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  1. #1

    Default Holley 350 jet size for a 2.3

    I have a semi built 2.3 with a new Holley 350 carb on it , with the stock jetting , plugs r black with soot , so I was wonder if I could get an idea of what I should go down to ? 58? I'm no carb expert so any help would b great , thanks .
    1985 mustang gt t-top
    looking for a pennsylvania ssp
    parting out 1979 fairmont futura

  2. #2

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    Please elaborate on "semi built"...

    Incorrect jet size isn't likely/necessarily what's going on, because unless you see your spark plugs real black after a shut-off after a horsepower peak high rpm/redline run, it's not necessarily the jet size that's not okay. What's the List #, 7448? What's the idle rpm and manifold vacuum at? How far out are it's mixture screws? Any fuel coming from it's boosters while it sits idling?...
    Last edited by Walking-Tall; 06-27-2016 at 06:26 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/

  3. #3
    FEP Super Member xctasy's Avatar
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    Although EAO Pinto 2000 related, the needs of a Lima 2300 aren't any different. Both have an exceptionally good 2-bbl intake manifold.

    See Page 70 from https://www.scribd.com/doc/26804743/...s-David-Vizard




    Read the whole carburation section first.


    Power valve 4.0
    Power valve channel restrictions need to be drastically reduced from 59 thou to 17 thou.


    Carb frothing due to vibration makes modifications nessecary.

    Jets at 130 hp flywheel net ( up 40% from the stock SOHC or just 10 hp up from a well worked 5200 Holley 2 liter Pinto engine) need to be 56's.

    I do feel a 500 cfm 4412 will provide just what you are looking for on a 2300.


  4. #4
    FEP Super Member xctasy's Avatar
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    The jets you have are fine, but the power valves and two channel resytritions need to come down. You can buy a brass insert restrictor kit called a PVCR kit if you shop around. Or push in a brass restrictor, and drill to 17 thou.

    My friend has a name of a US supplier if required.

    That will do the trick with ease.

    You can use fuse wire or an e string from a gitar in the two Power valve chanel restriction (PVCR) holes.

    The PVCR's are auxilary jetting equal to 8 primary jet sizes, but on 4 cyl cars, that is way too much fuel and it just kills the fuel air ratio with too much gas.


    Anytime the manifold vac drops, the valve pops open, making the total jetting at 58 suddenly like two 66 jets. When you restrict the PVCR's, you drop the fuel enrichment, and the little four cylinder with a 350 cfm Holley 2bbbl just works sensationally with a 4.0 or 4.5 Power valve.

    A smaller jet and lower power valve number than stock won't help at all unless the PVCR's are what David Vizard suggests.

    There is a reason those three pieces of info are on the dyno sheet...all three items work to gether to make the Holley 350 or 500 cfm a killer carb on a midly cammed 2300.





    See http://fordsix.com/viewtopic.php?f=1&t=75263

    Quote Originally Posted by wsa111
    Nick, you need to install screw in jets in the PVRC which is under the power valve.
    You need to remove the power valve & measure the orifice diameter. Its the same deal as leaning out a Holley in the same area.
    The only thing you can try is insert a .010" diameter guitar string into the both orifices, doing this will lean you out some. The correct way is drill out the orifices & tap the drilled out hole with a 6-32 tap & install screw in jets, then you can tailor the WOT A/F as needed by changing jets in that area.
    I do this several times a month for guys who need to lean out the WOT mixture. Bill

  5. #5
    FEP Super Member IDMooseMan's Avatar
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    More excellent information from xctasy.

    You simply insert the guitar e-string into the PVCR holes? They won't work their way into the carb's fuel stream? I'll need to add this info to my project book.
    Craig "IDMooseMan" Peters
    1979 Mustang Ghia Notchback, 2.3L, Holley 5200, 4-spd, 3.08:1 7.5" diff, A/C, PS, PB, AM/FM/8-Track, Sunroof, Rear Defroster
    USAF SSgt 63170 1983 - 1992; Co-Founder, Vice President, Omega Delta Sigma, ID-A 2/2015
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  6. #6
    FEP Super Member xctasy's Avatar
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    Just a U shaped piece is required...it wont come out. Uncrew the PV, inset a u shaped piece into the two holes, trim so it doesn't poke out too far, and job done.

    You can go to bigger or smaller diameter to control the effective anular radius of each hole, but as soon as some thing goes in the PVCR, the flow rate is reduced, and fixes the over enrichment problems these carbs always have on 4 cylinder cars.

