500 cfm edelbrock carburetor...

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firefighter1

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Hi guys,

My friend gave me a brand new four barrel edelbrock carburetor. I put it on my stock 225 slant six engine and it seemed to work great. After a few days it started running rough. Is this carburetor too big for my motor? Thanks.
 
Pull the spark plugs, if they are black yes.
 
on a stock slant with stock compression, thats too much carb. since an engine is an air pump, you slant with the stock cam, intake and exhaust, cannot attain high enough air flow to make that carb work properly. even if you adjust jets and needles. you will run into bogging issues on acceleration.
 
slantscamp said:
on a stock slant with stock compression, thats too much carb. since an engine is an air pump, you slant with the stock cam, intake and exhaust, cannot attain high enough air flow to make that carb work properly. even if you adjust jets and needles. you will run into bogging issues on acceleration.
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He said it worked fine for a week (till it loaded up the plugs apparently)
I guess it depends on the definition of fine.
 
Haha. What can I do? I Had a Holley 390 on it and it was giving me hell. This carburetor seems a lot better. Acceleration is much better. I'll check the plugs. Any other ideas. I'd really like to try and make this work. If It's not possible then I'm back to square one.
 
Pull your plugs and check them out, I was having problems after about 300 miles then a freash set of these plugs did the trick :cheers:
been running fine for 7.000 mile in town driving :happy1:

If you have an old drool tube head remove the washer :-k
If this does clear it up, remember what TrailBeast said :happy1:
 

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memike said:
Pull your plugs and check them out, I was having problems after about 300 miles then a freash set of these plugs did the trick :cheers:
been running fine for 7.000 mile in town driving

I looked at the plugs and they look a little dark but not horrible. I'll replace them with the plugs from napa and see how she runs.
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Once that gets settled, you can go to the Edelbrock.com website and find out about jets and needles.

Good luck.



firefighter1 said:
memike said:
Pull your plugs and check them out, I was having problems after about 300 miles then a freash set of these plugs did the trick :cheers:
been running fine for 7.000 mile in town driving

I looked at the plugs and they look a little dark but not horrible. I'll replace them with the plugs from napa and see how she runs.
Click to expand...
Click to expand...
 
Holley 390 (4160) is too much carburetor for a stock slant six. A stock super six set-up would give the best economy and performance for a stock engine.
If you have too much carburetor, or in other words a carburetor that is substantially flows more air than the engine can pump, the carburetor will suffer from a poor vacuum signal, and can’t supply the correct air fuel mixture needed all the time. In other words the engine will be running lean, than rich, than correctly depending on throttle plate opening. You will experience bog off idle, perhaps poor idle, and chances are good that if equipped with vacuum secondaries they will never open.
 
I just replaced the plugs. The engine is running a little better. I am trying to reconfigure my throttle and lockdown linkage setup with his lokar bracket I just bought. I have and automatIc transmission so I need space to mount both my throttle and my kickdown cable and Im having trouble finding the right spots because of my headers and intake. Anyone have good pictures of their setups. What brackets do I need to properly complete this with an edelbrock carburetor? I have a Clifford intake and Clifford headers.
 
You need one of these to get correct synchronization between throttle opening, and throttle pressure lever (kick down) movement or the engine and transmission won’t work well with each other resulting in possible transmission damage. http://www.edelbrock.com/automotive_new/mc/carbs_acc/access_throttle.shtml

You also need a bracket that holds both throttle, and kick down cables. There are many stiles available at Summit, Jegs, etc.
 
Okay. I got a lokar bracket and it doesn't accommodate my throttle linkage also. I'm sure I could fabricate something up but it'd be ugly. So I'll keep looking on summit for the right bracket.
 
If you have a rod operated throttle connection to carburetor, you may need to convert to a cable setup used in 66 with air equipped cars, and 67 on up.
 
I already have a cable operated throttle and a cable operated lokar kick down linkage setup. I just don't have the proper brackets. I'm looking on summit and most of the brackets look like they'll work for one and not the other. I mist be missing something because I'm sure many many other people have hooked up their cables without a problem. Hmmm.....

Is it bad to have a sharp bend in the throttle cable right before it reaches the carburetor linkage?
 
Now that I have changed the plugs, I am on to the carburetor fuel air mixture. I went onto the edelbrock website and I did not see the jets and needles that I need. Does anyone have part numbers or direct link to the web page that has what I need to convert my 500 cfm edelbrock carburetor down to the proper size jets and needles for my stock 225 / 6 motor?
 
If the Eddy is anything like the Carter AFB/AVS, it doesn't use a jet like a Holley does, but metering rods. I don't know if there's something small enough for an Eddy in a street setup.




FWIW
  • The setup for the Holley 390 on an Offenhauser manifold for street is as follows: Primary jet 49, secondary jet 52, Power valve 25R-591A-65, PV channel restriction .052" , Idle air bleed .043", Diaphram spring yellow.
  • 625 cfm on a HyperPak manifold: Primary Jet 120-389 (.089"), Secondary Jet throttle side 120-350 (.050") choke side 120-365 (.065"), Metering rod 16-51 (.060" W.O.T. x .065" PT)
From personal experience I was unable to get the #52 secondary (plate) jet for a 4160 style Holley, so I installed an AES plate to convert it to a 4150. This allows use of standard Holley jets.
 
You can spend a lot of time fiddling with carb jets & rods and pulling plugs to guess at O/F ratio, because you are flying blind. Next time you have your exhaust pipe down, weld an O2 bung in it as close to the manifold as possible. Anybody doing exhaust work should do this. You can install a plug until needed. You can get a small "rich/lean" box from Holley or MSD to use with any 3-wire O2 sensor. I got several for ~$25 off ebay, one was even new ($175 retail). Even better is wideband O2, but you might pay $100 used ($300 retail). Any muffler shop can quickly weld a bung in (use 3/4 hole saw). I even managed with my $90 Harbor Freight welder.
 
Your slant will run fine with an Eddy 500.
I ran one on a stock slant with the same Clifford intake/headers.
Took it out of the box,adjusted the A/F and idle and away I went.
Just a little understanding an tweaking is all thats necessary
For starters,make sure the floats are set correct.
Blow out all jets and passages with compressed air to make sure nothing is blocked.
Slap it on.
Make sure the A/F screws are set correct at idle.
Make sure you have the optimum timming setting.
If you think your rich in cruise mode,do a simple rod change. (couple sizes bigger).
You can also adjust the pump shot,on the arm.
With the vacuum secondarys,youll be fine at WOT.
We havent seen the rest of your car,so we dont know that it is running rough because of the carb.I will take your word that everything else is up to par.
With a little understanding of how the carb works,and a little tweaking,it will be fine.
 
It defiantly runs and it runs pretty nice. It's a rebuilt motor about 5k ago. All stock. It's complete and was my daily driver until I got another car. The timing has been locked in with the previous holley 390 that i had on it. I'll definitely play around with it some more. Are there any good instructional videos for tuning edelbrocks?
 
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