750 Edelbrock issue

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Not one Edelbrock carb I’ve ever seen has liked excessive fuel pressure. Holleys, yea they can take a little more but the Ebrocks blow the needles off the seats pretty easy in my experience. I’ve tuned a few and always the first thing I do now is set the floats correctly (even if brand new), and make sure it has no more than 5.5psi of fuel pressure. That’s step one.
 
TT5.9mag said:
Not one Edelbrock carb I’ve ever seen has liked excessive fuel pressure. Holleys, yea they can take a little more but the Ebrocks blow the needles off the seats pretty easy in my experience. I’ve tuned a few and always the first thing I do now is set the floats correctly (even if brand new), and make sure it has no more than 5.5psi of fuel pressure. That’s step one.
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Thought the same thing after a previous post.
 
E28C94B7-9272-4B71-987A-E73579E677F6.png

Straight from the horses mouth.
 
RRR was saying about timing i have my vac advance hooked to ported, but I am reading older cars should be hooked to manifold vacuum. So that there would give me advance. Distributor is a MP electronic kit from Mopar Performance but it is about 20 years ago I bought it.
 
Dartswinger70 said:
RRR was saying about timing i have my vac advance hooked to ported, but I am reading older cars should be hooked to manifold vacuum. So that there would give me advance. Distributor is a MP electronic kit from Mopar Performance but it is about 20 years ago I bought it.
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But you set it to initial per 1970 Dart specs????

So, in some situations using maniflod vacuum to bring additional advance at idle is a handy way to overcome certain issues with the advance curve.

But if you are using a MP distributor built by Chrysler (as opposed to Mallory) then that's not an issue at all. Set up the way MP/DC says to and it will be very close to what the engine wants for best power under all situations. If its the Mallory built version, we can make it work, but it will take a little more effort. (Send me a PM and we can just do it in person.)

Please see post #19 and the link.

Regardless. 12 to15* BTDC in the range of 600-750 rpm should be close enough not to have major issues. It should be close enough to be tuning it in. There's no reason to be adding significantly more timing at those rpms.
16"Hg is strong at those rpms would be strong. But if idle is at something like 900 rpm, then 12-15* is retarded.
 
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With the cap off you can look down an see the different mechanism
or just pull the rotor to see whether the shaft is bronze or steel
Inside Distributors
 
Mattax said:
But you set it to initial per 1970 Dart specs????

So, in some situations using maniflod vacuum to bring additional advance at idle is a handy way to overcome certain issues with the advance curve.

But if you are using a MP distributor built by Chrysler (as opposed to Mallory) then that's not an issue at all. Set up the way MP/DC says to and it will be very close to what the engine wants for best power under all situations. If its the Mallory built version, we can make it work, but it will take a little more effort. (Send me a PM and we can just do it in person.)

Please see post #19 and the link.

Regardless. 12 to15* BTDC in the range of 600-750 rpm should be close enough not to have major issues. It should be close enough to be tuning it in. There's no reason to be adding significantly more timing at those rpms.
16"Hg is strong at those rpms would be strong. But if idle is at something like 900 rpm, then 12-15* is retarded.
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The Chilton manual i have calls for 5 btdc,the engine didn't like that. It is set to 12 btdc
 
Found some gunk at the transfer slots. Came out of idle mixture ports. I guess I'm cleaning it out. I suspect plugs fouled also may get anew set

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I did recently hook this back up to the gas tank. No I didn't clean it out. This crud may have come from the tank but I would think the filter would have caught it.
 
I did throw my 600 Holley on last night but its running bad misfiring. i figure plugs fouled. I picked up a set of plugs at autozone during lunch and two cans of carb clean. i am going to throw the plugs in, and see if I can set timing Then set up the Holley. then open the edelbrock see the extent of the crud inside.
 
