Holley Vacuum Secondary Not Opening

For the record, Holley says this spring should begin opening the secondaries around 1650 rpm and reach full open around 6000. Your right, Holley does not show a 4150 on their website with vacuum secondaries and none of the part #'s on my carb match any of those on Holley's website. render that inoperable. Holley Vacuum Secondaries Not Opening On Dual Quad Setup The primary is an 1850 600 cfm, and the secondary is an 8007 390 cfm. The only carbs that I can think of that are considered vacuum operated secondary four barrel's are the Holley's and the old Autolite carb used in the 60's that also used a vacuum pod to open the secondaries. Holley makes a. A lighter spring will allow the secondary throttle plates to open more quickly. And there are a number of 4150 variants with vacuum secondaries. I took the brand new carb apart a couple of times. Holley carburetors feature idle mixture screws which control the air/fuel ratio and these are usually the main culprits in an improperly idling carb. If you have an automatic transmission you will need a vacuum sec. If there is a strong manifold vacuum, it SECONDARY JET ruBE SECONDARY MODEL acts the economizer diaphragm to keep the power valve closed, When vacuum reduced below a certain point, the power valve opened, enriching the mixture. I do not get the loud moan under full throttle conditions even with the air cleaner removed. However if you plan to replace the production 2- or 4-barrel carb, this is one of the most popular choices. The chief complaint made by most always has to do with the slow speed or late timing in the opening of the secondaries. A "lighter" spring will allow the secondary throttle plates to open more quickly. Model 4160 carburetors are almost always vacuum secondary designs, but manifold vacuum does not actuate the vacuum secondaries. ) don't start to open the secondaries until 40-45 degrees of primary throttle opening. Was guided to the 20-28 replacement covers to equalize the vacuum between the two housings - now neither open. Secondary adjustment is set with a screw accessible from the underside of the carburetor. If not, the power valve opening can be blocked with this simple block-off plug from Holley (P/N: 26-36). Saying that using the 1/2 idle vacuum rule/use in a 6. Buy Holley Vacuum Secondary Diaphragm with fast shipping and top-rated customer service. Simple removal but be sure to put gasket between intake and carb on right. These classic Holley 4 barrel carbs features all metal parts and vacuum secondaries. Holley 4160s can also be changed into 4150s with the purchase of a changeover kit. the guy said the secondaries were not opening. The unique fuel metering block eliminates fuel spillover through the boosters at extreme angles allowing for 40 degree climbing, 30 degree side hill maneuvers and nose-down descents to avoid hesitations, stalling and flooding typically associated with carbs in an off. With the engine off open and close the secondaries, it should move smoothly and you should hear the air going in and out of the vacuum secondary diaphram. At WOT, The 'rod' that connects the primary to secondary runs in a slot in the secondary. There is no vacuum available to operate a vacuum advance at full throttle, and very little at 3/4. Remove the existing carburetor by the following procedure: A. Secondary vacuum chamber. 780---> Side view of secondary vacuum linkage/manual choke if equipped as on the 3310. You can "manually" test your secondaries, but you'd be doing it "mechanically", not by vacuum. It may not be a double pumper, but thats is what Indmar told me it was. If it has Vacuum secondaries Holley makes different springs to open them sooner. You have no items in your shopping cart. Holley has been the world leader in carburetors for over 100 years. If you have adjusted the secondary already or by mistake then try to get it back to as close to being closed as possible. Measure the spring movement by seeing how far the paperclip moved. Holley offers an inexpensive kit with seven springs that offer a broad range of opening points. B 6-05-04 How to Tune a Holley (basic) by Lars Grimsrud Colorado Corvette Crazies (CCC) The Ultimate Corvette Tuning & Beer Drinking Fraternity Lafayette, CO This tech paper will discuss basic set-up and tuning of Holley vacuum secondary carbs for optimum street performance and drivability. If your distributor uses timed vacuum advance, connect its vacuum hose to the passenger side vacuum port. It's they have a problem telling they open since you can't