A box stock 4160 vs. a stock (rebuilt) 4180 - Head to Head Test (non-scientific)

[BigBrother-84]

if you live in the "twittersphere" consider yourself forewarned!

I am not! I really enjoy detailled threads, and I simply LOVE you way of writing!

Consider me as a "follower".

This thread is so interesting, the fuel cost is necessarily becoming more and more of a concern, for couple of us.

Keeping reading at your unscientific observations!

[mat in tn]

if you live in the "twittersphere" consider yourself forewarned!

I am not! I really enjoy detailled threads, and I simply LOVE you way of writing!

Consider me as a "follower".

This thread is so interesting, the fuel cost is necessarily becoming more and more of a concern, for couple of us.

Keeping reading at your unscientific observations!

personally, I prefer your scientific approach. it's a real-world type of analysis. I doubt any of us live in labs. all that matters is what do we get from the way we use our trucks. i just drove 1k miles pulling a 5x10 box trailer with my expedition. 5.4, efi, ohc etc. 10.5 mpg and I did not fly up any hills, that's for sure. when I drove this route years ago in my e350 with a 5.8, efi, e4od I could expect 13.

I'm not willing to buy a 75k dollar eco whatever to get 5 more mpg. but I know more is there to be had. not building an eco-truck yet but I may. my best mpg is from a 92 flareside with a 5.0 and got three more mpg pulling that same trailer.

[Jake Papageorge]

OK everyone, the new EGR valve showed up yesterday morning and by lunchtime, it was on the truck. I ran up to the Marathon station, took a quick fuel sample, filled the truck until the handle popped, and went about my days adventures! I had some service calls today, and under normal circumstances, I would take my MINI cooper because I can put as much as 250 miles on the ODO a day! Today, I took the Buffalo!

I ran the truck in mixed driving conditions for 152 miles before the engine started to sputter, forcing a fuel tank switch. I stopped at the filling station and it took 18.2 gallons to pop the pump handle. I got home later that day, and tested the fuel, still, just around 11%. Weather was a little bit cooler today, maybe on the average 5 degrees with moderate to high humidity.

The Results:

Do the math and the mileage increased to 13.5 MPG approximately. EGR definitely makes a difference in fuel consumption! Dont get me wrong, I knew it would, but these old mechanical EGR systems are kind of.....well you know.....

So a few observations citations:

The Vacuum arrangement was 100% all factory! Everything hooked up properly and EGR valve was validated for proper operation.

Keep in mind that these engines use a POSATIVE backpressure EGR valve. The positive backpressure EGR valve. A Positive backpressure EGR valve has a bleed port and valve positioned in the center of the diaphragm. A light spring holds this bleed valve open, and an exhaust passage is connected from the lower end of the tapered valve through the stem to the bleed valve. When the engine is running, exhaust pressure is applied to the bleed valve. At low engine speeds, exhaust pressure is not high enough to close the bleed valve. If control vacuum is supplied to the diaphragm chamber, the vacuum is bled off through the bleed port and the valve remains closed. As engine speed and load increase, the exhaust pressure also increases. EGR flow ensues! What does this all mean?

YOU CANT TEST THIS TYPE OF EGR VALVE WITH A VACUUM PUMP ALONE! You can pump until the cows come home, it wont move! It NEEDS backpressure to operate! So if you do what I did and hollowed out the catalyst, EGR flow is going to suffer a little bit.

OK....that's it! I guess I would monkey around with the timing a little to try to squeeze a little more out of her, but this is starting to cut into my "social fund" so I am all ears! Anyone else have any suggestions on how to squeeze about 3 to 4 or 5 more out of this flying fortress? All the tune up and maintenance type stuff has been done and the fresh air hose IS connected on the air cleaner!

BTW......anyone else notice that you will get a LOT of respect driving one of these trucks vs the every day cruiser? Not the "hey what a nice old truck" kind of respect, but the "I had better get the hell out of that guys way" and the "No, I am not going to tail gate that battleship" kind of respect. As I stated earlier, I usually drive a MINI and NO ONE respects that thing except other MINI people! They tailgate, get in the way, drive like.......well......you know........

 

[Gary Lewis]

OK everyone, the new EGR valve showed up yesterday morning and by lunchtime, it was on the truck. I ran up to the Marathon station, took a quick fuel sample, filled the truck until the handle popped, and went about my days adventures! I had some service calls today, and under normal circumstances, I would take my MINI cooper because I can put as much as 250 miles on the ODO a day! Today, I took the Buffalo!

I ran the truck in mixed driving conditions for 152 miles before the engine started to sputter, forcing a fuel tank switch. I stopped at the filling station and it took 18.2 gallons to pop the pump handle. I got home later that day, and tested the fuel, still, just around 11%. Weather was a little bit cooler today, maybe on the average 5 degrees with moderate to high humidity.

The Results:

Do the math and the mileage increased to 13.5 MPG approximately. EGR definitely makes a difference in fuel consumption! Dont get me wrong, I knew it would, but these old mechanical EGR systems are kind of.....well you know.....

