Set the idle mixture to the highest vacuum by using a vacuum gauge connected to the constant-vacuum port of the carburetor base plate. No sweatthere's a conversion kit for that. This might seem way too simple, but for a carbureted street engine this is the most important tuning step you can make because street engines spend a majority of their time at or just above idle. Make these changes very slight and note the effect on the engine. The only way a street small block can handle the extra airflow of a larger carb is if the engine is built and cammed to rev over 7000 RPM and the drivetrain is geared with a higher numerical final drive ratio. 237/ 247@0.050, 600 lift. Accelerator pump. Instead he drives in a lead ball and drills it to 0.040 inch to act as a restrictor so the secondary opens at a slow enough rate to prevent a bog or hesitation. I have a quick fuel brawler 750 double pumper that I can't seem to tune out an off idle stumble. 236-244 cam 10.5:1 compression, 213cc profiler heads. Automatic choke problems can also cause hard starting, cold stalling and idle speed problems. Cold start circuit. Let's say that the left side is three-quarter turn out and the right is one-and-a-half turns out. The dropped boosters are used in all of Holley's 4150 performance carburetors while the standard carburetors are equipped with straight boosters. Dont let the pursuit of perfection ruin your project vehicle. For example, the 0-3310-5 4160 750 carburetor comes stock with a PN 134-21 secondary metering plate that is equivalent to a 75 jet that is included in the kit. Fuel Type: Gasoline. Heads are stock 429 PI. If the engine doesnt hesitate or bog under acceleration, the secondaries could be opening too late. Im running a 3.5pv now with 68/79 jets with pretty close engine specs to yours. One of the tools at our disposal is the closed loop algorithm where the target air/fuel ratio commanded in the ECU is compared to the actual air/fuel ratio read by the O2 sensor. When changing jet sizes up or down, go two number sizes larger or smaller rather than one to see if it helps or hurts performance. Caution: make sure you are using a tested, known power valve. A 10-degree temperature change one way or the other may require increasing or decreasing the jets by two to four sizes. The Brawler was taken apart, made sure there was no junk inside it, put back together as it came except with 70 P and 80 S jets (74-84 stock) idle air bleed change (went from 70 to 73 IIRC), PV went from 6.5 to 3.5 with the crappy vacuum, 31 squirters front and rear. Note this is an older factory carb with the vent linkage on the primary fuel bowl. Adjust the linkage on the accelerator pump so that the instant the throttle moves the accelerator nozzle will squirt fuel. The Brawler family of carburetors delivers bare-knuckled performance for daily drivers, race cars, and everything in between. Cam is a solid lift from the mad porter. Vintage 1980 Yamaha Enticer Snowmobile Revival to Former Glory. If the initial change results in a loss of rpm or vacuum go back to the baseline and then turn the idle mixture screws in the opposite or counterclockwise direction. Almost anybody with a screwdriver can make the simple adjustments or swap jets, but it usually takes an expert to perform major modifications with success. But if your vehicle has an adjustable pressure regulator, set it for the ideal 6.5psi. Specs Service Parts Non-Stick Gasket Assortment 4150 Part# BR-67220 $19.19 Qty: Add To Cart With this carburetor, idle speed adjustments should be done with the bypass adjustment rather than at the throttle speed screw on the linkage. The first step is to obtain a low-speed tach that will show minor changes in rpm along with a vacuum gauge. That is primarily determined by the amount of engine vacuum available at idle. Quick Fuel Technology Carb Install and Tuning Walkthrough- RODDING REVOLUTIONS ISSUE #1 RoddingRevolutions 460 subscribers Subscribe 1.1K 288K views 7 years ago QFT install expert Teddy Barlow. On all Holleys there are two power valve channel restrictors (PVCR) that determine the amount of fuel delivered to the boosters over and above the fuel metered by the jets when the power valve opens. Innovate Motorsports and HGM Electronics both make nice conversion kits that work on the Holley. Enter The 2023 LS Fest West Trip Sweepstakes Today And Join Us In Las Vegas! 540hp small cubic inch and close to 600hp with 400 cubic inch, all on pump gas. To access the carb must be inverted. While the gaskets are thick, this still causes sealing problems that can lead to erratic performance. A balanced or neutral A/F ratio of 14.7 to 1 (stoichiometric) is good for fuel economy and emissions, but not so much for power. The float level is important because the fuel level inside the bowl affects how much fuel flows through the main metering circuit. So if you get a 12-inches of vacuum reading, you need a #6 power valve. In a properly adjusted curb idle setting, the tip of the throttle blade should just uncover the end of the transfer slot (above). Dalton at Pole Barn Garage wonders where all the love is classic double pumpers? To improve our situation, we contacted the officials at Brawler about a four-barrel (4bbl) carburetor to replace the restrictive 2bbl. The short block has been dynamically balanced and has been assembled by the rebuilder. Brawler carburetors are precision-machined and hand-assembled by craftsmen right here in the USA. There should be zero clearance or a slight preload on the linkage arm to the accelerator pump lever. This increases fuel flow making the idle air/fuel ratio extremely rich. The basic difference between a carburetor and electronic fuel injection is that a carburetor is totally dependent on intake vacuum for fuel metering and delivery. The traditional solution (which works very well) is to close the curb idle back to where it just touches the transfer slot and then drill a small initial hole; usually 3/32 inch (0.093-inch) in each primary throttle blade. Reading the spark plugs can also give you a rough idea of whats happening to the A/F mixture. So, you might want to check your air/fuel ratio at cruise with one of the many hand-held air/fuel ratio devices or gauges currently available. If its brand new, its history doesnt matter. Make sure the hole that seals the diaphragm transfer slot is uncovered. A slightly rich fuel mixture is necessary to make peak power, but if the A/F mixture is way too rich, excess fuel can wash down the cylinder walls and dilute the oil. I looked last night but cant find my dyno sheet. Some Holley tricks don't have to relate to performance. You can call me gearheads or petrolheads. I've been reading through posts and I might be in too deep, but I'm determined to get her running right. The carburetor will also deliver the optimum air/fuel ratio throughout the engines RPM range to achieve peak horsepower and torque. Most QFT carbs come from the factory with .043-.048 power valve channel restrictions. Related: 10 Biggest Carburetor Tuning Mistakes. Ive got the same issue with my Z-28 and a Summit 750. It can also foul the spark plugs. Big cams like a lot of initial, always use he vacuum advance. This is Holley's TPS conversion bolted to a 4160 Holley with an electric choke. Holey Goat Full Story: https://rdkll.co/HoleyGoat Remember to Like this Video, Subscribe to the Channel and Alerts, and Share with Your Friends! This warps the carb main body especially near the top of the main body where the main boosters feed from the metering blocks to the main body. Brawler carburetors are loaded with the latest technology in air fuel calibration to meet the demands of today's street, strip, and race engines. It can replace Holley, Edelbrock, Carter AFB, and Autolite style carburetors with 5 3/16 x 5 5/8 bolt pattern. The rule of thumb is for every 5000 ft. change in elevation, compensate by 3 jet sizes. Brawler BR-67199 Race Carburetor, Mechanical Secondary, 650 CFM. One of the most overlooked carburetor issues has to do with the secondary throttle opening. The main circuit also includes emulsion tubes and air bleeds that premix air with the fuel to improve fuel atomization. That's probably worthwhile if you are going into business, but otherwise it's easier just to ship your carb to SMI and have him recolor your cab quickly and easily. With a dyno, you can see whats happening with the A/F mixture, horsepower and torque curves as the engine makes a pull. To support the popularity of the Brawler carburetor it seems only natural to add rebuild kits and tuning parts for them. . If it surges, it is probably lean and will require jetting up. 3 0 obj Thats where the power valve circuit comes in. These days, the talk seems to be all about EFI and fuel injection retrofit kits. But the good news is that that original appearance is easy to restore. If it feels lazy and non responsive to slight changes in the throttle, it may be too rich and will require jetting down. Hear from the experts at Fluidampr. If your tailpipes are a light tan, you are probably in the ballpark. I'm thinking about putting a few more degrees of timing in it to maybe 18 initial, just dont want to go too high on total as this will put me in the 37 range. this thing runs SO pig rich I cant stand to be in the garage with it running. Let's say you have a 750 double-pumper Holley 0-4779. We also interviewed Holley carburetor tuner/restorer Sean Murphy of Sean Murphy Induction (SMI) to document a few of his tuning and assembly secrets. Is there a history of these Brawler carbs being questionable? This is the idle stop adjustment for most Holley carburetors. If you can tune a carb to deliver a consistent A/F within this range, the engine will usually run at its full potential from off-idle to wide open throttle. A set of calibrated pin vises really helps dial in restrictor sizes. The spec is between 120- and 144-inch pounds. There are many misconceptions about how to go about these adjustments, and of course there is no shortage of free advice. can I split off my trans modulator and the vacuum advance off the same source, the baseplate of the carb? You are using an out of date browser. There is one more adjustment left after you establish the correct power valve opening point. For this procedure we'll assume a Holley with only two idle mixture screws. If there is a step in this area, the surface has been machined. JavaScript is disabled. HGM's AccuLink is a very slick stainless steel conversion kit that adds a GM-style TPS sensor to all popular Holley, Q-Jet, and Edelbrock carbs. Despite not being a fancy, state-of-the-art set up, Mike and his team at H&H have a great thing going. Replaceable high speed air bleeds and idle air bleeds help you adjust to the changing conditions. The camshaft is a Lunati 60100 hydraulic flat tappet cam installed straight up. Too much fuel from an overzealous tuning approach can be just as detrimental to good throttle response and too little nozzle size, although the driveability symptoms will be different. Available in both vacuum and mechanical secondary versions to meet your needs, All models have dual inlet fuel bowls with sight glass windows for safe and easy float adjustments, All models come with an electric choke for easy starting in colder climates. When Holley redesigned the Ultra XP line of carburetors, they added an adjustable air bypass feature located underneath the air cleaner stud. If idle speed increases, lower it by closing the idle speed adjustment. You can build a killer motor using all the best parts and machine and assemble everything with the utmost care, but if its a carbureted engine and the carburetor isnt set up or tuned right your killer engine may never live up to its full potential. The dropped leg version boosters tend to be a bit more responsive at part throttle and therefore are a little better than their straight booster cousins. If the idle speed and vacuum increase, continue with similar changes in small increments until the idle speed or vacuum deteriorates. The jets (and rods in Carter/Edelbrock) carbs control the A/F ratio from off-idle to wide open throttle. To check manifold vacuum, attach a vacuum gauge to the manifold vacuum port on the carburetor, place foot on brake, engage in gear and record the reading. Another indication if the main jets are correct is how the car drives. Quick Fuel Technology (QFT) ships carburetors only after they have been thoroughly run-tested and adjusted on a typical engine. When it comes to selecting jetting the most accurate means. This is where the vacuum gauge and tach can really help. Tech Note: This model of carburetor has the square bore flange bolt pattern. Set the idle mixture for the best idle quality along with the leanest air/fuel ratio. QFT uses a patented Four-Door power valve that is calibrated to flow more fuel and respond more quickly to changes in manifold vacuum. The 3rd phase of new Brawler carburetors build on the success of the originals by adding more CFM sizes & a black coated finish with red billet metering blocks & throttle bodies. This can get a little expensive and it might be cheaper just to buy an older Holley just to obtain the parts. Reducing the main jets from 75 to 70 is equal to a 13 percent reduction in flow area. Setting opening rates for vacuum secondary carburetors is really important to the overall performance of the vehicle, and with QFTs Quick-Set adjustable secondary housing assembly the task is very simple. The Brawler carburetors also have four-corner idle adjustment, change idle and high-speed air bleeds for accurate tuning, and many other options. After pulling the carb I noticed that the curb idle setscrew was completely off the lever. Holley makes several kitsmainly for either the 0-3310 750 cfm or the 0-1850 600-cfm carbs. Once the rings have seated, you can make the initial idle mixture and speed adjustments. A continuing problem for street engines running big camshafts and lots of overlap is low idle vacuum. Add to Cart. The only problem with drilling these holes in the throttle blades is that this becomes a semi-permanent modification. Many other variables can also affect the air/fuel ratio such as open headers versus closed headers, changes in header length, camshaft changes, gearing and tire size changes, track length, etc. Snap On vs Daytona, Pittsburgh, ESCO, Husky, More. Ive got the idle set at 1000 rpm with the vacuum advance hooked up to manifold vacuum. Brawler would like to congratulate and thank you for purchasing this carburetor. Carburetor Installation & Tuning Segments. How you proceed from here depends on what kind of equipment you are using. Specs Service Parts Non-Stick Gasket Assortment 4150 Part# BR-67220 $19.19 Qty: Add To Cart Failure to follow the proper installation and tuning may result in damage or injury. Rusty but Rare 1976 Chevy K10 Sport Truck Revival! Holley Brawler Carburetor Installation How-To and Basic Tuning - YouTube 0:00 / 5:23 Holley Brawler Carburetor Installation How-To and Basic Tuning Pole Barn Garage 68.5K subscribers. The equipment does exactly what it needs to, his team is experienced and the shop has built thousands of vintage engines for customers everywhere! Manual chokes require no adjustment but do require a certain amount of finesse when it comes to starting a cold engine. So you bought a newer 0-3310 vacuum secondary 750 Holley for a great price, but later you realize it is the 4160 style with the secondary metering plate. Preadjust the idle speed screw on the throttle linkage so the throttle plates are closed, then tighten the screw one full turn for the initial idle setting. The crew shows how to save cold-hard-cash by overhauling an Edelbrock AFB-style 4 barrel performance carburetor. If the engine is on a test stand (not a dyno) or in a vehicle, you can use a handheld A/F meter with a wideband O2 sensor to measure the A/F ratio in the exhaust. Now you are ready to check and re-set the idle mixture screws. 850 qft brawler 75 main jet 85 secondaryjet 383 sbc 11.7 compression Motown single plane intake Lunati voodoo solid roller .605/.605 254/258@.050 Afr 210 heads Msd ignition locked out at 36 Full throttle and cruise it seems fine. A good tune means the engine should start and idle without stalling, and respond instantly when the pedal hits the metal. The change from 6.5" to a 5.5" power valve will most likely be too narrow a change, I'd drop to a 4.5". Here's the trick to assembling that tricky vacuum diaphragm canister. Setting up a rebuilt carburetor. Its true that a carburetor with larger throttle bores will flow more cubic feet per minute (CFM) than a carburetor with smaller bores. The newer HP and Ultra XP carbs come with screw-in restrictors. The 4 Piston Racing facility in Danville, IN houses two buildings one is 12,000 sq.-ft. and the other is 2,500 sq.-ft. I have dabbled some filler material at the ends of the slots before to shorted up the slots. For these kinds of venues a blue printed carb that pushes the specs to the absolute limit is usually necessary to be competitive. cant get more than about 7-8" of vacuum out of it. Who doesnt like a little bit of burnt rubber? To determine where the correct opening point is, you need to keep adjusting the screw out until you get a bog, then turn the screw in -turn. If your QFT doesnt have a choke it probably has a 4.5 power valve from the factory. Marvel at the beauty of a carburetor in its natural habitat onboard a large displacement American V8, this one under the hood of the Holey Goat 1970 Pontiac GTO. So unless youre ready to swap out the carb for a bolt-on fuel injection system, keep that screwdriver handy. If the secondary side opens too quickly the engine will bog. just crazy rich. Higher altitudes and decreasing barometric pressure thin the air, which causes the carburetor to run rich. Theyre a perfect replacement for your daily cruiser and they come in sizes ranging from 570 to 770 CFMs.Brawler street carbs sport billet metering blocks with calibration for todays street strip demands. The Brawler family of carburetors delivers bare-knuckled performance for daily drivers, race cars, and everything in between. Murphy brought it right back to life with a rebuild and a dip in his acid etching process that makes it look like new. 1 change at a time. 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. Follow @PoleBarnGarage on Instagram: https://www.instagram.com/polebarngar Join Pole Barn Garage on Facebook: https://www.facebook.com/groups/16497 Sport Yourself a Holey Goat T-Shirt: https://www.redbubble.com/i/t-shirt/T Support our Partners: Holley Performance: https://holley.com Roadkill Customs: https://m.RoadkillCustoms.com Luff Photography: https://luffphotography.myportfolio.com/ Thank you so much for being here, every single one of you is appreciated!#HoleyGoat #HolleyPerformance #RoadkillCustoms #WorstGTOever #holley #winwithholley #holleyequipped #HowTo #Carburetor Stay up to date with the latest releases, events, promotions and more. The full Installation Instructions appear below. On a Holley 4BBL, the level should be even with the inspection hole when the plug is removed. But over time, the carburetors lose that nice shiny appearance and end up faded and looking a bit haggard. There is a tip-over point between rich and lean where combustion is ideal. Airflow down through the venturis (and boosters) creates low pressure that pulls fuel from the fuel bowl through the main jets and into the airstream. Keep in mind that the jet sizes, power valve and accelerator pump adjustments that provide the best performance today may not produce the same results tomorrow. A typical smallblock Chevy will usually run best on the street with a 650 to 730 CFM carb. Drivability is just as important, and that requires a lot of air velocity for instant throttle response and good low to mid-range torque. Are the fuel bowl inlet valves in good condition and not sticking or leaking? But don't despair if you have a Holley with straight boosters. Dont just stick any old power valve in your carburetor. If they are black, your jetting is too rich. Do this 2 times. You can see if the carburetor is going too rich or too lean causing power and torque to drop off at certain engine speeds. A vacuum-sensing power valve opens when intake vacuum drops to allow more fuel flow through the main metering circuit. After a long stretch of steady-state highway driving pull off in a rest area and check the tailpipes. Another check to make before you start playing around with the jets, accelerator pump and power valve is the fuel level inside the fuel bowls with the engine idling. The full Installation Instructions appear below. Follow me on. Electronic fuel injection is also self-tuning and is constantly readjusting the A/F mixture based on feedback from the oxygen sensors. pig rich. A carburetor that is adjusted properly during installation will give a solid baseline for fine-tuning to achieve maximum performance. If the idle speed is still too low, larger holes or two more in the secondary throttle blades can be drilled. I do have the dyno sheet somewhere at the house, have to look tonight. Holley Brawler Installation and Basic Tuning Here's a quick "how-to" that covers installing a new Holley Brawler double-pumper carburetor. A brand new carburetor from a major aftermarket supplier comes prejetted and preadjusted for the average engine it will be bolted onto. The proper way to check fuel pressure is with the engine running at idle with the engine up to full operating temperature. Yet the carburetor is most often blamed. Set the back to 1000 rpm. All Brawler models have dual inlet fuel bowls with convenient sight glass windows for easy float adjustments. Hollow metal and plastic floats can leak and foam plastic can absorb fuel. If under, turn idle mix screws in 1/8 turn. This includes the choke, fast idle cam and linkage, and fast idle adjustment screw. Of course, you can also just convert the carb to a 4150 style with the metering block and retain the stock single inlet configuration. Tech Tip: E85 Conversion on a 4150 QFT Carburetor! 2023 HOLLEY PERFORMANCE PRODUCTS, INC. ALL RIGHTS RESERVED. They offer the tune ability and trick options that you typically only find in more expensive carburetors. In fact, the HGM AccuLink is designed to work with Holley, Q-jet, and the Edelbrock carburetors. Put a Brawler 750 DP on it in the car. Depending upon what altitude you live at (sea level in LA or at 5,000 feet in Denver) your carb may need a main jet change. Brawlers come with the latest technology in air/fuel calibrations for todays street or race engine demands. Save my name, email, and website in this browser for the next time I comment. Been playing with this for 2 months. This engine, named as part of the X engine family, is uniquely positioned to replace both the L9 and the X12 with the versatility to serve both medium and heavy-duty applications. 1 0 obj The conversion kit adds the rear metering block along with the required different metering block gasket. If the two do not match, the ECU makes small changes by either adding or subtracting from the commanded fuel in the fuel table to equalize the two. 2 0 obj Adjustable tapered idle screws for each barrel control how much fuel is pulled into the engine at idle by intake vacuum under the closed throttle plates. i hate living in asheville,