Close



Page 2 of 3 FirstFirst 123 LastLast
Results 26 to 50 of 75
  1. #26

    Default

    Here's that "1947" block I'm working on. If it does go onto the front of the LIST-3310, I'll drill Ø0.028" kill bleeds into the angled passages that feed the boosters. That's not usually common in straight leg booster carburetors, but is common in all 3310's I've had open, so the usual PVCRs (Ø0.062"), main jets (#72), and main air bleeds (~Ø0.025") will have (or should have) all been sized for kill bleeds.





    Last edited by Walking-Tall; 05-02-2017 at 03:35 PM.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  2. #27

    Default

    Pretty cool, Mike.

    I have a bit of a hard time wrapping my head around all these different bleeds. I understand they mix air into the fuel and change timing of the different circuits, but that's about it. Haven't had much luck finding info on effects of changes made to these circuits. What little I've found is so cryptic or you need a PhD in fluid dynamics to understand. Or maybe its just me.

    Anyway, put my carb back together with the .026 IFR's & .073 IAB's, didn't get a chance to drive it yet though. Was getting dark and starting to spit rain by the time I was done. Maybe tomorrow.
    Last edited by 85MUSTANGTGT; 04-27-2017 at 11:36 PM.

  3. #28

    Default

    Thanks.

    Here's a good descriptive image of the different modular tried and true old school Holley passages and orifices and their functions:




    Your changes should slightly richen the idle/transition, and maybe more importantly, extend the transition's ability to continue further to better meet with or overlap with when the main circuits are to take over, and should improve or eliminate the surging/missing the engine was doing between those two areas of function. Good luck with it.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  4. #29
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    Quote Originally Posted by 85MUSTANGTGT View Post
    My main problem is with transition cruise during warm up driving. After accelerating to speed, with engine RPM between 1500-2000 or so, the AFR will initially settle around 14:1 then after a few seconds start getting leaner and starts misfiring. I have to keep rolling in the throttle a bit until its fully warm. With the current settings, the car runs well when fully warm. Are these AFR numbers normal? I’d like to see the warm numbers a bit leaner if possible, but worried about the cold AFR getting any leaner than it is. I know numbers aren’t necessarily everything
    Thomas


    Its not Air Fuel, its igntion advance you need to play with.


    This is a cold start issue that Ford fixed in 1969 with vacuum lockout delay to cap advance on cold starts. It creates a more load during the early running. Its the whole reason the emissions gear is the way it is with Clean Air carb cars, killing the high compression, long duration cam relasted warm up matters by swapping to delay valved PVS sourced vacuum.


    Distr-o-vac was first,

    http://www.aus-ford-uk.co.uk/html/engines.html
    with the 10.7:1 351C, then 70-73 Mustangs

    and 200 Maverics,

    http://1bad6t.com/Maverick/repair/em...ntrols_02.html

    then the highly refined PVS and manifold vac interplay the 4-bbl HO's used.


    http://vb.foureyedpride.com/showthre...vacuum-advance


    Its was all over cold start emissions improvement, why things became so complicated.

    Its wasn't just Ford being diffucult, Cold start Parts Per million emission reduction helps cold start warm up.
    http://www.caee.utexas.edu/prof/kock...coldstarts.pdf

  5. #30

    Default

    Thanks xctasy,

    I'll look into my timing a bit more, along with this PVS.

    Rain finally on the way out here, so hope to get some time to tinker tomorrow.

  6. #31

    Default

    Point-blank, for reasons of acceptable longevity, which in my mind is as long or longer than as physically possible, I give no credence whatsoever to improved "cold drive-ability", because like every bearing clearance and piston-to-bore clearances, etc, there's a very good reason for the term "operating temperature". Warm up is a necessary evil, like it or lump it. There's no good reason to force an engine to run and even forcefully accelerate acceptably when it's cold, besides the encouragement of sales of the necessity of oversize pistons and rebuilds. Nothing is meant to run seamlessly prior to operating temperature, and anything forced to do so, will die an early death... get the choke and fast idle working acceptably for those situations, but don't expect to be able to turn the key and stand on the gas without consequences... 'nuff said.

    I'm very much looking forward to the findings from your tinkering...
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  7. #32
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    Love all your work Mike, and respect your view. Your carb work speaks for itself


    A 100% THUMB UP.

    I love carbs. Holley carbs in particular, although I've dabbled with much more annoying to tune European early Weber 2-bbls for a lot longer.

    Holley never went to the Carter BB/ Ball and Ball or Autolite 2100-4100/ Motorcraft 4300/4350/2150 needle valve transfer , so a whole raft of square and spread-bore mechanical secondary AVS AFB TQ solutions don't exist for die hard Holley lovers like me. Holley 4165/4175 were under appreciated as well. The plastic era new of 1988 era Holley 4-bbl aluminum carbs were lowest common denominators in terms of quality, and its only been Summit who have rescued that sad attempt from oblivion. Ford, Carter and Holley looked after themselves through the 80's, and I'd like nothing better than to see proper Holley 4--bl Carbs as a bolt on proposition. But its plug and play 4-bbl EFI systems that get the air play now.

