options for emissions compliant carb for '83

[FB71]

Ok, here's the skinny; my plan is to use my recently acquired '83 GT as a daily. As such, it will need to be MD emissions compliant. For vehicles prior to '96, this means tailpipe sniff of HC, CO, CO2, O2, and NOx at idle and 2500 rpm. I am considering SEFI, but would like to retain the dual snorkel air cleaner, so carb or tbi/cfi are my options.

Other than the stock 4180, or Edelbrock 1400, what aftermarket carbs have egr vac porting. If the answer is non, how tunable is 4180? I'm intimate with efi, and driveability in general, but the only carbs I have good knowledge of are the Autolite 2100s, CV motorcycle carbs, and related, the dreaded VV carb.

Engine plans are mild; roller block with stock roller HO can, 1.7 rockers on GT40 heads, full thermactor, egr and evap. Shorty headers and 2.5 duals with cats.

I've looked at the various tbi/cfi offerings, and if unable to find a satisfactory carb, I'll most likely build another MegaSquirt to drive a GM throttle body, and add emissions functions hardware and code.

So, any suggestions?

[FB71]

And yes, I've read Cruiser67s 4180c thread.

[Walking-Tall]

If you insist on EGR for NOx reduction, EGR requires ported (off idle) vacuum, and lots of carburetors provide a ported vacuum signal somewhere. Even the vacuum connection on the passenger side below and in front of the choke on a factory Autolite/Motorcraft 2-barrel provides ported vacuum there.

Suggestions for exacting the dial-in of anything:

- Autolite/Motorcraft 2100/2150's - have an idle feed restriction in the angle channel of the booster cluster that's easily drilled out. The idle feed restriction size is then easily changed by tapping those passages 8-32 and installing 8-32x1/8 (or 3/16 or whichever you can find (ridiculously inexpensively for a package of many) from Fastenal or McMaster Carr etc) brass allen-drive set screws, that you then drill with the restriction size that provides exactly 1-1/2 turns out with the idle mixture screws, obviously through experimenting, and ditto with their idle air bleeds sizing, upping their size until the car balks too lean with low speed and cruise driving, and then going down a few thou until perfection like you can't imagine is found. You can dial a carburetor (and ignition) in better and well below anybody's silly emission level ranges/maximums.

- Any Holley 2 or 4 barrel or equivalent other brand - same as above with IFRs (idle feed restrictions) and IABs (idle air bleeds)... except, a good Holley has it's IFRs down low and at the carb body side of the metering block, and require drilling out and tapping with 6-32 to install different size restrictions using 6-32 brass set screws. Usually smaller than what Holley put in it, and again until with your idle speed setting coincides with right around 1-1/2 turns out with the idle mixture screws... and then onward with IAB sizing the same, with either 8-32 or some take 10-32 in the primaries.

- Leaning more toward some performance, with any given typical 600cfm Holley 4-barrel, I'd start with Ø0.026" primary IFRs & Ø0.073" primary IABs. Blocking the small secondary constant feed idle ports that are below the secondary throttle plates at idle will minimize low speed and part throttle "HC". Proper lean-best jetting for cruise (cruise above ~2000rpm and +, that is, when the main circuit is functioning, and with light acceleration such that does not drop the manifold vacuum enough yet to open the power valve, and the idle/transition circuits are no longer doing the fueling) should take good care of the 2500rpm portion of the testing. As low in the 60's (trying 66's, 64's, 62's, etc.) in primary jetting as it will stand under light load prior to power valve opening, coupled with ~Ø0.046" PVCRs (power valve channel restrictions) for deeper throttle situations and wide open throttle, should have a guy in good shape function and emissions-wise.

[FB71]

Yes, I'll need to keep egr for my nox numbers. I'll be sticking with a performance oriented 4v. It's my experience, however, that spark ported vac provides a slightly different signal than egr specific ported vac. Spark comes in at tip in, and stays thru throttle travel, providing manifold signal at anything above idle. I thought egr vac was triggered above spark, and shut off at about 2/3 throttle, to prevent wot hesitation. Am I incorrect?