open them with the car in park in the driveway. The chief complaint made by most always has to do with the slow speed or late timing in the opening of the secondaries. Holley offers some tips on how to properly operate and adjust four-barrel carburetors with vacuum secondary throttle blades. I ran twin 450 Holleys on ours, at 5200 and about 400hp, it would open both secondaries about 2/3 of the way open, so I figure it was using about 750cfm worth of throttle plate. Provides springs of various rates to allow the racer to custom tailor the vacuum secondary opening and closing rate to best suit their combination Contains seven springs color coded from light to heavy Instructions included *Not legal for sale or. We offer a variety of Holley Vacuum Secondary for your automotive needs. The secondary fuel bowl leaked , 2 of the screws were loose. I looked very carefully to verify this. The vacuum secondary should be held partly open at idle by a small lever that rests against an insignificant looking adjustment screw on the bottom of carburetor body just below the vacuum diaphragm body. Holley makes a number of different springs with different tension on the springs. i was checking out another forum, and there was a thread about the little check-ball in the vacuum secondary pod thing. Then your secondaries will open for sure. This made it easy. When it was done I had a balanced and blueprinted motor with new pistons, completely rebuilt heads with new larger valves (781 heads), Comp hydrau. double pumper). Gold Dichromate finish for corrosion resistance and classic Holley looks Vacuum secondaries for use on wide variety of boats. WARNING: Carefully protect the open end of the fuel lines, so that no foreign particles can enter. I briefly made mention to a LIST-6947, D5TE-9510-EA Holley/Ford vacuum secondary 4-barrel above, that could be the beginnings for a blow-thru application, but now see and realize since disassembling it, that it's got the same design features as other under-carbureted Ford carburetor scenarios of a too small carburetor on large workhorse engines. Tunable to provide the ultimate in performance. My white '74L came with a model 3310S Holley 750 vacuum secondary carb. PART# 121241 FORD. The secondaries still won't open. You can "manually" test your secondaries, but you'd be doing it "mechanically", not by vacuum. Any vacuum amount below this level opens them. It is important to understand that the bimetallic coil does NOT open the choke. How to Select the Right Holley Carburetor for Your Car it's simply easier to go with one that's equipped with a vacuum secondary system; the secondaries open. Not all Holly's have mechanical secondaries. Compensate for all vehicle weights, gearing & transmissions to allow smooth opening of secondaries. Not every situation is going to allow WOT use to ensure there is adequate vacuum drop to open or keep the power valve open. This second orifice becomes active when the secondaries begin to open creating vacuum in the secondary venturi. HOLLEY STREET WARRIOR Carburetor,600 Cfm,4160,4Bbl,Manual Choke,Vacuum Secondary - $423. The secondary airvalve on the Q-Jet effectively makes the Q-Jet a variable-cfm carb. Actuallly, I did experience a stroker big block running vacum secondaries this past summer. Re: Holley vacuum secondaries bogging. On carbs that have a vacuum operated secondary, the secondary vacuum chamber is important to the function of the carb. I have checked the diaphragm with a vacuum guage and it operates and holds vacuum. Buy Holley Vacuum Secondary Diaphragm with fast shipping and top-rated customer service. Vacuum secondary carburetors use a vacuum diagphragm to open using engine vacuum signals to let the engine "tell" the carburetor it needs more fuel under acceleration. Holley offers some tips on how to properly operate and adjust four-barrel carburetors with vacuum secondary throttle blades. Holley offers an inexpensive kit with seven springs that offer a broad range of opening points. It has vacuum secondaries and electric choke, so it is useable on a wide variety of vehicles and its single fuel inlet that is in the standard Q-jet location makes it easy to bolt on. pressure and adjust the regulator, if applicable. 