    Since I've also dabbled with Rochester 4M's and Carters, and mech sec 650 4-bbl Holley's, I don't especially like vacuum secondary carbs, but the 780 cfm version of the 3310 is an absolute gem.


    The way Forward IMHO with the Holley is the best parts of emissions with the best parts of performance.


    I use the dreaded E word here by way of explanation, this is not a circumvented PM (Particulate Monitoring) Emissions Crusade. Period.

    A note that in the article above in line 61

    "high vehicle operating temperatures are still key to low-emissions operation". Its also a way of warming up (even overheating) an engine fast.

    Emissions engines use

    1. more fuel,
    2. make less power,
    and
    therefore,
    3. naturally make more heat.

    It's the ignition advance strategy, not EFI pulse-width or light off of the cats, that fixes the first four minutes of sub 65 deg F ambient and sub 190 deg F water operation.

    All that smog crap doesn't help acceleration or power during cold start, BUT it does help cold start performance, but in terms of setting of the "inside state" warm up, cutting peak advance in high gear, and running less advance at the plus 35 mph area while warming up, really wipes off about a minute of warm up time. That was the main reason people hated early emissions gear, the cars woulds overheat....

    Traditional carb tuning has to take advantage of a quick warm up strategy, or all those bazillion dollars of state enforced FTP protocol ideas
    (heat stove inlet air,
    vac motor control flapper valves
    choke pull down,
    spark sustain,
    vac delay by re sourcing the manifold and port vacuum, aka vac Load-O matic/Distrovac style)

    ...they were just ways of making an engine warm up without over advancing. Main issue, was after a lick of de icing road salt, the flappers rusted up, one part would stop working, and the whole lot would get pulled off.

    I'm lucky, it gets down to 14 degrees F in neighboring Ranferly, and to 1.4 degrees F in my old home town. In the 265 to 375 hp net area, you should just compare the warm up of an emission controlled heat stoved 750 cfm spread bore 351C March I with Distrovac verses a non emissions 375 hp 351C with 780 Holley. American emissions carb controls are just great for warm up, less so under wide open throttle.


    I had a succession of I6 Fords. My 81 Stang was the all time best warming up car I ever had.

    an 81 US smog 3.3 to an 1980-81 non automatic choke 1v 126 hp 4.1 Falcon, the non emission Falcon wasn't nearly as good.

    The next year, with an automatic choke 1982 2v 4.1 Falcon with 141 hp. Now those later cars were 13 to 15% more economical with quicker cold start light off just via some really basic thermatic valves. The 82-84's were downright fun to warm up even in the snow at 32 deg F in Dunedin where I live.

    85MUSTANGTGT, if you think solely that the carb is the solution to your problem your wrong. All my emissions cars with peak advance lock off under warm up were far better at reaching operation temperature quickly than my stripped down 4.1 engines were.

    I'm an advocate of attempting to keep the good parts of a smog engine, with the best parts of a performance engine

    Like Fords Australian 79-85 5.8 liter 4bbl; they did it the other way around, a retard lock-out, with ported to manifold switch-over.

    35°C = 95°F
    55°C = 131°F
    107°C = 224.6°F




    They had even worse than US 5.0/5.8 underhood heat issues, actually worse, because Australian V8's



    didn't get a 5.0 HO/460 style PVC/PE dual feed air cleaner. If ever an engine needed it, it was the high under hood heat X and F series series Fords 1979-1982(79-85 in Bronco/F Trucks) 302c 4V with 188/207hp and the 351c 4v with 200/216 hp


    (Even the lowly 120 to 141 hp I6's got those




    in our 83-92 Falcons)

    The basic PE collectors are so low rent, but even DH20's can be made a lot cleaner in side, but that's the basic idea http://www.myautopartswholesale.com/...-products/dh20

    Nor a blead back valve to limit percolation fuel pressure like the baby 3.3 and 4.1's Weber 2-bbl Weber ADM carb did.

    Bleed back was a very important way of making sure you don't get "before jet" fuel vaporization. Same as the carb Canadian Police Fords 1981-1991 non EFI got the VV 7200 carb, and a bleed back valve to limit peak carb pressure to less than 5 psi by a drilling for fuel back to the tank. Here is one on a 2150 2-bbl


    http://www.grandmarq.net/vb/images/g...-top-alpha.png

    And the core part



    GM Holdens




    83 kW 3.3 litre= 111 HP SAE Net 202 Holden L6, bleed back size,
    110 kW single exhaust 4.2 litre = 147 hp SAE Net 253 Holden V8
    126 kW dual exhaust 5.0 litre = 168 hp SAE Net 308 Holden V8
    The third line bleed back varies on application from 59 thou (1.5 mm) insert on an itty bitty 3.3 to 28 thou (0.7 mm) on a 4.2 or 5.0.

