A very informative video for the street afficionados and agree with the comments here on the video. May I also add another thing to further the information for those seeking a little bit more. When I won the Musclecar Nationals in the heads up format and the only one to win with a small block, I was the only one running a vacuum secondary carb wherein everyone in the heads up class ran a DP. Mine was a little different and hope it was tested here. I ran a yellow spring which opened much quicker than the purple color. I was able to use it by switching to a REO accelerator pump on my 750. It is a 50cc pump compared to a 30cc if I am not mistaken on all vacuum and even performance DP carbs. I did not change the squirters because the much bigger pump had a "longer pump shot duration" because of the added volume of 20cc more than the stock holley carbs. The longer pump shot allowed me to keep away from a lean bog when the secondaries opened up much quicker and many were wondering why I left real hard off line. I do these combination on many street engines and the customers are always very happy so I basically stayed away from the dp for most applications that are more oriented for street performance than all out power. Again thanks for a great video!
Great info there, running the yellow spring sometimes works. You covered it by adding the 50cc accelerator pump and this definitely helps. Great work!!
Thanks Ben, it is an honor for me to have accomplished engine builders like yourself comment on my channel. For anyone checking these comments, check out Ben's channel, it has lots of great content.AG
My old man and I run the same 750 vacuum secondary carb on my 68 Camaro because it was good carb for the mild build original engine in it now but will also be perfect for the nasty stroker that’s being built for it. My old man used to build 700 hp+ sbc for dirt late model cars way back in late 80s early 90s and he’s never been wrong yet across everything I watch or here or read trying to learn more. Just keeps reminding me that the old man’s surely forgot more then I’ve been able to absorb from him in my 40 years😂
Best street carburetor Ive ever owned was a Rochester quadrajet. It worked no matter the temp or weather. I currenty do not daily drive a carburated vehicle & run a Holley Ultra HP Dominator and love it. I plugged the power valves as the engine makes little vacuum (2.5"-3") at 1100 rpm and jetted accordingly. Works great on my 474 Pontiac. Made 689 HP/644'lbs on my SF901 as assembled. I ported the aluminum Kauffman Dport heads, longer valves & comp solid roller 278/286@.050 .440" lobe w/1.65:1 HS rockers, Victor intake ported. Ross pistons, 1/6" rings file fir by total seal. Keep up the vood work. Thanks to my Northern friends. Love that GTO!
Last summer rebuilt a 1977 chevy truck 454, had the good heads added dome pistons kept the quadrachoke , runs like a clock the smaller front bowls may help mpg.
No matter what carb you run, If you want it to be crisp all over the rpm band you have to spend plenty of time tuning it. Just a quick jet change is not enough. I ran the summit street strip 600 vacuum secondary on two very different sbf. The one in an F150 was a stock 5.0 with a dual plane intake , E303 cam, C-4 trans and 4.56 gears stock converter. Right out the box I set idle mix and idle and never touched again for years. It was super crisp. The other one was in an 86 fox body, ported heads high rise single plane intake, F 303 cam, C-4 trans, 3500 stall with 3.73 gears. I went though everything you can do to that carb before I got it right. the last thing that really made it work was getting the accelerator pump cam right. That car would punch from a dead stop or anywhere else you called on it. Buy the right CFM carb and do your homework tuning it.
Now I don’t know all about your builds, but it sounds like the second engine combo (cam, intake, heads, etc.) we’re not proper for what you were looking for, Making it more difficult for you to tune. But, I could be wrong.
I have a 670 truck avenger carb with vacuum secondaries, purple spring. It has an initial bog when the secondaries open the semi quickly moves to 12.5 afr after the secondaries start adding fuel. Since it is not a double pumper is there a way to get rid of this?
Thank you for this Alan and team. Different engines require different tuning methods to optimize performance for certain applications and for certain conditions. That includes carburetor sizing and type. Results for these carbs. run on a different engine would almost certainly be different. Nice comparison and results on this Pontiac nonetheless. And carburetors rather than EFI...Yeah! Help to keep old-school and Classic Hot Rodding alive!
Nice, mild street build that makes decent torque. I understand that your client probably wants the engine to be stock appearing, but a GOOD set of aftermarket aluminum cylinder heads would probably bump the power up by at least 50 hp and 50-75 lb/ft tq. Thanks again for another cool documentary video, Alan.👍🏻
Another Awesome video here , thank you AG I had a builder do a 383 for me and I had a a junk, plugged up , beat up Quadrajet and he had soaked it in everything to get the tar/varnish etc out of it , then used a spreadbore adapter to an Eldebrock performer to make wicked numbers for a mild build. We spoke about comparing Air Filter housings and we tested with An aftermarket open element drop base ( this made very good #s but would cost power in vehicle due to underhood air temps), , a reproduction factory 51-56 OLds /Cadilac type air cleaner housihg and a Factory 1967-70 Gm Twin Snorkel and the best numbers were from the Factory twin snorkel , it did cost about 7 peak HP compared to no air cleaner but average #s improved a little . I will not give exact #s but torque was over 460 ftlb @ 3500 RPM and just over 400 HP @ 5100 rpm , Idles around 750 RPM, air going into the engine using a Carb or THrottle body seems to have sensitivity to how the air enters, a lot of factory TBI Truck and van engines have an air filter housing spacer . We found the 1951 -56 Olds / Caddy housing had a flat base and power suffered a lot , possibly flowed a lot less here , lower average power,. tuning with a spacer between bottom of filter housing that affects how air flows through air horn ... maybe if you are going slighly rich , spacer can help tune , all things to comply with fit in vehicle , I like stock hood , nothing to see here ...... Spacers between filter housings and spacers/adapters for carb mounting all can have an effect on a engine. Your testing here shows the slightly different numbers and efficiency that Carbs make , I like these Videos a ton !!! Thank you for your videos .... keep them coming
Thank you for another great video = I just subscribed!!! Love the comparisons and all the data that is pulled off of the dyno = the dyno does not lie. That is a great running Pontiac 389!!!
Great seeing my old Flt. Test Buddy, Goatman! Awesome video, extraordinary numbers achieved. 750 vacuum secondary OUTSTANDING! Definetly gonna have fun short shifting and let that torque work it's magic. Joined your channel cuz I like how you guys Test!
Thank you guys. I like Yellow and purple depending on weight and gearing bb can handle yellow in a light vehicles if it bogs then purple. Plus more initial timing. Without much advance depends on fuel compression as load. I like 670 carb nice 750 nice if you want to tune it bit more. Like DP carb but easier to get mpg from vacuum carb. Bigger carb if race engine and or large BB
Good video! Disappointed with the power of the 389 ,really think my 400 TransAm makes a lot more. Just found out my brand new Holly carburetor on my 73 Mach 1, accelerator pump wasn’t working no wonder the car was so slow taking off! In my opinion the QJet is best Carburetor of all! Had a 800cfm QJet on my 1967 390 Galaxie and my 1971 Torino Cobra with a 351Cleveland 4v both of them worked amazing! Thanks for the video love them!
Sorry Glenn, the above comment was for another question. as to your point, I have never seen a QJet on a Ford but it is easy to do and would probably work well.AG
I have a 750 Vacuum secondary on my Chevy 383 too, BluePrint says it is the best carb option for the combination and this video makes it seem so. I know the butt Dyno loves it. Great work on the video.
Hey Alan, Tim here, YEA!!...yet ANOTHER Sunday morn vid from you, that i just LOVED!!!...i'm not surprised that a 750 vac sec did better than the 650 dbl pumper ON a Pontiac.....a Poncho has smaller runners, so a larger carb does better, as the velocity is higher than like a BB Chevy, so it pulls a nice signal even with the larger carb......now, i LOVED the whole vac spring change thing.....my neighbor needs the purple spring on his, based on ur evidence.......will get that goin......i cud go on and on.....but i blab too much already....haha, TY sir!!!......this is like a MONTHS worth of AWESOME Sun morn vids from you.......just SPECTACULAR!!...TY!!.....yes, ALL them other folks SUBSCRIBE!!!...I'm an engine builder, and i sub'd for a REASON!!!.....AG, you know i had to chime in, cuz its a Poncho!!!.....once more TY sir!!!...
I wish I got a dollar everytime some one would say "it worked on my sbc so it should be the same on a 400 pontiac" as if all engines are the exact same lol.
