Holley Carb Secrets... Get the most out of your Holley! 

Thanks Andy! Quality content! Not many people get in depth on carb tuning all makes sense. Thanks!

Thank-you so much for sharing your knowledge with us; you're a great mentor yourself and I reckon David is proud of you, (I've been a huge fan of DV for some time now). Hey, can you share with us where you source the plugs that you use for circuit restrictors?

I have a Fox 302 bracket car with 650 DP your videos have really help me, looking forward to learning more tuneing tips. Jetting for different weather would be nice.

I bought a 750 both times I had to purchase a streetcar band bought a 1100 for strip I am small time myself but my buddy’s they go all the way and I mean all the way but I haven’t been around the strip in a long while

Could you do a video on how to backwoods change the boosters out I have 2 carbs I want to change to annual and do you change out the secondary boosters to or just primaries

Lol nice, your video has the same name as my holley play list. When I was starting out, I watched a lot of your older carb videos and they really helped me understand Holleys. Now I build 100% tunable carbs for myself and know more than pretty much any "old timer" at any car show 👌

The timing of this is so perfect. Can’t wait for the 4 corner idle info. I’ve got a 650 DP that is in desperate need of a freshen up. Thanks

Best carb video I’ve watched on RU-vid

Great video. I just subscribed and will check out others. I have Dave's book. My race friend says I need to follow what you guys say.

G'day Andy , have u dragged ur Truck as yet ? And if so how did U go ? Another Q) 4U . How hard is it 2 find the Predator ×2 5000 or 6000 series in the USA .

Any video that starts with "whatsup everybody", I click off. Just letting you know before I go. Bye!

Something I learned recently is they make a throttle shaft bushing tool kit to repair worn throttle shafts. It comes with the drill bit and a brass sleeve, and it looks super easy to use. I'm going to fix my vacuum secondary spread bore 750 demon. And if it works good it will save a buttload of old carbs

Carburetion generally yields more power than EFI when they have a spot on tune. They tend to outflow air wise an EFI setup.

well I make video 600 Holley stock factory adjusted and LIST 8007 / 2871 and LIST 1850-3 087 if you can help need work Hot Rod magazine 80 front jets 90 rear jets new power valve & adjust OK to reply to channel Hoonigans runway drags etc. Tommy is old friend back in the day

I fix with The air bleed( low) sixpack.Littel bigger air bleed runns better on The idel.13.7-13.9. winter are coming (Sweden) Spell like hell..

This is a great how-to and WHY video, Andy. Thanks so much!

The 400 cu.in low block Mopar was new and not much race stuff was known so all I had was whatever 383 stuff was available.

Having DV in your corner is awesome! Great video! I'm a recent subscriber so I'm catching up on the older videos.

Ive always lived in mild climates, most of the time I remove the choke plate and toss it like a frisbee, pump the gas pedal a few times with ignition delete, crank the motor (my 2,3) then fire it up

I really wanted to use my holley 4160 on my LS with a 222/232 .550 cam but it was just pouring fuel out the tail pipes I did everything I could and all I was able to get was it to idle at 700rpm and it would still pour gas , the last thing iwas gonna try was lowering the float and the fuel just started pouring out the base plate , I got so irritated with it I tossed it and just threw my double pumper on it and it's running very well now I really don't know what I'm doing I'm new to holleys but lol imagine trying to learn on a leaky 1850

On an engine that's making good idle vacuum, ya know, more of a daily driver type, the IFR wire trick actually covers the transfer slot tuning too, and works best if the wire is sized to the transfer slot requirements. This is because the vacuum at idle and cruise on a stocker are much closer together than something cammed that only makes vacuum at cruise, which really negates the need for a separate circuit. Usually the idle circuit still has plenty of fuel left to do what it needs to do. I know your content is more racing oriented, but this could definitely still be relevant to lots of your viewers And don't think I'm trying to just smartass you here, you're actually the guy who turned me on to this idea in the first place! I just took what I learned from your channel and applied it to something much, much more mild than Casper. The end results I got out of my Holley outshined the Q-Jet it replaced in every single way. Economy, power, burnouts, you name it... These carbs can be made to work as good as any other in a daily with enough patience and attention, and you're one of the folks I have to thank for guiding me to that point. Thank you for the knowledge my man (And to those of you still reading this far down in this now embarrassingly long comment, if you wish to try the IFR wire trick, electric guitar strings are the absolute best for this. Precisely measured single strand wire available in .008" in diameter and up in .001" increments. Seriously can't beat it for hardcore precision tuning on a daily)

ANY ENGINE UPDATE? I HAD A HOLLEY 500, 600, 750 AND 850 ALL VAC STYLE NEVER HAD ONE PROBLEM

Great video. I like the drag footage and go-pro video. After helping UTG solve his problem based on phone call it is clear that you know what you’re doing. Now I need to go look for your other carb videos because although I’m old enough to have grown up with carbs I’ve never been able to tune one. Never to late to learn. Thanks again Andy.

