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  1. #51

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    Quote Originally Posted by Walking-Tall View Post
    The primary shafts don't come with the ribbon bushings. If I'm working with a carburetor where there's too much clearance between the primary shaft and the base plate bores, sometimes adding some used (or new, if very loose) bushings tightens up the clearance. There are also channeled areas where they can be positioned if needed.

    The steady idle vacuum you're getting is good, but the mixture screw position discrepancies indicate something is jacked up in the carburetor. The best example I can give of this phenomena is a Holley 650 double pumper recently refurbished, where upon disassembly one mixture screw was found to be very much so turned out further out than the other... and (lack of) quality control and manufacture of newer stuff is why... the image below is of a traditional Holley idle air:fuel discharge hole (controlled upstream by the mixture screw in the metering block) that was never fully drilled through, leaving only an 0.018" passage for idle air:fuel to get through:



    ... where the idle vacuum was pulling idle air:fuel properly through the other, this one had no chance in hell supplying enough, and it's mixture screw was turned out much more than the other... and I guarantee it could not have idled worth a darn from day 1... after that was remedied, the passage hole drilled fully through, everything worked like it should... the mixture screws are equally sensitive and adjusted outward the same amount of turns for best idle.
    Thanks; that will give me something to look for.

  2. #52

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    Quote Originally Posted by darkd0r View Post
    Walking-Tall,
    I have been following your project with great interest and appreciate your efforts very much. However, I don't have any Holley carbs (yet), just Motorcraft 2150's, so no experience and wouldn't know what to ask. So I won't clutter up the thread. I suspect there are many others in the same situation. Thanks for sharing your knowledge. We're out here learning, quietly.
    Glad you are. There isn't too much that's simpler or more reliable than a Ford 2-barrel It's no clutter, thank you for commenting. Quite welcome, and I appreciate hearing from you.
    Mike
    1986 Mustang convertible 3.8L ---> BUILD THREAD
    1983 Mercury Cougar 3.8L LS
    1986 Ford Thunderbird 5.0L ELAN
    1966 Ford Fairlane sedan 200-6
    1966 Ford Fairlane GT (390ci 4spd)
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang Fastback
    1974 Pontiac Luxury LeMans

  3. #53

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    Quote Originally Posted by JacksAO View Post
    Thanks; that will give me something to look for.
    Good luck with the looking... the reason I began this thread is because so much is hidden (and IMHO, unnecessarily installed within the circuits, and dirt-collecting that's not easily cleaned out, etc.) and anti-tamper with 4180's. I say again, if a 4180 is to remain as it is, as opposed to the way I am dissecting and re-engineering, the cleaning process of the whole primary idle circuit, from the idle feed restrictions behind the primary jets, to the idle mixture screw discharge holes and transfer slots in the base plate, as well as the multitude of passageways and for the FOUR primary idle air bleeds, needs to be repeatedly cleaned and blown out like nobody has ever cleaned and blown out the circuit passages of a carburetor before... as well as all circuit restrictions verified to be consistent side-to-side, in order for it to function somewhere near normally and efficiently.
    Last edited by Walking-Tall; 07-07-2018 at 08:02 PM.
    Mike
    1986 Mustang convertible 3.8L ---> BUILD THREAD
    1983 Mercury Cougar 3.8L LS
    1986 Ford Thunderbird 5.0L ELAN
    1966 Ford Fairlane sedan 200-6
    1966 Ford Fairlane GT (390ci 4spd)
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang Fastback
    1974 Pontiac Luxury LeMans

  4. #54

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    Important addition for post #49 (largely different primary idle mixture screw adjustments side-to-side):

    "The steady idle vacuum you're getting is good, but the mixture screw position discrepancies indicate something is jacked up in the carburetor."

