Help choosing a replacement carburetor

[Gary Lewis]

The 4180 is a peculiar carb.

I had one on my '85 Mustang, and my '87 f-250 as well.

They are jetted VERY lean.

The early ones had "4 corner idle"... there were mixture screws for each barrel.

(Consider the implications of that!)

Later ones like on the truck only had two mixture screws in the front.

Covered by hardened steel plugs to comply with federal "tamper proof" mandate.

Front and rear bowls had large elbow vent tubes that connected to the dual charcoal canisters by way of vacuum actuated check valves.

If you use a 4180 you're going to need all this emissions stuff installed.

Also note the carb body itself has different passages and a fixed metering plate front and rear.

You aren't able to change any jets in order to tune them.

So without a calibration code for your engine (or the blue anodized tag off the stock carb) it is going to be a challenge to get an exact match for which carburetor came on your engine.

With a calibration code and a VIN, Gary may be able to give you a part number for the 4180 you need.

But you're going to be stuck with whatever tune it has.

I may actually have a 4180 that would work. If I remember correctly it came from an '85 351HO, which should be the same engine Steve has.

But personally, I'd rather have the Eddy. As you point out, Jim, the 4180 isn't adjustable. It is a serious emissions carb. The Eddy is adjustable and if Steve has someone to help him I think it can be tuned to pass the test.

[ArdWrknTrk]

I may actually have a 4180 that would work. If I remember correctly it came from an '85 351HO, which should be the same engine Steve has.

But personally, I'd rather have the Eddy. As you point out, Jim, the 4180 isn't adjustable. It is a serious emissions carb. The Eddy is adjustable and if Steve has someone to help him I think it can be tuned to pass the test.

I guess the $64,000 question is whats required in central NY state?

I know here in Westchester, NYC and Long Island pre OBD II vehicles get a chassis dyno and only a cursory glance under the hood.

Remember that the over 8,500 gvw 250's with a 351 HO were non-catalyst and were exempt from the tune a 150 would have.

If Steve has a functioning AFB it can definitely pass the sniffer (and it won't cost a penny, let alone $565)

[Steves Lariat]

I guess the $64,000 question is whats required in central NY state?

I know here in Westchester, NYC and Long Island pre OBD II vehicles get a chassis dyno and only a cursory glance under the hood.

Remember that the over 8,500 gvw 250's with a 351 HO were non-catalyst and were exempt from the tune a 150 would have.

If Steve has a functioning AFB it can definitely pass the sniffer (and it won't cost a penny, let alone $565)

I was told by a garage that, similar to how Jim described the Westchester/NYC area, the truck wouldn't get a deep dive into the emissions during inspection. But it def won't pass with the hosing disconnected. You have to make a show of it at least.

Part of why I considered replacing the Edelbrock is I figured the issues with the poor performance right now are related to the aftermarket carb or the way it was set up. But as some have pointed out, it may be that with a kick-down linkage adapter and other fixes, the Eddy will run a lot smoother and I won't have to spend the money.

 

 

[LARIAT 85]

But personally, I'd rather have the Eddy. As you point out, Jim, the 4180 isn't adjustable. It is a serious emissions carb. The Eddy is adjustable and if Steve has someone to help him I think it can be tuned to pass the test.

The Edelbrock is a *universal* carburetor that is designed to work on any engine, while the Motorcraft 4180 is specifically calibrated for a particular [stock] application. Engine design, vehicle size and weight, and even transmission type was all taken into account when these were calibrated from Ford. That means - assuming you get the right one and the engine is relatively stock - it requires minimal adjustments to work well.

The Motorcraft 4180 has annular discharge boosters on the primaries, which atomize fuel almost as well as fuel injection. And the choke system works much better than anything the aftermarket offers. Yes, it is a "serious" emissions carburetor, but that also makes it a very "precise" carburetor. This was the very last carburetor designed by Ford, which means it was also the most accurate carburetor they ever offered.

I used to think those steel "tamper-proof" plugs were silly, too. But I get what they were trying to do. The plugs were put there to stop people from mis-adjusting the air/fuel mixture to cover up other engine problems. This usually hurt economy and emissions. In most cases, the carburetor is not the problem. If the carburetor isn't easily adjustable, then someone is more likely to look elsewhere to find and fix the real problem.

There are plenty of guys over on the four-eyed (1979 - 1986) Mustang forums that still run the Motorcraft 4180 with great results. The jets, power valve, and accelerator pump squirters can all be adjusted and tuned with Holley parts to run better on today's fuel.

 

[ArdWrknTrk]

I was told by a garage that, similar to how Jim described the Westchester/NYC area, the truck wouldn't get a deep dive into the emissions during inspection. But it def won't pass with the hosing disconnected. You have to make a show of it at least.

Part of why I considered replacing the Edelbrock is I figured the issues with the poor performance right now are related to the aftermarket carb or the way it was set up. But as some have pointed out, it may be that with a kick-down linkage adapter and other fixes, the Eddy will run a lot smoother and I won't have to spend the money.

 

 

You said "Edelbrock Racing", do you know if your truck wears an AFB or an AVS?