  7. #7
    FEP Super Member IDMooseMan's Avatar
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    The tips and tricks on this site blow my mind. Thank you. I'm not sure I would've thought to do this.
    Craig "IDMooseMan" Peters
    1979 Mustang Ghia Notchback, 2.3L, Holley 5200, 4-spd, 3.08:1 7.5" diff, A/C, PS, PB, AM/FM/8-Track, Sunroof, Rear Defroster
    USAF SSgt 63170 1983 - 1992; Co-Founder, Vice President, Omega Delta Sigma, ID-A 2/2015
    To those that serve and have served, "Thank You", to those that haven't, "You're Welcome"
    2.3L Horsepower Potential Thread
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  8. #8

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    So if I understand u correctly I will b putting the e string into the two holes that are behind the power valve when I unscrew it. Make it a u shape so it doesn't have the chance to slide into the whole any further than I want it to. As I said in my first post I'm
    Not a carb guy so I really appreciate all this info , I already ordered smaller jets and a 4.5 power before I got back on here to check for replys .thanks for all the help .

    Stock jets are 61 and power valve was a 8.5
    1985 mustang gt t-top
    looking for a pennsylvania ssp
    parting out 1979 fairmont futura

  9. #9

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    As to power valve opening, being a tapered valve with an opening spring that counters intake manifold vacuum against it's diaphragm, power valve opening isn't always in an instant. The rapidity or popping open of it is highly dependent on a rapid foot-down scenario. The rated vacuum number is when it's fully open, and I think that vacuum level rating should be tailored to your engine's needs, ditto with the jetting and PVCR area. I can't view that Vizard-ry, but I'm not certain why full enrichment through the PVCR's got drastically reduced from 0.059" down to 0.017" either, unless of course air bleeds got reduced too. Total flow area isn't screwed up at Holley, and I'd tread and test carefully while reducing total flow area.

    If interested, I showed how adjustable PVCR restrictions can be made in my build thread, posting #82 (red in signature).

    In case vibration is causing erratic float fluctuations, and maybe some of your richness, you might consider installing Holley's spring-bottom "off road" needle & seat in it as well, part # 6-513.

    Last edited by Walking-Tall; 07-11-2016 at 08:29 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. #10
    FEP Super Member xctasy's Avatar
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    http://vb.foureyedpride.com/showthre...ge-power-valve

    Post #5 03-23-2013, 01:53 PM


    8 jet sizes up from the stock jetting on a 4-bbl generally, but it varies as Holley carbs are generic castings with custom variations for some versions.

    It varies with 2300 2-bbls and 4150/4160/4180 depending on the configuration.

    Taking the three of the most coomon carbs, the common 2-bbl Holley 2300 series, the 350 cfm #7748 and the 500 cfm #4412 have two power valve channel restrictions of, IIRC, 59 and 62.5 thou respectively, and when the power valve circuit is opened, the fuel flow is huge in comparison to the stock 58 and 71 thou respective call size. But when put on a 4 cylinder 2300 cc Pinto/Mustang/Fox/Ranger engine, it only needs two PVCR's of just 16 to 19 thou, Power valves of 2.0 Hg, and base jetting as high as 65 for a 130 hp 350 cfm 2-bbl, to two 75 for a 155 hp 500 cfm engine.

    The third, the common 390cfm 4-bbl vac sec has about 40 thou channel restrictions.

    The Power Valve Chanel Restriction(PVCR) forumulae is in a few HP books on Holley carb systems. Generally, Holley over fuel carbs via PVCR to ensure that they don't ever run lean in the engines selections.

    These restrictions determine the amount of fuel enrichment the power valve circuit provides at wide open throttle or when the engine load is sufficient to reduce the manifold vacuum below the rated value of the power valve. The amount or percentage is in proportion to the jet size and normally would
    not be altered except in special or extreme circumstances. A situation is when the capacity of the engine is 140 cubic inches, when the 350 and 500 cfm carbs were designed for 292 to 390 cubic inch Ford and International engines in there first years.


    In normal cases, you just buy a kit, redrill the hole, and block off or screw in the right restriction jet in the two holes.




    On a 2150, its like this




    The high "E" string, has a diameter of 0.0100 inch, 10 thou. Fuse wire varies too much in type and coposition to reliably find a target size that works.

    The two PVCR's are 59 thou each.

    Putting one 10 thou wire through the two holes as above makes each 59 thou hole effectively 10 thou smaller.


    The total area reduction in size is actually pretty small with an E string.

    0.00273 sq in minus 0.000078 sq in, or effectively 0.00195 sq in, equal to a 50 thou hole.


    To get it down to the target 17 thou or approx a single 30 thou restriction, you need to add three twisted together E strings to get something down to the target 17 thou hole size of just 0.00023 sq in.

    Drop an E string to two twisted togehter if there isn't enough enrichment at wide open throttle.


    The PVCR's on engines this size are literally 90% of getting the jetting right, the rest is the Power Valve pressure which also has to be a heck of a lot less than a normal 8.5 they came with, and then the main jet is down quite a lot of what is stock.