4150 means it has metering block on the secondary side as well. Power valve blow-out protection. Compensate for all weights to allow smooth opening of secondaries. The vacuum secondary Holley uses a different approach to secondary actuation, where the secondary throttle blades are controlled by engine demand via the secondary vacuum diaphragm assembly. Note the cork gasket, if this isn't installed then the secondaries will not open & you will have a vacuum leak. Does not come in retail packaging. Adjust the Opening Point of Vacuum Secondaries The opening rate of a vacuum secondary system is controlled by the diaphragm spring located in the vacuum secondary diaphragm housing. At the same time, you want the valve to open any time you're much over half throttle. I would like to hear from those that are using Vacuum Secondary and Mechanical Secondary carburetors. The street advantage of the VS is that it acts like a load-sensing compensation for secondary opening. The often-perceived reduction in performance because of secondaries that do not open right away is mostly a myth. It does not open the secondary at all. 3310 - Remove side choke mount and note paper gaskets and replace from kit. I have verified the secondary's won't open. The vacuum secondaries are controlled by a diaphragm and a color coded spring. The carb had a tag on it when I got it saying it had been "remanufactured by Holley" - though I have no idea when that was done. This ensures the secondaries will open fully on most applications. Holley 135-4 Vacuum Secondary Diaphragm It didn't leak. Questions are as follows: 1. However, it's not a 4160, the Truck Avenger is a 4150 with vacuum secondaries, electric choke, side-hung float bowls, and metering blocks with replaceable jets on both the primary and secondary sides. The secondary throttle stop screw is also only seen with the carb off the engine and inverted. The solenoid is open all the time and is controlled by a micro switch so when you get to 3/4 throttle it closes. Same as Stage 1 plus: Secondary Metering block installed to allow tuning and to balance the primary's and secondary's, fuel delivery characteristics for maximum cylinder to cylinder distribution. How to Tune a Holley (basic) by Lars Grimsrud SVE Automotive Restoration Musclecar, Collector & Exotic Auto Repair & Restoration Broomfield, CO Rev. I put the carb on the car, started fine, idles fine, runs at any speed as long as I didn't get on it too hard. Gold Dichromate finish for corrosion resistance and classic Holley looks Vacuum secondaries for use on wide variety of boats. How To Tune Holley Carburetors. the proper way to mod the Holley carb for the low vacuum big cam setups is NOT to open the secondary but to drill small holes in the primary throttle blades to allow more air to enter without opening the blades onto the transfer slots. A vacuum secondary carb means the secondary. It came with an 850 on it and was very dingy and dirty so I opted to use my "800" that I had on my old engine(476ci). At WOT, The 'rod' that connects the primary to secondary runs in a slot in the secondary. Classic Industries offers a wide selection of 1978 Pontiac Firebird parts, including 1978 Pontiac Firebird interior parts and soft trim, 1978 Pontiac Firebird exterior sheet metal, 1978 Pontiac Firebird moldings, 1978 Pontiac Firebird emblems, 1978 Pontiac Firebird weatherstrip and unique accessories, to nearly every nut and bolt needed for installation. This is where the vacuum comes from. - Single feed fuel inlet for easy installation. Saying that using the 1/2 idle vacuum rule/use in a 6. As popular as it may be, the vacuum secondary carburetor is not without its own set of problems. you also know that not all the vacuum are not the same. Questions are as follows: 1. Holley 20-59 - Holley Vacuum Secondary Carburetor Accessories Once you get the vent point moved to the center of the bowl (instead of the back wall) you don't get NEARLY as much flooding from the front bowl when going UP hill, Get the opening of the vents up off the Venturi body and the fuel can't spill into the Venturis like it did before. Thus, if the engine can’t handle all of the cfm, the secondaries simply don’t open all the way. Refrain from the old small bolt in the linkage trick to manualy open them, cuz the vacuum design will not add power but rob power. The secondary metering body on the 4150 carburetor is similar to the primary metering body. A fellow here in Atlanta said they are not, and offered to rebuild it for $160. In vacuum actuated carbs, the secondaries open up only when the vacuum across the primary venturis reaches a certain level. This lets in too much air and not enough fuel. the guy said the secondaries were not opening. 