I have a few ( ok More than a few) vintage Mx bikes and carb tuning is both straightforward and at times challenging. “ You are the computer “ says it all. I ran double pumpers on the street when young and just re jetted , changed and adjusted accelerator pump cams etc and got them to work nice . I was too stupid to know I should’ve failed at it .

Good information, "but" if you care to be taken seriously as a well spoken educated professional, try not to use the word "but". I counted the use of the word 15 times. Just food for thought to help you speak the English language correctly. Take care and have a great day.

Mate i really like your videos. Would you mind telling me what booster would be best for me I have a 351c with a mild cam dual plane intake manifold non heated with a holley 600 cfm single feed two corner idle with a 1.5 inch spacer Will an annular booster better I also have very very lean idle when cold like 16 17 afr and the when hot it can come down sometimes to 12 at idle after being in the power circut too much or some lite driving

just found your channel over the last couple of days looking into tunnel ram tuning before getting one, love all the info you have. subscribed!!!!!

Question...how in the world can my engine guy have a Holley 500cfm 2 barrel that's been turned into a 450cfm for round track racing make 30 more HP than my 450 that is legal for my class... he swears his carb is legal and will pass tech...is there any help for mine without technically being illegal?

I love it when someone figures out how to make “trash” work like a dream. Good video Andy looking forward to watching part two.

love your videos I bought David's book on carburators about 35 years ago when I was running the same intake you have on mixed up boss it helped alot getting my cleveland to go in the 9's in a 53 studebaker . swtill have that cleveland might put it back in service in a 65 falcon . but I do appriciate your videos .

Outstanding tutorial, I thought I knew plenty about the Holley, now I know more, keep the faith brother. Keep on rocking that BLUE OVAL.

Almost makes me want a Holley to play with! Wonder what would work well for a blow through setup for a turbo poly 318. :-)

Even though I haven't raced in many years, I still enjoy watching videos like yours. Thanks Andy & keep the Fords a fly'n!❤

Hi Andy, I have what is probably a dumb question. I have a dual plane intake but my carb linkage plate is a single plane mount under the carb. This plate is 1/8th of an inch in thickness and being single plane Im wondering if pressure pulses coming back up the intake will cause interference across the dual planes, since this linkage plate does not separate/isolate the planes (allowing a gap of 1/8th of an inch or the thickness of the mount). Does this sound plausible that I could be getting pressure pulse interference?

The exact same throttle blade button head cap screws as I put in my Holley more than 25 years ago. It also had the brass feed restrictions that I also made myself before I had the RU-vid, social media or the internet.

What's your opinion on the street series Holley brawler double pumpers? Buy one or rebuild a 4779?

A 2 part white epoxy called Marine Tex works great on carb issues . its heat and cold proof and with stood a 48 hour test submerged in gasoline. I found it works great for re-gluing the fuel caps back on under the plastic body on thermoquad carbs . I bought it on amazon . 17.00 white box with red and blue lettering . you get a white paste in a small container and a clear glass vile of clear hardner . it's even sandable get stuff .

Good video, But I feel people don't correctly modify their Distributer or set the base timing correctly. They complain the carb is messed up.

Thanks Andy! Real informative. I have never played much with boosters, different types. I have a 1982 fox body with a 351, always smells a lot like those "cap" guns we had as kids, when you give it the gas. I've messed with jetting, and the idle restrictor, accelerator pump.

Thank you for doing the reboot of this topic. I've got the Holley 4150& 4160 red book and DV's How to Super Tune and Modify Holley Carburetors. I've gone through the red book and half way through DV's book. I will say that watching these videos is really helping to put the rubber on the road. I'm a kinesthetic learner, so the more hands on I get the more it will make sense. For not it's a virtual hands, but I'm looking for good junk carb to take apart and mess with to help with that learning process. Trouble is people want too much. I'd love to find someone that has a cracked carb with warn out shafts and give then $50 for it so I can play and learn. It's the details. How to remove the transfer slot restricture and how far in do you drill? Obviously it is not all the way though, so there must be some measurement that needs to be learned or communicated.