    And that 4.2 to 5.0 could be 147 hp in the 16.7 second 1/4 mile base model Commodore SS, or 295 hp in the improved performance ADP or New Zealand SS Commodores which could drop mid 14's with ease.


    The kit is allegedly a "vapor kit" or "regulator", as it has a bleed back or vapor return line, as well as a "flow sensor body." (For the Trip Minder MPG meter).

    Although the flow meter was designed for bleed back to protect a turbine wheel fuel flow sensor, it actually functions as a return line to reduce hot fuel handling problems, just like on a return line EFI vehicle. Carb cars ran it for fuel bleed back in Cop Cars, like the carb 4-bbl 5 liter GM Holden Commodores.

    The Australian 81-85 Holden Commodore 4.2 and 5.0 V8 copied the United States of Americas 1981-1982 Ford 4.2, 5.0 and 5.8 bleed back set up, as they use the same "vapor/regulator/flow sensor" body

    Fuel percolation, great cold start warm up, the US/CND 351 VV7200 Fords had all the right stuff.

    There wasn't a lot that Ford USA could do from 1980 to 1991 if you had a carb, you just had to comply.


    Firstly, the ignition system vac routing performed

    a) warm up and

    b) emissions functions, and worked to kill those two birds with one stone.

    Secondly, so did the Trip Minder "vapor kit", "regulator" or "flow sensor body."

    a) it was ostentatiously an electronic pick up

    but

    b) it was a bleed back valve for cool fuel to eliminate hot fuel handling.

    Thirdly, the ancient speed control part you find on all Fox Fords, the 1969 era Variable Reluctor (VR) speedometer sensor could be used for


    a) Emissions retard and early Vehicle Speed Sensor pickup

    but also

    b) Cruise Control (speed control)

    FoMoCo mastered the class in making Federal compliance maters ways of making better horsepower. Its should be noted that the last killer emissions donk before 1982 was the 266 hp net 351C 4-BBL HO Cobra Jet. The cam profile was the same as the 1985 roller cammed 5.0. If Ford had just converted that 1973 351c back to a 302C 4-BBL, or Boss 302 Windsor style combination, it would have made 228 hp, 3 hp more than the 225 hp 5.0 HO.

    Ford had just played a compliance game from 1972 to 1982, it started when Ford Australia tried giving the Queensland Minister of Transport a bollocking over the threat to stop car makers producing high horsepower per cubic inch 160 mph road burner engines. The “Supercar" blow-up invoked with Ford world wide, from June 1972 on-wards, a game of compliance game

    People who don't follow Dist-O-Vac, MPG fuel flow meters, Variable Reluctor (VR) speedometer sensors, the 1972 170/200 Ford Maverick Transmission Regulated Spark System, or the California 1972 market Electronic Spark Control System for 302's and auto 200's

    http://1bad6t.com/Maverick/repair/em...ntrols_03.html

    can all be forgiven for thinking all this emissions sh!+ is just anti Total Performance and just for federal compliance. It wasn't, it was for Total Convenience.

    Ford gained the ability to get right back to square one with performance vehicles in 1982, but it had been experimenting with 1980 high lift G code 351 cams and getting emissions compliance in Australian engines without catalysts for 10 years.

    Use the cold start routing devices for the 5.8 Cleveland engine (ABOVE),

    the improved flow version of the 17 inch 460 dual snorkel( you can improve on 535 cfm if you use better flapper valves and parts),

    and perhaps the better 5 psi fuel pressure limited device, but it must be fuel pressure, not fuel flow limiting,

    If you have a lot of crankcase ventilation, the ME Wagner balanced PCV valve ( because your engine will probably no longer have the PCV baffle below the PCV valve the way Ford intended, and will also have major increases in blow by because it'll have more than twice the design hp level of 180 odd hp they were designed around) .

    I don't get kickbacks from Wagner over the Adjustable PCV valve (Its Not cheap, and per item I'd make a lot on money doing it), but I've lost count of the amount of people whose cold engine won't idle, and its all because some of the other advice from performance suppliers is to perform a frontal lobotomy on the factories emission devices, first the rocker cover baffles, then its PCV, then the carb, then the exhaust primary light off cat, then the secondary AIR...

    .

    You don't have to spend a million bucks, just two TVS valves to rout the ignition advance right in that vital 58 to 65 deg F zone, proper intake heat stove supply from the headers under part throttle with proper full flow under wide open throttle, and proper PCV system. Basically, IMCO 1973. I'd personally stay with EGR, but that's up to you.

    Actually, all of its up to you....


    If you've got the stock 5.0 Holley 4180c chock pull down and the Vac Operated Throotle Modulator (VOTM) snubber against a modified Holley 4-bbl throttle shaft tang, then you'll not have a problem with cold start RPM's and the curb idle adjustment can be done off peak vacuum using Fords suggested hand pump target reading.


    85MUSTANGTGT, You should read all of Mikes posts. Basic rule is that for the added complication, a simple warm up should be the easiest solution. The fact that Canada gets so cold, well, he beats New Zealand for cold by many degrees F.