Also, how capable are carbs for minor altitude correction? I'm near sea level, and would need adaptability up to about 5k feet. I've worked on vehicles with feedback altitude correction air bleeds, both solenoid and stepper motor, but have little experience with Non electronic fuel control.

[erratic50]

Other than less dense air tending to weigh less and therefore draw slightly less fuel, carbs don't tend to correct much for altitude. They tend by nature to get richer as you go higher.

[xctasy]

The Thermoquad TQ 9600/9800













carb that really works well is the Thermoquad 4bbl , not a well thought of carb,


but used in the Aussie Falcon/Fairmont/Fairlane/LTD's 1976 to 1982 and some De Tomaso's from 1976 to 1989. The Aussie ones had an electric choke, and a common Part # is TQ-9142S



To use this, there is a common 76DA-9425-CB carb flange intake



Edelbrock makes an adaptor for 4bbl square bores to suit its range of Edelbrock Performers, but its also a good ThermoQuad adaptor too.



That version was listed in the Australian Ford bookes as the #9600 series, with its 800 cfm 1-3/8" primaries.

Rated at 188-207 hp net in 302/4.9 Clevelands, and 200 to 216 hp net in 351/5.8 Clevelands. In 1979, each were rerated downwards 16 to 19 hp, largely an on paper loss due in part to manadory single exhaust, added emissions gear, and DIN net ratings instead of SAE net.

They raced these in New Zealands provisional International Group A / FISA Group 2a sedan racing, with stunning results, later on, the ex butcher/long time Logistics Stichbury family used them in Paul's Red XF so-called "SVO" Falcon with a transplanted XE 351 C engine.

There is a common #6545S 850 cfm 1-1/2" primary version used in 1975 360 LA and 440 RD engines. There were 9000 to 9800 part numbers from 1976-1984.

1975 360LA Mopars in # 9004, 850-cfm form.

See http://www.hotrod.com/articles/mopp-...ad-carburetor/

See the reveal all Mopar details

https://www.youtube.com/watch?v=sv8ggASU1jE


Part 1. https://www.youtube.com/watch?v=fzNhCLg9veg&app=desktop
Part 2. https://www.youtube.com/watch?v=huzO53WB_1c
Part 3. https://www.youtube.com/watch?v=L8CnQWTUSNU
Part 4. https://www.youtube.com/watch?v=TrpUnviQp5k <----Very important cruise economy details
Part 5. https://www.youtube.com/watch?v=o9LUcYx2dEc
Part 6. https://www.youtube.com/watch?v=Dwh6SQ7kV6E
Part 7. https://www.youtube.com/watch?v=UZz6d1u9h08
Part 8. https://www.youtube.com/watch?v=9vQTEbLlkqM
Part 9. https://www.youtube.com/watch?v=2kZnyWOXeF8 <----Very important Float setting details
Part A. https://www.youtube.com/watch?v=moRAefFzX2Q
Part B. https://www.youtube.com/watch?v=Sw_xH7dKmOI
Part C. https://www.youtube.com/watch?v=IMEY40pKwzQ
Part D. https://www.youtube.com/watch?v=jJTtqJTpTqw
Part E. https://www.youtube.com/watch?v=gzAX0GZLkIg
Part F. https://www.youtube.com/watch?v=-6f2Ds5evNY
Part G. https://www.youtube.com/watch?v=OqyzvydzcwM
Part H. https://www.youtube.com/watch?v=ukjI6ltgXuU
Part I . https://www.youtube.com/watch?v=Zc9TQm-cP18
Part J . https://www.youtube.com/watch?v=yqD0Jdf9ZRE
Part K. https://www.youtube.com/watch?v=EaX97l4VQQQ
Part L . https://www.youtube.com/watch?v=jJt9kvu0y0Y
Part O. https://www.youtube.com/watch?v=Fa_Gi73z-6k
Part M. https://www.youtube.com/watch?v=7CY7etRxavk

Its basically a pumped up Rochester QuadraJet 4MV or Motorcraft 4350 750 cfm unit with some seriously cool stuff in the 1978-1984 ELB ( Electronic Lean Burn ) era versions, namely a throttle position sensor!