    Holley really did design these carbs for V8 IHI and Ford truck engines up to three times the size. Just swapping in a set of 56's won't down tune the wide open throttle enrichment enough.


    Bill (was111) and Rick (MechRick) on another website use either a restriction jet or the blankoffs..every non V8 Holley 350 or 500 cfm 2-bbl carb is different, and needs to be reworked with a quality kit. Basic work on PVCR's can be done many ways. Sixes, four cylinders, they need work on PVCR's and Air Bleeds.


    How far you want to go is price related,



    Here is a top notch kit that allows total adjusment that Bill uses






    but doing nothing to the PVCR's will result in a bad outcome

    Quick Fuel have the 6-32 brass blankoff kit, and can add annular discharge boosters and air/fuel bleeds, and others make custom metering blocks. For example, Sean Murphy Induction https://www.smicarburetor.com/ supply kits as well.


    See https://fordsix.com//viewtopic.php?f=1&t=66515


    https://fordsix.com/viewtopic.php?f=13&t=72863&start=50

    Quote Originally Posted by MechRick
    One thing that must be done is the power valve channels must be restricted to lean out the carb and allow it to work with the smaller displacement engine. This is done by drilling and tapping the channels and installing brass restrictors. I buy 6-32 brass plugs (Fastenal is a good source) and drill them.



    ......

  11. #11

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    Quote Originally Posted by xctasy View Post
    These restrictions determine the amount of fuel enrichment the power valve circuit provides at wide open throttle or when the engine load is sufficient to reduce the manifold vacuum below the rated value of the power valve. The amount or percentage is in proportion to the jet size and normally would
    not be altered except in special or extreme circumstances. A situation is when the capacity of the engine is 140 cubic inches, when the 350 and 500 cfm carbs were designed for 292 to 390 cubic inch Ford and International engines in there first years.

    The high "E" string, has a diameter of 0.0100 inch, 10 thou. Fuse wire varies too much in type and coposition to reliably find a target size that works.

    The two PVCR's are 59 thou each.

    Putting one 10 thou wire through the two holes as above makes each 59 thou hole effectively 10 thou smaller.


    The total area reduction in size is actually pretty small with an E string.

    0.00273 sq in minus 0.000078 sq in, or effectively 0.00195 sq in, equal to a 50 thou hole.


    To get it down to the target 17 thou or approx a single 30 thou restriction, you need to add three twisted together E strings to get something down to the target 17 thou hole size of just 0.00023 sq in.

    Drop an E string to two twisted togehter if there isn't enough enrichment at wide open throttle.


    The PVCR's on engines this size are literally 90% of getting the jetting right, the rest is the Power Valve pressure which also has to be a heck of a lot less than a normal 8.5 they came with, and then the main jet is down quite a lot of what is stock.

    Holley really did design these carbs for V8 IHI and Ford truck engines up to three times the size. Just swapping in a set of 56's won't down tune the wide open throttle enrichment enough.
    Just sayin', IMHO, adding a bigger carburetor doesn't force that amount of airflow, and it's attendant full fuel flow circuit amounts into the engine. It'll flow what it'll flow, and the fuel metering will flow according to whatever that percentage of airflow through the carburetor is. In the case of a warmed up 2.3L putting out roughly 130hp, that should take in about 180cfm of airflow, nowhere near 350cfm or 500cfm, with quite low WOT vacuum to boot. So, also IMHO, there ought to also be less "draw" on the internal fuel metering orifices (with correctly-sized main air bleeds for a bigger engine's WOT air:fuel mixture) in place. Also just sayin', the sole change in PVCR's from 0.059" down to 0.017" represents a diameter reduction of ~71%, an area reduction of ~92%, and a flow reduction of ~85%. Them's quite drastically reduced numbers, lol, and I would tread carefully on this path.
    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/

  12. #12
    FEP Super Member xctasy's Avatar
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    As the 4 cyl Ford engines get more power, the need no extra power valve enrichment. None. They behave like Individual Runner engines. IR engines don't need power valves because they deliver fuel by classic Bernoulli/ Venturi theory pressure drop. The excess fuel from the PVCR ruins proper 4cylinder air/fuel calibration.

    Power valves are generally for lower specific output engines with less than one venturi per cylinder.


    The Forth Dimension for 4 cylinder 2-bbl's is certainly carb venturi and throttle bore. I didn't go into them, but since you asked about cfm, then they are related. The reason is that the engine behaves like a classic idependent runner engine on a 2-bbl 2 to 2.5 liter four.