    Some of Fords 80's Better Ideas definitely deserve to die, but I personally won't go back to denuded pre 1972 emissions devices after experiencing almost 5 years of 1981 Mustang 3.3 and 1984 Falcon 4.1 cold start and hot fuel handling nirvana. Something Ford definitely got 100% right in those years.


    Any to you go off track from 1980's stock Carb, CFI or Port EFI 5.0 V8 back to performance 4-bbl, you have to have a game plan for cold start and hot fuel handling. I've been over the chat room circuit, and No body does. Except me. And that because I get badgered by it every day from other Kiwis down here who do the same stuff as Americans, and lop off the factory IMCO era on-wards parts, and then wounder why it "not workie" as well as it did when stock.

    Mike is the exception. He's dealt with a factory 3.8 CFI....they "not workie" as well as the best 2-bbl V6's from day one. He's earned his spurs...

  8. #33

    Default

    Unfortunately, didn't end up with enough time to tinker today (well yesterday now), was still raining off & on and one of my boys wasn't feeling well.

    Mike & xctasy, I really appreciate all the info you've given me and taking the time to post it all up.

    It was my hope when I built my new engine that I could at least get it tuned to the point that it would be tolerable to drive and keep it as simple as possible. Realistically, I wasn't expecting OEM fuel injection drivability, just something between that and where I'm at now. I'd like to be able to jump in the car in the morning and drive it to work occasionally or take kids to school in the future without having to get up 30 min early to warm up the car. My current warm-up times just seem excessively long.

    Would like to take this process one step at a time. Going to keep working with the carb & timing, see what can be done there. I've pulled my factory dual-snorkel air cleaner off the shelf and have disassembled it to make a couple modifications and repairs. We'll see if reinstalling it will make a difference, if any. If not, I/we can consider other options to try.

    I realize Ford spent a lot of time and money developing these system and wouldn't have put them on our cars without good reason, but again for simplicity's sake, I'd like to avoid as much of this stuff if at all possible.

    Thanks again guys,

    Thomas

  9. #34

    Default

    Thank you for the kind words, Sir xctasy.

    My sentiments exactly, Thomas. I can respect that some of the add-on gadgets were created in the name of improved function in some areas, but I've got nearly zero patience for any add-on gadgets that end up doing nothing but complicating a historically very simple process (start, warm up, conservatively be on your way smoothly at any point during that warm up, efficiently power the jalopy while sipping ONLY the fuel necessary to do those things). My developed lack of patience for gadgets has been honed by years of doing and seeing troubleshooting or adjusting or tuning get clouded, creating an inability to just see that the basics, like the engine's mechanical health, the ignition timing, the fuel mixtures, etc., are all working in harmony as they should. IMHO, gadgetry can end up distancing or disconnecting "man and machine" in the quest for best efficient function. The byproducts of best efficient function are always acceptable warm up taking minimal time (which has lots to do with how far that choke blade opens when the cold engine starts), and after warmed up, the idle/transition circuit tuning to find first, stupid lean, and then the sweet spot found heading slightly richer with IABs, coupled with amounts of ignition timing that she'll tolerate, produces peppy "let's go!" low-speed part throttle acceleration, nice clean spark plugs and engine oil, and rewarding fuel efficiency. Unless you live by the Autobahn or on a race track, the great majority of driving is done on the idle/transition circuit. It's more difficult to tune than the main circuit or WOT, but it returns the most reward in all of the above ways when dialed-in.

    The OEMs that were specifying the calibration inside of mass-produced carburetors in the past were no dummies either. Open up one of the first modular Holleys, a LIST-1272 from a 1957 312-powered Thunderbird (same or similar bore/venturi to these 600s we're talking about) and you'll find a calibration surprise or two that have long since been abandoned, for no real good reason, besides like other strangely eliminated things like the signal tube in bigger vacuum secondaries, fractions of a cent cost cutting... like pressed-in sized restrictions at the passages on the underside of the main body that lead to the transfer slots, transfer slot restrictions. There are tuning situations where the ability to trim air:fuel to the transfer slots becomes necessary, and surprising fuel mileage can be found. It isn't always absolutely necessary, because most situations can be dialed-in nicely with IFR & IAB tuning, but the ability to tailor and make very precise adjustment of the whole lower and upper range of the idle/transition circuit can then really be laid down.

    Keep at it, good luck with it
    Last edited by Walking-Tall; 05-02-2017 at 12:24 PM.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  10. #35

    Default

    I would just like to touch on something about your situation briefly. Your carburetor's calibration includes...