So a few observations citations:

The Vacuum arrangement was 100% all factory! Everything hooked up properly and EGR valve was validated for proper operation.

Keep in mind that these engines use a POSATIVE backpressure EGR valve. The positive backpressure EGR valve. A Positive backpressure EGR valve has a bleed port and valve positioned in the center of the diaphragm. A light spring holds this bleed valve open, and an exhaust passage is connected from the lower end of the tapered valve through the stem to the bleed valve. When the engine is running, exhaust pressure is applied to the bleed valve. At low engine speeds, exhaust pressure is not high enough to close the bleed valve. If control vacuum is supplied to the diaphragm chamber, the vacuum is bled off through the bleed port and the valve remains closed. As engine speed and load increase, the exhaust pressure also increases. EGR flow ensues! What does this all mean?

YOU CANT TEST THIS TYPE OF EGR VALVE WITH A VACUUM PUMP ALONE! You can pump until the cows come home, it wont move! It NEEDS backpressure to operate! So if you do what I did and hollowed out the catalyst, EGR flow is going to suffer a little bit.

OK....that's it! I guess I would monkey around with the timing a little to try to squeeze a little more out of her, but this is starting to cut into my "social fund" so I am all ears! Anyone else have any suggestions on how to squeeze about 3 to 4 or 5 more out of this flying fortress? All the tune up and maintenance type stuff has been done and the fresh air hose IS connected on the air cleaner!

BTW......anyone else notice that you will get a LOT of respect driving one of these trucks vs the every day cruiser? Not the "hey what a nice old truck" kind of respect, but the "I had better get the hell out of that guys way" and the "No, I am not going to tail gate that battleship" kind of respect. As I stated earlier, I usually drive a MINI and NO ONE respects that thing except other MINI people! They tailgate, get in the way, drive like.......well......you know........

I think you are doing very well to get to 13 MPG, and getting to 15 is going to be a major challenge. But what air pressure are you running? Have you played with ignition timing?

[Jake Papageorge]

I think you are doing very well to get to 13 MPG, and getting to 15 is going to be a major challenge. But what air pressure are you running? Have you played with ignition timing?

I run the tires pretty hard (45 PSI) and I would love to switch to a 31x10x15 tire from the 235's, but the tires on the truck are like new and road forced under 15 lbs. Seems like a waste to take them off.

I have jiggered around with the timing back when I first started the effort, but the truck being so heavy, the threshold for detonation on mid-grade fuel seems to be 36. I ran it at 38 and it started pinging and dieseling.

If it was not so much work, I would have loved to change the final drive gearing to 3.00 from 3.50, but I think if I was going to go to that much trouble, I would just assume put an AOD in there.

The good news is that school starts in a week so I will be able to go get on my chassis dyno. Maybe I can brainstorm a little and come up with a solution.

[Gary Lewis]

I run the tires pretty hard (45 PSI) and I would love to switch to a 31x10x15 tire from the 235's, but the tires on the truck are like new and road forced under 15 lbs. Seems like a waste to take them off.

I have jiggered around with the timing back when I first started the effort, but the truck being so heavy, the threshold for detonation on mid-grade fuel seems to be 36. I ran it at 38 and it started pinging and dieseling.

If it was not so much work, I would have loved to change the final drive gearing to 3.00 from 3.50, but I think if I was going to go to that much trouble, I would just assume put an AOD in there.

The good news is that school starts in a week so I will be able to go get on my chassis dyno. Maybe I can brainstorm a little and come up with a solution.

If you have already played with timing, then about all you have left to check is AFR, but it isn't likely you'll get much more MPG by leaning it out. And that leaves the tranny as the C6 is very inefficient.

But if you are going to tow you'd have to have a pretty serious AOD built. Ford didn't put them behind the 5.8L for a reason - too much torque. Yes, you can keep it out of OD for towing, but they really weren't built for that.

I think you'd be better off with an E4OD as you can probably get a mild one of those and a controller for about what a serious AOD would cost. And Ford put the E4OD behind the 460, so it can do it.

 

[Jake Papageorge]

Thank you for this anaylsis. I really enjoyed reading that!

The results are just what I expected. So many people are quick to dismiss the Motorcraft [Holley] 4180 as an "emissions" carburetor that should be replaced. Yes, it is that - but the 4180 is also one of the most *precise* carburetors Ford ever built. The primaries have annular boosters, which atomize fuel almost as well as fuel injection. The 2-stage power valve is much more precise than a standard single stage. (I am actually surprised you manged to find one.) And like you said, the choke system found on the 4180 is far superior to any other found on aftermarket carburetors. Ford engineers knew what they were doing when they designed these. There is actually much more engineering with the stock carburetors than most people realize. Ford engineers took into account engine type, engine size, transmission type, emissions, and even vehicle weight when they designed each carburetor for their application. They may look the same on the outside, but these carburetors can be much different internally.