What I've found so far is a gunned up 750 carb, fouled plugs. I picked up another set of plugs, installed my 600 Holley. I believe it's a 1460, the one with vac secondary and a metering plate on the secondary side. It's a common carb. I was able to check and a just timing at 12btdc, set idle at 850, with 16 in of vacuum. Now I am wondering if the 750 can be saved...I am going to open it up and take a look. The Holley is nice, it seems like better throttle response at idle, more responsive.
 
Don't care what Edel says, the AFB/AVS carbs will take a LOT more pressure than 5.5 psi. What more pressure does is raise the fuel level slightly, which might be what Edel is warning against. Flooding on AFB?AVS/TQ carbs is not a problem [ within reason ] because of the high leverage of the float assy. I have run 10 psi at the track to raise fuel level, never a hint of flooding.

Plus, the E carbs come with a tiny 0.0935" n/seat. In contrast, the Carter Comp series AFBs had 0.101" needles & seats. The smaller size can handle more pressure before it is overcome with excessive pressure. The Carter mech strip pump M4862 for BB Mopars is rated at 8.5 psi. Street pump M6903 is 6 psi.
 
Dart,
That 750 carb looks a mess. A thorough clean up/out should have it working perfectly.
 
Dartswinger70 said:
I did recently hook this back up to the gas tank. No I didn't clean it out. This crud may have come from the tank but I would think the filter would have caught it.
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Fuel filters will catch particulate matter to a degree, but not contaminants that are suspended in the solution. If the tank is not clean, you may have a repeat performance with the Holley carb as well. The Edelbrock carb can be taken apart & cleaned while you put a rebuild kit into it. If you have any thought that the tank is dirty, you should pull it and get it to a radiator shop to hot tank it. At the very least you should consider putting some fuel system cleaner into the tank for a few tanks to clean things out. Change your fuel filter a few times & use carb spray to clean the carb bores until the gunk is all cleaned out.
 
Did you ever get that carb working properly? If you buy an AVS2 get the off road version. I did and it's almost like FI.
 
I did. It was a bunch of gunk from the tank pumped through. fouled plugs etc. I replaced plugs ,opened carb and cleaned out got it back up and going. I just had it running the other night and it was a "cold start" in the 40s here in Pa. Once I got gas pumped up through the lines it started up. The car is going back together so it doesnt get started every day
 
Dartswinger70 said:
I did. It was a bunch of gunk from the tank pumped through. fouled plugs etc. I replaced plugs ,opened carb and cleaned out got it back up and going. I just had it running the other night and it was a "cold start" in the 40s here in Pa. Once I got gas pumped up through the lines it started up. The car is going back together so it doesnt get started every day
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Very good. I just rebuilt one of these and the varnish from the old gas had plugged some of the holes in the primary venturi secondairys. After poking them with wire and spraying carb cleaner through then I put a rebuild kit in it with orange stepper rod springs and rejetted it for my elevation. A lot of these carbs come set up to run way lean and run like crap till you put the orange spring in and stepper rods for your elevation. I ended up with 9 sets of stepper rods before settling on the ones that get the best cruise mileage but have zero hesitation and run hard.
 
Bewy said:
Plus, the E carbs come with a tiny 0.0935" n/seat. In contrast, the Carter Comp series AFBs had 0.101" needles & seats. The smaller size can handle more pressure before it is overcome with excessive pressure. The Carter mech strip pump M4862 for BB Mopars is rated at 8.5 psi. Street pump M6903 is 6 psi.
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Carter calls for different float height settings for different needle and seat sizes. Float height setting affects primary booster flow simply because a higher float height setting places the fuel closer to the booster outlet.
 
I do not understand how Edel arrived at the 7/16" float setting. The Edel AFB body casting is the same basic casting as the Carter AFB, yet some AFBs had float settings as high as 3/16". Which makes the Edel setting a full 1/4" lower & that is huge with float settings; plus, the E carbs use the tiny 0.0935" n/s, which keeps the fuel level even lower. I often wonder how many 750/800 Edel AFB/AVS carbs that performed poorly on the top end was simply because of insufficient fuel supply.
 
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