[xctasy]

And the most important, some genuine down to earth good knowledge.


https://www.youtube.com/watch?v=1pIEpV4PyvA
https://www.youtube.com/watch?v=HOFr3KRW_MQ


Ole Yella Carbed Ford 302 and 351's all the way, man!





This last one has a QuadraJet on it....

[xctasy]

Yes, I'll need to keep egr for my nox numbers. I'll be sticking with a performance oriented 4v. It's my experience, however, that spark ported vac provides a slightly different signal than egr specific ported vac. Spark comes in at tip in, and stays thru throttle travel, providing manifold signal at anything above idle. I thought egr vac was triggered above spark, and shut off at about 2/3 throttle, to prevent wot hesitation. Am I incorrect?

Correct!

this is an a9l EGR table(plagiarized from sbftech):


unless you're upgrading to non-egr heads or a non-egr intake, there is really no reason to remove it unless you want slightly worse economy and more pollution.

when you remove the TAB/TAD solenoids, leave the wiring intact. the red wires can be used as key on power for your future projects. i have the red wire from my TAD connector wired to the ignition+ wire for my electric fan controllers.

i just went through all this and i was helped greatly by the experts on sbftech.com if you delete the EGR and need to know which resistor to use in the connector, you can find info like that over there.

Also, how capable are carbs for minor altitude correction? I'm near sea level, and would need adaptability up to about 5k feet. I've worked on vehicles with feedback altitude correction air bleeds, both solenoid and stepper motor, but have little experience with Non electronic fuel control.

Not very, unless it has the MCU or Ford DSO Altitidue correction equipment. Mexican 2150's had an Aneriod compensator.


There is a way of doing it via a ported vac drilling, which is kind of how Ford did it with the fender gaurd mounted compensation equipment, but it wasn't dynamic.

You'll understand how the Holley Aero altitdude leaning system by Tom McNeilly?

On a good old 2-bbl 4412 500cfm Holley, the air horn gets machined off like what was done on the factory Six Pack Mopar carbs



Or a 4BBL



If the 2-bbl without an air horn is placed where the stock 2-bbl its is now, you'll get 1.75" of height off the carb.

With the Fox body 250 i6's conversion I do, a very good kit to eliminate the air horn on a 2 or 4-bbl Holley is this kit. Since most Holley 500cfm carbs on a 302 find the 73 jets too rich, and the stock 60F's on the motorcraft 2150 just a little lean. With this kit, you won't have rejet a Holley 2-bbl 4412, and you can get things under the hood, you can trim off the choke horn, and use the aviation Tom McNeilly throttle lean device, and never have to change the jets again. It produces 150% rich on straight up setting, then about 1/4 turn or so in a position that has to be determined by time on an exhast gas analyser or dyno , it drops back to the required jet size. If you do a dyno run with this, you could produce optimum jetting by measuring the degrees of movement of the carb float mounted crank.

For cold starts, it would get shifted upright via a bowden cable, and then throttled back to that positively stopped position when its warmed up. Its like a Percy's adjustajet, but it produces a much better 'roosters tail' of fuel atomisation. As Ford found with the need to put eye brow interpters into there CFI intakes, 2-bbl Holleys aren't great at fuel distribution, but the kit is from tomcn@earthlink.net for US $150 dollars excluding post and packaging.

These are throttle leaning devices used for light aircraft, see http://www.rotaryeng.net/HOW-TO-INSTALL-HOLLEY.html

It is best suited for a two barrel 350 or 500 CFM Holley carburetor. However, the unit has been successfully used on large four barrel carburetors. The mixture control WILL NOT fit other makes and models of carburetors! The unit replaces the fixed main jets with a rotating valve that is remotely operated by a push pull cable. The unit will go from total idle cut-off to overly rich by rotating the shaft, while the engine is running. Installation is very simple with step by step instructions provided.