    "-IFR’s: .0225P/.028S (.026P/.028S Stock)
    -IAB’s: .079P/.050S (Stock)"

    ... Ø0.028" secondary IFRs are a wee bit on the small side, and Ø0.050" secondary IABs are (more-so) on the big side. If you can feel when the secondaries open, or there's any kind of flat spot when the secondaries first open, those could be contributing factors. Traditional secondary transition calibration in a puppy such as this has ~Ø0.031" secondary IFRs, but more importantly, in the neighborhood of Ø0.028" secondary IABs. That brings about an adequately rich (though very brief) secondary transition when they first open. There's no secondary accelerator pump, so a situation like this for a second or two can be necessary for seamless secondary function. Just something to keep in mind and maybe address or play with if necessary later while dialing this in.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  11. #36
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    The only thing I've learned is to optimize your ignition first for your planned hp level, and then make sure you have a proper choke pulloff, heat stove and flapper ducted to the twin snorkle air cleaner. I guess thats basically how the CFI down to Holley carb downgrade worked for WT.


    Down here, all my V8 mates are just like Mike... they remove the clutter, and warm the beast up judiciously. But they aren't as clever, and most damage is done in the transition to fully warm. Once warm, they like to fiddle with the advance, and tend to use a vac gauge. Its the cylinder wash out, the numerous oil changes, the fumey smell and high sickly sweet smell of gasoline fumes. A carb V8 is just a romantic machine, Kiwi style...my views find no favour at car shows, my mates just sorta laugh, and enjoy the ride home...



    Emmissions Junk?






    I love the choke pulldown, love the spark delay valves, and like the fact that I can turn the car on, and its hands free while I have a cup of tea.....leave it for 3 minutes ideling, and the idle will just click off tempo to nearly stalling, and the car is warm and able to do everything you can ask of it. My car never got the Aussie style bleed back fuel pressure reduction, but it never had hot fuel handling problems. The primary light off cat kept the engine hot, and no issues with electric fans surging the idle or insufficient voltage to the battery unless I was using my inverter...killed a few battries, but it'd idle cleanly all the time. Never touched the 9 BDTC timing. Nor the VOTM.

    Care free. You don't get that with modified EECIV unless you know the systems.

    Best part is that the found Item 3, Green DVCV2 port PVS vaccum switches

    And Item 2, Blue TCVV 3 port vaccum switches

    and Item 5 (no letter suffix) the Black SDV Spark Delay or Vaccuum delay valve are so easy to get, it makes a hand free Idle warm up while getting Coffee at Toms Diner a way to warm your car up while listing to one Suzanne Vega song..


  12. #37

    Default

    Quote Originally Posted by xctasy View Post
    I guess thats basically how the CFI down to Holley carb downgrade worked for WT.
    Downgrade, schlowngrade, lol ... I will wave the UPgrade flag over this situation I have accomplished forever, lol. I would love to take you for a spin in this thing before (CFI) and after (Holley 500 2-bbl). The difference in function is truly night-and-day, all around, from when first turning the key on the coldest of January mornings here, it's smoother and quieter and slower rpm demeanor idling, it's brisk normal acceleration just off-idle, through seamless clean running with 30+ mpg AVERAGED on the highway, up to it's (admittedly, purposely slightly on the rich side) WOT now like it never had before.

    I appreciate all you're saying about these things, and I just do not have the patience, or see the necessity, or find myself needing any of them for what appears to me to be darn near perfect function.
    Last edited by Walking-Tall; 05-02-2017 at 09:08 PM.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  13. #38

    Default

    OK, just got back from a drive w/ .026 PIFR's & .073 PIAB's.

    Let it idle in the driveway for about 5-7 min or so. Choke opened after a couple minutes, idling @700-750 RPM. A/F gauge showing about 12:1, previously would hit 15-16:1. Leaned idle mixture screws 1/8 turn (1/2 turn out), no significant change, might have bumped to 12.5:1. Started driving, still in "warm-up" period, noticed throttle response seemed crisper, A/F gauge shows 10.5-11:1 @ 3rd gear 1800 RPM steady cruise, 22in Hg vacuum. Drove approx. 5 min to drug store, 10 min. stop. Started driving again, warm carb idling richer, 11-11.5:1, transition cruise (1500-2000 RPM) still 10.5-11:1. Got on highway, 70 MPH/5th gear/2000 RPM/18-19in Hg Vac, A/F gauge showing 12-12.5:1.

    So, I'd say the change helped the "warm-up going lean" issue, though its richer overall than I'd like to see.

    Mike, noted on the secondary IFR/IAB settings. In lower gears I can feel power pick up about 3000-3500 RPM, I attribute that to the secondaries coming in. Don't think I listed it earlier, but have currently have the medium (plain) spring in the diaphragm.

    xctasy, working on getting the factory air cleaner fitted now. I'm reasonably certain the timing is in an acceptable range. I'll see about enlisting some help and get my timing curved mapped to know exactly what's going on there.

    Let me know what you guys think.

    Thanks,

    Thomas

  14. #39
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    Yeah, I kinda think upgrade is right word for CFI to #4412, Mike....bad choice of words on my part..In your case,
    it now works,
    its uber cool,
    its economical,
    it performs well, and
    its adjustable and you probably don't have to fiddle with it.

    There you go, a self evident success.