    In either traditional Holley 2300/4150/4160/etc primary idle circuits and idle air:fuel mixture screw adjustment, or the primary idle circuits and idle air:fuel mixture screw adjustment for 4180's in the base plate, addressing a large discrepancy of idle mixture screws' number of turns out side-to-side is fine for making the engine's idle cooperate, but does not address the primary idle circuit discrepancy (be that incomplete/inconsistent passage/restriction sizing, debris blockage in one side, etc) that will remain for off-idle function, most of the rest of nearly all "normal" low-speed drive-ability and driving, most light part-throttle acceleration prior to the main circuits taking over (sometimes usually, and unnecessarily, all addressed by installing a larger accelerator pump shooter or cam), and even most instances of normal highway cruise speeds are (and should be) easily handled by the primary idle circuits. Hence the need to investigate what is jacked up in such a carburetor... the idle mixture screw adjustment discrepancies are a symptom/clue/hint that something's not right.
    Mike
    1986 Mustang convertible 3.8L ---> BUILD THREAD
    1983 Mercury Cougar 3.8L LS
    1986 Ford Thunderbird 5.0L ELAN
    1966 Ford Fairlane sedan 200-6
    1966 Ford Fairlane GT (390ci 4spd)
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang Fastback
    1974 Pontiac Luxury LeMans

  5. #55

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    Removed the lead from the jet-side of the primary metering block, where behind I looked for the what and the how of the hidden mystery "emulsion" (booster air correction) bleeds...




    Get a load of these, the brass tubes from within the main wells (shown standing upside-down here). The one tube while still inside showed me a drilled restriction after removing the lead plugs, the other did not, so yes, they had to come out in order to see and measure exactly what is going on in there, and one got destroyed, and that's not going to matter...



    ... so, with clearance around the small diameter of these tubes, giving full main air bleed access to all of these holes... two 0.040" thru-holes (so four of them) are drilled at what lands at about fuel level, and two more 0.029" thru-holes (also four) are drilled at about 5/32" above fuel level. That's over 800% more early-booster-flow-encouraging area connected with the main air bleed at fuel level than is normal in a traditional Holley. The booster-flow-delaying bleeds above those are contradictory and aren't usual in a traditional Holley. Those are connected with an early and rich encouraging 0.044" main air bleed that by it's size later encourages leanness if not dealt with with yet more variables in circuits, feeding annular boosters.


    Some visuals, and the tube shown as it is when inside the main well, to hopefully help explain what's been found...






    Tune in next time where it'll be much easier for me to explain what I'm going to do with pictures of the processes and what the final block circuits will look like with all the hidden unnecessary razzle-dazzle omitted, and it reverted back to basic, simple, reliable, easily clean-able, and efficient function.

    Mike
    1986 Mustang convertible 3.8L ---> BUILD THREAD
    1983 Mercury Cougar 3.8L LS
    1986 Ford Thunderbird 5.0L ELAN
    1966 Ford Fairlane sedan 200-6
    1966 Ford Fairlane GT (390ci 4spd)
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang Fastback
    1974 Pontiac Luxury LeMans

  6. #56

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    Because, "a picture is worth a thousand words", and will no doubt describe/explain better than a bunch of my wording probably can, here are some sectioned depictions of the 'as is' (was) and 'proposed changes' for booster air correction, eliminating more potentially dirt-collecting or sizing variation variables, and which will later be working with a smaller, more usual size main air bleed, and I suspect smaller than factory main jetting with the annular boosters... to provide a predictable, solid, stable, flat (as opposed to any sluggishness or slope or "curve") WOT air:fuel ratio from the lower speed main circuit activation point (jet + PVCR enrichment) all the way up to maximum engine operating rpm:








    Mike
    1986 Mustang convertible 3.8L ---> BUILD THREAD
    1983 Mercury Cougar 3.8L LS
    1986 Ford Thunderbird 5.0L ELAN
    1966 Ford Fairlane sedan 200-6
    1966 Ford Fairlane GT (390ci 4spd)
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang Fastback
    1974 Pontiac Luxury LeMans

  7. #57

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    awesome work!
    Jim DeAngelis
    Cornucopia of Useless Knowledge
    Connoisseur of Dearborn Ferrous Oxide
    '83 GT hatch, currently under the knife

  8. #58
    FEP Senior Member qikgts's Avatar
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    Fantastically detailed drawings! I'll have some q's at some point about how you've done a few of those...

    My ignorance may be showing with the next question... lol

    Am I understanding correctly that some of these mods in this last post are going to be creating an adjustable emulsion package?
    '85 GT

    The other one... 2016 F-150 XLT Supercab Ecoboosted with 3.73's...

  9. #59

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    Thanks guys!

