brawler carburetor tuning
<>/ExtGState<>/Font<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> An engine that stumbles, hesitates or bogs when the throttle opens usually needs more fuel from the accelerator pump, or the carburetor is way too large for the engine. Follow me on. The volume of the pump, the shape of the cam and position of the linkage that operates the pump, and the size and position of the discharge nozzles all affect how much fuel is delivered when the throttle opens. An engine only runs as well as it is tuned. Leave the locking screws for the choke housing cap slightly loose so the choke can be easily readjusted as needed. it will idle at 900 in park, 800 in gear. The Brawler family of carburetors delivers bare-knuckled performance for daily drivers, race cars, and everything in between. Dont let the budget friendly price fool you, the development of Brawler carbs focused on performance and not some flashy packaging. The best route here is to split the difference and make them both one turn out. One is to preadjust the idle mixture screws to about one full turn out. TPV Productions 32.9K subscribers Subscribe 605 Share 33K views 1 year ago Be sure to check. Holley Brawler Installation and Basic Tuning Here's a quick "how-to" that covers installing a new Holley Brawler double-pumper carburetor. Likewise, colder air is more dense than hot air, so the main jets can be increased in size so the fuel mixture doesnt go lean. With carbureted engines, its an ongoing process of tweaking and adjustment to find the settings that deliver the best performance. So instead, we focused most of our time on street driveability. Vintage 1980 Yamaha Enticer Snowmobile Revival to Former Glory. Inside the fuel bowl is a brass, hollow plastic or foam plastic float that maintains the fuel level. For street cars, depending on the vintage of the vehicle and state laws, a carburetor may have to be emissions legal. That means vacuum hookups for the PCV and EGR valves, a choke and possibly restrictors for the idle circuit so the carb doesnt run too rich and increase emissions. With minimal vacuum, these engines demand increased throttle opening in order to idle at an acceptable speed. The ledge means the metering block mounting surface has been machined. This can get a little expensive and it might be cheaper just to buy an older Holley just to obtain the parts. If memory serves, it "used" a little over 700 cfm on the dyno, 718 sticks in my mind but I dont want to just spout numbers out. Is there a history of these Brawler carbs being questionable? Brawler carburetors are loaded with the latest technology in air fuel calibration to meet the demands of todays street, strip, and race engines. If anyone has more ideas, please feel free to post. If the carb has screw-in fuel filters, are the filters clean and unobstructed? Again, the vehicle must be up to operating temperature and check to see if your fuel pressure is holding at 6.5psi and the float level is still correct. For most street applications, Murphy likes to use the purple spring. While it is possible to do this yourself, it involves buying chemicals and a knowledge of the technique. Dual inlet fuel bowls are not included in the kit but you can add them at the same time. The spec is between 120- and 144-inch pounds. If engine speed increases with that one screw, adjust all of the others to match. Dont just stick any old power valve in your carburetor. Find many great new & used options and get the best deals for Quick Fuel Technology BR-67212 Brawler Street Carburetor at the best online prices at eBay! Despite not being a fancy, state-of-the-art set up, Mike and his team at H&H have a great thing going. If there is no stepit has not and is a good candidate for this procedure. Open the secondaries too late, and you are missing the true performance potential of your carb and engine. Carburetor is a box stock tune Quick Fuel Brawler 750 Dual Line feed, 4 corner idle, manual secondaries, electric choke, adjustable everything. Street carburetors are set up to deliver good cold drivability and good fuel economy and performance, but not necessarily peak performance. If the engine is on a dyno, your exhaust gas oxygen readings can guide you as you monitor the A/F ratio at changing engine speeds. But the good news is that that original appearance is easy to restore. Slowly adjust the first idle-mixture screw. Along with these tuning tips, a check of your ignition system, as well as, the mechanical and vacuum advance curves in your distributor is suggested to eliminate any potential timing and ignition problems. 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. better idle, still a bit rich tho. What you are looking for is an increase or decrease in rpm. Im running a 3.5pv now with 68/79 jets with pretty close engine specs to yours. still waiting on MSD to get back to me with info on the vacuum can the 8365 distributors come with. As we mentioned earlier, a slightly rich mixture (12.8 to 13.1) usually produces the most power and torque. Closed-loop control can be programmed to either add or subtract up to a certain percentage of fuel in order for the engine to reach the target air/fuel ratio. If it helps, increase the jet sizes again to see if it helps even more. Brawler would like to congratulate and thank you for purchasing this carburetor. % This shops dedication to quality engine work, its growth, its machining capabilities and its impact in the diesel industry, all make Choate Engineering Performance well deserving of Engine Builders and Autolites 2022 Americas Best Diesel Engine Shop award. Bob (carb guru) says the carb looks like a really nice piece, and responded well to tuning. I'm going to hook up the vacuum advance to full manifold vacuum and then reset my base to 15 again. Place the vacuum secondary spring in the boss on the underside of the lid. 20 and changed the center cam in the distributor and got 33 total at 3,000rpm. It can also foul the spark plugs. It's now a long way from the endangered species list. If the engine feels sluggish when the driver steps on it, the carb may be going too rich or too lean. We need to determine the areas of the jets and the power valve restrictors. To improve our situation, we contacted the officials at Brawler about a four-barrel (4bbl) carburetor to replace the restrictive 2bbl. Luckily, several companies offer a simple conversion that will work with any 4160 or 4150 Holley carburetor equipped with an electric choke. Its true that a carburetor with larger throttle bores will flow more cubic feet per minute (CFM) than a carburetor with smaller bores. Now you are ready to check and re-set the idle mixture screws. To support the popularity of the Brawler carburetor it seems only natural to add rebuild kits and tuning parts for them. But if your vehicle has an adjustable pressure regulator, set it for the ideal 6.5psi. To keep within our space allotment, each of these tips will be quick takes, which unfortunately will leave some information on the table. Brawlers performance based race carburetors start off with a high flowing aluminum main body, and billet aluminum metering blocks that are packed with performance based air fuel calibration. Check price here Brawler Carburetor They offer the tune ability and trick options that you typically only find in more expensive carburetors. 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. The main circuit also includes emulsion tubes and air bleeds that premix air with the fuel to improve fuel atomization. Make these changes very slight and note the effect on the engine. An electric choke is available on some models and provides hassle free cold starts. Consequently, mechanical carburetors require constant fiddling and readjusting for prevailing weather conditions and track conditions. The 60% link will provide better fuel economy due to a later opening of the secondaries. The new products include non-stick gaskets, rebuild kits, power valves, needle and seats, and air bleed tuning kits. Are the fuel bowl inlet valves in good condition and not sticking or leaking? To access the carb must be inverted. thanks. changed all the plugs yesterday and reset the base timing to 20*. Next, the float level adjustment can be checked and adjusted if necessary. The Brawler name may be new but the carburetors themselves are a testament to the pat 100 years of carburetor research and development. The opening rate on mechanical secondary carbs can be changed with QFTs Quick-Link system that provides three links for a 40%, 60% and a one-to-one opening rate. Find Best Carburetor for Small Block 400 and about 400 sbc carb size. Before the engine starts, check the position of the idle mixture screws (located on either side of the metering block) by counting the turns on each one in until it lightly seats. Installing smaller jets will compensate for the difference. This is the idle stop adjustment for most Holley carburetors. Of course, this is also the perfect time for perhaps a upgrade or two to make the carb work as good as it will now look. Keep in mind that the meter readings are an average for all of the cylinders that are dumping exhaust into that pipe. QFT recommends an optimum fuel pressure of 6.5psi, (Maximum pressure of 7psi). Holley Brawler Carburetor Installation How-To and Basic Tuning Pole Barn Garage 26K views 11 months ago Setting up a rebuilt carburetor. It's best to start with the stock jet and PVCR combination first before you start tuning but this is a way to dial in the carburetion for what your engine really needs. Carburetors are amazing mechanical devices. Watch out for leaking or heavy floats. Dalton demonstrates just how simple and easy a carburetor can make your life bolt one on, make a few connections and simple adjustments, and you immediately get excellent throttle response and performance. This increases fuel flow making the idle air/fuel ratio extremely rich. 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. If your QFT doesnt have a choke it probably has a 4.5 power valve from the factory. This is Murphy's custom booster install tool that accurately positions the booster and flares the inlet in the main body flange. If you need a minor adjustment, be sure to shut the engine off and go through the adjustment procedure again. Carburetor tuning runs the gambit from simple idle speed and idle mixture adjustments, resizing main jets and fiddling with the choke adjustment (street applications only) to major modifications such as changing venturis, venturi boosters, air bleeds and emulsion tubes, metering blocks, accelerator pumps, cams and discharge nozzles, and power valves. Automatic chokes are supposed to make cold starting easier, but usually require some trial-and-error adjustment to find the best setting. The adjustment should be no more than an eighth or quarter turn. Electronic fuel injection is also self-tuning and is constantly readjusting the A/F mixture based on feedback from the oxygen sensors. This enriches the mixture when the engine is under load to maintain the A/F ratio. These are still great carburetors but you'd rather have the more race-inspired look of the 4150 style Holley with the secondary metering blocks. Their suggestion was a Brawler 570 cfm carburetor. Is the accelerator pump, pump linkage and power valve in good working condition, and properly matched for the application? Been playing with this for 2 months. If the idle speed is still too low, larger holes or two more in the secondary throttle blades can be drilled. Of course, if the opposite combination is what the engine needed, you could easily modify the PVCR system to tune in that direction as well. Set the idle mixture to the highest vacuum by using a vacuum gauge connected to the constant-vacuum port of the carburetor base plate. So check both pipes with a dual exhaust. Any carb that will bolt onto the manifold may be used and thats a real problem because a lot of guys over-carb their engines. If the carb will be subsequently used on a milder-cammed engine, it will probably not be possible to return the curb idle speed low enough because of the permanent holes. Your email address will not be published. I have a 385 in my Camaro, 11 to 1, Howards hydr roller (240-246 @ .050 with a 110 cl) AFR 195 heads and a street warrior air gap dual plane. After pulling the carb I noticed that the curb idle setscrew was completely off the lever. 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. There may be dirt or corrosion inside that can plug circuits and restrict fuel flow. There are many misconceptions about how to go about these adjustments, and of course there is no shortage of free advice. If an engine is hard to start, barely idles, coughs, bogs, sputters or stumbles every time the throttle opens, gets horrible fuel economy, spews black carbon from the tailpipe or never seems to run very well, chances are the carburetor needs to be tuned. Either condition can make the float sink and over-fuel or flood the engine. I want to do a little testing to see how much hooking up the vacuum advance actually advances the timing over the baseline. You'll likely have to reduce the size of the idle feed restrictions (IFR's) in the metering block rather than increasing the idle air bleeds (IAB's). If the main jets feel right and the engine is too rich under full throttle, then you can also reduce the size of the channel restrictions. EFI has many advantages thatallow us to dial in the fuel in a dramatically more precise fashion than was ever possible with a carburetor. Murphy has made his own fixture to hold the main body so he can mill not only both primary and secondary metering block surfaces, but also the throttle plate surface. Help with Quick Fuel 650 Brawler Tuning. Put a Brawler 750 DP on it in the car. This means the power valve will open at 8.5 inches of vacuum. Small adjustments (only a quarter of a turn) can make a big difference. If youre building an engine that will run on alcohol, is the carburetor properly jetted for alcohol (which requires a much richer A/F mixture) and additional corrosion protection). We thought we'd address a few common driveability issues that never seem to go away. 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 powertrain control module (PCM) controls the fuel mixture using inputs from the engines exhaust oxygen sensors, throttle position sensor, manifold absolute pressure sensor and airflow sensor. Check price here. HGM is the company that makes the very nice CompuShift controller for the electronically controlled overdrives. The fuel level should be exactly half way up the window. Dont let the budget-friendly price fool you, the Brawler development focused on the performance you want and not the pretty box that it comes in. On your engine, let's say someone (not you, of course) has messed with the carburetor and it now has 75 primary jet and an 85 power valve (71 jet is stock). The proper way to check fuel pressure is with the engine running at idle with the engine up to full operating temperature. But digest each of these and they will generate the energy to get your started on the path to pure Holley comprehension. There is a tip-over point between rich and lean where combustion is ideal. We planned to use the AEM Controller Gauge to assist in tuning our 570 CFM Brawler carburetor for power and economy. Murphy prefers later-model boosters with the gentler radius at the bend that improves flow and its inside diameter is slightly larger at 0.160 inch versus stock at 0.140 inch. Okay, now comes the fun part. Mechanical secondary carbs use a direct link to the secondary throttle shaft. They offer all the tunability that you would find from more expensive carburetors in the market, including four-corner idle adjustment on all models. it did seem to clean up, didnt have that cloud of fumes in the garage I normally do. on the dyno this thing made over 500 hp and darn near 500 ft lbs. Sean Murphy showed us how to do it without tearing the fragile rubber. A brand new carburetor from a major aftermarket supplier comes prejetted and preadjusted for the average engine it will be bolted onto. RetroBright LED Headlights offer plug & play compatibility, better visibility, and 6 times longer life over traditional sealed beam headlights. Set the back to 1000 rpm. This Holley Ultra XP and some older HPs employ a bypass idle circuit with an adjuster screw located underneath the air cleaner stud mounting boss. 2023 HOLLEY PERFORMANCE PRODUCTS, INC. ALL RIGHTS RESERVED. Start the engine and turn one of the idle screws in or out. But where is the love for the classic double pumper? fouls plugs like nobodys business, even tried E3 plugs. Higher altitudes and decreasing barometric pressure thin the air, which causes the carburetor to run rich. The first would be to lower the power valve opening point to 65 (which is stock at 6-1/2 inches Hg) that would open the power valve later when the engine vacuum is lower, with a greater load. The Brawler family of carburetors delivers bare-knuckled performance for daily drivers, race cars, and everything in between. Popularity also breeds carburetor misapplication, frustration, and the occasional bouts of misinformation. 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. If youre tuning a carburetor the old school way, test driving or taking a few hot laps will quickly tell you if the engine feels strong or not, and how well it responds to throttle changes. The newer HP and Ultra XP carbs come with screw-in restrictors. Before the actual tuning process, lets take a qlook at the various carburetor circuits and what they do: One of the most important things to always consider before you touch a carburetor is its history. The carb . Place the base on top of the vise and slide the diaphragm through the lower half until it sits flush. The crew shows how to save cold-hard-cash by overhauling an Edelbrock AFB-style 4 barrel performance carburetor. had a buddy from the dragstrip come down and tune it, this guy has been tuning and racing Holley carbs almost as long as I've been alive (50 this year). Vacuum secondary models are adjustable with a turn of a screw, allowing you to adjust the secondary opening rate with out replacing caps or springs. A continuing problem for street engines running big camshafts and lots of overlap is low idle vacuum. With the engine idling at normalized temperature, try leaning the mixture with a minor clockwise turn of both idle mixture screws. How you proceed from here depends on what kind of equipment you are using. Accelerator pump. 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. You bring the gumption. Make one adjustment only to the first screw. I've always been fascinated with cars and tools accessories. Just have fun with it and get the vehicle on the road and driving. Edelbrock 1906 vs 1406 Carburetor Edelbrock 1406 carburetorversus theEdelbrock 1906carburetor. Read honest and unbiased product . Dont let the pursuit of perfection ruin your project vehicle. Drivability is just as important, and that requires a lot of air velocity for instant throttle response and good low to mid-range torque. Position the rubber diaphragm on the base in the correct orientation. Hotter air is less dense than cold air, so the carburetor main jets usually need to be reduced in size to compensate so the engine doesnt run too rich. Chris Wright of Pro Car Associates and Greg Jones of Engine Builder review all that the Terminator X offers and why Holley has been a leader in this product category. Clamp the shaft in the vise and then carefully lower the lid in place. Theres no choke to restrict airflow into the carburetor, and the venturis, boosters, metering blocks, fuel bowls and throttle plates may all be heavily modified to deliver the kind of performance a race car driver expects. Stay up to date with the latest releases, events, promotions and more. For a lean condition, go to a larger squirter size; if the engine is running on the rich side, go to smaller squirter size. I looked last night but cant find my dyno sheet. It even raises my vacuum up from 5hg to 9hg in park and 6.5hg in drive at 800rpm. If it doesn't, the linkage is improperly set. In case you're taking notes, the secondary metering block is the main difference between 4160 and 4150 carburetors. Tools Bible is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising & linking to Amazon properties. ex 0.437 int lift 0.454 ex lift. Blip the throttle to 2300, no more. But if its a used carburetor, beware because a lot of unpleasant surprises can be lurking inside: The bottom line is you need to make sure the carburetor youre going to use is in good working condition and hasnt been screwed up, otherwise you may never get it to work well. I recently started a blog about welding gear.I am also a DIY welding enthusiast because it is affordable for any household work. The full Installation Instructions appear below. this thing runs SO pig rich I cant stand to be in the garage with it running. These carburetors work hard just as their name implies just raw bare knuckled performance that you can rely on. cant get more than about 7-8" of vacuum out of it. 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. An increasingly popular swap is to use the electronically controlled 4L60E or 4L80E automatic overdrive transmissions in older muscle cars. gonna call my builder today and see if he has any info. Of course, you can also just convert the carb to a 4150 style with the metering block and retain the stock single inlet configuration. The way to do this is to have your vehicle on level ground and with the engine running at an idle. Intake has a fully divided plenum, which is why I am running a 1/2" open spacer under it. We provide how-to and technical articles, vehicle and build features and examples, plus calculators and lookups that will help you get your ride from dream to driver. If it surges, it is probably lean and will require jetting up. When making adjustments -turn at a time is a good way to proceed. The float opens and closes a needle valve that allows fuel to enter the bowl. Dalton at Pole Barn Garage wonders where all the love is classic double pumpers? Street models are available in variations from 650 to 850 CFM Carb in both vacuum and mechanical secondary versions to meet any of your needs. When Holley redesigned the Ultra XP line of carburetors, they added an adjustable air bypass feature located underneath the air cleaner stud. This shows the curb idle set with a large exposed portion of the transfer slotthis is bad and will cause not only an overly rich idle mixture but also an off-idle stumble. Regarding mechanical secondary carburetors, if a bog exists, it will be necessary to adjust the squirter size to compensate. 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. Will put my AR3924 plugs in it, bump up the initial timing to 20 and see what happens. 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. I have dabbled some filler material at the ends of the slots before to shorted up the slots. The one thing you want to avoid is going too lean (especially at high RPM) because a lean fuel mixture is a prescription for detonation, preignition and burned pistons. Typical highway driving is done on the main circuit of the carb where the air/fuel ratio is largely determined by the main jets. If idle speed increases, lower it by closing the idle speed adjustment. The conversion kit (foreground) replaces the metering plate like on the 4160-style carb on the left and replaces it with a metering block like the 4150-style carburetor on the right. Ive got the idle set at 1000 rpm with the vacuum advance hooked up to manifold vacuum. The information supplied above should get your carburetor and engine in sync and pretty happy with each other. The full Installation Instructions appear below. However, sometimes a little more fine-tuning is needed because the customer has a fairly radical street setup with a big cam with lower than normal intake vacuum, or the carb is not properly sized for the engine it is being used on. Who doesnt like a little bit of burnt rubber? A 10-degree temperature change one way or the other may require increasing or decreasing the jets by two to four sizes. We've seen the standard accelerator pump diaphragm become brittle with age. changed idle air bleeds to lean it out. The equipment does exactly what it needs to, his team is experienced and the shop has built thousands of vintage engines for customers everywhere! This TPS can also be used for data logging for autocross racers who want to look at throttle position on track through the course. Black carbon deposits on the center insulator and electrodes would indicate an overly rich A/F mixture (or the spark plugs are too cold for the engine). 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. Much of this is determined by the tightness of the converter. Youll need it! These kits are inexpensive and are incredibly helpful when tuning PVCR's. 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 customers expectations. 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. Is the carburetor body, top plate and throttle housing flat and free from fuel or vacuum leaks? These components are usually necessary for most street driven vehicles, especially in cold climates, but can usually be eliminated in most racecar applications. Intake is a stealth. For a better experience, please enable JavaScript in your browser before proceeding. I have not had the greatest of luck with these, either the customers got "blems", or just a run of bad luck.but a 1/2 dozen in a row.I'll leave it at that. Thats where the power valve circuit comes in. I'll post back over the weekend with results. 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.