    Its the head bending to think through what maze of 13 to 31 devices a cut down system might have. In the case of the 4180C's, there is a similar plothora of bits. Aint nobody got time for piling parts on parts.


    Once people talk with one another, the parts are easy to track down especially the colr coded stuff. Stormin'Norman (links below) listed his sources from way back, and I'm just a total magpie for the schtuck everyone hates. For me, once I had pictures, lables names, and a grocery list, it was a no brainer. But it took me 35 videos and 700 photos of my Japanese Domestic Market Mustang to get a handle on the parts.


    And you know what song I sang when learning...

    The Vapors - Turning Japanese - YouTube
    https://www.youtube.com/watch?v=LR4XNqrqxrU


    Pun intended...

    http://vb.foureyedpride.com/showthre...CI-on-the-VECI!
    & "VECI Basics From Ford" https://fordsix.com/viewtopic.php?f=...559118#p559118

  15. #40

    Default

    Quote Originally Posted by 85MUSTANGTGT View Post
    OK, just got back from a drive w/ .026 PIFR's & .073 PIAB's.

    Let it idle in the driveway for about 5-7 min or so. Choke opened after a couple minutes, idling @700-750 RPM. A/F gauge showing about 12:1, previously would hit 15-16:1. Leaned idle mixture screws 1/8 turn (1/2 turn out), no significant change, might have bumped to 12.5:1. Started driving, still in "warm-up" period, noticed throttle response seemed crisper, A/F gauge shows 10.5-11:1 @ 3rd gear 1800 RPM steady cruise, 22in Hg vacuum. Drove approx. 5 min to drug store, 10 min. stop. Started driving again, warm carb idling richer, 11-11.5:1, transition cruise (1500-2000 RPM) still 10.5-11:1. Got on highway, 70 MPH/5th gear/2000 RPM/18-19in Hg Vac, A/F gauge showing 12-12.5:1.

    So, I'd say the change helped the "warm-up going lean" issue, though its richer overall than I'd like to see.

    Mike, noted on the secondary IFR/IAB settings. In lower gears I can feel power pick up about 3000-3500 RPM, I attribute that to the secondaries coming in. Don't think I listed it earlier, but have currently have the medium (plain) spring in the diaphragm.

    xctasy, working on getting the factory air cleaner fitted now. I'm reasonably certain the timing is in an acceptable range. I'll see about enlisting some help and get my timing curved mapped to know exactly what's going on there.

    Let me know what you guys think.

    Thanks,

    Thomas
    Thoughts:

    If it's really not warmed up to the thermostat's opening temperature after 5-7 minutes of running, I'd wonder about a stuck open thermostat...

    Reasons for minimally open, touchy primary idle mixture screws, in an order I would suspect and check/set:
    - Passages for mixture screw tips, between numbers 3 & 4 in the above (middle) metering block image, if much greater than Ø1/16". Easy check on the car. Remove mixture screws and insert a 1/16" drill shank - snug fit or slightly loose, fine - real sloppy fit, not so fine, and will have to remain minimally open and touchy (or the block exchanged with one with Ø1/16" passages)
    - The tiny constant idle feed discharge holes directly below the secondary transfer slots, if much bigger than ~Ø0.025", can contribute substantial idle air:fuel
    - Secondary idle speed screw setting the secondary throttle plates a bit too much open unnecessarily with a mild cam and stock-ish idle vacuum levels
    - IABs too small

    Regardless of those reasons for mixture screws at 5/8 or 1/2 turns out, I would prefer seeing them out more, but that could remain fine at that or near that as long as best manifold vacuum and adequate air:fuel mixture can be set at idle, shooting for as close to 13.5-14:1 (or more) as it will tolerate. My car did and does exactly this, partly because it's a 500 2-barrel on a 3.8, but mostly because the flow of the PVC valve's metered vacuum leak doesn't allow hardly any transfer slot exposure at idle at all, so my mixture screws are set best at about 3/4 to 1 turn out. I worked around that issue fine and continued similarly to what follows...

    At this point, and since you've already got them, I'd hit it with those Ø0.079" PIABs again, readjust the idle mixture screws, and take a spin and see what's up. If the car doesn't protest, if it transitions crisp, and seems to run fine to you, increase the PIABs a thou or two, readjust the idle mixture screws again, and continue until the car does protest with light part throttle acceleration, and then step back rich (down) with the PIABs a thou at a time (always readjusting the idle mixture screws), until it likes it and runs best at light part throttle acceleration. A quick check of sorts to see if transition air:fuel metering is in the ballpark, is to warm the engine up to temperature and increase idle rpm to about 2000 (whatever rpm is still prior to main circuit metering) and momentarily block one of the PIABs with a finger or pencil eraser or something. If the engine smooths and rpm increases a bit, it wants more air:fuel and the PIAB size can be decreased. If the engine staggers, stumbles, or nearly dies, it needs less air:fuel and you can increase the PIAB size. All of these adjustments should be done one small change at a time and tested. I know getting the idle/transition right is a fair bunch of work, but it's most rewarding when accomplished by how well it runs, and how little fuel it uses, happily. IMHO, WB O2 sensing is most important for monitoring WOT AFR, where highest loading and a too-lean mixture can wreak real havoc.