    Not ignorance at all, Steve. Yes, completely adjustable IF ever necessary... and a side bonus to these modifications is if ever a restriction gets accidentally dropped down the main well if changing one or whatever, if you remove that main jet, the restriction should be sitting right there looking at you to snatch back outta there, lol. Adjusting of correct "emulsion" (I prefer 'booster air correction', because that's what that aspect, introduced main air bleed air at the fuel level (and often some a bit below that too) in the main well of the main circuit does... corrects the tendency of a booster in a venturi with airflow going thru/past it to be rpm-dependent as to how much it flows, which is most usually increased flow with rpm and increased airflow, but increased disproportionately as to a steady air:fuel ratio. The tendency today of bigger and more "emulsion" and bigger main air bleeds screws up proper booster function real good... starting them sporadic and sluggish and early and rich, and lotsa times being so much introduced air that there isn't a main jet big enough made to get rid of top end lean out, due directly to too much introduced bleed air and too large of main air bleed. Booster behavior should provide at nice flat moderate hard throttle and WOT air:fuel ratio (~12.5:1) from beginning of full main circuit startup to the red line. Load-dependent, not a varying air:fuel ratio that's rpm-dependent) shouldn't be necessary besides adding a bottom restriction if the boosters don't want to flow enough at WOT thru the mid-range or at maximum rpm... but I'm very highly doubting that (finding the correct (smaller than factory, I haven't much doubt) main jet will pan out in the testing of this)... because the annular boosters should be able to get busy and mix and vaporize the fuel and air well, and flow all sorts enough air:fuel with this and the combination of a smaller normal-sized main air bleed to create the flat stable higher loading and WOT air:fuel ratio, but not fire up before that unnecessarily... previous to those conditions can be easily and much more predictably and efficiently handled by the primary idle/transition circuit.

    Last edited by Walking-Tall; 07-11-2018 at 09:12 PM.
    Mike
    1986 Mustang convertible 3.8L ---> BUILD THREAD
    1983 Mercury Cougar 3.8L LS
    1986 Ford Thunderbird 5.0L ELAN
    1966 Ford Fairlane sedan 200-6
    1966 Ford Fairlane GT (390ci 4spd)
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang Fastback
    1974 Pontiac Luxury LeMans

  10. #60
    FEP Senior Member qikgts's Avatar
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    I had to read that like 5 times... lol

    I think some of it is starting to sink in though...
    '85 GT

    The other one... 2016 F-150 XLT Supercab Ecoboosted with 3.73's...

  11. #61

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    Here's some more accurate juicy information for folks to sink their teeth into....

    Somebody at rfs posted a link to a good two-phase flow paper in pdf format online. Page 11 shows what an efficient, stable, and ideal homogeneous mixture of vertical two-phase fluid flow (just like in a Holley main well) looks like and acts like, which is what an "old school" Holley provides by default with it's design with minimal "emulsion" (sometimes only one 0.026-0.028" bleed at the liquid fuel level, and most commonly another about 7/16" below that), and usually a small 0.025-0.028" main air bleed to control the ultimate upper rpm air:fuel ratio, as well as contributing to the timing of when the booster will begin to flow.

    What you get with the "new and improved" excuses for carburetors out there nowadays, with swiss cheesed metering blocks with sometimes up to five comparatively giant "emulsion" bleeds (makes no matter even if they are all at 0.026-0.028"... there's too many, too much bleed air introduced), and a too-big main air bleed (because the too much "emulsion" has now convinced somebody the main circuit needs leaning because it's wicked rich down low and through the mid range... but alas, the big main air bleed will also make the highest rpm then too friggin' lean), as well as what I've read lots about with these 4180's that seem to frequently require more pump shot to eliminate some funny hesitation or off-idle stumble even when the float level and idle mixture and accelerator pump arm is right, and with a 0.028" primary idle feed restriction, which is big for a 600cfm on a stock or mild 302 engine, there's absolutely no excuse for idle/transition leanness... but then there's the primary idle air bleedS that are also oodles too big, and silly upside-down restrictive "emulsion" tubes in the passages to the base plate ... a whole lot of these WHY's is what's shown above in this thread... what you get is booster signal too-sped up or too-delayed, sluggish, spurting, non-homogeneous mixtures big clumps of fuel and clumps of air making their way to the booster and generating erratic air:fuel ratios all over the place. There's NO SUCH nonsense with an "old school" Holley main or idle circuit... the "new and improved" peddlers also insist on installing the primary idle feed restriction up near the idle air bleed, which generates all the same such erratic air:fuel ratio nonsense then within the idle circuit.... 'nuff said, lol... check out pages 12 and 13 for WHAT NOT TO DESIGN A CARBURETOR TO DO...