@@jasonnelson6624 yep, they just dont understand an ICE, and each's difrences......i have 462 Poncho.....with a 950 on it.....track testing proved the 950 did the best....again, smaller runner, creates GREAT signal......i was taught this in the '80's........smaller runner, BIG stroke, put a big carb on it, i dont care about charts, etc......one must look at the given combo!!.....TY my brother!!
Ok, one more rant.......given a mild BBC build, and a mild Poncho build......the BBC wud do best with a 750/850 depending, while the Poncho wud do best with a 850/950.....because.....BBC:...large runner, short stroke, use SMALLER carb to get signal (limited velocity, but great high rpm potential)....Pontiac: BIG stroke, smaller runner, use BIG carb, PLENTY of velocity to draw solid signal.....cant scream it tho.....or u'll see internal part u dont want to....hahaha.......as u said, yea, engines are all the same....yea, wish i had a dollar too!!!....i'm tryin to say, i'm with you my brother!
@@TimothyArnott-m7z lol maybe that extra dollar would help with the extra poncho price difference. Not as bad as mopar but still not as cheap as Chevy. But who wants to run what everyone else has right? 😉😂
Another outstanding video, Allan. This was a big moment for the restoration of my 1965 GTO and one that I have been looking forward to since I began the restoration five years ago. I mentioned it before but I'll repeat it here because it's worth mentioning again - the team you have assembled are first rate and I couldn't be more pleased with the result. To anyone who is looking for someone to rebuild the engine for their muscle car, Allan Gold and team get my highest recommendation. Thanks again. I look forward to your future builds and videos.
A friend of mine built a 389 with a Butler 4.25 crank and 6.8 rods and it tons more power and was reliable as they get. That Comp off the shelf was the wrong cam for that engine. Summit has a line of Ram Air cams and just saw a dyno of a 400 that was 9.5 compression make 450 hp with a stock 1977 intake and ram air manifolds.
Another test you can check is on booster types. Look at the atomization of annular vs. step down vs the booster type on the avenger carb. With manifolds that have no heat port under the carb is critical to get the best fog in the plenum to prevent part throttle surging
Great idea, boosters act differently for sure, the avenger uses a straight style, they flow well, but they do restrict air, both the Brawler and the Slayer uses a down leg style booster, they do have a curve to them, less sensitive but they do sit deeper into the Venturi. Annular boosters are very sensitive but huge in the way. They all have their advantages.
This is such great content. If the often cited formula is right, this engine at 100 VE is using every bit of the 180cfm those heads have to offer on intake. NICE WORK
Thanks very informative video ! I'm working a 69 351w & thinking double pumper ,would be better for my wants . Driver / cruiser a 66 Fairlane .. all great info ; )
I had a 67 Lemans. Swapped in 1970 or 71 Grand Prix SE engine and transmission. 455 and a 350 turbo. It was a 1 wheel peel KING. Below 40 mph it would break loose that right rear tire on request. It was a 11 year relationship with that car.
I have a Holly 700 Double pumper, mechanical choke. Tuned it using a SUN fuel ratio machine that you put into the exhaust pipe as you drive. You can set the jets well to get your Air Fuel ratio, primary and secondary. I should say on a SBC, 312 cid, 2X hump heads, solid lifter cam, windage tray, swirl polished SS valves, 2” fl headers, 4 speed Muncie close ratio.
I did carb cfm tests the old fashioned way. Ya bolt it on...tune it in...then ya go out late at night and find a long straightaway...and go full throttle. Write down max rpm's and mph. Ive seen top speeds change in excess of 25 mph just from a carb swap with almost no change in rate of acceleration from idle to 100 mph. Ive ran everything from 4100's to qjets to thermoquads to a wheelbarrow full of different holleys doing this.
I could never get the vacuum secondaries on my Holley 750 to open on my ZZ4 regardless of spring color. Ended up using a zip tie on the linkage to get the secondary's open at the cost of a low speed bog due to all 4 barrels opening up together.
Are you sure the vacuum secondaries were not opening? They will not open unless the engine is under load, (low vacuum and lots of throttle) so you won't see them open under the hood. AG
3310 Holley is one of the best with down leg boosters and vacuum secondaries but the summit carb I bought that favors the Holley with removable top has annular discharge boosters and it works even better. Throttle response is unmatched on the summit and it made more power, even on Engine Masters it won the show.
A well tuned Quadrajet, recurve the distributor & proper timing would really wake it up. I run a Quick Fuel BDQ 950 Cfm because I run KRE 340 Cfm CNC Ported D ports with Portmatched NorthWind intake & 1” Vortex Spacer now. 1969 406, Comp HEX Oil roller @110 .292/.288, . .262/.258, .540 lift with 1.65” dual roller stainless rockers. Built for racing bottom end & 200-4r with 9” full throttle use lock up converter set to 3200RPM. It’s a serious monster now after my MSD ProBillet Distributor was professionally recurved & timed. Gonna find out what it puts down on a wheel Dyno this weekend hopefully. Nice video but some things can be improved.
Thanks Josh. We have tested Quadrajets against Holley carburetors on the same engine and they perform very well. By popular demand we will do more with Quadrajets. AG
I've owned quite a few GTOs in various states of tune. Carbs aside, the '68-72 D port heads with screw in studs are by far a better avenue to power than carb changes. That said, a well tuned Quadrajet was my favorite carb for the street with ram air exhaust manifolds.
i always like these carb dyno shootouts. it seems alot different on the dyno testing than hooked up to a 4 speed or an automatic in the vehicle. besides im a carb nut also.
Great video, thank you all. Were all 3 of the carburetors, completely box stock, except for the vacuum secondary spring change, or were they previously set up in any way, by Dave?
Thanks for the question, the 670 Avenger came stock with 65/68 jetting. Ended up with 68/71 jets. The Brawler and the Slayer were both box stock didn't need any tuning
In 1980 I had a ‘65 Fastback 289/C4 and it would outrun my friends’71 GTO 400/Th400. He got pissed and bought an old Pontiac convertible with a 455 and swapped it in.....I still blew his doors off....he gave up. I had a ‘62 Falcon Ranchero drag car with a 289/C4 that ran 11’s that was much quicker than the Fastback! Nobody believes this story which makes it even sweeter! 😂😂😂
@@jerryhablitzel3333 Absolutely not! My 289 drag car weighed 2180 lbs. That tank GTO with a big block probably weighed just under 4000 lbs......which would require 500 HP to run 11.80’s. Them big Pontiacs have plenty of torque but they don’t make shit for HP without a lot of money to make them rev! Torque is grand for a street car, but HP wins drag races especially in a light weight car!
289 nice motor 455 just be tire burner while yours will launch better and that why. I raced very high hp motors and beat them with less but it is effective Hp not max unless they are at the track and they can get can get traction. I raced a guy who got put in other lane I bet him all because of traction
We're in the middle of a 389 build (actually with a 400 block since the 389 block was split in the lifter valley) using the 389 heads and just a flat tappet cam. If you're making 358, I guess we can expect maybe 330 HP.
Thanks for the comment Yarrda. If you have a 400 block, then you have a 400 now. Depends on the cam. A bigger cam will make torque at a higher RPM, so more HP. but with a loss of drivability. With a street cam about 350 is tylical.AG
Edelbrock carbs are easy to tune and jet without taking them apart. I also like they don’t have any rubber gaskets or power valves that can go bad with age and I ethanol fuel.
Thanks Dew. I have an Edelbrock here as well as the original Carter AFB's from a 409. Maybe we can do some testing on them in the future. Edelbrock is a very popular carburetor. AG
I'm a pontiac guy for 40 years. Pontiac guys will tell you those headers are killing hp bc of the center ports sharing one tube. Thank you for your knowledge and videos USA 🇺🇸 TRUMP
So a 670 street avenger isn't actually flowing 670cfm? I was considering going from a edelbrock 750 to the 670 street avenger just to see what all the fuss is about, but if it flows less air is it going to make less power?