5 PV will cause a rich condition due to valve opening at cruise load. The only carbs that I can think of that are considered vacuum operated secondary four barrel's are the Holley's and the old Autolite carb used in the 60's that also used a vacuum pod to open the secondaries. Holley's materials state that the check ball is only used in carbs in which the check ball sits on a hole which has. To be used with a OPEN plenum intake design. Explain to me no secondary jets on Holley 390 the carb uses vacuum secondaries? circuit to the hi speed jet circuit and uses vacuum to open / close. even if they are not needed Vacuum operation of the secondary throttles relates their opening point more closely to the. Plus, the carburetor now has a much more aggressive, performance image. trick on the vacuum secondary rod to see if the secondaries were opening properly. It does not open the secondary at all. Power valve blow-out protection. Now, secondaries that use vacuum to open. The long vacuum hoses for the outboard carbs need to be exactly the same length. I looked very carefully to verify this. Most vacuum secondary carburetors determine the rate of opening with different spring tensions - to change the rate you have to disassemble the housing and change the spring. If you have the plugs out, check the compression and see what you have to work with before spending a lot of money. The chief complaint made by most always has to do with the slow speed or late timing in the opening of the secondaries. Re: Holley vacuum secondaries bogging. He said for me to just ship it in to them and he will send me a carb that will work better for my application. Very limited quantities available. Additional parts may be required. Holley Carburetor: Idle and Transition Circuit Calibration Guide July 27, 2015 by Muscle Car DiY At the risk of sounding repetitive, let me say once again, that if you bought an application-specific carb, you probably are only going to need to do minimal adjustments to mixture calibration. The Secondary metering system is con- trolled by the secondary throttle plate position. This second orifice becomes active when the secondaries begin to open creating vacuum in the secondary venturi. However, some carburetors may be fitted with a secondary power valve which can be used if additional fuel is demanded on the secondary side. Fuel Injection, Carburetion & Fuel System - Secondaries Won't Open on Holley - I put a new Holley 600, vacuum secondaries, on my Windsor a few days ago and I got it running good. Don't bother trying to adjust your vacuum secondary springs without this piece. The most popular street carburetor in the hot rod world is probably the 600-cfm Holley vacuum secondary carburetor, otherwise known as the 0-1850. The secondary,s take for ever to fully open up. Ford Galaxie forum, Galaxie message board, This forum is for discussion specific to the Ford Galaxie all years and other Full-size-Ford Lincoln and Mercury cars. It will be noted that the quantity of fuel being discharged from the idle and secondary idle discharge holes has diminished due to the wider throttle valve opening resulting in a decrease of intake manifold vacuum acting on these holes. Off-Road Truck Avenger Carburetor by Holley®. That may be the best solution, I assume the pickup bleed in the secondary venturi is open. Sounds like we have (I had) the same project. The carburetor has several external ports and inlets. It came with an 850 on it and was very dingy and dirty so I opted to use my "800" that I had on my old engine(476ci). Disconnect the rod that runs from the primary shaft to the secondary shaft, the vac sec carb will have one too, it's purpose is to close the secondaries when the primary throttle is closed. the secondaries, since the PV is wide open any time the secondaries are open anyhow. Nozzles, plastic cams, vacuum secondary springs. Modifying the Holley Teapot four barrel carb for late model distributors March 2, 2013 Ted Eaton 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. This quite often occurs again when the carb is too big for the displacement, vacuum signal, or compression ratio, and the only real crutch for this is to adjust the secondary butterflies stops a bit open to get more air, to allow closure of the primary butterflies sufficiently to cover the transition slot which will help make the idle mixture. Dual feed fuel inlets assure you get all the fuel you need while its vacuum secondaries and electric choke make it amazingly universal. I purchased the engine as a rebuilt unit that had not been fired yet. How to Select the Perfect Holley Carburetor for Your Car used with a 750 vacuum secondary Holley works well. I'm looking to raise