Due to the outrageous cost of materials and the inflationary state of our economy,the price of the kit has recently been raised to $150.00.

The mixture control body is CNC machined from 6061-T6 aluminum which is alodine treated, the shaft is stainless steel and the screws are plated steel.

The first picture is what comes in the kit. The mixture control plate is in the background with the accelerator pump extension arm., power valve block off plug, and installation bolts in the foreground. I also include a set of three gaskets which are not shown.

-Tom McNeilly
14001 East Williams Field Rd.
Gilbert, AZ 85296
International phone number is +1-602-899-7613

He's in Arizona, USA.

Northwest Aero Products also has them available. They are at
13812 179th Avenue SE
Monroe, WA 98272
International phone number +1-360-805-8183
Call displayed telephone number to ask for respective email address of Northwest Aero Products.

Follow those recomendations and you'll be able to adjust total jetting via a simple line of feedback code from Audrino.


Add TPS, and you can seamless resolve air fuel mapping by narrow band and an open/closed loop code test.

[Walking-Tall]

Yes, I'll need to keep egr for my nox numbers. I'll be sticking with a performance oriented 4v. It's my experience, however, that spark ported vac provides a slightly different signal than egr specific ported vac. Spark comes in at tip in, and stays thru throttle travel, providing manifold signal at anything above idle. I thought egr vac was triggered above spark, and shut off at about 2/3 throttle, to prevent wot hesitation. Am I incorrect?

Also, how capable are carbs for minor altitude correction? I'm near sea level, and would need adaptability up to about 5k feet. I've worked on vehicles with feedback altitude correction air bleeds, both solenoid and stepper motor, but have little experience with Non electronic fuel control.

Just like the aspect of ported vacuum (equivalent of manifold vacuum, but initially less by partially open throttle plates to get the ported vacuum passage exposed to manifold vacuum, up to a point, and then the two are equal for a time, and then they both diminish to zero upon further throttle opening (unless the carburetor's too small for the engine)) use for the distributor, ported vacuum, from anywhere up the bore below the venturi dissipates pretty quickly much past <1/4 throttle. The two virtually act the same way, minus at idle. If politically correct EGR passages (I believe it was "mrriggs" (***) here that dissected this very subject pictorially and brought any disagreements to an end, that the EGR vacuum port on the side of 4180's picks up vacuum at roughly the same, or the same, or close enough to the vertical location in the throttle bore as any other ported vacuum passage in carburetor bores, just above the closed-at-idle throttle plate) for vacuum actually are higher up in the bore, it can't be much higher, and so it's really like splitting hairs, and EGR function would be a wee tad bit later IF the passage is actually higher, with a comparatively weaker vacuum signal due to lower vacuum simply because the throttle's required to be open that much more, and be over and done with quickly upon a little more throttle opening. So, besides EGR not meant to be activated at idle or at WOT, but just off-idle and for an amount of time dictated by the throttle position, I don't see a difference.

If you're talking about frequent WOT or racing, 5000' of difference should get a jet change, lesser jet for the altitude increase and vice versa, but just regularly motoring along loafing under very little load and producing very little horsepower doesn't require the carburetor's main circuit (jets) to be what does the administering of those conditions' fueling (directly) at all. The main circuit does supply the idle/transition circuit, but has no bearing at all on their function any more than that. The vast majority of normal driving operation is handled by and adequately covered by the idle/transition circuit.



***

The port coming out of the body on the 4180 is different depending on application.



On the truck carbs it hooks to a small hole in the venturi but on the Mustang carbs it doesn't.

There is a hole drilled down to the throttle body.



That connects to a passage milled into the throttle body which goes to a hole that is blocked from manifold vacuum when the throttle is closed (ported vacuum).