    Note Well // (EAO's and Limas shared the same basic design, but the bigger Lima engine had Volvo B series like 4.17" average bore spacings, the smaller EAO engine has Cologne/Yamaha/Duratech spacing of 4.0157 inches. The Lima manifold consequently has ports 1 and 4 in the head curved from the stock EAO block used in the earlier Pinto's and early pre 1974 Capri's .


    The whole Lima 2000/2300/2500 engines have a myriad of really good other changes too, like

    effectively, an enormus 0.6172 inches of extra bore spacing over the entire block,

    4 bearing cam shaft heads and different block,

    downsized piston wrist pins,

    upsizded crank pins and

    a taller deck

    compared to the EAO engine).


    Both 2 liter Pinto engines and Lima 2.0/2.3's in 2-bbl form use effectively the same kind of intake manifold design, and its is subject to wide 180 degree impulses, and it starts to behave like an independent runner intake when the carb throotles and veturis are upsized. On a V8, that doesn't hapen unless you use a flat planed crank and a devided intake manifold. The flow efficency from port to port on the Lima and EAO's is very good, and since its cylinder to cylinder flow rates are nearly equal, it able to produce quite brilliant results with bigger carbs. When relieved of its prodction aluminum casting slag and flow mix lumps, the total flow loss between a bare head without an intake, and the head with a manifold attached, can be about 10%, which is very effiecient. Among the best. More than that, it has none of the rev range cylinder to cylinder flow variations that 2-bbl V8's suffer from. Holley 2300 series carbs are the worst around for mixture variation form idle to wide open throttle, but on the Lima ands EAO manifold, it doesn't produce the cylinder to cylinder flow variations you normally find. Its only when you go up to Esslinger like hp figures of 265 hp with the 500 cfm carb that the intake requires correction.

    http://vb.foureyedpride.com/showthre...otential/page6

    The intake for race Limas uses a different kind of intake with a carb oriented the normal way.

    EAO's and Limas had a strange carb position.

    Anyway, a 3.80 bore by 3.35 stroke 152 cubic inch 2.5 Liter version of the 2300 Lima easily makes 268.1 hp at 7500 rpm and 211.2 lb-ft at 5750 rpm with just two 79 jets, the 6-32 PVCR block off, a trick as Essinger custom bias plate which corrects cylinder to cylinder EGT temperatures to 5 deg F variation,



    all for a V8 style Esslinger intake and 269 degree at 50 thou cam installed heads up.

    Same 35 mm venturis that make 135 hp on a near stock 2.0 EAO engine.

    I'm quite sure a routed out 2300 series carb with 650 cfm like the 1.4375" 37 mm #6245 sieries 2-BBL,




    or the brilliant, unlimited # 4412 2300 series based aftermarket 890 cfm C&S 1.56" (40 mm ) 2-bbl carbs would make even more, but they are illegal in circle track.



    There is even the Split Billet Dominator unlimited 2 barrel 2” with 1.69" (over 43 mm) venturi carbs for unrestricted V-8 2 barrel classes that outflows 890 cfm carb above for even more excellent power.






    http://www.powerblocktv.com/episode/...e#.V4bcEX2vQgR

    Below that approx 265 hp level, what actually happens in a 4 cylinder like all SOHC Ford I4's with that really efficeint 2-bbl 1970 to 1982 intake manifolds, is it can really use the bigger venturi sizes...a bigger 500 cfm 4412 series carb with two 35 mm venturis makes a lot more power on a well set up 2300 (or 2000) compared to all other 2-bbl options.

    When comparing those bigger 500 cfm carbs with 35 mm venturis

    with the downsized 5200/6500 series Holley Webers with 27/23's,
    or the earlier Weber or Hlley Weber 5200's with bigger primaries 27/26's
    or any other bigger variant (like the routed out Holley Weber with 27's, 29/31's or the Holley 350 7448 with 31's



    On engines that have a little more cam not above 295 degrees at lash duration, they really respond to the bigger 500 cfm 2-bbl.

    Its different to a bigger engine with a lower duration cam in the 351, 390 size.



    The classic air flow and signal calibrations we use for V8's just don't follow through in itty bitty fours with 2-bbls.

  13. #13

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    How do you hook up the Jolley to the intake and to the throttle cable. I have a 500 sitting around

  14. #14
    FEP Super Member xctasy's Avatar
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    Quote Originally Posted by shadowwolffe View Post
    How do you hook up the Jolley to the intake and to the throttle cable. I have a 500 sitting around
    Coverd in Page 69 of



    How-to-Modify-Ford-s-o-h-c-Engines-David-Vizard


    https://www.scribd.com/doc/26804743/...-Vizard#scribd



    Depending on intake. you can use the 1 or 2-bbl Lima intake. D9 is round port, E1 is D port, after 1982, E3 intakes had 1-bbl adaptors.