I strongly considered running a Motorcraft 4180 from a Mustang GT when I replaced the original feedback Motorcraft 2150 on Lucille. Against my better judgment, I decided on a brand-new Holley Street Avenger instead. It ran okay, but I never could seem to get it tuned just right. And it seemed to constantly need to be fiddled with. I think the electric choke was the worse part. But Holley makes the best carburetor, right?

One day about 9 months later, the Holley developed a slow leak at one of the fuel bowls. Feeling defeated, I began to regret my decision of ever converting to a 4-barrel carburetor to begin with. I never seemed to have any of these issues with my original Motorcraft 2150. "If only Ford made a 4-barrel version of the original Motorcraft 2150" I thought. So after a bit a researching, I found that Ford *did* make a 4-barrel version of my original Motorcraft 2150 (which started out as the Autolite 2100) in the form of the Autolite 4100. But Ford stopped making them in 1968, and there were MANY different calibrations over the years. And they could be costly, because the Mustang guys want these for their restorations. Undeterred, I managed to find one designed for a 289 Windsor engine with an automatic transmission with the exact same bowl size (1.08) as my original 2150!

I paid about double what my brand-new Holley carburetor cost me, but I have been satisfied ever since. Like you, my fuel mileage was quite a bit better with this old Autolite 4100 than it ever was with the Holley. My idle speed is set to 600 RPM and it returns there no matter what. And the thermostatic hot air choke works flawlessly. And most of this is because the Autolite 4100 I have was specifically designed for my engine, whereas the aftermarket Holley is a "universal" style carburetor. I can honestly say that I can't tell much difference between driving Lucille and any of my other vehicles with EFI. And I haven't had to touch the carburetor in years!

Hey, I need to ask you a question LARIAT....

So I have had this 4180 back on the truck for over a week now and I have it tuned beautifully. In a word, it just runs....Great! BUT.................

I am not quite sure what is going on with the choke. Even on a hot summer day, the 4160 will kick the choke shut after 5 or 6 hours of sitting. This 4180, for some reason, just does not kick the choke shut or even partially shut, seemingly, until it is over night cold.

The other thing I am noticing is that even when it is over night cold, occasionally, this choke just sticks open. I give it a stab and nothing. I literally have to get out and give the choke plate a shove and than, it works great for a few days, and than, it sticks again.

I went so far as to take the choke pull-off assembly apart, carefully hone the bore and polish the shaft, put it all back together everything is moving nice and peachy, and than, a few days later, it will stick again. It still does not like to close, even partially after it has been started.

Any ideas? I have never run into something like this on one of these.

[LARIAT 85]

I am not quite sure what is going on with the choke. Even on a hot summer day, the 4160 will kick the choke shut after 5 or 6 hours of sitting. This 4180, for some reason, just does not kick the choke shut or even partially shut, seemingly, until it is over night cold.

The choke on my Autolite 4100 will close like your 4160 did, making an instant start. But I have a thermostatic choke with electric assist.

Does your 4180 have the thermostatic choke/electric assist (I think this style was used up until 1983), or a fully electric choke?

The other thing I am noticing is that even when it is over night cold, occasionally, this choke just sticks open. I give it a stab and nothing. I literally have to get out and give the choke plate a shove and than, it works great for a few days, and than, it sticks again.

Mine did that a couple of times when I first started running it, and I found that my [hot air] choke tube was picking up very fine debris that would jam up the choke piston, and ultimately, the choke. Like you, I could give it a little shove and it would work again. After I plumbed in a fresh air tube that picked up *filtered* air from the carburetor air horn, the problem went away.

 

[Jake Papageorge]

I am not quite sure what is going on with the choke. Even on a hot summer day, the 4160 will kick the choke shut after 5 or 6 hours of sitting. This 4180, for some reason, just does not kick the choke shut or even partially shut, seemingly, until it is over night cold.

The choke on my Autolite 4100 will close like your 4160 did, making an instant start. But I have a thermostatic choke with electric assist.

Does your 4180 have the thermostatic choke/electric assist (I think this style was used up until 1983), or a fully electric choke?

The other thing I am noticing is that even when it is over night cold, occasionally, this choke just sticks open. I give it a stab and nothing. I literally have to get out and give the choke plate a shove and than, it works great for a few days, and than, it sticks again.

Mine did that a couple of times when I first started running it, and I found that my [hot air] choke tube was picking up very fine debris that would jam up the choke piston, and ultimately, the choke. Like you, I could give it a little shove and it would work again. After I plumbed in a fresh air tube that picked up *filtered* air from the carburetor air horn, the problem went away.

My truck has fully electric choke. I MUCH prefer a hot air choke to electric.

[LARIAT 85]

I went so far as to take the choke pull-off assembly apart, carefully hone the bore and polish the shaft, put it all back together everything is moving nice and peachy, and than, a few days later, it will stick again. It still does not like to close, even partially after it has been started.

Any ideas? I have never run into something like this on one of these.

If you did all of that, I would try a replacement choke cap.

This may sound funny, but also make sure the air cleaner is not over-tightened on the carburetor.