To the left of that hole you can see the curb idle [with needle sticking out of it] and the transfer slot. To the left of that is the "spark port" which has a small hole above the [closed] throttle plate and one hole below it. This is what feeds the small tube on the front of the throttle body. The signal from this port doesn't shut off vacuum completely when the throttle is closed. Instead, the vacuum is lowered just enough to retard the timing but some vacuum is still present. I assume this was done so the vacuum advance would react more quickly when the throttle is opened.

The truck carbs do not have this spark port. Instead there is a single hole above the throttle plate that feeds the small tube on the front of the throttle body (ported vacuum).

I saw that extra hole in the 4180 bodies and the passage in the 4180 throttle bases on 'net search pictures, and wondered by it's location whether or not it connected with the EGR nipple up top. What you've shown and explained here (thanks very much), and your last post including explaining the thermal switches incorporated for EGR function as well, might be the most in-depth 4180 information on the internet. Trust me, I looked and looked regarding this subject, and it's just not out there... and whaddaya know, nothing new under the sun, ported vacuum for EGR.

[FB71]

Excellent! This is exactly the information I was looking for.

[Mgino757]

You can tune a 4180 to do just about anything you need it to.

[Walking-Tall]

To explain further for the use of an Autolite/Motorcraft or a Holley to achieve best economy, and "compliance" with the least amount of "emissions"...

Autolite/Motorcraft 2100/2150 2-barrels (and 4100 4-barrels)


IFR/IDCR (make adjustable with 8-32 brass socket setscrews):




Primary IAB (make adjustable with 8-32 or 10-32 brass socket setscrews):





Holley 2300/3160/4150/4160/4165/4175/4500 (and Demon, AED, QFT, etc.)

IFR (left) and PVCR:




Primary IAB (outers):





For working with a 4180, different (but the theory/aspect of the modifications as above applies the same) operations/locations to modify the idle/low-speed/transition circuit will be necessary to get outside of the box of it's limited adjustment window for idle AFR, but especially for lean-best low-speed/transition/cruise (efficiency, economy, and least emissions) AFR.

[FB71]

The Thermoquad TQ 9600/9800
Its basically a pumped up Rochester QuadraJet 4MV or Motorcraft 4350 750 cfm unit with some seriously cool stuff in the 1978-1984 ELB ( Electronic Lean Burn ) era versions, namely a throttle position sensor!

I've looked at, and am a proponent of the ThermoQuad! Highly under-rated carb. My only issue is that here in the states, it seems to be poorly supported now. Additionally cost of even a core unit seems to be getting ridiculous... I could almost buy a FiTech EFI system new, for the cost of a used ThermoQuad (or nearly any other new carb) plus parts for tuning. In fact, I'm beginning to lean that way. I'm more skilled, knowledgeable, and comfortable with EFI, not to mention lazy! I think I can get the functionality and ease of tuning I want, with the driveability I need, by going TB/EFI. I'll use a fan output to run an EVR solenoid to lockout EGR function until ECT is satisfactory, maintain the factory non-electronic Thermactor, but route the upstream air downstream of the O2s to prevent false lean conditions. That will still aid cold start emissions, just not as well as locating it in the exhaust port. Fortunately in my state, there is no visual inspection beyond verifying presence of converters, and cold start isn't part of the eval.

[FB71]

I've looked at, and am a proponent of the ThermoQuad! Highly under-rated carb. My only issue is that here in the states, it seems to be poorly supported now. Additionally cost of even a core unit seems to be getting ridiculous....

OK, now I have some egg on my face... A month ago when I searched for thermoquads, all I found was reman units for over $500, or really bad cores over $100. I just looked today, and found several decent cores under $100... -_-

So I'm back to a toss-up between carb and efi

[Mgino757]

I would stick with a 4180, especially since that's what the 5 speed 83 5.0 HO's came with. Once I set my mixtures with my wideband O2 sensor, I haven't had to mess with it in a while.