    Your initial ignition timing, curve, and vacuum advance listed above seems fine, but by all means have it all verified.
    Last edited by Walking-Tall; 05-03-2017 at 09:04 AM.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  16. #41

    Default

    A few more thoughts to try to help:
    I have a sneaking suspicion that might not be the right, or the original primary metering block (as you mentioned, it could be a return, resold...). The replacement block for the primary for the 0-80670 carburetor from Holley is part number 134-57, and if the image of it there is accurate, it's showing all four cup plugs up top of it for the wells... meaning no emulsion-tubes in the main wells, probably no kill-bleeds at the angled passages to the boosters (since the carburetor does have straight-leg boosters) or unknown internal IFRs, and likely has 4 emulsion-bleeds like the ~Ø0.028" ones your secondary block has. All of this might be a part of the lean-appearing problems when you were close to nice AFR numbers before with your WB. Kill-bleeds to the boosters delay the main circuit, and are most usually in the metering blocks of carburetors with down-leg boosters, because of their stronger signal. If this is a mismatch situation, it could very well require the transition to have to provide fueling well past the normal/usual ~2500rpm when the mains start up, potentially explaining the lean hole, surging and protest whatnot you were experiencing. I'd consider calling them and asking for a full description of the 134-57 metering block (e-tubes/no e-tubes, kill-bleeds/no kill-bleeds, etc...), because that might clear some things up here, because this is appearing a bit like tail-chasing with the AFR numbers you last got that went quite a ways in the rich direction for the fairly small changes you made...

    Their image:
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  17. #42

    Default

    Thanks Mike.

    I'll work with the IAB some more and see what happens and also check the idle mixture screw & idle feed passages.

    Would you not recommend reducing size of PIFR's below the .026? I initially changed them to .024 and it really seemed to help clean up the idle & transition A/F ratio wise & make idle mixture screws a bit more responsive. The change to .0225 was more or less just to see what would happen, which I couldn't really tell much difference.

    I did open the secondary throttle blades when setting idle speed to compensate for closing the primaries. Not sure exactly how much, but don't think it was more than half turn of the stop screw. Secondary T-slot does not show from bottom of carb FWIW.

    I'm fairly certain my thermostat is working correctly. Upper radiator hose stays cool until coolant temp gauge reads 190 or so then hose starts to get warm. It will hit that temp within the initial warm-up. I think it just takes a bit longer for the intake to get there.

    I'll contact Holley to confirm the metering block ASAP.

  18. #43

    Default

    Quite welcome, Thomas.

    It's just easier to change out IABs and test to find which direction to go when it's all together and on the car. Yes, I believe you that the Ø0.002" change with PIFRs helped clean up idle and transition and make the mixture screws a bit more responsive, but then you hit a wall. That's WAY too finicky considering Holley put their safe (rich) Ø0.026" PIFR in there in the first place, which admittedly might be better suited to something with more camshaft duration, but shouldn't be too far off the mark for your combination. For (somewhat of a) comparison, the original Ø0.036" IFRs (original correct block with no e-tubes, just in your face 4 emulsion-bleeds and low position IFRs) in my 500 cfm 2-barrel on this 3.8L V6 ended up reduced down to Ø0.029", and could probably be reduced further down to Ø0.026" or so, but I continued on in the leaning direction by increasing the IAB diameters, which were originally Ø0.068" and ended up and are now at Ø0.074". This is why I'm thinking something might be off. Minimal turns out & touchy or not, idle and mixture screws can be adjusted for most any situation for idle, but transition behavior is solely controlled by the fixed size IFRs & IABs, the transfer slots acting as feeds or bleeds depending on where the throttle plates are... but the inclusion of idle feed or emulsion tubes or kill bleeds dictating how soon or late the mains starts, that makes transition have to be necessary for much longer until the mains do go to work.

    Cool. Secondary setting sounds fine.

    Okay, I see.

    Looking forward to hearing what you find out...
    Last edited by Walking-Tall; 05-03-2017 at 03:21 PM.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  19. #44

  20. #45
    FEP Power Member Ethyl Cat's Avatar
    Join Date
    Oct 2010
    Location
    Lebanon, IL
    Posts
    1,240

    Default

    Usually when I see someone trying to rescience a carb this much, the carb is not the problem. More often then not it is an ignition issue. In your first post you state you are running a stock Duraspark II. This is an ignition design to provide spark for a 8.3:1 302 and you have it powering a 10.5:1 347.

    I thought an 85 had TFI?

    Lean cruise stresses ignition quite a bit. Usually if I want to find a misfire i get a car in high gear and lug it up an incline. Lean mixture with some load(cylinder pressure). That Dura II is 33 years old!!!

    A weak pick up output signal starts coil saturation late and ends it early resulting in a weak spark.

