Carter (Edelbrock) tuning questions.

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RustyRatRod

I was born on a Monday. Not last Monday.
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I have an early Edelbrock carburetor on my 75 F250. 351M engine, 4 speed, 3.73 Dana 60. I have very limited tuning experience with these carburetors, although I have built a couple of hundred, I am sure.

This thing is very lean. I do not have the choke hooked up.....I live in Georgia. lol Anyway, when the truck is cold, it is so lean it will pop through the carburetor until it gets some heat in the engine. Once warmed up, it runs very well.

As far as I know, the carburetor is all stock. I did not built this one. I chanced it and bolted it on and it runs extremely well.....when warmed up.

I would like to richen it up a little. I have an Edelbrock tuning kit with springs and rods and jets. And I know changes can be made before you have to rejet. I would like to get by with just a spring and metering rod change.

How many steps rich would yall recommend? Thanks.
 
What’s your rod and jet combo now?
How is the lean/rich condition when it is warmed up?
And yup! Your gonna need that choke. If you don’t have one, I gotcha in that.
 
I guess my question is if it runs good warmed up why do you want to richen it up?
It really wont help it cold you just need to hook up the choke or let it run till it gets warm enough to drive.
 
I guess my question is if it runs good warmed up why do you want to richen it up?
It really wont help it cold you just need to hook up the choke or let it run till it gets warm enough to drive.

And that's a good question. The answer is, I want to try it, because it runs SO poorly cold. I know I could put a holley 650 on it with NO choke and it would be a big improvement. I like the Edelbrock though, so it stays.

Just because one runs well warmed up, doesn't necessarily mean it is optimum.

And rumblefish, I do not know what is in the carburetor now.
 
I would just put a manual choke on it, fix the cold running problem first then when it's hot pull a hill and slightly close the choke and see if it pulls harder or not.
It's a cheap test.
 
I would just put a manual choke on it, fix the cold running problem first then when it's hot pull a hill and slightly close the choke and see if it pulls harder or not.
It's a cheap test.

Yes it is. I might try it.
 
I recommend getting an air/fuel gauge you can look at while driving it around. I bought a new 750 and the springs/rod kit for my 48. It was too rich on the highway and I ended up using the leanest combo of jets and rods on the supplied chart to get it close. I never would have figured it out without the A/F gauge. I think it was 150 bucks or so from summit... I don't remember the brand.
 
I recommend getting an air/fuel gauge you can look at while driving it around. I bought a new 750 and the springs/rod kit for my 48. It was too rich on the highway and I ended up using the leanest combo of jets and rods on the supplied chart to get it close. I never would have figured it out without the A/F gauge. I think it was 150 bucks or so from summit... I don't remember the brand.

Yeah I knew that was comin. Aint happenin. lol I can tell when one is rich or lean. I just needed some guidance as to about how far to go. Evidently, no one has a clue, so I'll just try it myself. I can always put it back like it is, if I get it out of hand.
 
I would go up 2 steps in spring "stiffness", if you know what I mean. I would go 2 sizes smaller on the metering rods.

I will tell you, I twice had to pull 600 eddies off of my Dusters because the plugs were scary white, and neither have headers. I too, could tell they were lean. I now have Holleys on both, and it's a difference in how crisp they are on part throttle, and mph went up with both cars on the ET slip. But I get it, your running the Eddy, so I guess my suggestion is above.
 
Sorry Rob, leaning out the carb to run well when a choke is missing isn’t a good way to go about it and then let it ride like it is OK when it’s warm.

Sorry bud, I’m not handing out the answer out on this one.
Oh wait! I did, install the choke! ;)
 
Sorry Rob, leaning out the carb to run well when a choke is missing isn’t a good way to go about it and then let it ride like it is OK when it’s warm.