    Link to info --------------> http://notendur.hi.is/~halldorp/UNU/...se_regimes.pdf

    Last edited by Walking-Tall; 07-12-2018 at 09:23 PM.
    Mike
    1986 Mustang convertible 3.8L ---> BUILD THREAD
    1983 Mercury Cougar 3.8L LS
    1986 Ford Thunderbird 5.0L ELAN
    1966 Ford Fairlane sedan 200-6
    1966 Ford Fairlane GT (390ci 4spd)
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang Fastback
    1974 Pontiac Luxury LeMans

  12. #62
    FEP Senior Member qikgts's Avatar
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    Mike, can you post a link to RFS? Is it a "tech" site?
    '85 GT

    The other one... 2016 F-150 XLT Supercab Ecoboosted with 3.73's...

  13. #63

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    Hey Steve. If you knew about "tuner", by your previous comment regarding possible explanation for the upside-down brass tubes out of the bottom of the main body, I thought you already knew about rfs, lol... racingfuelsystems... where there are nuggets of gold of explained, proven, logical and un-debate-able WEALTH of carburetor and ignition and vehicle-dialing-in information all over the place there, and some of the smartest, fastest, experienced guys on the planet, that, time and time again, help folks get their things working as best they can and better than ever by debunking and subverting all of the "new and improved" BS.

    The racingfuelsystems forum link: http://www.tapatalk.com/groups/racin...tems/index.php
    Mike
    1986 Mustang convertible 3.8L ---> BUILD THREAD
    1983 Mercury Cougar 3.8L LS
    1986 Ford Thunderbird 5.0L ELAN
    1966 Ford Fairlane sedan 200-6
    1966 Ford Fairlane GT (390ci 4spd)
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang Fastback
    1974 Pontiac Luxury LeMans

  14. #64
    FEP Senior Member qikgts's Avatar
    Join Date
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    Geez... It sucks getting old... I didn't make the connection to the acronym...

    I'm on there...
    '85 GT

    The other one... 2016 F-150 XLT Supercab Ecoboosted with 3.73's...

  15. #65

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    Sometimes, yes, it's sucking to get old... lotsa good stuff too though

    Excellent, the racingfuelsystems forum is a great resource of very experienced and knowledgeable folks and information that money cannot buy... large amounts of money today certainly does not buy correctly working carburetors from the mainstream "makers".

    Thanks very much to you, Steve, "qikgts", for the nice condition primary float bowl that landed here this morning. Now if this Holley 4180 gets put to use where it's original application was, pre-'86 Mustang/Capri, or other, it'll have the option of sporting the correct float bowls with the extra large vent pipes that get connected to the vehicle's charcoal canister.





    ... I still haven't had a chance to get back to the primary metering block... I will, stay tuned...
    Mike
    1986 Mustang convertible 3.8L ---> BUILD THREAD
    1983 Mercury Cougar 3.8L LS
    1986 Ford Thunderbird 5.0L ELAN
    1966 Ford Fairlane sedan 200-6
    1966 Ford Fairlane GT (390ci 4spd)
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang Fastback
    1974 Pontiac Luxury LeMans

  16. #66

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    Oh, and, the following is a more accurate and vertical locations' dimension-ed depiction of the proposed changes, of the equivalent to a traditional Holley's system of booster air correction, otherwise incorrectly known as "emulsion" or "e-bleeds":



    Mike
    1986 Mustang convertible 3.8L ---> BUILD THREAD
    1983 Mercury Cougar 3.8L LS
    1986 Ford Thunderbird 5.0L ELAN
    1966 Ford Fairlane sedan 200-6
    1966 Ford Fairlane GT (390ci 4spd)
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang Fastback
    1974 Pontiac Luxury LeMans

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