There are some subtle differences in how you tune them.

But in my experience, if properly chosen, Edelbrock's run pretty well right out of the box.

Poor performance can be a lot of things.

Plugged Cat

Worn out timing chain

Even a dirty fuel filter

A baseline tune-up with new plugs, rotor, filters and check the timing will eliminate a lot of possibilities.

But something like a worn out cam gear will have it sluggish, rich and spitting out the carb.

 

[ArdWrknTrk]

But personally, I'd rather have the Eddy. As you point out, Jim, the 4180 isn't adjustable. It is a serious emissions carb. The Eddy is adjustable and if Steve has someone to help him I think it can be tuned to pass the test.

The Edelbrock is a *universal* carburetor that is designed to work on any engine, while the Motorcraft 4180 is specifically calibrated for a particular [stock] application. Engine design, vehicle size and weight, and even transmission type was all taken into account when these were calibrated from Ford. That means - assuming you get the right one and the engine is relatively stock - it requires minimal adjustments to work well.

The Motorcraft 4180 has annular discharge boosters on the primaries, which atomize fuel almost as well as fuel injection. And the choke system works much better than anything the aftermarket offers. Yes, it is a "serious" emissions carburetor, but that also makes it a very "precise" carburetor. This was the very last carburetor designed by Ford, which means it was also the most accurate carburetor they ever offered.

I used to think those steel "tamper-proof" plugs were silly, too. But I get what they were trying to do. The plugs were put there to stop people from mis-adjusting the air/fuel mixture to cover up other engine problems. This usually hurt economy and emissions. In most cases, the carburetor is not the problem. If the carburetor isn't easily adjustable, then someone is more likely to look elsewhere to find and fix the real problem.

There are plenty of guys over on the four-eyed (1979 - 1986) Mustang forums that still run the Motorcraft 4180 with great results. The jets, power valve, and accelerator pump squirters can all be adjusted and tuned with Holley parts to run better on today's fuel.

Rick, I get what you're getting at.

Don't mess with success

And if you have a concours (all stock) truck I understand.

The 4180 in my truck didn't have jet plates like my 'notch, or the one pictured in the article you linked.

There were a bunch of differences between the two, and why I said the pn needed to be identified before ordering a 4180.

I did have a chuckle at photo 20 where hot rod shows some generic 750 with a StubStack.

(750 because it has a dual feed log on the right)

The steel plugs are there because the federal government mandated the carb to be tamper proof.

The same reason the choke cap was held by breakaway screws.

And (on my truck's carb) just pressed orifices in the metering plates.

Whoever butchered the base flange to get those plugs out should have their tool box taken away.

There's NO reason for that except you're lazy and don't know how to use a drill.

 

[Whisler]

I was told by a garage that, similar to how Jim described the Westchester/NYC area, the truck wouldn't get a deep dive into the emissions during inspection. But it def won't pass with the hosing disconnected. You have to make a show of it at least.

Part of why I considered replacing the Edelbrock is I figured the issues with the poor performance right now are related to the aftermarket carb or the way it was set up. But as some have pointed out, it may be that with a kick-down linkage adapter and other fixes, the Eddy will run a lot smoother and I won't have to spend the money.

 

 

If you need the kickdown linkage I will send you mine for free. It was too much of a pain to hook up and I don't need it as I use a ratchet shifter and can just reach down and slap it into 2nd gear.

[Steves Lariat]

You said "Edelbrock Racing", do you know if your truck wears an AFB or an AVS?

There are some subtle differences in how you tune them.

But in my experience, if properly chosen, Edelbrock's run pretty well right out of the box.

Poor performance can be a lot of things.

Plugged Cat

Worn out timing chain

Even a dirty fuel filter

A baseline tune-up with new plugs, rotor, filters and check the timing will eliminate a lot of possibilities.

But something like a worn out cam gear will have it sluggish, rich and spitting out the carb.

Jim, still figuring out which model Edelbrock I have. The truck is at a local garage at present.

I probably should have said I'm turning to dealing with the carb after taking care of several other things, including: New ball joints, new tie rods, tightened steering box, new alternator, new battery (one with the proper CCA), new voltage regulator, new air filter, new fuel filter, new plugs and plug wires, oil change and new distributor cap.

 

[ArdWrknTrk]

Jim, still figuring out which model Edelbrock I have. The truck is at a local garage at present.

I probably should have said I'm turning to dealing with the carb after taking care of several other things, including: New ball joints, new tie rods, tightened steering box, new alternator, new battery (one with the proper CCA), new voltage regulator, new air filter, new fuel filter, new plugs and plug wires, oil change and new distributor cap.

Okay, that's great!

Beyond getting the charging and steering in order, having new tune-up components will eliminate a bunch of variables and possibly highlight your problem if it doesn't solve it.

You should take Whisler up on his offer.

Having the kickdown properly connected will make the truck easier to drive.

[Steves Lariat]

If you need the kickdown linkage I will send you mine for free. It was too much of a pain to hook up and I don't need it as I use a ratchet shifter and can just reach down and slap it into 2nd gear.

Hey, thank you. If I keep the Edelbrock, I'll take you up on that offer.