Thx for the explanations

Great Video...David is the man!! You had an amazing mentor..

Awesome video ! Really appreciate your knowledge and sharing it with us ! I remember my dad always saying talk to the older mechanics at a garage. And I’m not saying your old ! And asked why he said that. He said because things aren’t always stock and to understand exactly how things work and what they need to work correctly only comes from experience !! And you, my friend, clearly have that kind of experience !! Always appreciate your videos Andy!! Take care

Hi Andy, Do you think these small annular boosters have enough area behind the annular insert to flow enough fuel for a 625 hp small block that turns 8400 rpms on a 1/2 mile dirt track? Using a 750 Holley centre section...Thanks love all that you and David do!

660 centre squirters on a Edelbrock X-C96 X-RAM with 650 hp . What's Ur thoughts Andy pls ?? Or Holley Sniper EFI ...

Andy I always thought i was a Holley guru and for the most part I have been but buddy there is a boat load of information I’ve learned from you and for that i thank you sir……. You are the man 👍👍👍👍👍👍✅✅✅✅✅✅❤️❤️❤️❤️❤️❤️

I'm idling around 13.5 on my HP950 after it warms up. But 12.5 when it is cold. (No choke) no issues any where else. Is that a good idle AFR?

Hi Andy, thanks for sharing the details, I just pulled the holleys off my impala to put restrictors into the carb body's. Almost operating perfectly just isn't good enough now that I understand how to limit the flow to the off idle circuit. Can't wait to see Casper running again.

I always loved tuning on a carb, especially a holly. Nothing Beats a good book on hollys. Thanks for the booster info. I never totally understood the reason for different boosters but now i do. Thanks andy love the videos

Interesting discussion here on boosters. One thing your video doesn’t mention and 99% of other’s don’t (not a bad thing) is mixed boosters. I learned this recently but I didn’t realize Ford actually used annular primary and down leg secondary boosters on their Holley carburetors that were used in the final carburetor Mustangs. I would be interested to see a carburetor test with that kind of setup on a tuned aftermarket carburetor.

I'm running a 532 stroker in my jet boat mild build 600 hp. Edelbrok torkerII intake WHAT HOLLY carburetor do you think would be good to purchase for it? Thanks

Good video mate! Can you show us how you change the boosters please. I’d like to do it myself. The ones that screw in like you gave UTG Thanks

Did you change the rear metering plate.on the 660s

Is this secondary adjustment screw also on a vacuum secondary carb?

Cant fathom having vizard in your corner,,,how cool

I have a street demon 750 that has annular boosters in the main (front) two barrels and downleg boosters in the secondarys (rear two barrels) what would be the advantage to this type of set up? Have not used carb yet but I plan on putting it on a big block Mopar

Good Video and thanks for sharing! Are you gonna change the cam for mixed up Boss?? I saw Darin Morgan podcast on DragBoss Garage: You could use more cam with those heads and that Cubic inch displacement! My 430W with TFS 225 R Series from TEA is using more cam than the mixed up boss. I made 716/592 on motor; see video here ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-kfjikQnWjxM.html Your combo has way more potential with those heads. Curious to see what you do.

Oh and have to mention this was with the first of the Edelbrock Tarantula manifolds. I had done the oiling system mods recommend by Chrysler for engine seeing 6500 rom or more with a milodon 7 qt pan.

l glad you brought this up as I have experienced some of this . I was at the finals at San Antonio years ago running a 68 Camaro power glide with a 427 and a 9 inch . I took the 1050 off it and carried it to the holly tech booth . He removed the float bowels and installed new gasket adjusted the floats and installed 2.5 power valves . That the only size he had . I never for got . Later on I took my 302 that had a lot of cam and a decent heads off a g gas car that had set the record once and installed it in a econ rail with a power glide . Sure enough it ran rich at idle in gear . I drilled the holes in the throttle plate and installed the wire in the mettering plate as you suggested and the 2.5 power valve . I ran reo pumps and I used the trial and error on the nozzles . That fixed the idle problem . I talked to T Willy at isky and he said I could use less cam as I was running a 600 isky roller . That was a long time ago . If I had it to do over I use a ls and a lot more cubic inches . Thanks for the videos

Cool vid 👍🏼🏁 Totally agree on the booster selection✅ Have a story of my own on that topic, wrong carb / booster was worth almost 5tenths back in the day on my na 4V Cleveland. It ran strong but Once the right carb was put on, my god!....... was like a 100 shot of nos lol night n day difference 🤷🏼‍♂️🏁

is an annular booster or a down leg for a 45-7500 rpm 306? my 700 straight leg i believe is causing unequal fuel in the chamber and i believe might contribute to some detonation rich/lean areas of the camber. my thoughts were annular for mixing and a bit more torque at the hit and move to an 830 from the 700 (9381) thanks Andy, where in Tn are you?

When i first saw that kit you sent Tony over at UTG I became very interested in the matter. Is that a one of a few kits you have some up with for experimentation or are they available for others?

I tuned my 2 POS Holly Carbs with a SLEDGEHAMMER !! I Smashed the $hit out of them....... NO MORE cylinders being washed down w/fuel & NO MORE STUPID POWER VALVES 1 of my Happiest Days of my Life was Installing a Carter AFB Carb on my 340'Cuda. The Carter gave BETTER drivability, ease of starting & Performance !!!! To say I had a 3 years bad experience with Holly Carbs is an understatement

What are your thoughts on the Thompson power last plates? I have a Holman Moody boss 429 that has a box ram intake that has a slight big when you nail it during acceleration. There is a video of it on our you tube channel that is old and we haven’t done much with if you need to see it it is under Henk Brothers. I don’t drive it much but it bothers me and I would like to fix that. Great videos by the way ! Can’t wait to see Casper running those Hammerheads.

I have a 950 HP and it runs 11:1 af from 2200 and up idle is 12:8 l don't think that is bad. I have an aggressive cam 268/274 duration at .050. The carb has .073 primary jets and a 3.5 PV any guidance would be appreciated

Getcha notebooks out! KING Andy isa speaking!

Wow I didn't know

GOOD STUFF!

Thanks for teaching about Holly

I am loving your videos my wife recently surprised me by buying me a 1923 T Bucket Roadster small block Chevy 350 with a mild cam I really want to put a dual quad tunnel ram on my motor I was really hoping that you could tell me what would be the best tunnel ram for it and what two Holly carbs should I run. by watching your video I know I should run a one-to-one linkage a vacuum secondary and a annular booster with your help I would know which tunnel ram to get and what 2 Holley carburetors to buy

You sound like you know your stuff, I have a 360ci sbc. Having rich issues on idle burn your eyes. 550 lift came 10 degrees on cam. 750 quick fuel helpppp

I used to run a Holley 390 four barrel carb on a split port manifold (offy) on a lima 2.3,so the two primary throttles fed the top half of the port (divider), which would ice up due to port velocity, and when the second second throttle opens up hahaha, my lima had engine other mods......I dont give a fuck what tony says, but if your running a 4 barrel carb, on a after market slant six manifold, The carb has to have the primaries face the fucking valve cover, plus a two inch spacer under the carb, , to increase plenum volume .

running a 426 cub Ford fe with a dual plane heated intake, spent tones of money on a proform 950 and its too rich for the engine, motor makes about 425 horse. got the billet base plate and billet metering blocks with tunable air bleeds but i don't have a clue where to start to make it run on the engine. the engine will run above 4500 rpm but not below the 4500 rpm

this is a great follow up video to uncle tonys I commented on about tuning the holley carb for a tunnel ram setup really appreciate extra levels of detail you go into. can i ask where you order the brass inserts you use or if you have a kit with the drill bit, tap and inserts needed to perform these modifications i could order from you?

I suddenly realize I don't even know how to change jets !!!!!! Great video, and one sure to be referenced by many !!!!

Love the video! Thanks for the great information!

can i tune a spread bore or Q jet carburetor to get awesome precise performance the same as an HP ultra or Pro systems SV? because i am leaning toward the SV for an all out fuel mileage record holder build. Although i like q jets and spread bore for their part throttle and wot dual personality. This is a performance/fuel economy build with major emphasis on efficiency. The engine is pump gas of varying qualities. The fuel cell is 40 gallons.

I bought a 650 holly carp from my nabor that bought it brand new and put it on his 350 chevy engine and he couldn't get it to work rite so it sat in the box for 5 or 6 year's I built a 289 in college wen I was going to be a machinist I had free use of all the machines so I built a super 289 the nabor sold me the holly for 35 dallars but I couldn't get it to work rite so I went to the wrecking yard and find a 750 and took the metering blocks and I took out the power value out it was a 2.5 if I stuck my foot in it I had to get out of it quick or it would die so I put a vacuum gage in side of the car so I could watch to see wear the vacuum would drop to it would drop to 4 inches of vacuum so I bought a 5.0 power valve put that in and when I put my foot in it it took all I could give it and never starved out again I also went to 850 jets and this 289 was willed I could beet a 454single tunnel ram wy holly puts in such a small power valve floors me that's why the nabor couldn't get it to work rite I put this engine in a 2 door versie I had a hot rod Lincoln I still have the engine and it's unreal just a story hope someone likes it