    You might take some time to stress test that ignition system and see if it can keep up. Anybody with an ignition scope around there that knows how to test?

    Just some thoughts

    Steve
    BBD PERFORMANCE
    HIGH PERFORMANCE PARTS
    CUSTOM ENGINE BUILDS
    CUSTOM CAM DESIGNS
    1983 CRIMSON CAT OWNER

  21. #46

    Default

    Steve, there's no re-science thus far, but a return to basics for what this thing is, a 600cfm vacuum secondary, that I'm thinking has an incorrect primary metering block on it, completely f-ing with basic normal idle and transition function. Classically and frequently, "Street Avenger" (and all sorts of others, like "HP" & "Ultra XP" & etc newer wanna-be) carburetors are a problem, choke pull-off function and with whacked out (non-linear, stupid rich at mid-speed, and lean up top, BS numerous "emulsion bleeds" gone wild calibrations, etc) fuel mixtures, right out of the box.

    Duraspark II adequately provides spark for much hotter combinations (for folks around this forum) than with a 10.5:1 347 w/214-degrees @ 0.050" intake duration.
    Last edited by Walking-Tall; 05-04-2017 at 07:01 PM.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  22. #47

    Default

    Steve,
    '85 5.0L 5-Speeds were carbed, auto trans cars were CFI. Mine is a 5-speed. I've always read that the duraspark II was a fairly capable ignition system. Seems many are quick to yank the Duraspark out to slap in fancy MSD junk for little gain. Yes, my ignition module is going on 33 years old, but its never left me anywhere. Though it has crossed my mind to pick up a spare should the time come that it needs replaced.

    Mike,
    Pending the metering block issue, is my carb really worth investing the time in? Regardless of what Holley says I expect I'll be stuck with this metering block. What kind of work would I be looking at to emulsion mods this block like the one you posted pics of previously? I'm not afraid to drill & tap holes. Would I be better off with something else? If so, recommendations? There's a few 3310's locally on craigslist if I can find a few nickels to rub together.
    Last edited by 85MUSTANGTGT; 05-05-2017 at 12:59 AM.

  23. #48
    FEP Super Member erratic50's Avatar
    Join Date
    Dec 2016
    Location
    Nebraska
    Posts
    4,575

    Default

    I should clarify - that car ran great when warm. It was just difficult with a giant intake in cold weather until it had a chance to warm up.... but who had time to wait.

  24. #49

    Default

    IMHO:
    Bucks down option #1, IF that primary block's idle mixture screw tip holes measure okay, at or close to 1/16", I'd disassemble it and get my drill, 1/16" & 1/8" bits, center punch, a screw to extract 'em (sometimes the drill bit will grab and loosen them spinning. So you can pull them up and out like that, or wind a screw into the drilled hole and pull them up and out), and vice grips out and remove those emulsion caps and their tubes out of the main wells...






    ... and the cup plugs out of the idle wells (like I've done so far with the block I showed above), get some inexpensive 1/4" brass cup plugs from AllState Carburetor or wherever's closest/cheapest for you, and clone the secondary block's 4 e-bleeds (in your image below) into the main wells of your primary block with the drill size and tap necessary (#43 for 4-40 thread, #36 for 6-32 thread, #29 for 8-32 thread) for the emulsion restrictions you will be adding to your primary block...





    ... blow out all the passages real well, block any passages you may see from up top that directly connect main wells to idle wells with jb-weld, clean lightly with a drill bit and also block these two e-bleeds and kill-bleeds (in your image below) with small dabs of jb-weld... don't use too much, just enough to block the small holes. Don't block the channel with epoxy, the top of that channel makes connection with the main air bleeds.





    ... create and add 4 Ø0.028" emulsion-hole restrictions to your newly drilled and tapped primary emulsion holes, like so...





    ... install the 4 cup plugs (the main well plugs will go down deeper than the idle well plugs)...




    Blow everything out again for good measure, and reassemble the block.
    Then you'd have the adjustable IFRs & PVCRs block you already had, and there should be no mysteries about it's adjustment, function, and your testing results. Especially after the elimination of those booster signal kill-bleeds, that should allow the mains to start up sooner, more normally when they should, at ~2500rpm or thereabouts, and you're not likely to any longer have such a "hole" between transition and main circuit startup.

    Bucks down option #2, hunt for a good cheap 3310 (because, yes, if I had a stump-pullin' thumpin' 347 under the hood, I'd be putting a 750 onto it) for it's body, base, and primary block, tap those IFRs & PVCRs, and put your secondary block and bowls onto it.
    Last edited by Walking-Tall; 05-05-2017 at 10:57 AM.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  25. #50

    Default

    While I am confident of your skill to do the cloning, Thomas, here are some dimensions for reference for whomever may happen upon this thread:

    So, the vertical location of the top two emulsion bleeds' centers should be about at the bottom of the accelerator pump passage hole's bottom...



    ... and the bottom two emulsion bleeds should be about 7/16" below the uppers:

    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

Page 2 of 3 FirstFirst 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •