The float level is important because the fuel level inside the bowl affects how much fuel flows through the main metering circuit. For those who know Holley carburetors, if you have a choice about which carburetor to buy, the recommendation is to always go with a carburetor with dropped instead of straight leg boosters. Bob (carb guru) says the carb looks like a really nice piece, and responded well to tuning. 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. Make these adjustments turn at a time. I road race mine and use it. Start the screws lightly to avoid winding up the diaphragm, which could tear the rubber. If anyone has more ideas, please feel free to post. 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. on the dyno this thing made over 500 hp and darn near 500 ft lbs. If the engine decreases rpm when you are adjusting the others, take them all back to the original setting, because the settings were already correct. You must log in or register to reply here. Their suggestion was a Brawler 570 cfm carburetor. Heres a quick how-to that covers installing a new Holley Brawler double-pumper carburetor. <>/ExtGState<>/Font<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> No sweatthere's a conversion kit for that. 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. 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. Brawler carburetors are precision-machined and hand-assembled by craftsmen right here in the USA. The Brawler carburetor product line has expanded to include rebuild kits and tuning parts. EFI has many advantages thatallow us to dial in the fuel in a dramatically more precise fashion than was ever possible with a carburetor. We planned to use the AEM Controller Gauge to assist in tuning our 570 CFM Brawler carburetor for power and economy. Inside the fuel bowl is a brass, hollow plastic or foam plastic float that maintains the fuel level. it will idle at 900 in park, 800 in gear. MSD did say the timing would start advancing at 7", and thats all I have so I guess par for the course. To support the popularity of the Brawler carburetor it seems only natural to add rebuild kits and tuning parts for them. One of the requirements for this conversion is it requires a throttle position sensor (TPS) signal to work properly. These components are usually necessary for most street driven vehicles, especially in cold climates, but can usually be eliminated in most racecar applications. Check Worlds Original High-Performance Carburetor Holley 1850 vs 4160 Click for more about theHolley 1850, Holley 4160 carburetors. The way to do this is to have your vehicle on level ground and with the engine running at an idle. Drivability is just as important, and that requires a lot of air velocity for instant throttle response and good low to mid-range torque. Of course, you can also just convert the carb to a 4150 style with the metering block and retain the stock single inlet configuration. If idle speed increases, lower it by closing the idle speed adjustment. 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. The carburetor will also deliver the optimum air/fuel ratio throughout the engines RPM range to achieve peak horsepower and torque. revs quick and starts right up and idles whether its cold or at running temp. Float. After you have attained the highest rpm possible, you might have to turn down the idle adjustment on the throttle linkage to get the correct idle speed you want. Best Tuner for 6.0 Powerstroke [Review and Buying Guide]. This includes the choke, fast idle cam and linkage, and fast idle adjustment screw. JavaScript is disabled. Holley makes several kitsmainly for either the 0-3310 750 cfm or the 0-1850 600-cfm carbs. 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. 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. 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. just crazy rich. Here's the trick to assembling that tricky vacuum diaphragm canister. better idle, still a bit rich tho. Edelbrock 1906 vs 1406 Carburetor Edelbrock 1406 carburetorversus theEdelbrock 1906carburetor. A low fuel level can make the A/F ratio run lean, while a fuel level that is too high can make the carburetor run rich or even flood the engine with fuel. This enriches the mixture when the engine is under load to maintain the A/F ratio. Brawler carburetors are loaded with the latest technology in air fuel calibration to meet the demands of today's street, strip, and race engines. Running 6.5 psi fuel pressure, floats are set correctly. 236-244 cam 10.5:1 compression, 213cc profiler heads. Required fields are marked *. If it helps, increase the jet sizes again to see if it helps even more. A vacuum-sensing power valve opens when intake vacuum drops to allow more fuel flow through the main metering circuit. fouls plugs like nobodys business, even tried E3 plugs. 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 you've ever tried to change the vacuum secondary spring in a Holley diaphragm module, you know it requires dexterity and patience. The first step is to obtain a low-speed tach that will show minor changes in rpm along with a vacuum gauge. One is to preadjust the idle mixture screws to about one full turn out. this thing runs SO pig rich I cant stand to be in the garage with it running. If the engine feels sluggish when the driver steps on it, the carb may be going too rich or too lean. However, setting the vacuum secondary opening point requires trial and error road testing of the vehicle. 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. Most performance engines will need to be richerusually around 13.5:1. 540hp small cubic inch and close to 600hp with 400 cubic inch, all on pump gas. Yet when additional throttle is added for light acceleration, the engine stumbles. Leave the locking screws for the choke housing cap slightly loose so the choke can be easily readjusted as needed. Read honest and unbiased product . 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. This is near a lean mixture as long as the idle is stable. 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. Was nowhere near close out of the box. 4 0 obj If it does not, look first for slack or clearance between the vertical accelerator pump linkage arm and the lever that moves the actual accelerator pump diaphragm. With a dyno, you can see whats happening with the A/F mixture, horsepower and torque curves as the engine makes a pull. vacuum was still only at 7, with a 1,000 rpm idle. Rusty but Rare 1976 Chevy K10 Sport Truck Revival! According to Jeff Teel from Holley, the Brawler carburetors are geared towards anybody looking for a high-caliber carburetor for their induction needs. Keep in mind that the meter readings are an average for all of the cylinders that are dumping exhaust into that pipe. If the secondary side opens too quickly the engine will bog. So if you get a 12-inches of vacuum reading, you need a #6 power valve. Position the rubber diaphragm on the base in the correct orientation. The rule of thumb is for every 5000 ft. change in elevation, compensate by 3 jet sizes. I used to use a lot of initial timing too but you have to limit the amount of advance or you could end up way above 50 total while cruising light throttle.just saying be mindful of the total as the HEI dizzys have a lot of advance built into them and need to be limited by closing up the slots in the advance plate by some margin. Power enrichment circuit. The crew shows how to save cold-hard-cash by overhauling an Edelbrock AFB-style 4 barrel performance carburetor. Accurate tuning of the idle mixture with a combination of a vacuum gauge and sensitive tachometer can offer excellent resultsand the best part is these tuning efforts cost nothing to achieve. The carb . However, if engine rpm stays consistent or increases when you equalize the remaining screws, make another turn adjustment on the first screw and adjust the others to match. Understanding Holley Vacuum Secondary Carburetors, How To Choose A Regulator For Carbureted Vehicles. Holley Brawler Carburetor Installation How-To and Basic Tuning Pole Barn Garage 26K views 11 months ago Setting up a rebuilt carburetor. Make these changes very slight and note the effect on the engine. One way to do that is to increase the size of the power valve channel restrictors. Brawler BR-67199 Race Carburetor, Mechanical Secondary, 650 CFM. Over the decades, tribal knowledge has determined that many carburetor-related issues come down to vacuum leaks, ignition, or fuel delivery problems unrelated to the carburetor. The carburetor is a Holley Brawler 570. Zach says that .005 change in size will be a noticeable difference. Help with Quick Fuel 650 Brawler Tuning. If the idle speed and vacuum increase, continue with similar changes in small increments until the idle speed or vacuum deteriorates. Drag Racing 101 ~ Everything You Need to Know! Electronic Fuel Injection (EFI) is all the rage today and rightfully so. Dual inlet fuel bowls are not included in the kit but you can add them at the same time. 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. If the engine doesnt hesitate or bog under acceleration, the secondaries could be opening too late. Obtaining a good idle can be a challenge with a long duration cam because of the reduced intake manifold vacuum, so the best you can do is aim for an idle mixture and speed that keeps the engine from stalling. Im running a 3.5pv now with 68/79 jets with pretty close engine specs to yours. 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. Set the front an additional 400 for 1400 total. Make one adjustment only to the first screw. Our original factory '60s Holley was haggard looking.