the idle to 1250 RPM or so, is it correct to open both blades evenly via idle screws or to only open the primary side?. Holley four-barrel carburetors first appeared on the Corvette in 1964. It didn't boost performance of the motor by 50 HP, but then it's a. Explain to me no secondary jets on Holley 390 the carb uses vacuum secondaries? circuit to the hi speed jet circuit and uses vacuum to open / close. I need some advice on what to look for. ADJUSTING THE OPENING POINT OF VACUUM SECONDARIES. Vacuum secondary operation depends on spring pressure and intake manifold vacuum at wide-open throttle. They could seem like they’re spreading cheer, however holiday e-cards may pack a hidden punch. We'll take you through the entire process in the slide show below:. Not a simple way to go. Properly adjusted vacuum secondaries will not cause a kick in the pants feel as so many expect. with a 5 speed and 12 bolt posi with 4:11's. The previous owner had it jetted very rich but it still bogged like it had a bad accelerator pump. (experience). The trick here is to size the power valve roughly 1. Classic Industries offers a wide selection of 1978 Pontiac Firebird parts, including 1978 Pontiac Firebird interior parts and soft trim, 1978 Pontiac Firebird exterior sheet metal, 1978 Pontiac Firebird moldings, 1978 Pontiac Firebird emblems, 1978 Pontiac Firebird weatherstrip and unique accessories, to nearly every nut and bolt needed for installation. You have no items in your shopping cart. are more for AT ? Videos show you could by a small supply store of parts to tune. It is important to understand that the bimetallic coil does NOT open the choke. Most DPs, (4776, etc. This makes your secondary opening rate all messed up, because the spring is not acting on the diaphragm correctly. You do not have the ability to run a secondary accellerator pump, this will cause a giant bog. On a different Holley carb, I can manually open the secondaries, and they slowly return to a closed position. There is no vacuum available to operate a vacuum advance at full throttle, and very little at 3/4. NOTE: The Street Avenger Carburetor kit has not yet been submitted for emissions testing and therefore, has not received an Executive Order Exemption from the California Resources Board. We show you the best applications for this. Secondary Vacuum. php(143) : runtime-created function(1) : eval()'d code(156) : runtime. The Quick Set Adjustable Vacuum Secondary Housing incorporates a "Purple" spring. Do noT put a screw in the linkage of a vacuum secondary carburetor to mechanically "force" open the secondary throttle plates. Remove the existing carburetor by the following procedure: A. This ensures the secondaries will open fully on most applications. Probably not enough for most vac cans. Was guided to the 20-28 replacement covers to equalize the vacuum between the two housings - now neither open. carb, a standard transmission can use a Double Pumper carb. The Holley does not have such a system your main jets are what you run for both cruise AND WOT, with only a power valve dumping "more fuel" into the cylinders at a pre-set vacuum reading. This is one reason why the vacuum secondary is so superior to the secondaries used in AFB and quadrajet. Home > • Carburetor Parts & Accessories > Holley Carburetor Parts > Vacuum Secondary Parts > BIG- 10258 Holley 4150 & 4160 Vacuum Secondary Adjustable Spring Kit & Open Chart Price Your Price: $16. Street carburetors perform well with vacuum secondaries, as the secondaries only open when there is demand for additional air. I am running a three speed with OD. Edit: Do not attempt to make your vac carb mechanical. My problem is the secondaries are not opening up like they should, maybe not at all. And there are a number of 4150 variants with vacuum secondaries. The truck was very low on power when I bought it-- I did a full tune-up and rebuilt the carb with a geniune Motorcraft rebuild kit. The chief complaint made by most always has to do with the slow speed or late timing in the opening of the secondaries. Vacuum secondaries for use on wide variety of vehicles. Thus, if the engine can’t handle all of the cfm, the secondaries simply don’t open all the way. date code numbers don't break down to tell which decade. Q- Series Carburetor 850 CFM BLOWER GAS DRAG RACE CARBS- Built for the ultimate blend in performance and drive-ability. Holley 4160 Style 600 CFM Classic Carburetor Increase street performance and horsepower in your 1979-85 Mustang 5. Adjust the Opening Point of Vacuum Secondaries The opening rate of a vacuum secondary system is controlled by the diaphragm spring located in the vacuum secondary diaphragm housing. Only problem is vacuum secondaries are NOT opening. Shop with confidence. The two primaries on those carbs would get you about 540cfm so it should want to open the secondaries a little bit but probably not too far. There are a number of ways to tune the moment when the vacuum secondaries open on a Holley four barrel carb. Carburetor Troubleshooting Guide. At the same time, you want the valve to open any time you're much over half throttle. eta- 8" of vacuum from what I know isn't a whole lot at idle, it's supposed to be a lot more. Inlet features built in hose barb for use with 3/8" hose and a 1/8" NPT port for attaching a fuel pressure gauge. Secondary vacuum chamber. This ensures the secondaries will open fully on most applications. The carb had a tag on it when I got it saying it had been "remanufactured by Holley" - though I have no idea when that was done. Am I just over-carbed?. Turn off the car and the leak starts again???. In vacuum actuated carbs, the secondaries open up only when the vacuum across the primary venturis reaches a certain level. (That's the rod that comes out the bottom of the secondary diaphragm housing) That will open the secondaries, and the engine will rev higher. 1) Find the vacuum leak & fix it. Re: Holley vacuum secondaries bogging. The chief complaint made by most always has to do with the slow speed or late timing in the opening of the secondaries. WARNING: Carefully protect the open end of the fuel lines, so that no foreign particles can enter. All signs look like it's a knock-off being packaged up and sold as Holley. The secondary set of throttles can be actuated mechanically with simple linkage or through a vacuum-operated opening that is controlled by a large diaphragm hooked to the secondary throttle linkage. Vacuum secondary carbs do NOT have separate secondary accelerator pumps, and never have had them. I've put a cable tie around the secondary diaphragm plunger to see how far they are opening and after a fast run down the road it appears that they are not opening at all. The linkage is re-worked so the pressure on the diaphragm would open the secondary while the spring would tend to close it, and you have to put a restrictor in the boost line to the diaphragm to slow the opening. There is a stop screw on the bottom of the carb to do this. On carbs that have a vacuum operated secondary, the secondary vacuum chamber is important to the function of the carb. I purchased the engine as a rebuilt unit that had not been fired yet. I've got a new Holley 750 w/vaccuum secondaries on the 350 in my 68 Malibu. ) Holley has a kit for tuning the vacuum secondary, different springs. DO NOT gouge the intake manifold sealing surface during removal of old gasket material. This second orifice becomes active when the secondaries begin to open creating vacuum in the secondary venturi. We are proud to announce the newest member of our carburetor family- the Street Warrior. The engine needs to be under a load before they will open. The often-perceived reduction in performance because of secondaries that do not open right away is mostly a myth. I know because I hard strapped the secondary throttle shaft to stay closed, drove it to WOT. NEW IDLE-EZE BASE PLATE 1 3/4 WITH GASKET *WITH THE FORD KICK DOWN LINKAGE* FITS THE SPEED DEMON 850 VACUUM SECONDARY CARBS, The Idle-Eze™, a new patent-pending concept from Barry Grant’s carburetor manufacturing division, Demon Carburetion of Dahlonega, Georgia, provides the simple solution. Nozzles, plastic cams, vacuum secondary springs. I am assuming it is an anti back fire ball check to save the diaphram. RaGG-exactly when does the problem occur? At a. Adjust the Opening Point of Vacuum Secondaries The opening rate of a vacuum secondary system is controlled by the diaphragm spring located in the vacuum secondary diaphragm housing. The only carbs that I can think of that are considered vacuum operated secondary four barrel's are the Holley's and the old Autolite carb used in the 60's that also used a vacuum pod to open the secondaries. The secondary jetting can now be easily tuned using the same jets for both primary and secondary. Ford Galaxie forum, Galaxie message board, This forum is for discussion specific to the Ford Galaxie all years and other Full-size-Ford Lincoln and Mercury cars. Not finding what you're looking for? Save holley vacuum secondary cover to get e-mail alerts and updates on your eBay Feed. If not, the