than it should.

With car in gear, put your hand on the PCV. If you can feel movement, it is not working properly.

You are also going to need a LOT more timing at idle, which will improve vac. Try turning the dist, engine idling, to about 35*. Rpm & vac should increase, idle gets smoother.

On a Carter/Edel 4bbl carb, AFB, AVS, TQ, I have never had to use the inner holes on the acc pump arm because the metering system is so efficient.

 

[mvent]

G thank you for the info, 22* is vacuum disconnected, when connecting to manifold vac it increases to 32* but I neglected to check vacuum number. I really didn’t like the rpm drop from park to drive if I remember correctly it was a 200rpm drop. But if it brings vacuum up enough for smooth idle I’ll live with it.

 

[YY1]

Timing and idle mixture to minimize RPM drop is one of the first tuning issues to resolve.

What cam?

Have you ruled out a vacuum leak?

That could potentially cause both issues-

High idle RPM and drop to drive.
Off idle stumble.

 

[mvent]

YY1, yes agree, went through carb to clean, checked idle speed screw to check where it needs to be to get .020 exposed transfer slot, reset float height and drop, new pump assy going to start with yellow step up springs hopefully with vacuum from manifold it will increase vacuum . Car does not have power brakes, going to put Edelbrock insulator under carb.

 

[Geoff 2]

Post #11. Sounds like you have vac adv connected to a man source [ MVA ]. That is GOOD. But that often leads to quotes suçh as 'MVA didn't work for me', when the real problem is the MVA was not dialled in... MVA itself was not the problem.
The fact that MVA only added 10* of timing makes me suspicious that the VA is not fully deploying. Chrys units I have used have about 22* of range, some have 30*. Unless your dist has a travel stop made for the VA, then I suspect that when you put the car into gear, the extra VA timing is dropping out causing a large drop in rpm.
You have to use an ADJUSTABLE VA unit, with the Allen screw wound fully CW as a starting point. Using MVA is also in the Edel tuning instructions.
Dialling in MVA is a process of tuning; it has to be done in the correct order....such as tuning the carb. You get the float level correct BEFORE you change jets.

Did you check the PCV?
A PCV that is oscillating at idle will play HAVOC with setting idle speed & idle mixture. There is an easy fix.
More on MVA & idle timing...

 

[Geoff 2]

Post #11. Sounds like you have vac adv connected to a man source [ MVA ]. That is GOOD. But that often leads to quotes suçh as 'MVA didn't work for me', when the real problem is the MVA was not dialled in... MVA itself was not the problem.
The fact that MVA only added 10* of timing makes me suspicious that the VA is not fully deploying. Chrys units I have used have about 22* of range, some have 30*. Unless your dist has a travel stop made for the VA, then I suspect that when you put the car into gear, the extra VA timing is dropping out causing a large drop in rpm.
You have to use an ADJUSTABLE VA unit, with the Allen screw wound fully CW as a starting point. Using MVA is also in the Edel tuning instructions.
Dialling in MVA is a process of tuning; it has to be done in the correct order....such as tuning the carb. You get the float level correct BEFORE you change jets.

Did you check the PCV?
A PCV that is oscillating at idle will play HAVOC with setting idle speed & idle mixture. There is an easy fix.
More on MVA & idle timing...

 

[Geoff 2]

And...

 

[mvent]

Pulled distributor cap off and connected Mitivac to canister, plate starts moving at 6hg and stops advancing at 12, holds pressure fine. Not sure what this means in terms of vacuum advance. Carb is not back on yet so not sure on PCV. Hopefully weather holds out. Is dimension of accelerator pump arm above carb body critical?

 

[Dave6T4]

I found my vacuum advance worked best when turned 1-1/2 turns clockwise from rest. You can adjust 1/4 turn at a time from there for your best. This is with ported VA. Fairly stock 440 Magnum with 1407 Edelbrock. One stage fatter (leaner) metering rods and one stage lighter springs from stock Edelbrock.

 

[mvent]

Checked vacuum canister today, found it fully CW.

 

[Geoff 2]

What is the idle vacuum with the VA unit connected to manifold vacuum? The man vac port is the lower port on the front of the carb.