Edelbrock carb question

[nqkjw]

The problem with Edelbrocks is that their pump shot is not very big(compared to a holley)thus making it harder to overcome flat spots.
You'll get there.
Just gotta think outside the box a little more.
Usually the yellow stepup spring works best with low vacuum cams.
Also rods with a really small second number so you run richer when you stand on it.

My 2c

[shadango]

The problem with Edelbrocks is that their pump shot is not very big(compared to a holley)thus making it harder to overcome flat spots.
You'll get there.
Just gotta think outside the box a little more.
Usually the yellow stepup spring works best with low vacuum cams.
Also rods with a really small second number so you run richer when you stand on it.

My 2c

My problem is I cant seem to tell which springs are yellow......I guess the paint is worn off....LOL

re: the rods.....do you also have to change  the jets when you change rods?

I tried reading the edelbrock tuning guide a couple of times...just made my brain ache.  LOL

[nqkjw]

With edelbrocks a jet change is a big change.
A rod change is a small change.
The two don't need to be changed together although they can be.
If you have a rod size of , say,6862 (just inventing numbers here as an example,not sure what yours are)then changing to a,say,6847 will maintain your same light throttle characteristics while riching it when you stand on it.
You really need to get the stepup springs right first.Think of the stepup spring the same way you'd think of a powervalve in a holley and you'll be on the right track

A couple of general rules to guide you.
Flat spots mean lean 99% of the time.It's actually very difficult to tune so rich as to cause a flat spot.
Low vacuum cams mean a poor vacuum signal to the carb which means less fuel pulled through so you have to tune richer to compensate.

[Bullitt-]

This may or not be of help but you need to know

"Idle transfer slots
Pay close attention to the idle transfer slots(rectangular)in the front of the primary bores of the base plate. When the carb is correct in cfm's and jetting, the slots will only show a square when the butterflies are in the normal idle postition. If the slot is a rather large exposed area, the carb will need the inital timing bumped up which will increase the idle speed and will allow the idle speed screw to be backed down, thus exposing less of the transfer slot. If the slot is less than a square, back off the inital timing and crank up the idle speed."

[Supercuda]

This has not yet been mentioned as a possibility, but also could cause some issues. If there seems to be no change inthe flat spot, it is possible that the secondaries are getting more air than they should, off idle. This isa rare occurence with AFB-styled carbs, but does happen. Perhaps the air valve is not heavy enough, allowing secondary response before there is sufficient fuel flow to cover the additional air. To check for this possibility, tape the secondary air valve closed, and launch the car. If the flat spot is gone, the problem is a light air valve, and more weight on the counterbalance is needed. The problem is usually a heavy air valve, but this can happen with a radically-tuned engine. From the amount of tail-chasing that seems to have been involved in this problem so far, this is a possibility worth considering.

[shadango]

Supercuda....

I hjadnt thought of that.....will try it

One thing I noticed -- with air cleaner off, andworking throttle by hand, sure seems like secondaries dont open as far as I have seen others go.....I didnt think these are adjustable in the Eddies.   I think someone had posted in another thread that you would have to drill out the counterwieghts to lighten them etc....

[Supercuda]

You either drill holes in, or grind material off of the counterweights. It's a pretty drastic tuning step, so it should be considered only if it definitely turns out to be part of the problem. This has always been a sore point for AFB tuners, as springs are soooo much easier to work with. If you wind up doing this step, make no radical changes to the counterweights; taping small washers to the counterweights might be a good first step in experimenting with this. The usual problem is that the weight is too much; yours would be somewhat unique in needing more weight. Good luck and keep posting.

[shadango]

Changing to the orange springs did seem to help some, but then again the weather has been dramatically cooler.....thinking heat could have a play in this too.....so may not know the actual results of the spring change til the heat comes back....

[UKcuda]

What rods and jets have you actually got in there?

I wrote a spread-sheet for calculating the overall percentage change when you change rods and/or jets.  It's just based on a bit of simple circle geometry but it's a lot more flexible than the Edelbrock tuning charts.  I'll try to attach it.

You just change the rod/jet numbers and it tells you how much difference you are making plus or minus as a percentage of the existing.  The "existing" is set up as an Edel. 500 stock jetting but you can make it whatever you like.

OK, it's not an allowed file type - PM me your e-mail and I'll e-mail it to you.

[shadango]

Thanks, will PM ya.

I am moving in the right direction......doesnt do it as much....but still, when the idle settles down and then I try a quick pedal, it does it.

Wondering if the carb is loading up at idle?   I know my exhaust smells really rich and whatnot.....no black smokethough and last time I checked the plugs they looked fine.....

[UKcuda]

I've sent it.

They are quite sensitive to fuel level so if its filling up a bit too much perhaps 

What rods/jets have you got?

[shadango]

Thanks

Re:float level...I set itper the edelbrock site's instructions a couple times and then ended up setting it a bit higher cause I thought I was flooding out.....just a hair, per the tech at edelbrock.  I wrote down the setting and the rods/jets in there now but cant find it...LOL....will gave to put it apart to see I guess....

One thing about setting the float.....where is the correct reference point on the float? The picture they provide is kind of vague...maybe thats where I am going wrong...

[UKcuda]

Yeah I know what you mean - the float setting spec. is a bit vague - but I was thinking more like maybe you have an inlet valve bleeding in a bit too much fuel.  So when you let it idle for a while it is filling up.  It's a long shot though.

On a fairly ordinary engine like yours (no offense) you shouldn't be having any real problems with close to basic settings.  Like I'm dubious about whether your pump shot was ever too small.

That's why I'm wondering what your rods/jets actually are.