Thanks Moose, the engine will take how much CFM it needs. Typically on the dyno, that is leagss than the CFM rating of the carburetor. Without knowing more about your engine, I would say, keep your Edelbrock 750.
the best carb for the street hands down is spread bore carb. Q-jet or Holley 4165/4175. the 4175 is vacuum secondary and has been discontinued for a very long time but you can still get a 4165. the Edelbrock Quadra-Jet #1910. they have also been discontinued for a long time. but if you can find one, that is the best Q-jet ever made. and really the only Q-Jet designed for performance. the smaller primaries increase throttle response and improve fuel economy from off idle to about 2500 rpm. the large secondary provides plenty of air flow for high performance needs. Both Pontiac and Buick both used Q-jets on all their high-performance engines. the Holley 5165/4175 flows about 600CFM, the factory Q-jets were all around 750 CFM with the exception of a few high performance Pontiac and Buick carbs that were 800CFM, the Edelbrock Performer RPM Quadrajet #1910 is about 850 CFM. you can make more power with Holley or Carter/Edelbrock AFB, but you sacrifice in throttle response and fuel economy at idle, off idle and cruising RPM ranges. and honestly on engine below 400 HP range, you really won't see a difference from a Holley at the higher end of the RPM range, but you will certainly see the loss of drivability on at lower rpms. I am not hating on the Holley and the Holley clones. they are good carbs and probably the best for racing application due to the better tuneability with things like replaceable high and low speed air bleeds. but simply due to the spread bore design of the Q-jet vs the square bore design of the Holley and Edelbrock/Carter AFB's, it is impossible for them to match the low-speed drivability of a Q-jet. that just my 2 cents. i know the Q-jet is one of the most hated crabs out there. but it is not the fault of the carbs design, it is because of lack of knowledge on how to tune it, and the difficulty in tuning the primary side of the carb, which required disassembly to change primary jets and primary metering rods. but once you have the primary side dialed in, it's easier to tune the secondary side, then even a Holley. just swap the rods and hangers for the secondaries. 1 screw and you don't have to remove the fuel bowls. the only other draw back to the Q-jet is the small fuel bowl size. but you don't need that on a streetcar. you can compensate for the smaller fuel bowl with a bigger needle and seat assembly. but it still won't be a good as a Holley or AFB fuel bowl. one benefit to the smaller fuel bowl is less heat saturation of the fuel and they are less likely to get vapor lock.
I dont think a dominator would be a wise choice for this build. The owner doesnt seem like he wants to be pulled over along side the road with the hood up and a flat blade screwdriver leaning over a hot engine because his car is running crappy
@GoldsGarage- Around the 28:15 to 28:30 part, the guy saying shift @ a Low 4k to 4,200 Rpm, what is he talking about? You don't shift @ peak TQ. Ideally the shift point should be high enough, so that rpm doesn't drop below peak TQ., but sometimes this is not possible, but closer is better. If your going for quickest/best E.T. In a drag race, you should shift approx. 400 to 500 Rpm past your peak HP. So for the 750 vac. Sec. Carbed dyno pull, that would be a shift point of 5,400 to 5,500 Rpm. If peak Hp @ a given Rpm is not known, i make a pass shifting @ 5k, cool the engine to same temp as the prior run, and shift 250 Rpm higher. If E.T. keeps improving, i keep repeating this procedure, increasing the shift Rpm 250 per run, until the E.T. stops improving. I have drag raced, for over 30 years, and this has worked very well for finding the best E.T.s. Thanks for taking all of your time, to make this video❤️
A Holley spreadbore is an aftermarket carb. They're not as common like they were before. The famous one is the 6210 , 650 mechanical secondary. When there wasn't many options for intake manifolds, and guys were using their stock intakes, guys were buying these spreadbore Holleys. They worked pretty good
Nice info here. I just subscribed. Question. I have an early 350 4 speed roller rebuild and it’s gonna be almost 450 hp. What’s best for secondaries on my 4 speed corvette. Mechanical or vacuum? Thanks again and I look forward to hearing from you. Also thanks to you I’ve made the switch to roller from now on.
i bought a new 850 holley dp in 1986 or 1987. mech sec. it ran great for many years on my 428 ford,real snappy for a 850. i bought a new 850 in 2020 just like it,but it is nowhere as snappy as the old one,so i put my old one back on and put the new one away
Roller camshafts and lifters give peace of mind from flat tappet cams, but if link bars, their pins or the roller needle bearings fail its wipes out faster than flat tappets and the engine. Buy Amzoil z-rod oil or Joe Gibbs Racing GP1 engine oil for flat tappet setups.
@@goldsgarage8236 I choose a hydraulic flat tappet cam for a street performance build from David Vizard's book. All new Dart SHP 400 block 4.125" bore, Scat F-43 lite weight internally balanced 3.75" stroker crank, 6" Scat stroker rods ARP bolts, Mahle flat top pistons, block decked 9.005", .011" ss shim copper coat sprayed to .013", 11.5:1+ CR, ARP head studs and ported/polished 64cc Edelbrock Performer heads. Cranking pressure @ 8500' elevation 200psi.. Lunati nitride coated DV 268 HFT camshaft @105 LSA, .538" lift w/1.65 ratio CompCams XD roller rockers, 3/8" pushrods, CC adj. timing gear dual roller and CC removable timing cover. I built this engine following very tip and trick in DV's how to build book 'Max-Performance Chevy Small-Blocks On A Budget' but didn't go budget. Also FiTech Mean Street 800 HP EFI and the Ram-Air Cold Air-box, lots more. Great read and information, I highly recommend it!
Thanks for the question. In this video, the customer just wanted a Holley. We will test a variety of carburetors including the Quadrajet in the next dyno video. AG
Im hoping to upgrade my pierburg 2e3 carburettor on my transporter T3 van that has 1.9 WBX engine. Mostly for fuel economy and reliability. Any ideas what should I go for?
I have a Chinese Edelbrock off. Amazon. cost me two hundred and seventeen dollars It's an avs 2 but unlike Edelbrock it came with Site glasses and you can adjust the Float from outside the Carburetor. Took some tuning, but it's the best carburetor I've had. And i've had them all
What a missed opportunity for that 389 to really make some great reliable power. A Butler 4.25 stroker kit and Butler Ram Air series rolling cam would have made so much more power. Honestly, I think y'all really missed on the off the shelf camshaft.
On the Slayer they use a purple spring as well, as an added feature they use a more or less a mixture screw, this limits the vacuum source to the diaphragm
My last bracket car ran 12.63 at 104 with an 1850 600 CFM vac secondary carb on a Performer intake. The problem was that the foot brake class was 13.00 and slower so I had to retard the timing and limit the throttle pedal travel. This was at Commerce, GA in the early 90s.
@@MidnightinSavannah White 78 Camaro with black lettering. Raystech Racing was the sponsor on the sides. Fully stripped. It weighed about 2800 with me in it. 4.88 gear. The ET/weight calculation said 286 hp . shifted it at 5000, 6300 through the lights. Dial in at 13.00 and better drag the brakes at the finish line.
I have a 91 Chevy Truck. It's a TBI 350. Is there any way to get decent Horsepower out of this type of Fuel System? I'm only wanting 300 Horses,plus a 100 Shot of Nitrous.
@@johncalhoun8011 well like I mentioned better cylinder heads, your TBI heads don't flow well, the aftermarket is endless on cylinder heads, your 2 barrel TBI isn't going to flow enough air, so the choice is yours to go with a 4 barrel EFI or carburetor. Its fairly easy to get 350hp plus out of a 350.
The single carb 389s for the '65 GTO utilized a Carter 4-bbl carb. I initially considered a Quadra-Jet because it looks similar to the old Carter carb. In the end I chose the Holley style carb mainly for its ease of maintainability.
Does this cause damage? Having your mechanical fuel pump installed with no fuel? I’m curious because I want to break-in an engine with an electric pump but I’ll be using a mechanical one.
Pontiac engines suffer from some poor cylinder heads. It's great that you used a roller cam BUT with nothing better than those factory heads and I could not see the casting numbers but until you put some better heads on it you will struggle to get much above 350 HP. Just look back at all the older factory engines they never made any power even at 455 cubic inches. The cylinder heads are the key to every engine. Take a lesson from the LS engines, they use small cams but great heads and make great power. The vacuum secondary carbs are not opening fully because the engine with the stock low flowing heads is not demanding any more air and thus the carb doesn't need to open further. Even installing all those carbs with mechanical secondaries is not helping the power really and that tells the tale. When you look at the dyno numbers and see the torque numbers high at a low rpm and more than the HP then you have an engine that is struggling to breath. You can see the horsepower is flattening out because there is not enough air flow into the engine. All the Buick, Olds, and Pontiac engines suffer the same problem. They were made for large heavy vehicles that needed low end torque to get them moving, not high rpm were the horsepower is made. Chevrolet is the one that does that. A better carb test would be on an engine that has some real air demand like a 540 cubic inch BBC and let's see which carb is the restriction.
There probably a roller cam In the motor because most engine builders won't risk putting a flat tappet cam in the motor with all the problems of rolling the dice and having a cam go flat and ruin the motor. You are definitely right about the heads. There is a reason they made the ram air 5 head to make good power. Pontiac was onto head design for making power and then the performance era was killed.