While I agree with all this, in that you absolutely can get a carb like that 660, or anything else for that matter, to work well on the street with enough time and effort (and sometimes money), but in the end your doing things with it that it was never designed to do, evident by the fact that to make it work you have to drill and tap, or use a piece of wire ina hole, or fill with epoxy to make it small, etc... I think all the "it's not a street-able carb" stories come from the fact that it's absolutely not a street-able carb in it's stock form, and it can't be made street-able without jury rig fixes like that to make it work in a way it wasn't designed to work from the factory. There's nothing wrong with doing fixes like that to make it work for what you need though as long as you have the know-how.

How did you get annular boosters in the 660s, I’m trying

I found the part about boosters very informative and good to know, something I didn't know. I have open the air bleed holes on some holleys to get them to idle without burning your eyes with unburned fuel.

It doesn't dump much fuel no 50 Cc pumps ,those holes are in the wrong spot those carbs need lots of help great for there time maybe but not for all out performance the modern day 650 double pump mechanical secondary is much better carb and has more potential

Great content topic Andy.

I was hoping you would add something like this to your library so I have a good as gold reference for doing what I need to do with my setup when I get it all assembled. Thanks for your video Unity Motor Sports!

Thank!!! You and D V are god’s of motors and you guys talk real. I can’t wait to see your next video. I have been going nuts till it comes out. Thank you again so much sir . Now I wish I had a Dino to test on to put all this together. Again thank you!

What stall converter was is Casper?

Andy, my hubby drills the hole inline with the slot and closer, says it may atomize the incoming fuel better ?

Do you think quik fuel 450 tunnel ram carb set would need 1/4 or 1/2 isolator

Great video Andy. Love any info on carbs, since I am so old school. 👍👍

Fantastic vid as usual Andy. Incredible seeing the boosters pass fuel in pulses as each intake valve opens!

andy i need a base plate for my 3310-3 750 what other 1's can i use...or do you have a old 1 you would like to sell

love your info all good stuff love the truck too. I do have a question for you you mentioned having too wide of a transfer slot causing rich issue you added a jet to the passage to control flow to it. I have exactly the same problem but lean. I have a brand new holley DP on my engine I have opened up IFR slightly to point where I only out 1 turn idle screws helped very little have replaced the screw in air bleeds etc spoke with holley tech. Of corse they tell you not to modify anything. Ignition is set to 18 deg idle 38 deg total cent adv and vacuum adv hooked to man vacuum set to 45 deg with full vacuum. comes on at 8 in vacuum and 6.5 power valve. still idles perfect AFR 14.5 ish cruise ok just slight accell goes lean 15 then 16 then 17 then 18 then 19 AFR you can feel a lean stumble at 19 in sometimes. This is all very light throttle, till at 10 in vac cruising the jets kick in and kit drops right down to 14 or 13 AFR again all light throttle. cant get enough full through the transfer slot and always have this lean condition in that light throttle area. idle vac is 12in using a 6.5 PV Im no where near that vacuum when this occurs so changing to a higher PV is not going to solve this. I need to get more fuel through the transfer slot. have you ever opened up the tran slot a couple thousandths like putting a larger jet in? Exactly the opposite of the scenario you spoke of in your video.

A few yrs ago I began a carb build of a dual feed 750 buying the new modern center section and base plate but metering info of entire carb is what I need to find and wondered if you can point me in a direction.I have carb books but they lack total info

Hello bud, running 650 on a 289. Runs rich black smoke. When I lean it out it loses vac. Float levels are good. Any ideas. Thank you.

Yes but your car doesn’t weight anything compared to the other car you were racing

I think the 660 doesn't come close to a real double pump Holley it worked in its day but that was long ago

Thanks for passing on the knowledge bro!!!👍🤠👍✅🇺🇸

I have a ton of DV books, for decades now. But maybe it's they way you described xfer slots and especially Boosters...I finally understand what booster and why. Also didn't know they actually pulsed! If you put this together on DVD or something, showing the different systems, and mild to wild carbs....I WOULD BUY IT. Hey you know DV, package it up, i'll buy it.

Another great informative video from Unity Motor Sports. Should me tackling Holley carburetor tuning easier, and a much less daunting task.

Haver to make the restrictions in the transfer slot orifice in both primary and seccondary sistems???