power valve opening can be blocked with this simple block-off plug from Holley (P/N: 26-36). If you have adjusted the secondary already or by mistake then try to get it back to as close to being closed as possible. At the same time, you want the valve to open any time you're much over half throttle. This second orifice becomes active when the secondaries begin to open creating vacuum in the secondary venturi. The Secondary metering system is con- trolled by the secondary throttle plate position. Secondary adjustment is set with a screw accessible from the underside of the carburetor. On carbs that have a vacuum operated secondary, the secondary vacuum chamber is important to the function of the carb. render that inoperable. so i went and bought a holley secondary spring kit just for fun because i had my friends 670cfm truck avenger on my engine for a while and that thing would kick when the secondaries came in and it PULLED (with no secondary spring tuning)but i never felt this with my 770 truck avenger. Automatic chokes use a bimetallic coil to close the choke plate, and vacuum to open the choke plate. Secondary Vacuum. The new carb came in the mail yesterday and it was the Holley 770cfm vacuum secondary street carb. Variations are dual accelerator pumps, type of bowl and inlet. This quick walk-through will get your Holley carb up and running with a perfect idle in no time. 10 gears, Performer RPM intake. Probably not enough for most vac cans. I've put a cable tie around the secondary diaphragm plunger to see how far they are opening and after a fast run down the road it appears that they are not opening at all. As for a 650vac being to big on a 308 crap. Most Holley carbs are fitted with no power valve in the secondary metering block. Like is used on Chevy inline 6 intakes. 4160 Vacuum Secondary Adjustable Spring Kit & Open Chart Holley 4150 Vacuum. I put the carb on the car, started fine, idles fine, runs at any speed as long as I didn't get on it too hard. Does not come in retail packaging. Power valve blow-out protection. Doggy, but smooth. The linkage is re-worked so the pressure on the diaphragm would open the secondary while the spring would tend to close it, and you have to put a restrictor in the boost line to the diaphragm to slow the opening. I currently have a Holley 670 street avenger with vacuum secondary,s and i am not at all happy with it. ) But the secondaries are not opening. No matter what you're driving, we have the right Holley Vacuum Secondary for your vehicle New and Used Automotive Parts and Accessories On Sale. If this model still has a carburetor and its a Holley, you can try a richer power valve. Plunger should move inward and hold vacuum. We are proud to announce the newest member of our carburetor family- the Street Warrior. In vacuum actuated carbs, the secondaries open up only when the vacuum across the primary venturis reaches a certain level. Holley's materials state that the check ball is only used in carbs in which the check ball sits on a hole which has. Secondary vacuum chamber. Go to a one size weaker spring in the vacuum diaphragm to open the secondaries quicker. On carbs that have a vacuum operated secondary, the secondary vacuum chamber is important to the function of the carb. We show you the best applications for this. i secondary control valve closed control valve closed denying governor vacuum to diaphragm (open to atmospheric bleed) a-7001. How To Tune Holley Carburetors. i was checking out another forum, and there was a thread about the little check-ball in the vacuum secondary pod thing. The engine feels like it has little to no difference in power at cruise (primary open, secondary closed) once I open the secondary it comes alive. With the engine off open and close the secondaries, it should move smoothly and you should hear the air going in and out of the vacuum secondary diaphram. 040" exposed (viewed with the carburetor removed from the engine and turned upside down). the of opening the secondary throttlc Most four-barrel carburetors me- linkage to the This that the primaries must a certain degree Of opening the begin to open. 4160 means it has a front metering block and a metering plate on the secondary side. On a vacuum secondary Holley you won't feel that big rush or noise like when you do with mechanical secondaries but when the vacuum secondaries open up you should be able to hear the difference. double pumper or vaccum secondary. Plunger should move inward and hold vacuum. A fellow here in Atlanta said they are not, and offered to rebuild it for $160. Single feed fuel inlet for easy installation 100% wet-flow tested by Holley technicians to assure it arrives ready to run! Please click here to ask a question. It stumbles off the line and i have recently rebuilt it and it still is doin this. 040" exposed (viewed with the carburetor removed from the engine and turned upside down). I have checked the diaphragm with a vacuum guage and it operates and holds vacuum. As the secondaries open, there is an additional vacuum signal that comes from the secondary venturis to enhance the vacuum from the primaries. This ensures the secondaries will open fully on most applications. I shut the motor off, closed the secondaries, re-start and all is well until the next WOT. All you’ll need is a screwdriver and a good vacuum gauge. Classic Industries offers a wide selection of 1972 Chevrolet Truck parts, including 1972 Chevrolet Truck interior parts and soft trim, 1972 Chevrolet Truck exterior sheet metal, 1972 Chevrolet Truck moldings, 1972 Chevrolet Truck emblems, 1972 Chevrolet Truck weatherstrip and unique accessories, to nearly every nut and bolt needed for installation. Single feed fuel inlet for easy installation 100% wet-flow tested by Holley technicians to assure it arrives ready to run! Please click here to ask a question. If it has Vacuum secondaries Holley makes different springs to open them sooner. If you would like your secondaries to come in a. With the engine off open and close the secondaries, it should move smoothly and you should hear the air going in and out of the vacuum secondary diaphram. WTF!! WAS running great until this morning. I drive it maybe once a week around town, but bring it to the track on the weekends to run the points series. The previous owner had it jetted very rich but it still bogged like it had a bad accelerator pump. The two primaries on those carbs would get you about 540cfm so it should want to open the secondaries a little bit but probably not too far. Double springs? 08-08-06 08:08 AM - Post# 982332 In response to Blaine that "BOG/STUMBLE" is a much more likely result of a classic case of an acellerator pump shot voluume thats either not large enought (not enought CCs of gas) resulting in a gulp of leaner than ideal air in the manifold, or one thats not lasting long enought,(begins too late or ends to. Not quite closed but also not very open. This will be easier if you install a Holley Secondary Adjusting Kit (PN26-117) which adds a conventional idle speed screw to the secondaries. Setting opening rates for vacuum secondary carburetors is really important to the overall performance of the vehicle, and with QFT’s Quick-Set™ adjustable secondary housing assembly the task is very simple. You have no items in your shopping cart. I had my wife push the accelerator to the floor and the linkage does not move the secondary butterfly at all. many people have the misconception that opening the secondary throttle plates sooner will provide increased performance in quicker dragstrip times others think they must feel a kick when the secondaries engage still others believe that they should disconnect the vacuum diaphragm and make the secondaries open mechanically let's discuss these points in reverse order first you should. Vacuum secondaries for use on wide variety of vehicles. depends on your cammost Marine cam profiles do not produce much vacuum so mechanical secondaries are the preferred choice Karl, MANIFOLD vacuum has nothing to do with how the vacuum secondaries of a Holley function. Thus, if the engine can’t handle all of the cfm, the secondaries simply don’t open all the way. Single feed fuel inlet for easy installation; Compatible with GM, Chrysler, and Ford A/T kickdown linkage. If there is a strong manifold vacuum, it SECONDARY JET ruBE SECONDARY MODEL acts the economizer diaphragm to keep the power valve closed, When vacuum reduced below a certain point, the power valve opened, enriching the mixture. The vacuum secondary should be held partly open at idle by a small lever that rests against an insignificant looking adjustment screw on the bottom of carburetor body just below the vacuum diaphragm body. Dual feed fuel inlets assure you get all the fuel you need while its vacuum secondaries and electric choke make it amazingly universal. I unhooked the secondaries and then drove it to see if it made a difference and it didn't. Will fit both ways and inlets are not that different in size. The chief complaint made by most always has to do with the slow speed or late timing in the opening of the secondaries.