Those holley square bore carbs, vac and mech secondarys all get horrible gas milage on the street. Just running on primarys. Should have shown benefits of a Q-jet, and Carter based Edelbrock carbs..
Thanks for your comments Terry. We will do more testing with Quadrajets and Edelbrock carbs. I also have a Carter AFB from a 409 to test. we will get to it. AG
Compared to torque and HP numbers, the 650 DP won this, with the huge increase of power. It is suprising that the 100CFM larger carb made very small gains over the smaller 650DP, that would tell me the engine wants the DP better than the larger VS carb. numbers don't lie, but you can read the results to say what ever you like, lol
Quick fuel for the win...dp is better for track... I have 750 slayer on my 318...with 1 Inch spacer. Made good torque and top end, so it depends on the application. Vehicle weight, etc. Thanks
Holley came out with the “shiny” finish in the nineties and ever since they charge you MORE for the old style gold finish than they do the shiny plated finish. WHY? U prefer the original gold finish but why do they charge more for a finish that is just a dip whereas the zinc plating should be more labor intensive? Is the gold finish not EPA friendly or something?
It all depends on the size and tune of the motor and car! If it's a daily driver you should err on the smaller side! In my opinion! I used to have a 68 Camaro daily driver with a 12 1/2 to one 454 with a opened up 800 double pumper. The car had a stock converter and 4.10 gears! It would pass anything but a gas station! Ha! Ha!
I used to believe that crap about carburetors could be too big as well. It's not true. They are sometimes set up for a larger engine but that doesn't mean you can't tune them to any application. Because they work only on the amount of air that goes through them, you just tune them to the application you can't have two smaller carburetor but you can't have two large of one
The carburetor should be paired with a fuel pump ! A weak fuel pump won't keep up with the pressure needed to idle.. I installed a demon carburetor on my 383 68 Camaro, the idle was terrible and belching fumes out the tail pipe, I installed a high pressure electric pump with a regulator and the problem disappeared.
Thanks for the question Dale. i would think that a 390 Holley would be sufficient. Not sure if they can be available with vacuum secondary. Dave Forrest, can you comment here please? AG
A long time ago a friend wanted to sell me a 750 cfm AFB. For those of you who are wondering I would have bought it but I tried it out on my 1971 olds Cutlass 455 at Hallsville dragway and it ran exactly the same time as my stock quadrajet. Sorry but I can't buy it my friend.
I run 3 tube headers on my mild 400, but I would just love to see a head to head comparison between 3 tube and 4 tube pontiac headers on the same engine back to back pulls.
Not entirely true about rollers be the savior. The roller lifter has a failure rate also. What %tage I'm unsure, BUT we are being bombarded with junk from across the pond and the companies we relied upon 20 years ago have been taken over by the offspring of the original owner. They know only one thing of business and that is: How much profit can we make? I won't name names but this Hobby is serious trouble. I know who's to blame, it ALL started in the '60's. Back to the flat tappets vs rollers when the open spring pressure goes over 1000 PSI a lot of the rollers are failing.
I would have liked to see a Quadrajet included in the test.
me too. smaller primaries for better mileage and same if not more hp usually. size for size
I like quadrajets as well
Thanks William, we will do more testing with Quadrajets.AG
Yes please do I'm guessing it would have done quite well against those Holly's
Please do
Please keep making these informational test videos. They show us the facts in black and white thanks
Great comment, thanks Nasty.AG
A very informative video for the street afficionados and agree with the comments here on the video. May I also add another thing to further the information for those seeking a little bit more. When I won the Musclecar Nationals in the heads up format and the only one to win with a small block, I was the only one running a vacuum secondary carb wherein everyone in the heads up class ran a DP. Mine was a little different and hope it was tested here. I ran a yellow spring which opened much quicker than the purple color. I was able to use it by switching to a REO accelerator pump on my 750. It is a 50cc pump compared to a 30cc if I am not mistaken on all vacuum and even performance DP carbs. I did not change the squirters because the much bigger pump had a "longer pump shot duration" because of the added volume of 20cc more than the stock holley carbs. The longer pump shot allowed me to keep away from a lean bog when the secondaries opened up much quicker and many were wondering why I left real hard off line. I do these combination on many street engines and the customers are always very happy so I basically stayed away from the dp for most applications that are more oriented for street performance than all out power.
Again thanks for a great video!
Great info there, running the yellow spring sometimes works. You covered it by adding the 50cc accelerator pump and this definitely helps. Great work!!
Thanks Ben, it is an honor for me to have accomplished engine builders like yourself comment on my channel. For anyone checking these comments, check out Ben's channel, it has lots of great content.AG
My old man and I run the same 750 vacuum secondary carb on my 68 Camaro because it was good carb for the mild build original engine in it now but will also be perfect for the nasty stroker that’s being built for it. My old man used to build 700 hp+ sbc for dirt late model cars way back in late 80s early 90s and he’s never been wrong yet across everything I watch or here or read trying to learn more. Just keeps reminding me that the old man’s surely forgot more then I’ve been able to absorb from him in my 40 years😂
Nice build and good enjoyable power. I love the data , testing multiple carbs is top notch customer service. Great Job Mr. Gold!
Thanks Scott. Glad you found it helpful.AG
Best street carburetor Ive ever owned was a Rochester quadrajet. It worked no matter the temp or weather. I currenty do not daily drive a carburated vehicle & run a Holley Ultra HP Dominator and love it. I plugged the power valves as the engine makes little vacuum (2.5"-3") at 1100 rpm and jetted accordingly. Works great on my 474 Pontiac. Made 689 HP/644'lbs on my SF901 as assembled. I ported the aluminum Kauffman Dport heads, longer valves & comp solid roller 278/286@.050 .440" lobe w/1.65:1 HS rockers, Victor intake ported. Ross pistons, 1/6" rings file fir by total seal. Keep up the vood work. Thanks to my Northern friends. Love that GTO!
Sounds like an awesome Pontiac engine. Thanks for commenting Terry. AG
Last summer rebuilt a 1977 chevy truck 454, had the good heads added dome pistons kept the quadrachoke , runs like a clock the smaller front bowls may help mpg.
Another Northern folk here. At what Rpm are your peak numbers at?
No matter what carb you run, If you want it to be crisp all over the rpm band you have to spend plenty of time tuning it. Just a quick jet change is not enough. I ran the summit street strip 600 vacuum secondary on two very different sbf. The one in an F150 was a stock 5.0 with a dual plane intake , E303 cam, C-4 trans and 4.56 gears stock converter. Right out the box I set idle mix and idle and never touched again for years. It was super crisp. The other one was in an 86 fox body, ported heads high rise single plane intake, F 303 cam, C-4 trans, 3500 stall with 3.73 gears. I went though everything you can do to that carb before I got it right. the last thing that really made it work was getting the accelerator pump cam right. That car would punch from a dead stop or anywhere else you called on it. Buy the right CFM carb and do your homework tuning it.
Now I don’t know all about your builds, but it sounds like the second engine combo (cam, intake, heads, etc.) we’re not proper for what you were looking for, Making it more difficult for you to tune. But, I could be wrong.
I have a 670 truck avenger carb with vacuum secondaries, purple spring. It has an initial bog when the secondaries open the semi quickly moves to 12.5 afr after the secondaries start adding fuel. Since it is not a double pumper is there a way to get rid of this?
Need more info about when the bog is occurring. When you stomp it from an idle or when on the highway and you roll into the throttle, etc.
Thanks for this !😮
You could try a 50cc accelerator pump and maybe a 25 squirter to cover up the purple spring@@paulhershberger8774
Keep them coming these are great videos
Thanks you Dave.AG
Thank you for this Alan and team. Different engines require different tuning methods to optimize performance for certain applications and for certain conditions. That includes carburetor sizing and type. Results for these carbs. run on a different engine would almost certainly be different. Nice comparison and results on this Pontiac nonetheless. And carburetors rather than EFI...Yeah!
Help to keep old-school and Classic Hot Rodding alive!
i always enjoy your comments Bill, thanks for supporting my channel.AG
excellent content Gold, Thanks for the real world comparisons
Thanks Michael.AG
Nice, mild street build that makes decent torque. I understand that your client probably wants the engine to be stock appearing, but a GOOD set of aftermarket aluminum cylinder heads would probably bump the power up by at least 50 hp and 50-75 lb/ft tq.