    Under the adaptor, its a similar manifold, so same Race Walsh style alloy plate will do the job.

    Or a Holley 2300 sriers or Autolite 2100 or Motorcraft 2150 adpator plate.

    See https://fordsix.com//viewtopic.php?f...72863&start=50 for power valve CR


    and these on https://fordsix.com//viewtopic.php?f=13&t=72863









    Quote Originally Posted by MechRick
    I'll paint the Bronco gray with a red stripe, so the engine ended up in similar colors. I had a long tube header left over from my Pinto project. I was hoping it would fit the Ranger, but #3 tube wanted to occupy the same space as the evaporator plenum. I went back to the wrecking yard and picked up a Ranger shorty to run for now.









    The Holley 7448 2 bbl is a V8 carb. It must be modified to work on the 4 cylinder. There are two problems. Vibration, and vacuum signal. Vibration can cause the accelerator pump circuit one way check valve to resonate and pump fuel, even when the throttle isn't moving. The fix is to spring load the ball or pintle under the squirters, or chose a carb that uses the steel check ball instead of the rubber flapper valve in the float bowl. Vacuum signal problems happen with big venturis at wide open throttle and low rpm. The 4 cylinder only has power pulses (and intake pulses) every 180 degrees of crankshaft rotation. At low engine speeds, the air flowing past the venturis can reverse and flow backwards through the carb. With multiple passes through the venturis, the air will pick up fuel each time, causing a rich condition.

  15. #15
    FEP Power Member Ethyl Cat's Avatar
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    You might be chasing your tail trying to calibrate the carb with jetting. A 2.3 I built several years ago showed me some interesting stuff.
    SBC valves, converted to 2.0 pinto adjusters and pretty serious cam.

    Put the holley 2 barrel on it and the wide band and made a pull on the chassis dyno. It went progressively richer as rpm climbed. Did some math and made a large jet change. Still went rich.

    Took the air cleaner off and did a pull. As rpm climbed a cloud of fuel standoff developed over the carb that maybe reached 8-10 inches in height. The lack of plenum volume paired with the increased overlap of the cam was sending reversion waves back through the carb. The carb does not care which direction the air is flowing, if there is a pressure drop fuel is added.

    So air was getting fuel going in, changing directions, getting fuel as it left the carb and then getting more fuel when it went back in the engine.

    Not saying that is what you have but I would check if I were you.

    Also you need to see what your cruise afr is before you go changing main jets. If it is fat go ahead, if it is good then you need to reduce the PVCR size. I calculate your engine at 95% ve, 5500rpm and a 12.5 afr needs right between 60 and 61 main jets assuming that the PVCR is .042" like most are.

    Good data helps make good decisions, do not guess at this stuff it will take longer and do more bad than good.
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  16. #16

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    "As the 4 cyl Ford engines get more power, the need no extra power valve enrichment. None. They behave like Individual Runner engines. IR engines don't need power valves because they deliver fuel by classic Bernoulli/ Venturi theory pressure drop. The excess fuel from the PVCR ruins proper 4cylinder air/fuel calibration."

    You can't be serious...? I'm not understanding. Vacuum is vacuum (idle and transition), and airflow is airflow (main metering/WOT)...

    A statement like the one above is entirely dependent on main jetting, and main air bleed affect, and even the IFR's affect on WOT... and... Is the main metered (also known as wide open throttle) air/fuel not delivered by "Bernoulli/Venturi theory pressure drop" with a carburetor on a non-IR engine at WOT? I would say yes it is, and I would also say that power valve enrichment is necessary if anything reasonable is to be expected out of it for fuel mileage and clean transition and best (least) fuel consumption from idle to main metering to WOT, with optimized (finding the lean surging point with the mains providing the mixture in top gear and at civilized highway speeds, level road load, and upon very light acceleration from those speeds (prior to power valve opening), then sneaking back up richer with the jets until there's no surging) main jetting, for (ideally) better than "stoich" (14.7:1 is about catalytic convertors, it's not about what most any healthy engine will like and operate best at) across the board for anything less than WOT, and for ~12.5:1 AFR for WOT.

    FWIW, 7448 350cfm 2-barrels have 0.059" PVCR's, originally.
    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. #17

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    Quote Originally Posted by Ethyl Cat View Post
    You might be chasing your tail trying to calibrate the carb with jetting. A 2.3 I built several years ago showed me some interesting stuff.
    SBC valves, converted to 2.0 pinto adjusters and pretty serious cam.

    Put the holley 2 barrel on it and the wide band and made a pull on the chassis dyno. It went progressively richer as rpm climbed. Did some math and made a large jet change. Still went rich.

    Took the air cleaner off and did a pull. As rpm climbed a cloud of fuel standoff developed over the carb that maybe reached 8-10 inches in height. The lack of plenum volume paired with the increased overlap of the cam was sending reversion waves back through the carb. The carb does not care which direction the air is flowing, if there is a pressure drop fuel is added.

    So air was getting fuel going in, changing directions, getting fuel as it left the carb and then getting more fuel when it went back in the engine.

    Not saying that is what you have but I would check if I were you.

    Also you need to see what your cruise afr is before you go changing main jets. If it is fat go ahead, if it is good then you need to reduce the PVCR size. I calculate your engine at 95% ve, 5500rpm and a 12.5 afr needs right between 60 and 61 main jets assuming that the PVCR is .042" like most are.

    Good data helps make good decisions, do not guess at this stuff it will take longer and do more bad than good.
    That is an interesting predicament. How was that remedied?
    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/

  18. #18
    FEP Power Member Ethyl Cat's Avatar
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    It was for a dirt car and the owners was in a hurry. (go figure)

    We calibrated the carb to a happy medium and agreed to start talking about a new manifold. The car went home got a new radiator before the race and never got filled back up entirely with coolant. He proceeded to melt it down ( even with the cooling rich mixture) the first race.

    He was way out front for the time it ran. He was frustrated and broke so he sold the package to another racer that saw him running out front. Did not see the engine again.

    The required plenum volume for that ( 140in3 ) would have been equivalent to a cylinder 8" in diameter and 12" long. Picture that on the end of a 2.3 manifolds runners. That also would have DRASTICALLY reduced the instantaneous demand on the carb and made it work MUCH better.
    Last edited by Ethyl Cat; 08-21-2016 at 07:32 AM.
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  19. #19
    FEP Power Member Ethyl Cat's Avatar
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    "FWIW, 7448 350cfm 2-barrels have 0.059" PVCR's, originally."

    The 2 that I did did not. Maybe someone had been in them before.

    Anyway, .059" is almost exactly the same size as a #61 jet (.060"). If that is the case fuel flow is nearly doubling when the power valve is open. Yikes!
    BBD PERFORMANCE
    HIGH PERFORMANCE PARTS
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    1983 CRIMSON CAT OWNER

  20. #20

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    Quote Originally Posted by Ethyl Cat View Post
    It was for a dirt car and the owners was in a hurry. (go figure)

    We calibrated the carb to a happy medium and agreed to start talking about a new manifold. The car went home got a new radiator before the race and never got filled back up entirely with coolant. He proceeded to melt it down ( even with the cooling rich mixture) the first race.

    He was way out front for the time it ran. He was frustrated and broke so he sold the package to another racer that saw him running out front. Did not see the engine again.

    The required plenum volume for that ( 140in3 ) would have been equivalent to a cylinder 8" in diameter and 12" long. Picture that on the end of a 2.3 manifolds runners. That also would have DRASTICALLY reduced the instantaneous demand on the carb and made it work MUCH better.
    When we nearly ran the mini-bike out of oil, and raved how fast it was going that day, my father said, "yeah, things usually work real good right before they go BANG." ... lol
    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/

  21. #21

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    If the OP ever returns here... back to on topic... plugs black with soot.

    We'll need some more information. How was this thing being driven prior to discovering the plugs issue? Just bombing around on the street, full-time WOT racing?

    What's the idle rpm and manifold vacuum at? Are the transfer slots squared (~0.020" exposed below the throttle plates) in the bores with idle speed setting? Are there idle bypass air holes in the throttle plates? Are there tiny (~0.025") holes just above the transfer slots up in the main body of the carburetor? How far out are it's mixture screws? Has the carburetor been modified? All gaskets sealing? Any fuel coming from it's boosters while it sits idling (float level too high, leaky needle and seat or float)? How's the power valve and gasket's condition? What's the initial and total ignition timing and the condition of the ignition system? Has the distributor got a vacuum advance unit functioning on it? Compression ratio? Camshaft?...
    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. #22
    FEP Power Member Ethyl Cat's Avatar
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    You forgot SS# and D.O.B
    BBD PERFORMANCE
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    1983 CRIMSON CAT OWNER

  23. #23
    FEP Super Member xctasy's Avatar
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    Quote Originally Posted by shadowwolffe View Post
    How do you hook up the Jolley to the intake and to the throttle cable. I have a 500 sitting around

    Oh yeah, and for accelerator cable, see the David Vizrd articel, and not the kidwon requirments if its an automatic

    http://vb.foureyedpride.com/showthre...e-and-tv-cable

    Quote Originally Posted by xctasy View Post

    To make it work for any Holley, you need to do FOUR things A, B, C and D.




    The Autolite 2100/4100 or Motorcraft 2150/4300/4350 linkage is cut off and connected to the Holley 2 or 4-bbl at position A.

    Then at Position B, the throttle cable is attached.

    Then at Position C, the kickdown is attached.


    Item D is the kickdown rod, made of tube steel flattened at both ends, and bent in between on the X, Y and Z axis to clear the headers and steering column union and firewall and frame gussets.

    Item D




    Its end at the rod operated automatic transmission lever



    Its intermediate bends to clear the obstructions




    You use thicker wall stuff of nominal 1/2" to 5/8" diameter, and fashion it the same way as the stock instillation. A greenfields new instillation takes a bit of work, but the rod operated kickdown to throttle valve conversion follows this.


    I did this on my Pinto 2000 engine with the 390 4-bbl and C3 auto.

    The AOD style transmission throttle valve I used the AMC Rambler Rebel 231 L6 six Borg Warner 35 automatic /Chrysler Hemi 265 Valiant kickdown cable and linkage made by Chrysler Australia, and a Chevy Rochester 2CG kickdown linkage.






    When using the Lokar, they just use the lower existing Holley bolt holes, as the linkage is designed to use the lower forward motion, not the top backward motion as the C3/C4/C5/C6/FMX rod linkage does. That's important, because THE aod FOLLOWS THE Borg Warner pullout method. Not the C3/C4/C5/C6/FMX rod linkages

    You can use a kickdown rod as a throttle vlave, but it has to be torsionally strong, and has to meet the idle freeplay and pullout requirments, and be adjustable for line pressure.

    Quote Originally Posted by Walking-Tall View Post
    "As the 4 cyl Ford engines get more power, the need no extra power valve enrichment. None. They behave like Individual Runner engines. IR engines don't need power valves because they deliver fuel by classic Bernoulli/ Venturi theory pressure drop. The excess fuel from the PVCR ruins proper 4cylinder air/fuel calibration."

    You can't be serious...? I'm not understanding. Vacuum is vacuum (idle and transition), and airflow is airflow (main metering/WOT)...

    A statement like the one above is entirely dependent on main jetting, and main air bleed affect, and even the IFR's affect on WOT... and... Is the main metered (also known as wide open throttle) air/fuel not delivered by "Bernoulli/Venturi theory pressure drop" with a carburetor on a non-IR engine at WOT? I would say yes it is, and I would also say that power valve enrichment is necessary if anything reasonable is to be expected out of it for fuel mileage and clean transition and best (least) fuel consumption from idle to main metering to WOT, with optimized (finding the lean surging point with the mains providing the mixture in top gear and at civilized highway speeds, level road load, and upon very light acceleration from those speeds (prior to power valve opening), then sneaking back up richer with the jets until there's no surging) main jetting, for (ideally) better than "stoich" (14.7:1 is about catalytic convertors, it's not about what most any healthy engine will like and operate best at) across the board for anything less than WOT, and for ~12.5:1 AFR for WOT.

    FWIW, 7448 350cfm 2-barrels have 0.059" PVCR's, originally.



    As for jetting, I'm really serious.



    I've put the 350 cfm Holley on a 1725 Hillamn and a 2000 EAO, and then my 2294 cc V6 Cortina (Colgne V6). I used a Rochester 2GC, an Autolite 2100 1.33, and a Holley 350 cfm 9117 anular discharge economiser.

    My experience with each is that power valves are just a secondary fueling system to avoid having an intermediate ciruit. Any 2-bbl Holley on a Four Cylinder 2000 or 2300 is such a dead easy easy swap, as long as the PVCR are taken down to 17 thou.

    The stock 1974 to 1988 pre EFI 2 and 1-bbl Ford Lima, IMHO, the intake finishing isn't a patch on the smooth, well casted 1969 to 1974 German designed EAO intake; the Pinto 2.0 intakes are not reversion prone, but the US Lima 2300 sure lookes like it is with its sharp mix flow lumps and bumps. But the intake flows, and has good efficiency, Ford spent time getting it right.


    The power valve augmentation has to drop off as the 2.3 liter hp horspower level goes up. The peak air flow damands at the carb is is now much less than the 292 to 390 engines this carb was designed for. So the air fuel demands are screwed up compared to the big easy V8 and I6 engines with a 2-bbl carb.


    I put a 424 cfm Autoilite 390 FE engine carb on a 265 Hemi in line six, and it stood up an begged. No PVCR, or jetting requirments from a 265 hp gross 390 carb.

    The same carb on a 1.725, 2.0 or 2.3 liter car is a dog, and the whole fuel augumentation by the power vale is what screws it up.

    On a 4 cylinder Ford SOHC, it behaves like an IR engine past about 125 hp, and it just needs less augmention form the PVCR, at a lower Hg value. The Holley 2-bbl 2300 well tubes can be pulled, and have another 25 thou hole added or removed to trim air fuel ratios through the off idle to peak rpm rev limit.