Sorry bud, I’m not handing out the answer out on this one.
Oh wait! I did, install the choke! ;)
rrr, as smart as u are, I`m surprised at u even asking this question. A re f---ing w/ these guys ? LOL
 
I’m no carb expert like you are Rusty. In my opinion these carbs are made to run on the street with a choke connected. It seems to me that would provide you with the richer mixture you need while the engine warms up and then once it is fully warmed a properly adjusted choke would be of no consequence.
 
I have to agree on the choke, and another plus would be the manual high idle for warm ups if you use a manual choke.
Then next spring you might not even have to use it if you don't want to.
That said, I also agree with 318willrun, in that two steps at a time is the common practice if there is a seat of the pants lean feel. (and obviously there is when cold)
Lets say you have 73/47 rods now, then 70/37 rods would be my attempt.
You can also check your metering rod springs first.
If you have yellow springs now, try pink, as this will allow the rod to come up out of the jets sooner and give a little more fuel earlier.

Man, I hate to see you go through all this over a choke.
It's getting winter time and it's just going to be worse.
 
do you have headers on it / does ford use a heat riser/heat stove from ex manifold?on my carbed chevy if I leave off the heat riser tube the throttle will ice up at abuot45degs and humid /theirs no coolant going through that intake manifold if I remember that could make take longer to warm up the engine if you have headers with no exhaust back pressure (just thinking out loud)
 
do you have headers on it / does ford use a heat riser/heat stove from ex manifold?on my carbed chevy if I leave off the heat riser tube the throttle will ice up at abuot45degs and humid /theirs no coolant going through that intake manifold if I remember that could make take longer to warm up the engine if you have headers with no exhaust back pressure (just thinking out loud)
also on a 318 dart I've been working on it has a very difficult time when cold because the heated port in the head is stopped up and we installed a performer manifold with new elderbrock carb and mopar air filter and that's with a electric choke the choke goes off before the engine fully warms up I hate those straight fans in the winter but great in summer
 
for 30 years I did not have a choke on the old 1970 340 avs-8 months a year in Mass.-pump it 5 times and go. last year I added a manual choke-half a plastic knife for a lever and a 5' piece of string=better-now I pump her twice and
 
If ur just guessing I would put in the smallest rods u have. Fords always seem to want more idle fuel that anything else. Kim
 
Sorry Rob, leaning out the carb to run well when a choke is missing isn’t a good way to go about it and then let it ride like it is OK when it’s warm.

Sorry bud, I’m not handing out the answer out on this one.
Oh wait! I did, install the choke! ;)


Well, we live in completely different climates. I have had precious carbureted vehicles with a working choke. All the Holleys I've had with no choke, busted right off and idled in all but the coldest conditions and even then only took maybe 30 seconds to a minute to idle. This one is way too cold natured. I do appreciate your input, but I am not trying to tune out leanness due to a missing choke. It is lean all the way around.
 
I would go up 2 steps in spring "stiffness", if you know what I mean. I would go 2 sizes smaller on the metering rods.

I will tell you, I twice had to pull 600 eddies off of my Dusters because the plugs were scary white, and neither have headers. I too, could tell they were lean. I now have Holleys on both, and it's a difference in how crisp they are on part throttle, and mph went up with both cars on the ET slip. But I get it, your running the Eddy, so I guess my suggestion is above.

That's about what I was looking for. Thanks. I will try it and keep yall posted.
 
Even on FL, my old cars need a choke to help warm up.

Simply not reinstalling the heat stove from the exhaust manifold on my 73 318 caused it to take noticeably longer to warm up and introduced a part throttle stumble- the kind that can cause the car to die when turning into traffic at an intersection.

Once warm- no issues at all.
 
Some of the Eddy carbs are very lean on the primary side right out of the box.
Any change you make in the rich direction will help. If your kit has richer (smaller) rods on the cruise step, try them first.
If you can't read the numbers on the current rods, check the size (diameter) with a caliper.
If the rods in the kit aren't richer, you'll have to change the main jets.
Try the next richer size, be conservative since your richening the whole primary side.
If you're new at this I'd take the carb off and do it on the bench, you don't want to drop any small parts on the engine!
Let us know how you make out.
 
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