Holley Carb Lean At Part Throttle

Begin the final needle valve adjustment with the boat running at a slow speed. Its a vacuum secondary with electric choke. It idles great at 14. However, sometimes a little more fine-tuning is needed because the customer has a. For example, if the carb is equipped with a 65 power valve, and the engine vacuum sometimes drops to, say, 5 Hg at idle, installing a 40 power valve that opens. When I am at part throttle, I like my A/F to be around 14. Your cruise surge can be because your jetting is borderline too lean. secondary annular booster carburetor. It has check-ball assemblies for both ends of the carb and includes a stop drill for installing them. I took both carbs and broke them down to prepare for a rebuild. If the mixture is still lean at 1,000 through 1,800 rpm after enlarging the idle jet, the idle channel restriction (if used) may have to be enlarged slightly to allow more fuel. I have a Holley 4150 950 that is very rich at part throttle. When introduced, this carburetor only came in one size, 270CFM at three inches of mercury. At part throttle while driving you can hear it stumble for a bit. Some words about the power jet. When using a Holley vacuum-secondary carb on a vehicle with a non-electronic overdrive automatic transmission, such as the 200-4R or 700R-4, a throttle kick-down bracket must be used. That will cause a binding. HTS990) 900. 16 Holley 554-100 NTK WB02 SENSOR. Slowly depress the throttle pedal to wide open. I've seen several videos spreading false information and function about the power valve. The Holley one-barrel carburetor is the simplest of the Holley designs, with one intake bore, one throttle plate and one fuel delivery system. Fuel distribution is the cylinder-to-cylinder variance in fuel-air ratio. There is approximately a 4-1/2% flow difference fro m one jet size to the next and one size won't make that much of a differ-ence. Back out your idle screws 1/4 turn, that will stabilize the idle and help slow-speed metering. Well, I think I might know the answer, but some clarification wouldn't hurt. If you are at part throttle, only the front is trying to give it fuel so you are going to need way more jet or pvcr (since your a/f's are lean). A Holley carburetor is made with four basic parts, the throttle plate, main body, metering block and float bowl assemblies. Install the new throttle ball, lockwasher, and retaining nut to the carburetor throttle lever in the same position as the existing carburetor. Holley even made a 4 bbl carb that's almost a dead ringer for the 4100, this carb is the Holley 4010. Electric choke works great, after the choke comes off and the car idles at 800 rpm glass smooth. 042 and no change so dropped it to. 5:1 ratio at part-throttle. Aftermarket Holley carb numerical listing by carb number Holley HP series carb specs by carb number Holley's accelerator pump instructions are on pages 6 and 7; Holley instruction manuals by part number; Manual, Exploded View and Nomenclaturefor Holley models 2010, 2300, 4010, 4011, 4150, 4160, 4165, 4175, and 4500 Holley technical library. Holley's catalog includes all the automotive and marine products offered. In addition to this circuit, there is a tiny slot cut into the throttle opening on the primary side (and on all four barrels if the carburetor is equipped with four-corner idle mixture adjustment). Read his FAQ and decide for yourself. Last year, just a few months after finishing my install of the high performance engine I'd had built, my '81 Bronco was rear ended and totaled. Transmission has B&M shift kit. When I am at part throttle, I like my A/F to be around 14. It has check-ball assemblies for both ends of the carb and includes a stop drill for installing them. If the mixture is still lean at 1,000 through 1,800 rpm after enlarging the idle jet, the idle channel restriction (if used) may have to be enlarged slightly to allow more fuel. When I'm trying a different carb I like to put them back to stock specs and eliminate any changes someone else may have made. If the air/fuel mixture is too lean at idle or part throttle and the idle mixture screws do not provide enough adjustment, the correction may involve enlarging the idle “jet”. He was able to tune his transition circuit with T-slot restrictors, adjustable idle feed restriction and idle air bleeds to cruise at 15:1. The stock primary main jet is #80. 90 the idle mixture screws are out to 3. I don't know about that type of Holley, but some Holley carbs ( like the 4500 model, and I believe the 4150 also) have an idle speed screw for the primaries, and one for the secondaries too. Main Circuits-or a Trip Down Venturi HighwayIf there is one part in the world of high performance that everybody knows, it has to be the Holley four-barrel carburetor. The only problem with this model was a backward idle system (lean for emissions) but can easily fixed to eliminate the off idle lean stumble and secondary mixture due to metering plate. 3" L Ford 38-48 (900. You should observe a healthy squirt of fuel from the pump jet. Added Holley electronic choke kit and Holley gasket 108-52, both highly recommended for easy startups and to protect the carb from heat far better than the stock gasket. A similar item was used on the 4v versions of that intake manifold along with a Holley 4150 or 4160 carburetor (depends upon model year and platform). Please use our product search boxes below to find the correct Carburettor or spare part for your Motorcycle, alternatively look around our store to find a range of other accessories!. The TQ is a metering rod based carburetor like other Carters (AFB, AVS, BBD). Inlet system air leak. Regards, Gary. I used a 12-24 heli-coil and it worked fine with Holley 12-28 screw. I held the throttle blade down with a screwdriver and got a drop in idle speed. Chevrolet OEM use of the Holley Carburetor was generally limited to use on special high performance engines. 5 grams) for Rochester Dualjet and Quadrajet 4M, 4MC, 4 MV, M4M Nitrophyl Replacement for Rochester: 7041468, 7043379, 7044332, 7046300, 17067153, 17067273, 17067275, 17078725, 17079405. Replace with a new filter element. Notes: When replacing a Quadrajet or Thermoquad Carburetor, with an aftermarket Holley, or Edelbrock. 010" feeler gauge, you don't want to totally bottom out the pump diaphram. At part throttle or cruise, the carb is running off the main circuit, the primary jets. (Check by pushing accelerator pedal to floor). Identifying the Carburetor’s Circuits of Operation. Is there a kit or something for a conversion to do this? I have not been able to find anything from Holley or other parts dealers. With the carb off of the intake manifold, you simply adjust the primary transfer slots with the primary idle speed screw. WOT runs hard no problems. 90 classes and there are a couple of suggestions we can provide that might help your throttle stop racing. fuel level is below the sight plug on the float, adjustment screws are about as lean as you can go on the carb the idle is about 850, if i mash the gas it shoots a fireball out the carb, there's some preignition when i shut the car off, and it's definitely running rich. I held the throttle blade down with a screwdriver and got a drop in idle speed. Use the screwdriver and turn the needle valve screw clockwise 1/8 turn to lean the fuel mixture. More HARD STARTING - HOT: 1. I found a bigger problem than the carb tho, part of my idle issue is the fact that the #1 and 3 cylinders arent firing. CJ Pony Parts offers many Mustang carb options and Mustang carburetor parts, from vendors like Holley and Edelbrock. Th clean barrel design of the Holley-styl carb allows efficient fuel flow in wideopen- throttle conditions. If you haven't already done so, you May be able to actually improve the idle quality by cleaning that pcv valve I see in the passenger side valve cover. Remember, if you modify your carb as per the following instructions, it will be set up for blowthrough, but not tuned for blowthrough. We now stock thousands of carburetor parts, shipping orders daily to our customers all over the world. If the mixture is still lean at 1000 through 1800 rpm, the idle channel restriction on a carburetor such as a Quadrajet or Edelbrock Performer or Thunder series may have to be slightly enlarged to allow more fuel to be delivered at part throttle. These carbs have the less desirable needle and seat assembly and float fulcrum location, so unless the carb is being used on a restored or period correct build, the later carbs- especially those with the adjustable part throttle adjustment or 'APT' located on the airhorn- will be a better choice for a performance application. Re: Tuning Holley for pulling truck 392 More than likely you need a boost referenced power valve. The carburetor used for this demonstration is an 850cfm, vacuum-secondary, marine carburetor that has both primary and secondary power valves. 7:1)…that is operation in the lean range. 1 Adapter Plate Installation Determine which type of mounting flange you have on your intake manifold. To me, bogging is that lack of response with a rich mixture. On the throttle linkage side they are connected by a very unique linkage (P4529061) which allows the center carb to open without opening the end carbs until the engine wants the extra air flow. Neighbor helped me rebuild it and it I ran for three years until the throttle shafts wore out and I went to a 2-barrel. Order online or by calling 1-800-888-6473 and speaking to the sales team. Engine vacuum at part-throttle may be too much for the light spring, causing the piston to stay down, centering the lean step on the metering rod in the jet. In both cases it turned out that I had the idle transfer slot over-exposed. Rochesters do not suffer from many of the maladies that plague the Holleys in high g-load or tilt situations, and the square bore configuration of the Holley does not have the throttle response and economy that spread-bore offers. Electric choke works great, after the choke comes off and the car idles at 800 rpm glass smooth. 9 300-6 1 Barrel Carter Carb. The stock primary main jet is #80. As the throttle opening is varied,the air flow varies and. The carb is new and was built by Biggs for my engine. Carb Kits for 37-67 Carter, 55-71 Rochester, 36-61 Stromberg. After ensuring you have NO vacuum leaks and a proper float level, I'd jet it up a little like mstngjoe and Holley recommended. 020 of the transfer slot was showing, everything magically fell into place. With the timing, I found the happy place at the track, then would add vacuum advance until I got a little pinging under normal cruise, then. Electric choke works great, after the choke comes off and the car idles at 800 rpm glass smooth. 78 Quantity in Basket: none: Holley 390CFM 4 Barrel Carburetor Z/ZX Code:11-2996 Price: $549. Install the new throttle ball, lockwasher, and retaining nut to the carburetor throttle lever in the same position as the existing carburetor. The power valve is a 4. In 1956, Rochester produced a special high performance 2GC carburetor for the Oldsmobile 88. Your huge swing in idle RPM from neutral to drive, is partly tight convertor, and part carburetor. Make sure that all the mating surfaces are flat (a piece of glass and some 400 grit helps if it need to be fixed). We are long time (35+ years) car guys, driving, drag racing, tuning and restoring muscle cars. and the float levels have been checked. If the air/fuel mixture is too lean at idle or part throttle and the idle mixture screws do not provide enough adjustment, the correction may involve enlarging the idle “jet”. I am using an AEM wideband. Vacuum advance from carb and advancing timing is working New cap, rotor and plugs I finally bought new spark plug wires (they usually are a waste of money as is the case this time, runs the same) I'm pretty sure it's the carb as it's still running lean with #70 Jets. INTRODUCTION: CONGRATULATIONS on your purchase of a Holley carburetor! We feel that you have purchased the finest performance carburetor manufactured today. Since I am new at working on automobiles, let alone scouts, I took the scout to a place in Tucson called Carbon and Fuel Injection Systems and they recommended that the carb be rebuilt. RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. 95 : Holley 94 Stainless Steel Screw Set Ford V8, Lincoln V12 + 2100 2110 & 59 Carbs (900. 9L / 300 - Holley Sniper EFI install - Hi all, So, I finally got my engine installed into my new Bronco. I had a Holley 4160 750 cfm off a different engine so put it on. I’ve run different sizes carbs on a 440 in the dyno room and they make max hp with a surprisingly large carb, that 440 really liked an old BG CLAW 950 we had. Thankfully, adjusting the mixture on a Holley carburetor is quite simple, as the mixture screws are located on the outside of the carburetor and can be quickly adjusted with a screwdriver. You should observe a healthy squirt of fuel from the pump jet. Holley’s first 4-barrel carburetor was the 2140 in 1953 on Lincolns, then the infamous 4000 “Teapot” in 1955. Part of the carb testing was to establish the value and the optimal point of opening of the secondary barrels of a 4-barrel carb on a single- and a dual-plane intake. Exploded Parts Drawing of Stromberg Carb. Which can be downloaded for free from the Support section of Holley's website! Features: 8’ communication cable for easy access to your ECU. Bring the engine up to operating temperature. Regards, Gary. I will take it for a spin and see how it runs. As the throttle opening is varied,the air flow varies and. Help is just a click away!. White or light grey spark plugs. The carb is of the 4150/4160 series (the most popular Holley's); technically its a 4160 series, because it has a secondary metering _plate_, rather than a complete secondary metering _block_. Holley even made a 4 bbl carb that's almost a dead ringer for the 4100, this carb is the Holley 4010. It has alet's call it a "fitting" on the passenger side of the carb exactly where Carter BBD's have the ported vacuum port for the distributor. I've built a few customs carbs myself. Now, Holley manufactures high performance carburetors, manifolds, superchargers, water pumps, throttle body fuel injection and fuel pumps for street and race applications. Dirty or damaged air cleaner element. A Holley carburetor is made with four basic parts, the throttle plate, main body, metering block and float bowl assemblies. Not for computer-controlled engines. If I go to 1/2 turn out it will lean and die. Lean Burn is removed Orange box ECU Edelbrock Performer Intake 4BBL Holley 390 cfm 904 Auto Trans I am unable to hookup the kickdown linkage after putting the new Holley in. I held the throttle blade down with a screwdriver and got a drop in idle speed. Wide-open-throttle mixture should be adjusted by changing the secondary jets, but only after all other circuits are properly tuned. Main Circuits-or a Trip Down Venturi HighwayIf there is one part in the world of high performance that everybody knows, it has to be the Holley four-barrel carburetor. I think you can get most tuning even at napa or kragen/oreilly, etc. The construction of the carburetor IS such that is as simple as it get, The basic carburetion no differ- in the Holley four-barrel than in any Of our other carburetors. Again, there is usually a separate screw for this. Its only like the most oversold/overrated carb brand out there. This is a Holley 4150 carb, 750 cfm and it's only about a year old. Please use our product search boxes below to find the correct Carburettor or spare part for your Motorcycle, alternatively look around our store to find a range of other accessories!. Holley now uses a sealed throttle shaft and had to gain nascar approval as this was a process that had been used for some time. I have an older Holley 4010 on a Cleveland (. Carb idle issues with a 1920 Holley(lean) or the thin ones from the local parts shops? and bottom of the carb near the base gasket, throttle shaft and studs. 5:1 ratio at part-throttle. Not on a stock CV carb. For 3 cylinder 158 CID engines. If you are experiencing a bog or hesitation off idle, you can try a larger, higher # shooter size. The pattern of fuel discharge produced by this design more closely emulates that of a carburetor. 4- Holley 1945 that I got from a junkyard to replace carbs 2 and 3. txt) or read online for free. Re: 3000 Ford Holley carb/timing advance. secondary annular booster carburetor. 7:1) is always expressed as parts of air to 1 part of fuel. happy to answer any tuning issues. Holley's catalog includes all the automotive and marine products offered. Its a vacuum secondary with electric choke. The Holley 1945 isn't too hard to rebuild, but it has some 'tricks' because it uses a separate top from the throttle body like the Carters. My original Holley 4160 in my 1970 300 went 29K miles before it started acting bad, and thereafter, I couldn't just rebuild it. Observe the pump jet in the carburetor, and with your hand, work the carburetor throttle to the wide-open position. E-mail Us: Terrill Machine, Inc. Not saying Holley is better than Edelbrock, just when putting extra ponies in there, it responds much better with the 750 cfm than the 600 cfm. Thinking to either rebuild the 4100 or buy something new like a Holley 570 Street avenger, Edlebrock or summit carb. The nozzles help richen this momentary condition and eliminate the stumble. (I recommend the Mike Urich book for understanding how Holley carburetors work. If the throttle isn't as responsive, or you still feel a lean miss, then you need a smaller metering rod. 8:1 static cr, ported and polished 2. Another carburetor that people often overlook is the Rochester QuadraJet. The bog or hesitation may be caused by a momentary lean condition when the carb goes from the idle throttle position to the main metering system. If the Holley was a factory part, it may have a reverese idle system. At the other throttle positions the mixture is either leaner or richer depending on whether the throttle is opened less or more. accelerate hard(3/4 throttle) I either get a carb backfire or popping in the exhaust pipes. Part Throttle Lean; If this is your first visit, Your huge swing in idle RPM from neutral to drive, is partly tight convertor, and part carburetor. However, if manifold vacuum is very low at idle or part-throttle, a lower opening point may be needed to obtain a power valve that doesn’t open until the engine needs the added fuel. For starters: It's a Ford Bronco with a 300 I6. secondary annular booster carburetor. See our Performance Carburetors, Intake Manifolds, Cylinder Heads, Crate Engines, Electronic Fuel Injection. Welcome to AMAL. I will take it for a spin and see how it runs. In 2006 we started offering carburetor parts for fellow enthusiasts, allowing one stop shopping for all their carburetor needs. After ensuring you have NO vacuum leaks and a proper float level, I'd jet it up a little like mstngjoe and Holley recommended. Run the boat at high speed and repeat the procedure if necessary until the carburetor is adjusted for high speeds. Replaceable idle air bleeds (yellow arrows) are used in the top-of-the-line street and race Holley carbs, making a change easy. Holley 650 cfm carburetor. Your order may be eligible for Ship to Home, and shipping is free on all online orders of $35. Both sides are jetted differently. I hate cars. 613 s, 2 3/8" center to center on base mounting studs, for use with intake manifold 641084 or 641095. However, this also reduces the amount of fuel delivered at WOT. It runs perfect at idle no problems. Limited Warranty. With the timing, I found the happy place at the track, then would add vacuum advance until I got a little pinging under normal cruise, then. Fuel Pressure Regulator Holley Carburetor Carb Quick Fuel 30-803 4 12 - 9 Psi. Re: 3000 Ford Holley carb/timing advance. Removed idle air screws and cleaned those as well. Do yourself a favor and have the front, back, bottom and both sides of the throttle body broached by a mill. Classic Industries offers a wide selection of 1970 Dodge Challenger parts, including 1970 Dodge Challenger interior parts and soft trim, 1970 Dodge Challenger exterior sheet metal, 1970 Dodge Challenger moldings, 1970 Dodge Challenger emblems, 1970 Dodge Challenger weatherstrip and unique accessories, to nearly every nut and bolt needed for installation. street/strip carb cfm size = rpm x displacement / 3456 x 0. Power system not operating. Th clean barrel design of the Holley-styl carb allows efficient fuel flow in wideopen- throttle conditions. But I do not believe the '950' Holley (essentially a 750 carb body on an 850 baseplate) having 3/8" venturi will flow 950 cfm at the same depression as the 830 and older Holley 4bbl carbs were flowed. Additional. 6 the A/F is at the theoretical ideal ratio with no excess fuel or oxygen after combustion. Ok I have a brand new quick fuel 650 holley carb. Although Holley carbs were seen on a few Chevy engines during the '60s and '70s- most notably on high performance small and big block Chevy engines (including the three 2-barrel 'Vette big block engines)- the Q-jet carb was original equipment on most GM muscle car engines from that era. This is more complicated than a simple spring change. We are long time (35+ years) car guys, driving, drag racing, tuning and restoring muscle cars. 05 shipping. We now stock thousands of carburetor parts, shipping orders daily to our customers all over the world. txt) or read online for free. This is usually when the carb is too large, and even distribution suffers. Is there a kit or something for a conversion to do this? I have not been able to find anything from Holley or other parts dealers. Explaining the Holley Carburetor power valve and how it works. After ensuring you have NO vacuum leaks and a proper float level, I'd jet it up a little like mstngjoe and Holley recommended. In this way, the air flow is controlled and the mixture is kept from getting too lean if the throttle is opened suddenly. Some carbs have an adjustable bolt you can screw in or out to let air past the throttle blades, Holley even has a carb that has an adjuster beneath the air cleaner stud. As the throttle opening is varied,the air flow varies and. Metering Block Service Parts Part # FINISH APPLICATION 34-6 standard 0-1850 or most any model 4160 with side hung float bowls 34-6S shiny 0-1850S & 0-80457S 34-13 standard 0-3310 or most any model 4160 with center hung float bowls 34-13S shiny 0-3310S & 0-80508S 08 Holley Catalog pages 5/15/08 6:15 PM Page 90. Slowly depress the throttle pedal to wide open. In this way, the air flow is controlled and the mixture is kept from getting too lean if the throttle is opened suddenly. I have an issue I have been hoping to resolve through searching and lurking, but to no avail. The Holley model 4000 four barrel carburetor that came as original equipment on single four barrel equipped 1956 and earlier Fords, Mercurys, and Lincolns is not up to its full potential when used with the ’57 and up Y-Block distributors. All bases are resurfaced, and throttle shaft bushings are replaced. CARBURETORS/FUEL INJECTION/FUEL PUMPS/PARTS Holley-Vacuum Secondary spread bore- “general” Rochester Quadrajet replacement [non computor] Holley 650 cfm 4 clear view sight plugs are fitted to make float level adjustment linkage is fitted as standard, two corner idle system with lightweight mixture screws. 9 300-6 1 Barrel Carter Carb. 5psi with your. 3" L Ford 38-48 (900. I think it does, some, anyway; obviously a smaller and smaller effect at wider open throttle positions. Inlet system air leak. Trick Kit: Needle & Seat Primary Main Jet Secondary Throttle Bore Diameter Secondary R1848-1 4160; 465 37-119: 37-933. In both cases it turned out that I had the idle transfer slot over-exposed. At part throttle while driving you can hear it stumble for a bit. E-mail Us: Terrill Machine, Inc. It will feel like someone is moving the throttle when they are not or a hesitation on light throttle acceleration. Holley carb tuning tips. It still drove fine. We also tried a 350 Chevy equipped with a long-duration cam and a Holley 750-cfm 0-3310 vacuum-secondary carb that suffered from a bad off-idle stumble and a pig-rich 10. My stock throttle and kickdown cable assembly bolted right up, no adjustments needed. Read his FAQ and decide for yourself. Holley 650 cfm carburetor. Remember, if you modify your carb as per the following instructions, it will be set up for blowthrough, but not tuned for blowthrough. With the timing, I found the happy place at the track, then would add vacuum advance until I got a little pinging under normal cruise, then pulled a few degrees of vacuum. Quadrajet Carb Float Nitrophyl Alcohol Resistant Rochester Dualjet Carburetor 100-17 Alcohol Resistant Nitrophyl Float (6. Check for vacuum leaks at the carb base, the intake manifold where it installs to the block (or the heads if not a flathead) and any vacuum-driven accessories and their hoses or pipes (even a leaking 1/4" wiper motor or trans modulator hose/pipe can affect idle characteristics). Replace with a new filter element. They presumably understood that it was a Holley 2245 and said that they had the part. I'm running a Holley 4781-8 double pumper on a 496 with canfield 310's, an LS6 camshaft, and 4:11's fead by a M22. A Holley carburetor is made with four basic parts, the throttle plate, main body, metering block and float bowl assemblies. Series : Holley Sniper EFI 2300 Product Fit : Universal Rated CFM : 500 CFM Fuel Type : Gasoline Condition : New Number of Barrels : Four Material : Aluminum Choke Type : Manual Color/Finish : Polished Emissions : 50-State Legal for use on Non-Emissions Controlled Vehicles or Racing Vehicles Carburetor Model : Holley 2300 Warranty : 90-day Holley limited warranty Anticipated Ship Out Time : 15. This is a Holley 4150 carb, 750 cfm and it's only about a year old. The Domino Effect of Carb Tuning. i have never had to drill the butterflies of a holley. Hi Patrick my carb number is 30792 i need to richen up the idle circuit its a touch lean at idle. The Holley 1945 isn't too hard to rebuild, but it has some 'tricks' because it uses a separate top from the throttle body like the Carters. Holley carburetors have four distinct circuits of operation: idle, off-idle, cruise, and wide open throttle. It always had a lean bog to it while normal to hard accelerating, even after tuning. Adjust throttle linkage to obtain wide open throttle in carburetor. 9 300-6 1 Barrel Carter Carb. A single barrel carburetor will normally squirt a single stream; while a two or four barrel carburetor will normally squirt 2 streams. · An exhaust backfire when decelerating, is usually caused by: a lean condition (especially when the throttle blades snap shut) exhaust header gasket leak. I'll probably put the 80 in and start from there also. WARNING: Over-tightening may result in warped or cracked throttle bodies and/or binding throttle action resulting in an unstable return-to-idle. Holley carbs come with a standard shooter size which differs by carb list#. And the Holley rep stationed in the carb lab at Chrysler in Highland Park, where I worked, admitted the carbs could not just be rebuilt due to warpage when they started to go bad. On the throttle linkage side they are connected by a very unique linkage (P4529061) which allows the center carb to open without opening the end carbs until the engine wants the extra air flow. I have a problem with my Holley 750 stumbling as I round a corner. The engine ran fine with the 4742 with stock jetting (65/72), but was just a little on the lean side during warm-up under part-throttle and slight acceleration conditions. Put my name into the search and you'll find the set up info on my 304. On GM Quadrajets it is underneath the choke assembly. My intent was to test carbs, intakes, and exhausts. The switch to winter formulation gas can make a borderline mix go a bit lean. Adapter part number 5765 (SKU 228351) may be needed, to properly seal the carburetor to the stock factory intake manifold. txt) or read online for free. V-8 Part #2198 INSTALLATION INSTRUCTIONS. A Holley carburetor is made with four basic parts, the throttle plate, main body, metering block and float bowl assemblies. Carburetor Rebuild Kit Selector. This is a Holley 4150 carb, 750 cfm and it's only about a year old. Carburetor CFM Calculator. I am an efi guy so I am really not very good with carbs so this could be a very simple problem I am overlooking. Idle speed improperly adjusted. Lean Burn is removed Orange box ECU Edelbrock Performer Intake 4BBL Holley 390 cfm 904 Auto Trans I am unable to hookup the kickdown linkage after putting the new Holley in. MV9564C $27. The company’s wide range of products also includes high-performance fuel pumps, water pumps, throttle bodies, superchargers, intake manifolds, and dress-up parts for an enormous variety of street, race, and marine applications. 500 inch Throttle Linkage. Page 8: Installation Of The Marine Pro-Jection Fuel System 8. Holley was great at full throttle, but I could never get it to idle well nor get rid of the nasty hesitation / stumble. 563 inch Throttle Linkage Type. On the throttle linkage side they are connected by a very unique linkage (P4529061) which allows the center carb to open without opening the end carbs until the engine wants the extra air flow. Re: Tuning Holley for pulling truck 392 More than likely you need a boost referenced power valve. If you have a regular carb, the air bleeds are press-in (red arrows) items, so changing them is limited to drilling larger or pulling them out and installing smaller ones. 5:1 ratio at part-throttle. Some words about the power jet. I believe that the small venturi/ large throttle bore arrangement would improve signal and metering. Here is my situation, 351 PCM with Holley 4160, 1. circuit? On a carb that is in good condition with good, tight throttle shafts, there is really nothing you can do to the idle circuit of a Holley, especially if it idled well when in newer condition. Note: A carburetor can wear a lot during a quarter century of use, and one of the major wear points is the throttle shaft bore hole(s) through the bottom of the carburetor. This is a description of the procedure I've used to diagnose air/fuel mixture problems in computer controlled carbureted engines; the outlined procedure can also be used to set the idle air/fuel mixture without resorting to infrared exhaust gas analysis. Holley carbs come with a standard shooter size which differs by carb list #. Replaces OEM# C9NN9510A, C7NN9510B, D8NN9510AA, D6NN9510A, and Holley P\N R4119, R7867, R8552. A little known fact is the 452 will outflow the 906, why is this relevant? We ran a 650 Holley on a tm6 with a six-pack 484 cam, in a Dart with 452 heads. Good A/F for part throttle cruise and light to moderate acceleration. Ran great but throttle shaft still leaked at shaft/accel pump area 6. You may have to experiment a little further by balancing all the other aspects. The carb is a quick fuel Q750. Here is what we have tried so far. The carb I am using is a NOS Holley 9834-1 Here is what happens: Car starts fine hot or cold. The carb is of the 4150/4160 series (the most popular Holley's); technically its a 4160 series, because it has a secondary metering _plate_, rather than a complete secondary metering _block_. Flashback F-150 Holley Street Avenger 4bbl Carb: Trucks & 4x4 : It s as American as hot dogs and apple piehaving a Holley 4 bbl bolted under your hood, that. Holley even made a 4 bbl carb that's almost a dead ringer for the 4100, this carb is the Holley 4010. Carb Kits for 37-67 Carter, 55-71 Rochester, 36-61 Stromberg. A higher relative number indicates a larger jet size. Everytime you let off the gas and pick it back up and stumbles and runs like dump. description: application: price: r/b: 641123. However, sometimes a little more fine-tuning is needed because the customer has a. All bases are resurfaced, and throttle shaft bushings are replaced. Remove the top of the carburetor (slide vacuum chamber cover) being careful to loosen the throttle linkage stop plate. Notes : Number of Circuits - 2; Booster - Straight Series : Holley 4160 Aluminum Street Product Fit : Direct Fit Rated CFM : 600 CFM Fuel Type : Gasoline Condition : New Number of Barrels : Four Material : Zinc Flange Style : Square bore Choke Type : Electric Secondary Type : Vacuum Number of Fuel Inlets : Single Color/Finish : Polished Throttle Bore Diameter : 1. The secondaries should have nothing to do with your problem unless something is drasticly wrong. Mechanical Secondary Carbs are used in race cars that operate at max throttle. We've tried this on a normally aspirated Holley carburetor and it works very well to improve the part throttle air-fuel ratio without worrying about getting too lean on the primary side when the throttle goes to WOT. Re: Tuning Holley for pulling truck 392 More than likely you need a boost referenced power valve. Holley carbs run on the idle circuit up to about 2000 RPM at light throttle. This was using a Holley 4150 carb (870 cfm VS Avenger) which is very similar to the 3310 that I have (which is a 4160 Holley). Holley 4160/ model 8007, 390 CFM, p/n 8107. NOTE: Unless replacing an existing Holley Carburetor, you will need to purchase Holley P/N 20-91, spring and perch kit, for Ford automatic transmissions. Run the boat at high speed and repeat the procedure if necessary until the carburetor is adjusted for high speeds. By 1904, the Holley brothers were seriously in the carburetor business with the original Iron Pot single-throat carburetor. The plastic body keeps the fuel ~20 degrees cooler than an all metal carb in the same environment, leading to less percolation problems and increased performance due to a denser charge. You may have to experiment a little further by balancing all the other aspects. Added fuel pump shims til it ran lean, then removed 1/16" shim 5. If the carb is a Q-Jet manufactured under license by Carter, it will. Now that we have a good understanding of the tools available, let’s take a look at what we’re trying to achieve. Engine vacuum at part-throttle may be too much for the light spring, causing the piston to stay down, centering the lean step on the metering rod in the jet. I don't see and corrosion and yes, it can be cleaned up nice but be careful who you let do the job because the Holley's are cheap metal. ) Hope this helps!. This carb has 4 bores that are approximately 43mm in diameter. A similar item was used on the 4v versions of that intake manifold along with a Holley 4150 or 4160 carburetor (depends upon model year and platform). Not for computer-controlled engines. NEW HOLLEY CARBURETOR 1978 CHRYSLER PRODUCTS $ 250. Another carburetor that people often overlook is the Rochester QuadraJet. The OEM numbers are located on the driver's side of the carb, near the throttle linkage. I'm wondering why get rid of the p. Notes : Calibrated as a replacement for 1969-70 Chrysler 440 CID 390 HP engines; Center Carburetor; Booster - Straight Series : Holley 2300 Product Fit : Direct Fit Rated CFM : 350 CFM Fuel Type : Gasoline Condition : New Number of Barrels : Two Material : Zinc Secondary Type : None Number of Fuel Inlets : Single Color/Finish : Dichromate Throttle Bore Diameter : 1. The enlarged bore sizes allow for increased airflow to support your higher horsepower needs, a progressive throttle. Unlike most other 4-barrel carburetors, the Rochester Quadrajet 4-barrel carburetor allows the throttle plates to be opened wider, making the carburetor more efficient. Regards, Gary. Throttle bore diameters are 32mm and 36mm with a 43mm center spacing on a metric flange. It runs perfect at idle no problems. I won't get into the temperature compensation in the type HIF, or the Thermostatic choke in the later Strombergs. A simple jet carburetor cannot maintain the needed air/fuel ratio under varying suction levels and becomes too rich at high suction levels. thats an old trick that people. 5 and the engine didn't seem to have much power either. Ok I have a brand new quick fuel 650 holley carb. Weber Carburetor Kits, Parts, and Information : New Chevy and Ford V8 kits and accessories: Before you buy a carburetor make sure it is the right one for your application. When using a Holley vacuum-secondary carb on a vehicle with a non-electronic overdrive automatic transmission, such as the 200-4R or 700R-4, a throttle kick-down bracket must be used. Although Holley carbs were seen on a few Chevy engines during the '60s and '70s- most notably on high performance small and big block Chevy engines (including the three 2-barrel 'Vette big block engines)- the Q-jet carb was original equipment on most GM muscle car engines from that era. Make sure the choke valve is completely. Refer to your carburetor manufacturer’s model. If I go to 1/2 turn out it will lean and die. At this point I have ruled out ignition & I am looking at a part throttle lean condition. You need a carb with screw in air bleeds, emulsion bleeds & PVCRs. Engine testing all carburetors prior to shipment ensures that when a new QFT™ carb is bolted on an engine, it will start, idle and perform up to the customer's expectations. THROTTLE POSITION SENSORRunning an electric choke Holley carburetor and having trouble figuring out. In producing these parts, Holley prides itself in utilizing the latest technology in a lean environment to provide the highest quality parts at the best value to the customer. if you turn the screwin all the way the car should die if it doesn't there is a problem with the metering block. White or light grey muffler end pipes. Now that we have a good understanding of the tools available, let’s take a look at what we’re trying to achieve. You may have to experiment a little further by balancing all the other aspects. Refer to your carburetor manufacturer’s model. Some automotive carbs apparently used valves that would enrich the mixture at wide throttle and others, the MS carbs and Zenith small engine and tractor carbs, lean the mix at mid throttle. If the cruise mixture is off, first change the jets in order to get the air/fuel mixture correct at the 2500-3000-cruise rpm range. There is approximately a 4-1/2% flow difference fro m one jet size to the next and one size won't make that much of a differ-ence. Put my name into the search and you'll find the set up info on my 304. Make sure the choke valve is completely. What is a carburetor? Carburetors are the devices responsible for mixing oxygen and fuel in the right ratio to achieve optimum combustion within your car's engine. CARBURETORS/FUEL INJECTION/FUEL PUMPS/PARTS Holley-Vacuum Secondary spread bore- “general” Rochester Quadrajet replacement [non computor] Holley 650 cfm 4 clear view sight plugs are fitted to make float level adjustment linkage is fitted as standard, two corner idle system with lightweight mixture screws. Says "Blocks the p. Quadrajet Carb Float Nitrophyl Alcohol Resistant Rochester Dualjet Carburetor 100-17 Alcohol Resistant Nitrophyl Float (6. carburetor throttle bores. Edelbrock is the most respected name in performance. 8:1 static cr, ported and polished 2. The newer design Holley has an accelerator pump that squirts extra fuel while the throttle is opening wider. Some carbs, and I do mean SOME, have yet another idle mixture restriction JUST BEFORE the mixture gets to the idle mixture screws. idle fuel pressure is set to 7. 78 Quantity in Basket: none: Holley 390CFM 4 Barrel Carburetor Z/ZX Code:11-2996 Price: $549. Fortunately, we've got throttle bodies from Edelbrock (track use only) and Holley designed with just this adaptive ability to mount on square bore intake manifolds where a carburetor once sat. Street Avenger Carburetor. The adjustable part throttle (APT) screw can be used to fine tune the cruises (steady throttle, freeway speed) mixture. Check the manual for more info. Another carburetor that people often overlook is the Rochester QuadraJet. 14-15 CHEMICALLY IDEAL: At 14. Holding the carburetor upright, remove the cover and spring. I just assumed because of the large a/f ratio drop that was the carb coming off the idle mixture screw adjustment and going into the main jet fueling. Reproduced by permission of Bohdan Bodnar. The company’s wide range of products also includes high-performance fuel pumps, water pumps, throttle bodies, superchargers, intake manifolds, and dress-up parts for an enormous variety of street, race, and marine applications. I have pulled the top off & there is no APT adjustment on this model. Everytime you let off the gas and pick it back up and stumbles and runs like dump. On a stock Holley 750DP 4150 carb, the stock power valve is a 6. Holley's kit is simple to install, using a standard TPS sensor adapted to follow the primary throttle linkage movement, but this kit does require a carburetor using an electric choke. If your engine is performing lean, K&N’s ECI system will help make up for the fuel deficit. The secondaries should have nothing to do with your problem unless something is drasticly wrong. It is desired that the cylinder not be too lean or too rich, and that all the cylinders be the same fuel-air ratio throughout the engine rpm range. The tool bends which will make adjusting easier. Fuel Injection, Carburetion & Fuel System - 390 Holley Carb - Vacuum Secondary - Ok heres what I got check galery pics for more info 77 F100 300 L6 390 CFM Holley Offey Intake OK I bought the carb jc whitney and jegs both said I needed it is vac. Holley 650 cfm carburetor. (Note: Tom Van Gunten has been running four barrels on 3. I ran the Holley 1940 and Autolite with a DuraSpark II ignition on my 1965 F350 300 / 4 speed NP435 / with 4. RPM's fall, engine gets rougher - mix is lean. If it is lean at idle, it can be lean during normal driving until the main jets come fully online. Some holley carbs have. Holley's catalog includes all the automotive and marine products offered. Carb Number Carb Model Number CFM Renew Kit. Off idle is fine. My stock throttle and kickdown cable assembly bolted right up, no adjustments needed. WARNING: Over-tightening may result in warped or cracked throttle bodies and/or binding throttle action resulting in an unstable return-to-idle. Your cruise surge can be because your jetting is borderline too lean. For this article, we’ll be using a Holley 4150 Series 750 double pumper, pictured here. He explained that the Webers would fall flat on their faces when. make sure the timing is currect & its advancing propperly, then adj. the aluminum bowl cover assembly and the lower throttle flange assembly. I can get 20" hg at idle, steady gauge with no fluctuation. ) Holley has all types of specific information for their carburetors in their technical section, but you must know which model you have. That will cause a binding. Fast, secure e-book download. Both sides are jetted differently. Tuning a four-barrel carburetor for the highest performance requires jetting as well as adjustments. For those of you with a Holley carburetor and need to tune it, you can find tuning parts at Holley Carburetor Components and the Holley Carburetor Tech Info will give you a basic understanding of the operation of a Holley carburetor. Model 4150. full on race carb cfm size = rpm x displacement / 3456 x 1. The OEM numbers are located on the driver's side of the carb, near the throttle linkage. Holley carburetors have four distinct circuits of operation: idle, off-idle, cruise, and wide open throttle. I turned the mixture screws out some to richen and the pops seem to disapper under hard acceleration (maybe 3/4 thorrtle) but it feels like it wants to backfire through the carb or it does. The secondaries should have nothing to do with your problem unless something is drasticly wrong. 4- Holley 1945 that I got from a junkyard to replace carbs 2 and 3. If you haven't already done so, you May be able to actually improve the idle quality by cleaning that pcv valve I see in the passenger side valve cover. Choose top quality brands Edelbrock, Holley, Uremco. Holley carbs usually come with 2 kinds of serial numbers, stamped in the choke blade housing. I used it when the current engine went in, but it developed a flat spot in part throttle acceleration. Simply turn the screw DOWN ½ turn at a time until you experience a “lean surge”. The Holley has evolved. You have to take the throttle body part of the carb off the main body to see this restriction, so its best to check for this at the same time you are drilling out the idle discharge ports. Other than that, I went to the factory supplied lighter vacuum spring (not a good idea if you still have a 302ci engine). circuit for racers who prefer to run without one". They presumably understood that it was a Holley 2245 and said that they had the part. There is nothing you can do about it except replace the carb. Adjust throttle linkage to obtain wide open throttle in carburetor. Stock Holley® discharge nozzles are very close to the throttle plates. Trick Kit: Needle & Seat Primary Main Jet Secondary Throttle Bore Diameter Secondary R1848-1 4160; 465 37-119: 37-933. Th clean barrel design of the Holley-styl carb allows efficient fuel flow in wideopen- throttle conditions. Remove the throttle cable ball and automatic transmission kickdown stud (if any) from the original carburetor, and mount these in similar locations on the Holley throttle lever. It works for this carb but not for Holley's that don't have the center idle adjuster. However, sometimes a little more fine-tuning is needed because the customer has a. Covers the Carter AFB carburetor used on 1957-1967 Cadillac and Pontiac cars. Free shipping when your order includes this part. I'm looking in the Summit catalog at the Holley carb parts and came across a power valve plug and gasket kit (part #HLY-26-36) which eliminates the p. ) Hope this helps!. Street Avenger Carburetor. Contents[show] Terminology Lean: referring to the tuning of a carburetor in which the fuel/air mixture contains too little fuel and too much air Rich: referring to the tuning of a carburetor in which the With the engine running at working temperature, hook your finger under the pin and raise the piston about 1/32in. 5- Supersix BBD that I rebuilt myself and is still going strong. The 650 d/p may use a different [larger] high speed airbleed which will lean part throttle and slow down response. Holley 2 Barrell Carb 350cfm - Free download as PDF File (. You may have to experiment a little further by balancing all the other aspects. Holley carbs come with a standard shooter size which differs by carb list #. 4800 converter. Carburetor-parts. 00 : Holley Power Valve 4. Rich/lean Indicator Part # 534-50 without oxygen sensor HOW TO CHOOSE A CARB. holley carburetor renew kit,carburetor rebuild kit,fits carter afb carburetors,4bbl April 1, 2020 Carburetor Service Kit Carter 1 Barrel for Jeep CJ3B CJ5 CJ6 53-71 17705. I have a Holley 4150 950 that is very rich at part throttle. We ordered a Holley Power Valve Check Ball Kit No. I just assumed because of the large a/f ratio drop that was the carb coming off the idle mixture screw adjustment and going into the main jet fueling. Order online or by calling 1-800-888-6473 and speaking to the sales team. In my opinion this is where carbs suck compared to FI. The plastic body keeps the fuel ~20 degrees cooler than an all metal carb in the same environment, leading to less percolation problems and increased performance due to a denser charge. I would expect #80 MJ to be rich at part throttle. In 1952, a new 250,000-square-foot manufacturing plant was opened in Bowling Green, Kentucky, and product development continued with the first Holley modular carburetor, the model 4150 that was made standard on the 1957 Ford Thunderbird. Wide-open-throttle mixture should be adjusted by changing the secondary jets, but only after all other circuits are properly tuned. INTRODUCTION: CONGRATULATIONS on your purchase of a Holley carburetor! We feel that you have purchased the finest performance carburetor manufactured today. What has been done to the carburetor?. 050, 507lift, 108 ls,rpm range 2200-6200, 69 z-28 intake port matched to heads. I had to open up the secondaries slightly to allow me to move the primary throttle blades down so the idle mixture screws would work. With the carb off of the intake manifold, you simply adjust the primary transfer slots with the primary idle speed screw. Correction: replace needle with next leaner diameter and test again. Extreme part throttle lean out, Holley HP Greetings. My original Holley 4160 in my 1970 300 went 29K miles before it started acting bad, and thereafter, I couldn't just rebuild it. Part throttle cruise is better, since at light throttle the engine is now running on the transition slot/idle circuit so likely the fuel mileage will be better. The construction of the carburetor IS such that is as simple as it get, The basic carburetion no differ- in the Holley four-barrel than in any Of our other carburetors. Used carb cleaner and thorowly cleaned every passage. In producing these parts, Holley prides itself in utilizing the latest technology in a lean environment to provide the highest quality parts at the best value to the customer. Install the new throttle ball, lockwasher, and retaining nut to the carburetor throttle lever in the same position as the existing carburetor. Which can be downloaded for free from the Support section of Holley's website! Features: 8’ communication cable for easy access to your ECU. Street Avenger Carburetor. i also tried dropping the idle air bleeds from. 5:1 and goes to 12:1. My car is stock 1980 350 Chevy SB, with aftermarket headers, manifold, and ignition. Some words about the power jet. 95 : Holley 94 Stainless Steel Screw Set Ford V8, Lincoln V12 + 2100 2110 & 59 Carbs (900. That 2 X 1 adapter isn't helping you I think if you want better MPG I would just go back to a 1V carb like a Carter YF, a Holley 1940, or the best one for MPG a 1968 Autolite 1101. Now, Holley manufactures high performance carburetors, manifolds, superchargers, water pumps, throttle body fuel injection and fuel pumps for street and race applications. Buy and install a stock jet needle for a 1988 or '89 1200 Sportster (H-D Part No. If the air/fuel mixture is too lean at idle or part throttle and the idle mixture screws do not provide enough adjustment, the correction may involve enlarging the idle “jet”. Holley carbs come with a standard shooter size which differs by carb list#. For low-RPM wide open throttle you can drill out the pump nozzle (and lower the level pin to compensate). The carb idles pretty. I don't think most people who have running cars tune in this area! At part throttle, even with boost this lean "may" not be a problem because the. At the other throttle positions the mixture is either leaner or richer depending on whether the throttle is opened less or more. In my opinion this is where carbs suck compared to FI. A better idea would be to source a carb - new/used/reman/whatevah that is actually appropriate for the application so the thing will run properly instead of futzing around with a square peg in a. No matter what I do I am still getting part throttle detonation at lower rpms. Air Valve Carbs provide the best throttle response on street cars. Help is just a click away!. Other things that will contribute to a lean condition under accelleration is the power valve not coming in soon enough or a PVCR not big enough as well as the usual suspects. If the carburetor is adjusted to make it work well at high speeds, it will be too lean at low speeds. I used it when the current engine went in, but it developed a flat spot in part throttle acceleration. Everytime you let off the gas and pick it back up and stumbles and runs like dump. Install the carburetor holddown nuts and snug nuts progressively in a “criss-cross pattern” (Fig. The Holley 4150, 4 barrel carburetor was introduced in 1957 on some Ford engines. 9L / 300 - Holley Sniper EFI install - Hi all, So, I finally got my engine installed into my new Bronco. A Holley carburetor is made with four basic parts, the throttle plate, main body, metering block and float bowl assemblies. Holley EFI TERMINATOR X MAX MPFI Kit w/ EV6 Injector Harness & DBW Throttle Body Control (2007-2012 CHRYSLER HEMI) [550-1423] Fits 2007-2012 GEN III HEMI engines with EV6 injectors, and a Drive-By-Wire throttle body. Good A/F for part throttle cruise and light to moderate acceleration. amoparguy, try this on your carb before you drill out the plates anymore, on the passenger side of your holley, look under the adjustment screw that opens the back barrels, you will need a small screwdriver to go up in the housing to adjust this screw, what this does is it opens the back barrels up a little to let more air into the engine, I have used this little trick on several carbs I have. I forget the exact part number but it is the cheaper priced one that doesn't have externally adjustable floats. At part throttle or cruise, the carb is running off the main circuit, the primary jets. That carb has the idle adjuster where the carb stud is, so your not really adjusting the idle with the throttle blades. 5 and at part throttle I'm above 10 inches of vacuum, don't recall the exact number but no where near the power valve opening. Install the new throttle ball, lockwasher, and retaining nut to the carburetor throttle lever in the same position as the existing carburetor. On Holley 4bbls it is usually behind the choke housing. There is a spring under the top cover, so hold it with a finger until all screws are loose. a darker color indicates that the carburetor is jetted rich. Remember, primary jets and metering rods will affect steady cruising and part-throttle operation. The Holley technical resource library. I have pulled the top off & there is no APT adjustment on this model. I've built a few customs carbs myself. the aluminum bowl cover assembly and the lower throttle flange assembly. Extreme part throttle lean out, Holley HP Greetings. Improper clearance will cause either poor throttle response or premature pump failure. Adapter part number 5765 (SKU 228351) may be needed, to properly seal the carburetor to the stock factory intake manifold. Slightly confusing – but the scientific ratio (e. Holley carbs come with a standard shooter size which differs by carb list #. Neighbor helped me rebuild it and it I ran for three years until the throttle shafts wore out and I went to a 2-barrel. Well, I think I might know the answer, but some clarification wouldn't hurt. Replace with a new filter element. This is adjusted by compressing or r elaxing the pump override spring as shown in Figure 9. If your engine is performing lean, K&N’s ECI system will help make up for the fuel deficit. Holley Ultra HP aluminum 950 carb in new Hardcore Gray is nearly 40-percent lighter with 20-percent greater fuel bowl capacity. However, applica- tion of thcsc principles does vary slightly, so the first part of this reference Ixx'k is devoted to a description of these variations. The only bummer is for this first time in my life after countless Holley carbs and 20 years of drag racing I stripped a bowl screw hole. in reply to jtrovillion, 06-17-2018 17:26:36 Could be ether one but I'd check the accelerator pump in the carb first, if it's stuck any time you accelerate or load the engine it will experience a instant lean condition. That will cause a binding. Your next job is to lean out the carb’s calibrations, and that is done mostly on the idle fuel and air jets, with the main jet and air corrector coming in only at the higher speeds. The Holley Terminator Stealth EFI Base Kit throttle body is designed to mimic outside appearance of an original carburetor. I can richen the idle mixture up and help this problem, but then the idle is way to rich and it will black smoke after idling for about 5-10 seconds. Buy and install a stock jet needle for a 1988 or '89 1200 Sportster (H-D Part No. GM 3 bar MAP Sensor part# 12223861. But I do not believe the '950' Holley (essentially a 750 carb body on an 850 baseplate) having 3/8" venturi will flow 950 cfm at the same depression as the 830 and older Holley 4bbl carbs were flowed. 4- Holley 1945 that I got from a junkyard to replace carbs 2 and 3. FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428) - Holley Carb tuning on 390 - Ok so i have been really trying to dial in the carb on my 390 in a 75 F100. Since parts for these are so common, you can tune without risk to your carb. secondary throttle valves. I've got a holley red pump and regulator, set to 5 1/2 psi. You may have to experiment a little further by balancing all the other aspects. 5 liter Big Sixes for several years. I am also using a two-stage power valve, which can help prevent lean part-throttle issues when using near-lean main jets. Fuel pressure is good at approximately 8 lbs. That will cause a binding. In photos the carb looks identical and one number even matches - 12R-1073BP. The Holley technical resource library. I had a Holley 4160 750 cfm off a different engine so put it on. If the mixture is still lean at 1000 through 1800 rpm, the idle channel restriction on a carburetor such as a Quadrajet or Edelbrock Performer or Thunder series may have to be slightly enlarged to allow more fuel to be delivered at part throttle. For those of you with a Holley carburetor and need to tune it, you can find tuning parts at Holley Carburetor Components and the Holley Carburetor Tech Info will give you a basic understanding of the operation of a Holley carburetor. After pulling the carbs off and closing the primary blades (via idle speed screw) so that only. I have read Lars' paper on tuning Holley's (I am no expert by a long shot) and was unable to find anything covering this particular issue. Again right out of the box the Holley started up and performed well although burning rich due to the 7500ft altitude. Holley 5200 (Size Matters) Most models primary venturi diameter is 26mm and the secondary is 27mm. Air Valve Carbs provide the best throttle response on street cars. Weber Carburetor Kits, Parts, and Information : New Chevy and Ford V8 kits and accessories: Before you buy a carburetor make sure it is the right one for your application. On the EDELBROCK type carburetors, that cam is metal and no damage occurred, but on the HOLLEY type carburetors, the "fast idle cam" is plastic and setting the "fast idle screw. Open 24x7 - Same Day Shipping! Save $10 off $299, $20 off $599, $30 off $799, $100 off $1,599 Orders. The secondaries should have nothing to do with your problem unless something is drasticly wrong. The tuning changes needed to cure the lean off –idle problem involves enriching the off-idle circuit through enlarging the idle well of a Holley-style modular carburetor or enlarging the idle channel restrictor (ICR) of the Rochester carburetors or the Carter AFB and AVS carburetors (including the Edelbrock Performer and Thunder series. If you have a regular carb, the air bleeds are press-in (red arrows) items, so changing them is limited to drilling larger or pulling them out and installing smaller ones. The carb idles pretty. Part of the carb testing was to establish the value and the optimal point of opening of the secondary barrels of a 4-barrel carb on a single- and a dual-plane intake. Holley 0-80457S Model 4160 600 CFM Square Flange 4-Barrel Vacuum Secondary Electric Choke Carburetor By Holley 27 offers from product price $347. You may notice black exhaust smoke, trouble starting, and reduced. My car is stock 1980 350 Chevy SB, with aftermarket headers, manifold, and ignition. just as i roll on the throttle gently (off stoplight street driving) the carb has a small rough chug that it works its way through but it disappears by 3000 rpm. Engine vacuum at part-throttle may be too much for the light spring, causing the piston to stay down, centering the lean step on the metering rod in the jet. Series : Holley Sniper EFI 2300 Product Fit : Universal Rated CFM : 500 CFM Fuel Type : Gasoline Condition : New Number of Barrels : Four Material : Aluminum Choke Type : Manual Color/Finish : Polished Emissions : 50-State Legal for use on Non-Emissions Controlled Vehicles or Racing Vehicles Carburetor Model : Holley 2300 Warranty : 90-day Holley limited warranty Anticipated Ship Out Time : 15. As such, it is richer in the off-idle to ¼-throttle range and works just right. 5:1 ratio at part-throttle. On the EDELBROCK type carburetors, that cam is metal and no damage occurred, but on the HOLLEY type carburetors, the "fast idle cam" is plastic and setting the "fast idle screw. Mechanical Secondary Carbs are used in race cars that operate at max throttle. 5 and at part throttle I'm above 10 inches of vacuum, don't recall the exact number but no where near the power valve opening. Your next job is to lean out the carb’s calibrations, and that is done mostly on the idle fuel and air jets, with the main jet and air corrector coming in only at the higher speeds. The end carbs use a diaphragm (P4349321) like the vacuum-secondary Holley 4-bbl above and the color-coded springs are available from Holley. I have read Lars' paper on tuning Holley's (I am no expert by a long shot) and was unable to find anything covering this particular issue.