Thanks again for another cool documentary video, Alan.👍🏻
Thanks for your comments Leo.AG
Another Awesome video here , thank you AG
I had a builder do a 383 for me and I had a
a junk, plugged up , beat up Quadrajet and he had soaked it in everything to get the tar/varnish etc out of it ,
then used a spreadbore adapter to an Eldebrock performer to make wicked numbers for a mild build.
We spoke about comparing Air Filter housings and we tested with
An aftermarket open element drop base ( this made very good #s but would cost power in vehicle due to underhood air temps),
, a reproduction factory 51-56 OLds /Cadilac type air cleaner housihg and a Factory 1967-70 Gm Twin Snorkel
and the best numbers were from the Factory twin snorkel , it did cost about 7 peak HP
compared to no air cleaner but average #s improved a little . I will not give exact #s
but torque was over 460 ftlb @ 3500 RPM and just over 400 HP @ 5100 rpm , Idles around 750 RPM,
air going into the engine using a Carb or THrottle body seems to have sensitivity to how the air
enters, a lot of factory TBI Truck and van engines have an air filter housing spacer .
We found the 1951 -56 Olds / Caddy housing had a flat base and power suffered a lot
, possibly flowed a lot less here , lower average power,. tuning with a spacer between
bottom of filter housing that affects how air flows through air horn ...
maybe if you are going slighly rich , spacer can help tune , all things to comply with fit in vehicle ,
I like stock hood , nothing to see here ......
Spacers between filter housings and spacers/adapters for carb mounting all can have an effect on a engine.
Your testing here shows the slightly different numbers and efficiency that Carbs make , I like these Videos a ton !!!
Thank you for your videos .... keep them coming
Great info, thanks for sharing Nerrad..AG
Thank you for another great video = I just subscribed!!! Love the comparisons and all the data that is pulled off of the dyno = the dyno does not lie. That is a great running Pontiac 389!!!
Thanks for subscribing, it means a lot to us. AG
Great seeing my old Flt. Test Buddy, Goatman! Awesome video, extraordinary numbers achieved. 750 vacuum secondary OUTSTANDING! Definetly gonna have fun short shifting and let that torque work it's magic. Joined your channel cuz I like how you guys Test!
Thanks for your comments and for subscribing Austin.AG
Glad you enjoyed the video, Austin. Miss you my brother.
Thank you guys. I
like Yellow and purple depending on weight and gearing bb can handle yellow in a light vehicles if it bogs then purple. Plus more initial timing. Without much advance depends on fuel compression as load. I like 670 carb nice 750 nice if you want to tune it bit more. Like DP carb but easier to get mpg from vacuum carb.
Bigger carb if race engine and or large BB
Thanks for watching and commenting J.AG
Good video! Disappointed with the power of the 389 ,really think my 400 TransAm makes a lot more. Just found out my brand new Holly carburetor on my 73 Mach 1, accelerator pump wasn’t working no wonder the car was so slow taking off! In my opinion the QJet is best Carburetor of all! Had a 800cfm QJet on my 1967 390 Galaxie and my 1971 Torino Cobra with a 351Cleveland 4v both of them worked amazing! Thanks for the video love them!
You had a q jet on Ford's ?
Thanks for your comments Elaine. The power was typical for a stock build with a street cam. AG
Sorry Glenn, the above comment was for another question. as to your point, I have never seen a QJet on a Ford but it is easy to do and would probably work well.AG
Thanks for the nice compliment Elaine, the power was typical for a stock build with a street cam. AG
@@goldsgarage8236Some late 60s and early 70s Fords had them factory including the 428 Cobrajet and 429.
I have a 750 Vacuum secondary on my Chevy 383 too, BluePrint says it is the best carb option for the combination and this video makes it seem so.
I know the butt Dyno loves it.
Great work on the video.
Thanks Jimmy, a nice affirmation for us. AG
Hey Alan,
Tim here, YEA!!...yet ANOTHER Sunday morn vid from you, that i just LOVED!!!...i'm not surprised that a 750 vac sec did better than the 650 dbl pumper ON a Pontiac.....a Poncho has smaller runners, so a larger carb does better, as the velocity is higher than like a BB Chevy, so it pulls a nice signal even with the larger carb......now, i LOVED the whole vac spring change thing.....my neighbor needs the purple spring on his, based on ur evidence.......will get that goin......i cud go on and on.....but i blab too much already....haha, TY sir!!!......this is like a MONTHS worth of AWESOME Sun morn vids from you.......just SPECTACULAR!!...TY!!.....yes, ALL them other folks SUBSCRIBE!!!...I'm an engine builder, and i sub'd for a REASON!!!.....AG, you know i had to chime in, cuz its a Poncho!!!.....once more TY sir!!!...
I wish I got a dollar everytime some one would say "it worked on my sbc so it should be the same on a 400 pontiac" as if all engines are the exact same lol.
@@jasonnelson6624 yep, they just dont understand an ICE, and each's difrences......i have 462 Poncho.....with a 950 on it.....track testing proved the 950 did the best....again, smaller runner, creates GREAT signal......i was taught this in the '80's........smaller runner, BIG stroke, put a big carb on it, i dont care about charts, etc......one must look at the given combo!!.....TY my brother!!
Ok, one more rant.......given a mild BBC build, and a mild Poncho build......the BBC wud do best with a 750/850 depending, while the Poncho wud do best with a 850/950.....because.....BBC:...large runner, short stroke, use SMALLER carb to get signal (limited velocity, but great high rpm potential)....Pontiac: BIG stroke, smaller runner, use BIG carb, PLENTY of velocity to draw solid signal.....cant scream it tho.....or u'll see internal part u dont want to....hahaha.......as u said, yea, engines are all the same....yea, wish i had a dollar too!!!....i'm tryin to say, i'm with you my brother!
@@TimothyArnott-m7z lol maybe that extra dollar would help with the extra poncho price difference. Not as bad as mopar but still not as cheap as Chevy. But who wants to run what everyone else has right? 😉😂
@@TimothyArnott-m7z but according to holley a 550cfm is all you need 😂😂😂
Another outstanding video, Allan. This was a big moment for the restoration of my 1965 GTO and one that I have been looking forward to since I began the restoration five years ago. I mentioned it before but I'll repeat it here because it's worth mentioning again - the team you have assembled are first rate and I couldn't be more pleased with the result. To anyone who is looking for someone to rebuild the engine for their muscle car, Allan Gold and team get my highest recommendation. Thanks again. I look forward to your future builds and videos.
A friend of mine built a 389 with a Butler 4.25 crank and 6.8 rods and it tons more power and was reliable as they get. That Comp off the shelf was the wrong cam for that engine. Summit has a line of Ram Air cams and just saw a dyno of a 400 that was 9.5 compression make 450 hp with a stock 1977 intake and ram air manifolds.
Thanks Todd, it was great working with you on this engine. I will be watching your progress on the restoration.AG
Love the videos just subscribed, Memphis,TN
Very nice, thank you for subscribing John.AG
Another test you can check is on booster types. Look at the atomization of annular vs. step down vs the booster type on the avenger carb. With manifolds that have no heat port under the carb is critical to get the best fog in the plenum to prevent part throttle surging
Very god point, thanks James.AG
Great idea, boosters act differently for sure, the avenger uses a straight style, they flow well, but they do restrict air, both the Brawler and the Slayer uses a down leg style booster, they do have a curve to them, less sensitive but they do sit deeper into the Venturi. Annular boosters are very sensitive but huge in the way. They all have their advantages.
This is such great content. If the often cited formula is right, this engine at 100 VE is using every bit of the 180cfm those heads have to offer on intake. NICE WORK
Thanks for the comment William.AG
I’m pleased by the results because I have a 750 vac secondary on my engine.
That works, thanks Unicorn.AG
Thanks very informative video ! I'm working a 69 351w & thinking double pumper ,would be better for my wants . Driver / cruiser a 66 Fairlane .. all great info ; )
I had a 67 Lemans. Swapped in 1970 or 71 Grand Prix SE engine and transmission. 455 and a 350 turbo. It was a 1 wheel peel KING. Below 40 mph it would break loose that right rear tire on request. It was a 11 year relationship with that car.
Thanks Michael, too bad you had to end the relationship.AG
I love the 3310s I agree,they work.
Thanks David That's why there are so many.AG
I have a Holly 700 Double pumper, mechanical choke. Tuned it using a SUN fuel ratio machine that you put into the exhaust pipe as you drive. You can set the jets well to get your Air Fuel ratio, primary and secondary. I should say on a SBC, 312 cid, 2X hump heads, solid lifter cam, windage tray, swirl polished SS valves, 2” fl headers, 4 speed Muncie close ratio.
That is great information Joel. Thanks for commenting.AG
Love it! Thank you!!
Thanks for watching and commenting Dan. AG
I did carb cfm tests the old fashioned way. Ya bolt it on...tune it in...then ya go out late at night and find a long straightaway...and go full throttle. Write down max rpm's and mph. Ive seen top speeds change in excess of 25 mph just from a carb swap with almost no change in rate of acceleration from idle to 100 mph. Ive ran everything from 4100's to qjets to thermoquads to a wheelbarrow full of different holleys doing this.
Jesse. Thanks for the info. I am staying off the road late at night.AG
I'd like to see it with a properly tuned 3 deuces like it should have had from the factory.
So would I and I would do that if i had a 3 deuce set up. AG
65 GTO I think is the best looking body style I love Richard g. Black 5 speed that does all the drag and drive events. Beautiful car.
Thanks Richard. AG
I could never get the vacuum secondaries on my Holley 750 to open on my ZZ4 regardless of spring color. Ended up using a zip tie on the linkage to get the secondary's open at the cost of a low speed bog due to all 4 barrels opening up together.
Are you sure the vacuum secondaries were not opening?
They will not open unless the engine is under load, (low vacuum and lots of throttle) so you won't see them open under the hood. AG
3310 Holley is one of the best with down leg boosters and vacuum secondaries but the summit carb I bought that favors the Holley with removable top has annular discharge boosters and it works even better. Throttle response is unmatched on the summit and it made more power, even on Engine Masters it won the show.
Thanks Bo. Yes, we should do some tests with different boosters. Thanks for the suggestion.AG
I enjoy the dyno testing.
So do we! Thanks for watching and commenting Dean. AG
A well tuned Quadrajet, recurve the distributor & proper timing would really wake it up. I run a Quick Fuel BDQ 950 Cfm because I run KRE 340 Cfm CNC Ported D ports with Portmatched NorthWind intake & 1” Vortex Spacer now. 1969 406, Comp HEX Oil roller @110 .292/.288, . .262/.258, .540 lift with 1.65” dual roller stainless rockers. Built for racing bottom end & 200-4r with 9” full throttle use lock up converter set to 3200RPM. It’s a serious monster now after my MSD ProBillet Distributor was professionally recurved & timed. Gonna find out what it puts down on a wheel Dyno this weekend hopefully. Nice video but some things can be improved.
Thanks Josh. We have tested Quadrajets against Holley carburetors on the same engine and they perform very well. By popular demand we will do more with Quadrajets. AG
David Vizard explains exactly why the bigger carb produces the most power on a dual plane manifold. Most people are using too small a carb.
Thanks James, I think i just watched the same video. AG
I've owned quite a few GTOs in various states of tune. Carbs aside, the '68-72 D port heads with screw in studs are by far a better avenue to power than carb changes. That said, a well tuned Quadrajet was my favorite carb for the street with ram air exhaust manifolds.
Thanks Bob. We will do more with Quadrajets.AG
i always like these carb dyno shootouts. it seems alot different on the dyno testing than hooked up to a 4 speed or an automatic in the vehicle. besides im a carb nut also.
Thanks for the comment Sandra.AG
Looks like an accurate assessment to Me.
Thanks for commenting Allan.AG
Great video ! Liked/Subscribed !
Thanks Dan, welcome aboard, lots more to come.AG
Im suprised you guys havent tried the edelbrocks performers and avs2 as well in the tests. 600,650, 750 and 800
Great video, thank you all. Were all 3 of the carburetors, completely box stock, except for the vacuum secondary spring change, or were they previously set up in any way, by Dave?
Thanks for the question, the 670 Avenger came stock with 65/68 jetting. Ended up with 68/71 jets. The Brawler and the Slayer were both box stock didn't need any tuning
In 1980 I had a ‘65 Fastback 289/C4 and it would outrun my friends’71 GTO 400/Th400. He got pissed and bought an old Pontiac convertible with a 455 and swapped it in.....I still blew his doors off....he gave up. I had a ‘62 Falcon Ranchero drag car with a 289/C4 that ran 11’s that was much quicker than the Fastback! Nobody believes this story which makes it even sweeter! 😂😂😂
I believe you! Thanks for commenting.AG
Your friend should’ve put the 400 heads on the 455. A little bit of cam and carb and he could’ve eaten all 289 fords he could find.
@@jerryhablitzel3333 Absolutely not! My 289 drag car weighed 2180 lbs. That tank GTO with a big block probably weighed just under 4000 lbs......which would require 500 HP to run 11.80’s. Them big Pontiacs have plenty of torque but they don’t make shit for HP without a lot of money to make them rev! Torque is grand for a street car, but HP wins drag races especially in a light weight car!
289 nice motor 455 just be tire burner while yours will launch better and that why.
I raced very high hp motors and beat them with less but it is effective Hp not max unless they are at the track and they can get can get traction. I raced a guy who got put in other lane I bet him all because of traction
@@jmanke6057 That GTO had 50 series tires on it and didn’t spin....
It would have been great to also see a Eddy VRS carb tested, just for a comparison!
Those new Edelbrock carbs look great, not a fan of the multi circuit carbs, but I would love to try one
That vrs leaves all holleys in the dust .
Thanks Alleyoop, i do have an Edelbrock carb, maybe we will include it in the next test. AG
@@goldsgarage8236 The Eddy VRS looks like a Holley, but they are a $1,000 carb!
@@alleyoop1234 I would like to get my hands on the new edelbrock VRS. Like I mentioned they are like a 4 circuit carb, lot's of tunability.
We're in the middle of a 389 build (actually with a 400 block since the 389 block was split in the lifter valley) using the 389 heads and just a flat tappet cam. If you're making 358, I guess we can expect maybe 330 HP.
Thanks for the comment Yarrda. If you have a 400 block, then you have a 400 now. Depends on the cam. A bigger cam will make torque at a higher RPM, so more HP. but with a loss of drivability. With a street cam about 350 is tylical.AG
Carb selection is critical
No kidding.
For sure, thanks AG
Edelbrock carbs are easy to tune and jet without taking them apart. I also like they don’t have any rubber gaskets or power valves that can go bad with age and I ethanol fuel.
Thanks Dew. I have an Edelbrock here as well as the original Carter AFB's from a 409. Maybe we can do some testing on them in the future. Edelbrock is a very popular carburetor. AG
I'm a pontiac guy for 40 years. Pontiac guys will tell you those headers are killing hp bc of the center ports sharing one tube. Thank you for your knowledge and videos USA 🇺🇸 TRUMP
Thanks Patrick. They are just my dyno headers. Todd will be using the Pontiac manifolds in the car. AG
I ve never worked on Pontiac heads but have been told that their ex. Ports are lacking and the camshaft cores are small
The best carb ive ever bought box stock was the hp4780 it picked up 40hp on every engine we put it on!
Thanks for your comment Anthony. 40HP is impressive. AG
@@goldsgarage8236 over a tuned 650 though and a 750 double pumpers! Just sumthing about that 800
Please include the specific model number of the Holley carbs being tested
Dave, have you got this? AG
670 Holley Street Avenger Vacuum Secondary
650 Brawler Mechanical Secondary
750 quick fuel slayer Vacuum Secondary
Add 20 to 30 horsepower to the 357 (377 to 387).
Because the water 💧 pump at @ 6,000 rpm consumes that mych horsepower.
Thanks for your comment Billy. For sure the water pump uses power, not sure how much. An electric pump would definitely improve the numbers. AG
I wish you'd do some fords especially the 351 Cleveland
We plan to do that in the future. Thanks for the suggestion.AG
So a 670 street avenger isn't actually flowing 670cfm? I was considering going from a edelbrock 750 to the 670 street avenger just to see what all the fuss is about, but if it flows less air is it going to make less power?
Thanks Moose, the engine will take how much CFM it needs. Typically on the dyno, that is leagss than the CFM rating of the carburetor. Without knowing more about your engine, I would say, keep your Edelbrock 750.
I'm interested in a t-shirt and hat AG. Have you thought about decals too?