    The Holley is such a great carb, but you can't tune it on V8 logic when slapped on a 4 cylinder, and if the cam has too much at lash or 50 thou cam duration then it requires reversion preventaitive measures. An extra 1/4" to 2" of alloy spacer works well, as does some reversion plates from 9/16" to 1" aluminum on the intake ports. The stock 650 cc EOA intake then becomes a 1000 cc intake runner intkake. I did that when I put the 500 cfm 2-bbl on my 250 Falcon six.


    See the crazy mess my 4.1 liter engi e was in the last picture. Flitched up like Frankenstien, but it worked great, and made a poor intake manifold work better than any other..

    http://i1215.photobucket.com/albums/...015d1ce68f.jpg


    The well tube redrill but certainly the PVCR's sizing fixes 90% of any issues.

    I'd personally use a 390 or 465 cfm 4-bbl Holley on the 2.3 Turbo EFI intake.


    Of the 2-bbl US carbs, the Holley 2300 and Autolite 2100/Motorcraft 2150 series are just the greatest carbs, but 4-bbls 4150/4160's vac sec or mech sec carbs are much less senstivie to high duration cams and have smaller PVCR's that are easily fiddled around with. They give you more options on a 2300 Lima

  24. #24

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    Quote Originally Posted by Ethyl Cat View Post
    You forgot SS# and D.O.B
    As did you.
    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. #25

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    Isn't just WOT fuel supply being addressed? Unless we are only talking about WOT, the optimizing balancing act between jetting and PVCR is about finding best (smallest, leanest) low-load jetting that the engine and combination likes, when the mains are doing the supplying of the air:fuel prior to and with light acceleration, down to and prior to the power valve opening, manifold vacuum-wise. Less augmentation through the PVCR's I can agree with maybe as a starting place, albeit a dangerous place to start hacking largely, IMHO, if the main jets appear good as is but the PVCR supplies too much for WOT... but every engine and combination is different, and there's not ever normally a carved-in-stone recipe for a carburetor's orifices, like the repeatedly stated 0.017" PVCR diameter. The safest way to tune WOT AFR (air:fuel ratio) so the engine getting blown to hell isn't the result, is to begin rich and work slowly leaner to the sweet spot. The idle, off-idle, low-speed/load conditions (all prior to PVCR's at play, above the power valve's full-open vacuum rating) can be tuned vice versa, finding too lean, so then you know where that is, and then richening up in small increments to suit, without the same potential dangers of lean mixtures with full load and at WOT.

    For instance, power valve removal and blocking off is a good way to establish an ideal ~12.5:1 WOT AFR with main jetting only, but that will usually always end up with jetting that's too rich for low-speed, cruise, and light acceleration within the operation of the carburetor's main system jets only. Even the attached exerpt from "MechRick" states, "At low engine speeds, the air flowing past the venturis can reverse and flow backwards through the carb. With multiple passes through the venturis, the air will pick up fuel each time, causing a rich condition."... I assume he's talking about low engine speeds at WOT... at low engine speeds, I'd have to say that the larger of the two circuits has more influence on AFR, and that is the main jets... and all these folks are speaking of fueling problems either at part throttle or full throttle when RPM is lower, all the territory of the main jets, and later augmented by the PVCR's... and/or, six of one and a half dozen of the other. I still say idle, low-speed and load and transition and cruise and light acceleration prior to PVCR supply as being cleanly lean-best calibrated is just as important, if not more important for reasonable fuel mileage, than just the AFR for WOT. FWIW, continued reading of that posting reveals that gentleman later quit using his Holley due to inconsistent function due to either incorrect modification or debris blocking internal orifices enough to cause malfunction with mixture screws. So, something wasn't right with his carburetor in the first place... and the Weber used afterward touted as better manageable with the ability to tune transition mixture.

    Sir xctasy, if I'm understanding your explanations correctly, you're saying there's less need and draw on the PVCR's with certain level of horsepower certain engines for WOT, but that the PVCR's need to be made smaller so there isn't over-fueling at WOT. Without trying to be argumentative whatsoever, I'm missing something, or aren't those two aspects a contradiction? With the near elimination of WOT enrichment through PVCR's, how is the balancing act possible to have best-lean low-load/cruise/transition AFR as well as best AFR for WOT? The only way known to be do-able is how it's already done in a Holley and others. Through equally drastic IFR (idle feed restriction) and/or idle air bleed size tuning, and/or the addition of and tuning of some transfer slot restrictions?...

    Anyway, sounds like to me if such engines are such anomalies (what a guessing game!) in how they run, intake manifolding is what really could use addressing. Increased runner lengths and plenum volume in all cases probably wouldn't hurt these little fellas
    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/

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