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  1. #51

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    erratic50,
    When I said it ran "great" when fully warm, I guess I should have said "better". I think the problem was still there, it just got masked because the entire A/F curve shifted richer. For the record, it is extremely hard to drive and watch bouncing numbers on a display mounted in the center console. At some point in the future I plan to purchase and install the Aux-box to complement my gauge in order to datalog meaningful data and be able to review it after driving.

    Mike,
    Thanks for all that. Was about ask about locating the e-bleeds then saw you added the second post. I assume MAB will need to change?

  2. #52

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    Quite welcome.

    No to MAB change... if it's at Ř0.028", that should be close enough to the usual Ř0.025". Just, be prepared to probably have to reduce the main jet size, when eliminating the kill-bleeds and accordingly to your WB gauge.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1966 Ford Fairlane sedan
    1966 Ford Fairlane GT
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang
    1974 Pontiac LeMans

  3. #53

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    Well, measured idle mixture screw holes. Quite a bit bigger that 1/16".

  4. #54

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    Okay, that sufficiently pi$$es me off, Thomas, and I would like to contribute to your combination working right. I am so sick of newer carburetors and all of their flashy and pretty razzle dazzle bull$hit, that just plain DO NOT WORK as they should. That, idle mixture screw passage hole size NOT RIGHT, is not an easily fix-able problem at all... and, what the hell are all of us paying $600 or more for a carburetor for? A$$holes, 'nuff said. If you want, private message me your location, and I would like to finish prepping the above "1947" block with new brass main and idle well cup plugs, send a handful of blank 6-32x1/8" set screws for IFRs and 8-32x3/16" set screws for PVCRs for adjustments if you end up needing to, install Ř0.026" IFRs and Ř0.046" PVCRs and new idle mixture screws and cork seals into it, and send it to you for shipping plus $30 through paypal, AFTER you receive it and install it and try it out and it's okay. Lemme know, my friend...
    Last edited by Walking-Tall; 05-05-2017 at 10:30 PM.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1966 Ford Fairlane sedan
    1966 Ford Fairlane GT
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang
    1974 Pontiac LeMans

  5. #55

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    Thanks Mike, very generous of you. Sending PM now.

    As I mentioned in my original post, I've been dinking with this thing for several years since building the 347 (technically, since it was "new" 10 years ago). If I was smarter, I probably should have just ditched it in favor of something better long ago. May still keep an eye out for a 750 to tinker with when a deal comes along.

  6. #56

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    Yea -I was mainly talking about my -10 F adventures with my 351W that had a 360 degree Offy on it. I won't say that I miss trying to drive that cold blooded old thing every day. raw fuel out the pipes and still being "lean" due to bad atomization was a real pain.

  7. #57

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    PM returned, the block will be off to you Monday.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1966 Ford Fairlane sedan
    1966 Ford Fairlane GT
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang
    1974 Pontiac LeMans

  8. #58

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    Here's what's headed out to you tomorrow:





    It didn't come with one, and I don't have a vacuum nipple (or plug) on hand for the ported vacuum passage. The passage is drilled/connected with the leg channel inside, so, you'll need to plug this hole off or add a vacuum nipple if you use ported vacuum. Pretty sure it's 1/8-NPT thread...




    After you drill and add the sizes of IFRs & PVCRs you want (I'm sending set screws in case the depths that I have tapped in the block don't coincide with the length of set screws you have on hand), and assemble it with cup plugs and mixture screws, she should be good to go.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1966 Ford Fairlane sedan
    1966 Ford Fairlane GT
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang
    1974 Pontiac LeMans

  9. #59

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    Awesome, Mike. Thank you very, very much.

  10. #60

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    Received Mike's care package today. Thanks Mike.



    Drilled some new restrictors with a holder I made.



    Installed all the well plugs, restrictors, jets, & PV. Same settings as last drive except IM screws are 1-turn out.



    Reassembled carb & went for a drive. Honestly, not sure that I could really tell much difference from when I drove it last in post #38. Gauge still showing ~11:1 going down the highway @ 2000 RPM.

    I changed the PIAB to .076, but no significant change.

    I did lean the IMS's to ~7/8 turn and got A/F to mid-13:1.

    Other than showing rich on the gauge, it runs fine. Fuel curve seems fairly flat, drops a bit as RPM increases.

    I think I'm going to drop the PIFR's to .024. Seemed to make a considerable difference before.

    What say the experts?
    Last edited by 85MUSTANGTGT; 05-14-2017 at 06:06 PM.
    Thomas

    1985 Mustang GT - Build Thread

  11. #61

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    Quite welcome, Thomas.

    Are the spark plugs black?

    If the WB isn't out to lunch (misfires of any of the three varieties (lean, rich, or plain 'ole ignition misfire), or exhaust leak ahead of oxygen sensor/s, or oxygen sensor/s mounted too close to exhaust exit (outside air), will all register as lean on the WB, so I'd say it's probably not out to lunch... indicating rich, sometimes plug-fouling rich... unless it's out to lunch in general and reading inaccurately rich everywhere... the best clue is that the car seems to run "fine", and continuing with prior to main circuit start up, low load idle/transition tuning by the seat of the pants won't hurt a thing), I say there may be a significant contribution to idle and transition fueling from the secondaries, and so, if you haven't yet, I'd still look at these things:

    - The tiny constant idle feed discharge holes directly below the secondary transfer slots, if much bigger than ~Ř0.025", can contribute substantially to idle, transition, and highway cruise AFR. If necessary, and because there's not enough meat to add brass restrictions there, they can be shrunk by peening them smaller with a small (~1/8") ball bearing and re-drilling them to ~Ř0.022".
    - The secondary idle speed screw... setting it to very minimally opening them from being right shut in their bores, say just 1/4-turn. Setting the primary transfer slots square with the primary idle speed screw is ideal, but is not set in stone. Variables like throttle shaft location, throttle plate fit in bores, and transfer slots' width and length, all can play into setting them square not being ideal in every situation. Closing the secondaries like above and opening the primaries a wee bit to compensate back to desired idle rpm, could help this situation if there's too much influence (fuel) coming from out back.
    - Secondary closure/return link binding, pulling them open some?... just spit-ballin' possibilities...
    - Try the finger covering an IAB test...

    As well, because it's an unknown (at least to me), you should find out at what rpm the primary main circuit goes to work, by increasing rpm in neutral until fuel dribbles from the boosters, and noting at what ballpark that rpm is in. It should be sooner now than it was, by eliminating booster kill bleeds from the equation. Regardless, it's good to know so we're not chasing our tail when there could be a defective/cocked-open-by-debris/leaky PV diaphragm, or MB gasket seal affected by the PV head resting against the screw boss for the base plate not allowing the MB to sit flush, etc...

    Light/moderate acceleration transition, prior to main circuit function and/or PV opening vacuum point, with increased load (not necessarily rpm) should be increased AFR, upwards of 16-17:1 or more.

    Try the 0.024" IFRs and see what she does. Just remember the lean window prior to the mains taking over before. If with an IAB in the neighborhood or on the big size, such a window can get created simply because the IFR fuel simply max's out before transition necessity is over, and due also to the comparatively larger IAB, prior to the main circuit taking over. If you run into any such a lean window again, consider the following: smaller IABs in conjunction with smaller IFRs can provide about the same amount of idle/transition air:fuel metered, but extend the air:fuel metered further up to or to overlapping some with main circuit start up, which is what it should (as conservatively as possible) do.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1966 Ford Fairlane sedan
    1966 Ford Fairlane GT
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang
    1974 Pontiac LeMans

  12. #62

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    Need to make a list of these things to check when I go out to the garage.

    Haven't checked plugs recently, will do so.

    My Innovate gauge has a sensor calibration feature. I have yet to recalibrate the sensors since the initial install. Should probably look into doing so, just hard to get excited about putting the car on jackstands and rolling around on the concrete floor.

    Will do these things and report back.
    Thomas

    1985 Mustang GT - Build Thread

  13. #63

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    Was able to pull plugs tonight. I'd say gauge corresponds with plugs, definitely rich. Cyls 2,3,5,8 (DS half of carb) are running richer than others for some reason. Idle mixture screws were set slightly different, but wouldn't think those would make that much difference.

    Sorry pics are a dark, lighting not pic-friendly in garage.









    Going to clean up these plugs and put them back in for now. Only have a couple hundred miles on them at most. Will pick up some new plugs once this rich issue is resolved.
    Thomas

    1985 Mustang GT - Build Thread

  14. #64

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    Yep, all sorts from the driver's side. To what I suggested to check above... surely she's clean as a whistle... but just for the process of elimination, I'll add that I would check to see that none of the air bleeds (or their passages through the upper body to the metering blocks) are blocked or partially blocked, providing this unnecessary fuel coming from somewhere...
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1966 Ford Fairlane sedan
    1966 Ford Fairlane GT
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang
    1974 Pontiac LeMans

  15. #65

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    Took carb apart last night. Blew everything out with carb cleaner and air.

    Pulled IAB's out, ran wire through passages to make sure chip wasn't left after drilling & tapping. Looking closer, noticed vertical portion of passage below bleed was smaller on drivers side. Measured about .070 vs. .120 on passenger side. Not sure if it was like this from Holley or if it was an upset as a result of the drill & tap. Opened up the passage to match the other, then cleaned and reassembled carb.

    Was late when I got everything back together, will drive it tonight and see if anything has changed.

    Hopefully this was source of rich DS barrels. Did not see anything else obvious that might be causing the problem.

    Also, while carb was off, eyeballed idle discharge ports. Did not measure them, but look to be .060-.070 dia. No other restriction that I could see, though not sure why one would be necessary if mixture screws are controlling fuel flow.
    Thomas

    1985 Mustang GT - Build Thread

  16. #66

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    That 0.050" passage difference might be enough to make a difference, being that we're talking about air bleeds that exceed 0.070"...

    Not to hijack your thread, but, case in point, with newer carburetors (IMHO, the corporation IS sabotaging it's own products, the carburetors... after all, THEIR fuel injection systems and retro-fit systems garner FAR MORE $ than their overpriced piece of $hit newer f-ing wanna-be carburetors)...

    I got a LIST-1850-13 to rebuild, date coded about 2012, all aluminum, all shiny, real f-ing razzle dazzle... It's not even on the newest of Numerical Listings to check out it's innards. Anyway, upon checking things out, I found 2 of the 4 f-ing emulsion bleeds were not even drilled through into the main wells, as well as bleeds up high into the main wells and a metering block that doesn't even have emulsion tubes in the main wells to work with those. Complete and total f-ing idiocy!!!

    If you want to run a carburetor, do not even think about buying anything new.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1966 Ford Fairlane sedan
    1966 Ford Fairlane GT
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang
    1974 Pontiac LeMans

  17. #67

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    Yeah, I don't plan on buying any more new carbs.

    Drove car tonight, ran pretty damn good. .024 IFR's, .076 IAB's. Went ahead and dropped to #66 main jets. Had to back IMS's out to about 1 1/4-1 3/8 turn out. Getting 19in/Hg vac @ idle. Bumped primary throttle open a bit to increase idle speed from 700 to 800 RPM.

    A/F gauge showing hi-14's warm idle. Transition cruise varied a bit, 13-15:1 depending on RPM. Didn't notice any lean spots, seemed pretty smooth. It was showing pretty lean on the gauge during warm-up, had to keep idle up a bit to keep it from stalling. Once it got up to temp, all was good.

    Will drive it a bit more and check plugs again.

    Not sure what else to do with idle/transition circuits at this point. Mike, I know you didn't like going smaller on the IFR's, but hard to argue with the results.

    Was digging through my tool box couple days ago and found the RPM pick-up for my digital multi-meter I thought I had lost. Going to use it to see when boosters come in and map my timing curve. Try to do that this weekend.

    Guess getting the mains dialed in is the next step.
    Thomas

    1985 Mustang GT - Build Thread

  18. #68

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    Very nice, glad to hear it.

    The choke plate might be opening a little bit too much when it starts cold.

    No, hell no. Results are what matters. If that's what it likes, then that's right.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1966 Ford Fairlane sedan
    1966 Ford Fairlane GT
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang
    1974 Pontiac LeMans

  19. #69

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    Quote Originally Posted by 85MUSTANGTGT View Post
    Also, while carb was off, eyeballed idle discharge ports. Did not measure them, but look to be .060-.070 dia. No other restriction that I could see, though not sure why one would be necessary if mixture screws are controlling fuel flow.
    I missed this previously. If that is the size of the primary idle discharge ports, that's on the small side but shouldn't be an issue, but if those 0.060-0.070" holes are the size of the secondary idle discharge ports directly below the secondary transfer slots, that's miles too big. If so, they need to be 0.025" or less, in order to not be a sizeable influence on the idle/low-speed air:fuel mixture. They are only there so that fuel doesn't go stale in the secondary bowl of a conservatively-driven vehicle that doesn't see much or any secondary opening.
    Last edited by Walking-Tall; 05-18-2017 at 04:56 PM.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1966 Ford Fairlane sedan
    1966 Ford Fairlane GT
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang
    1974 Pontiac LeMans

  20. #70

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    Mike,

    Those are the size of the primary discharge ports. There are none on the secondary side that I recall seeing, only a transfer slot. I'd have to look again to say for sure.

    On the varying transition cruise, is that normal for it to get leaner with increasing RPM? Or should it stay relatively flat? Should I maybe try a size smaller IAB, or is it fine as is? It wasn't getting lean enough to misfire like it was previously.
    Thomas

    1985 Mustang GT - Build Thread

  21. #71

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    Okay. Yep, hard to see, very tiny, and ideally <0.025". Secondary idle discharge ports are on every aftermarket Holley carburetor that I've seen. Some of the older OEM Holley carburetors do not have them, since their intent was shooting for least "emissions"... but there's not much sense in fuel being allowed to go stale out back if the secondaries rarely or never get opened up...

    That's better than "normal", to progress leaner with increasing part-throttle load/rpm, hand-in-hand with lean best jetting when the main circuit starts, all the way down to the vacuum level when the power valve opens. That's approaching or at best efficiency, where the magic happens with a carburetor, upwards of a possible safe and happy 16+:1 AFR. WOT (jets + PVCRs) should go rich (~12.5:1) and stay as flat as possible. If all seems well, dialing in lean best transition is to increase PIAB size until it does progress too lean and the car protests (surging or misfire) with easy/moderate part-throttle, while still within the idle/transition circuit, what's referred to as finding "stupid lean", and then take small steps back smaller with PIABs until it likes it.
    Last edited by Walking-Tall; 05-19-2017 at 11:22 AM.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1966 Ford Fairlane sedan
    1966 Ford Fairlane GT
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang
    1974 Pontiac LeMans

  22. #72

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    Excellent. Sounds like I'm getting close then.

    Thanks again for all your help, Mike. And thanks again to everyone else who has contributed.

    Been thoroughly frustrated with this thing for too long.
    Thomas

    1985 Mustang GT - Build Thread

  23. #73

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    Yes, I think so too. You'll get it running nicer than you thought possible. My car with it's 3.8L V6 is so tired and so under-powered, but after ditching the EEC-IV and CFI and putting this Holley 500cfm two-barrel onto it and dialing it in, it's an absolute pleasure each and every time driving it, because it runs so nice.

    Quite welcome. I commend you and anyone willing to dive in DIY and make things work right.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1966 Ford Fairlane sedan
    1966 Ford Fairlane GT
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang
    1974 Pontiac LeMans

  24. #74

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    Drove car again tonight. Ran well, no complaints.

    Only change this time was dropped secondary main jets from #72 to #70. Cleaned up top end. Had been seeing A/F gauge dip into the 10:1 range, now its mid-high 12:1 range. Much better I think.

    Think I'm probably 95% to ideal. Aside from some air or emulsion bleed tuning, not sure what else I can do to make it much better. And I think that stuff will have to wait until I get some datalogging capabilities and can see all the variables of what's going on in one place. Will see about getting the Innovate Aux-Box soon and getting it installed.

    Any further tuning progress I plan to document in my build thread (link in signature), along with continuing the refurb/reinstallation of my factory air cleaner and any other changes.

    Probably see about getting some catalytic converters installed to clean up the exhaust smell now.

    Thanks everyone!!!
    Thomas

    1985 Mustang GT - Build Thread

  25. #75

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    Nice

    Increasing PIAB size a bit at a time until it doesn't like it, and then decreasing a few thou back from that, will bring about the crispiest powerful throttle response and maximum efficiency. After transition is the best it's going to get in your view... when I dialed in lean-best main jetting, I did so by plugging the PVCRs with 8-32 blanks, and then took the car on drives where I could tip into the throttle further than I had been for tuning transition, far enough to activate the main circuit with the most load, but still above the vacuum level where the power valve would open, in my case, in 3rd gear, in "Drive" out on the highway. The primary main jet size is decreased until the car does not like it, and then step back rich about two sizes and retry. After finding out lean-best primary jetting for heavier but still part-throttle acceleration, the PVCRs need to get opened back up and addressed, sized for best WOT AFR.

    Looking forward to the build thread.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1966 Ford Fairlane sedan
    1966 Ford Fairlane GT
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang
    1974 Pontiac LeMans

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