Thanks Steve. We are trying to determine if there is enough demand for now. I will keep you informed.AG
the best carb for the street hands down is spread bore carb. Q-jet or Holley 4165/4175. the 4175 is vacuum secondary and has been discontinued for a very long time but you can still get a 4165. the Edelbrock Quadra-Jet #1910. they have also been discontinued for a long time. but if you can find one, that is the best Q-jet ever made. and really the only Q-Jet designed for performance. the smaller primaries increase throttle response and improve fuel economy from off idle to about 2500 rpm. the large secondary provides plenty of air flow for high performance needs. Both Pontiac and Buick both used Q-jets on all their high-performance engines. the Holley 5165/4175 flows about 600CFM, the factory Q-jets were all around 750 CFM with the exception of a few high performance Pontiac and Buick carbs that were 800CFM, the Edelbrock Performer RPM Quadrajet #1910 is about 850 CFM. you can make more power with Holley or Carter/Edelbrock AFB, but you sacrifice in throttle response and fuel economy at idle, off idle and cruising RPM ranges. and honestly on engine below 400 HP range, you really won't see a difference from a Holley at the higher end of the RPM range, but you will certainly see the loss of drivability on at lower rpms. I am not hating on the Holley and the Holley clones. they are good carbs and probably the best for racing application due to the better tuneability with things like replaceable high and low speed air bleeds. but simply due to the spread bore design of the Q-jet vs the square bore design of the Holley and Edelbrock/Carter AFB's, it is impossible for them to match the low-speed drivability of a Q-jet. that just my 2 cents. i know the Q-jet is one of the most hated crabs out there. but it is not the fault of the carbs design, it is because of lack of knowledge on how to tune it, and the difficulty in tuning the primary side of the carb, which required disassembly to change primary jets and primary metering rods. but once you have the primary side dialed in, it's easier to tune the secondary side, then even a Holley. just swap the rods and hangers for the secondaries. 1 screw and you don't have to remove the fuel bowls. the only other draw back to the Q-jet is the small fuel bowl size. but you don't need that on a streetcar. you can compensate for the smaller fuel bowl with a bigger needle and seat assembly. but it still won't be a good as a Holley or AFB fuel bowl. one benefit to the smaller fuel bowl is less heat saturation of the fuel and they are less likely to get vapor lock.
I like quadrajets as well, bit more difficult to tune the primaries. But once that done you're correct one screw, pair of Metering rods and a hanger
I think e dominator would give more hp. But I could be wrong.as usual thanks for a great video
I dont think a dominator would be a wise choice for this build. The owner doesnt seem like he wants to be pulled over along side the road with the hood up and a flat blade screwdriver leaning over a hot engine because his car is running crappy
@@jaminturner4585 I thought as a test of that engine and others. personally, I think the dominator gives the most hp, maybe every time
@GoldsGarage- Around the 28:15 to 28:30 part, the guy saying shift @ a Low 4k to 4,200 Rpm, what is he talking about? You don't shift @ peak TQ. Ideally the shift point should be high enough, so that rpm doesn't drop below peak TQ., but sometimes this is not possible, but closer is better. If your going for quickest/best E.T. In a drag race, you should shift approx. 400 to 500 Rpm past your peak HP. So for the 750 vac. Sec. Carbed dyno pull, that would be a shift point of 5,400 to 5,500 Rpm. If peak Hp @ a given Rpm is not known, i make a pass shifting @ 5k, cool the engine to same temp as the prior run, and shift 250 Rpm higher. If E.T. keeps improving, i keep repeating this procedure, increasing the shift Rpm 250 per run, until the E.T. stops improving. I have drag raced, for over 30 years, and this has worked very well for finding the best E.T.s. Thanks for taking all of your time, to make this video❤️
And thank you for taking time to watch it and share your own knowledge and experience Evil.AG
Can you test a Holley Spread Bore like the one that came with my 1968 SS 396 ?
A Holley spreadbore is an aftermarket carb. They're not as common like they were before. The famous one is the 6210 , 650 mechanical secondary. When there wasn't many options for intake manifolds, and guys were using their stock intakes, guys were buying these spreadbore Holleys. They worked pretty good
Thanks for replying Dave. AG
Excellent video AG!!
Where can i purchase some of those springs??
Any speed shop can get them, it comes as a kit with all springs
Holley or AED sells the springs
Thank you. I'll look into it.👍@@daveforrest6243
Nice info here. I just subscribed. Question. I have an early 350 4 speed roller rebuild and it’s gonna be almost 450 hp. What’s best for secondaries on my 4 speed corvette. Mechanical or vacuum? Thanks again and I look forward to hearing from you. Also thanks to you I’ve made the switch to roller from now on.
Thanks for the question Rick. Vacuum secondaries work great on the street, I would go with vacuum. AG
i bought a new 850 holley dp in 1986 or 1987. mech sec. it ran great for many years on my 428 ford,real snappy for a 850. i bought a new 850 in 2020 just like it,but it is nowhere as snappy as the old one,so i put my old one back on and put the new one away
Thanks Lone, I cannot explain that? AG
Roller camshafts and lifters give peace of mind from flat tappet cams, but if link bars, their pins or the roller needle bearings fail its wipes out faster than flat tappets and the engine. Buy Amzoil z-rod oil or Joe Gibbs Racing GP1 engine oil for flat tappet setups.
Thanks Anthony.AG
@@goldsgarage8236 I choose a hydraulic flat tappet cam for a street performance build from David Vizard's book. All new Dart SHP 400 block 4.125" bore, Scat F-43 lite weight internally balanced 3.75" stroker crank, 6" Scat stroker rods ARP bolts, Mahle flat top pistons, block decked 9.005", .011" ss shim copper coat sprayed to .013", 11.5:1+ CR, ARP head studs and ported/polished 64cc Edelbrock Performer heads. Cranking pressure @ 8500' elevation 200psi.. Lunati nitride coated DV 268 HFT camshaft @105 LSA, .538" lift w/1.65 ratio CompCams XD roller rockers, 3/8" pushrods, CC adj. timing gear dual roller and CC removable timing cover.
I built this engine following very tip and trick in DV's how to build book 'Max-Performance Chevy Small-Blocks On A Budget' but didn't go budget. Also FiTech Mean Street 800 HP EFI and the Ram-Air Cold Air-box, lots more. Great read and information, I highly recommend it!
I only see 1 type of carb and thats holley. Wheres the Q-jets and edelbrocks? Or maybe thermoquads?
Thanks for the question. In this video, the customer just wanted a Holley. We will test a variety of carburetors including the Quadrajet in the next dyno video. AG
Im hoping to upgrade my pierburg 2e3 carburettor on my transporter T3 van that has 1.9 WBX engine. Mostly for fuel economy and reliability. Any ideas what should I go for?
Sorry Crotoan, I don't have any experience in this area.AG
What!
No Edelbrock VRS?
I’m disappointed
Thanks for watching and commenting TK.AG
Were you dynoing that engine without secondary extensions on the headers? I couldn't tell if they were hidden in the extractor tube..
There was 12” extensions on it.
I have a Chinese Edelbrock off. Amazon. cost me two hundred and seventeen dollars It's an avs 2 but unlike Edelbrock it came with Site glasses and you can adjust the Float from outside the Carburetor. Took some tuning, but it's the best carburetor I've had. And i've had them all
Thanks for the info David.AG
What a missed opportunity for that 389 to really make some great reliable power. A Butler 4.25 stroker kit and Butler Ram Air series rolling cam would have made so much more power. Honestly, I think y'all really missed on the off the shelf camshaft.
Thanks for your comments Midnight.AG
lets see a holley 3 barrel test
I have not seen a Holley 3 barrel for a long time, does anyone have one? AG
What vac sec spring did u use on the largest /final carb??
Can u overlay torque/ hp curves ??
On the Slayer they use a purple spring as well, as an added feature they use a more or less a mixture screw, this limits the vacuum source to the diaphragm
Thanks for helping me with the comments Dave.AG
My last bracket car ran 12.63 at 104 with an 1850 600 CFM vac secondary carb on a Performer intake. The problem was that the foot brake class was 13.00 and slower so I had to retard the timing and limit the throttle pedal travel. This was at Commerce, GA in the early 90s.
which car was that, i use to race there.
@@MidnightinSavannah White 78 Camaro with black lettering. Raystech Racing was the sponsor on the sides. Fully stripped. It weighed about 2800 with me in it. 4.88 gear. The ET/weight calculation said 286 hp . shifted it at 5000, 6300 through the lights. Dial in at 13.00 and better drag the brakes at the finish line.
I have a 91 Chevy Truck. It's a TBI 350. Is there any way to get decent Horsepower out of this type of Fuel System? I'm only wanting 300 Horses,plus a 100 Shot of Nitrous.
TBI Cylinder heads and that 2 barrel TBI is choking your engine
@@daveforrest6243 So what would be my best option? Thank you for responding. 👌🏿
@@johncalhoun8011 well like I mentioned better cylinder heads, your TBI heads don't flow well, the aftermarket is endless on cylinder heads, your 2 barrel TBI isn't going to flow enough air, so the choice is yours to go with a 4 barrel EFI or carburetor. Its fairly easy to get 350hp plus out of a 350.
@@daveforrest6243 Thank you Sir! I will do just that when I rebuild my Engine. 😊👌🏿
The 600 vac secondary might still give better drivability on the street.
True enough, the 670 street avenger and the true and tested 1850 600 are almost identical. So for a cruiser for best economy, agreed
aaa thanks job well done
Thanks Tim.AG
Is the AFR readout accurate on this dyno?
No that reading is comparing the fuel flow to the air coming in, its not an oxygen sensor in the exhaust
Were, all the carburetors stock, out of the box?
The Brawler and the Slayer were box stock. Perfect out of the box. 670 was 65/68 stock ended up 68/71 with a 6.5 power valve. Added the purple spring
if numbers matching, why not stick with the Rochester?
The single carb 389s for the '65 GTO utilized a Carter 4-bbl carb. I initially considered a Quadra-Jet because it looks similar to the old Carter carb. In the end I chose the Holley style carb mainly for its ease of maintainability.
Does this cause damage? Having your mechanical fuel pump installed with no fuel? I’m curious because I want to break-in an engine with an electric pump but I’ll be using a mechanical one.
Thanks for the question timbo. No it does not hurt the pump. AG
@@goldsgarage8236thank you for the timely response.
BTW, if you are concerned, you can purchase a block off plate (for some engines) to eliminate the pump during break in. AG
Why don't you test a Q-Jet
Thanks for the question Tim. We have tested Quadrajets on previous videos and we will do more in the future. AG
You left some horsepower on the table with the first 2 carbs. The A/F ratios on the first 2 carbs were too lean.
thanks Kevin.AG
Did umention what carb did the best nmbrs?
750 Slayer most power and torque, I will have to check the numbers
Pontiac engines suffer from some poor cylinder heads. It's great that you used a roller cam BUT with nothing better than those factory heads and I could not see the casting numbers but until you put some better heads on it you will struggle to get much above 350 HP. Just look back at all the older factory engines they never made any power even at 455 cubic inches. The cylinder heads are the key to every engine. Take a lesson from the LS engines, they use small cams but great heads and make great power. The vacuum secondary carbs are not opening fully because the engine with the stock low flowing heads is not demanding any more air and thus the carb doesn't need to open further. Even installing all those carbs with mechanical secondaries is not helping the power really and that tells the tale. When you look at the dyno numbers and see the torque numbers high at a low rpm and more than the HP then you have an engine that is struggling to breath. You can see the horsepower is flattening out because there is not enough air flow into the engine. All the Buick, Olds, and Pontiac engines suffer the same problem. They were made for large heavy vehicles that needed low end torque to get them moving, not high rpm were the horsepower is made. Chevrolet is the one that does that. A better carb test would be on an engine that has some real air demand like a 540 cubic inch BBC and let's see which carb is the restriction.
There probably a roller cam In the motor because most engine builders won't risk putting a flat tappet cam in the motor with all the problems of rolling the dice and having a cam go flat and ruin the motor. You are definitely right about the heads. There is a reason they made the ram air 5 head to make good power. Pontiac was onto head design for making power and then the performance era was killed.
Thanks for your comments guys. AG
Those holley square bore carbs, vac and mech secondarys all get horrible gas milage on the street. Just running on primarys.
Should have shown benefits of a Q-jet, and Carter based Edelbrock carbs..
Thanks for your comments Terry. We will do more testing with Quadrajets and Edelbrock carbs. I also have a Carter AFB from a 409 to test. we will get to it. AG
Compared to torque and HP numbers, the 650 DP won this, with the huge increase of power. It is suprising that the 100CFM larger carb made very small gains over the smaller 650DP, that would tell me the engine wants the DP better than the larger VS carb. numbers don't lie, but you can read the results to say what ever you like, lol
Thanks for your comment Lane.AG
Quick fuel for the win...dp is better for track... I have 750 slayer on my 318...with 1 Inch spacer. Made good torque and top end, so it depends on the application. Vehicle weight, etc. Thanks
Holley came out with the “shiny” finish in the nineties and ever since they charge you MORE for the old style gold finish than they do the shiny plated finish. WHY? U prefer the original gold finish but why do they charge more for a finish that is just a dip whereas the zinc plating should be more labor intensive? Is the gold finish not EPA friendly or something?
Good points Angela. I still like the original finish.AG
It all depends on the size and tune of the motor and car! If it's a daily driver you should err on the smaller side! In my opinion! I used to have a 68 Camaro daily driver with a 12 1/2 to one 454 with a opened up 800 double pumper. The car had a stock converter and 4.10 gears! It would pass anything but a gas station! Ha! Ha!
Thanks for contributing Rick. AG
I used to believe that crap about carburetors could be too big as well. It's not true. They are sometimes set up for a larger engine but that doesn't mean you can't tune them to any application. Because they work only on the amount of air that goes through them, you just tune them to the application you can't have two smaller carburetor but you can't have two large of one
Thanks for your thoughts 44. AG
The carburetor should be paired with a fuel pump ! A weak fuel pump won't keep up with the pressure needed to idle.. I installed a demon carburetor on my 383 68 Camaro, the idle was terrible and belching fumes out the tail pipe, I installed a high pressure electric pump with a regulator and the problem disappeared.
Thanks for watching and commenting D.AG
Paddle wheels on the fuel line... what..?
Dave or Darrell, can you please respond to this comment.AG
Its like a vane wheel it measures how much fuel is being used @@goldsgarage8236
👍🇺🇸
Thanks Mike.AG
I don't care what they say about about fuel injection, carburetor's make more HP and torque!
Thanks for your comment Anthony.AG
Good morning really like your shows what's the best street carburetor for a small block Ford 289 mild cam automatic transmission mild torque converter
Thanks for the question Dale. i would think that a 390 Holley would be sufficient. Not sure if they can be available with vacuum secondary. Dave Forrest, can you comment here please? AG
@@goldsgarage8236 I have a Edelbrock 500 on it now and friends tell me I should buy a 600 for more airflow?
I would personally run a 600 vacuum secondary 1850
Holly vs Holly vs Holly,,,,, which is better? Quadrajet!
Thanks for watching and commenting Bil.AG
thanks Wayne.AG
Again 👍
Thanks Marc. AG
Looks like a dyno mule spit a rod out the side of the block and blew a hole in the wall.
Good observation Toby, just glad it wasn't mine.AG
A long time ago a friend wanted to sell me a 750 cfm AFB. For those of you who are wondering I would have bought it but I tried it out on my 1971 olds Cutlass 455 at Hallsville dragway and it ran exactly the same time as my stock quadrajet. Sorry but I can't buy it my friend.
Thanks for sharing your experience Christopher.AG
I ran a 670 SA on a mild 390 fe and that was the biggest joke of a carb ive ever owned.
Box stock, they don't run well unless it's on a stock 350, I had to jet it up 3 sizes front and back
Low HP for a 389 with a roller
I run a 750 brawler on my 389. It makes 527/554
I like the 33101 which is the drop booster and flowing 780, with jets in secondary metering block.
3 tube pontiac headers, yes switch to a 4 tube header on this engine and see how much HP gain you get with real 4 tube headers.
Thanks Skip. these are just my shop headers. Todd will be using the Pontiac manifolds in the car. AG
I run 3 tube headers on my mild 400, but I would just love to see a head to head comparison between 3 tube and 4 tube pontiac headers on the same engine back to back pulls.
Not entirely true about rollers be the savior. The roller lifter has a failure rate also. What %tage I'm unsure, BUT we are being bombarded with junk from across the pond and the companies we relied upon 20 years ago have been taken over by the offspring of the original owner. They know only one thing of business and that is: How much profit can we make? I won't name names but this Hobby is serious trouble. I know who's to blame, it ALL started in the '60's.
Back to the flat tappets vs rollers when the open spring pressure goes over 1000 PSI a lot of the rollers are failing.
Thanks for your comments Anthony. My engines never get anywhere near 1000 lb. force. AG