Holley Carb Secrets Part 2... Get the most out of your Holley!

We look into the Holley Carb and I talk about the different circuits and how they affect the fuel curve on your engine! I include my real world experiences that i have learned over the years that has shaped my understanding of the Holley Carb design This is a part 2 of 2 because there are alot of things to talk about regarding these Holley "Secrets" I hope you got something from these 2 videos!
#Holley #Carbtuning #Davidvizard
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[@terryheimerl8674]

Thank you. Another great informational video with no BS.

[@BareRoseGarage]

I have the reputation around here as "The Carb Guy", but watching your stuff shows how little I actually know (everything I do is for driving not racing). And I Thank You For That! Keep 'em coming Andy because you're freekin' GREAT!

[@UnityMotorSportsGarage]

Thanks for the kind words! It means alot to me. Andy

[@Lagrange1186]

I don’t think I’m anywhere near where you are with understanding holley carbs BUT I learned a TON of important information from this two part series. Thank you so much for taking the time to explain what you have learned over the years. And that tease on mixed up boss playing peekaboo in the background was almost mean! Have you decided what carbs you are gonna run on it yet?

[@UnityMotorSportsGarage]

I'm going to start out my 660's but I think a set of 850's will be more suited to the power it will be making! Thanks for Watching and the kind words Andy

[@thomasleclair7418]

@@UnityMotorSportsGarage ,,,,what size is that motor with the billet heads........Back in my day,,,,experts [Grumpy and Smokey ] kept there carb findings secret.......I'm 71.....Thanks again.....

[@UnityMotorSportsGarage]

@@thomasleclair7418 it's a 429" Stroker Windsor with BOSS 429 style heads... I ended up running 750 Dominator carbs on it! Thanks for watching.. I don't mind sharing what I have learned over the years... Andy

[@thomasleclair7418]

@@UnityMotorSportsGarage ,,,wow.....a windsor with super breathing heads,,,,,,,,,,,,devastating....................

[@LesMorrisracing]

Thank you so much on the Power Valve description (10 Stars) I purchased a Dominator from e-bay and the guy said he removed the PV and jetted up 10 on the main jets and it was junk. I rebuilt the carb when I got it put the factory PV back in it and ran it with no problems. I messed around with the air bleeds some and the jetting but the car ran the best with all of the stock stuff in the carb. ran 9.945 1/4 @ 136 and 9.2 1/8 mile @ 109 Thanks again for the video.

[@TonyGeneseo]

Another great video ! When u explain these things it is hard for me to not think : how did anyone come up with this as a fuel/ air delivery system for the earliest combustion engines ! But like anything it starts with smaller requirements and increased from there. I truly appreciate the endless and never ending research you’ve done and sharing your knowledge with us ! Looks Ike the channel is picking up viewers and momentum and I’m really happy to see that ! Take care Andy !

[@UnityMotorSportsGarage]

Thanks Tony... It is pretty amazing that the engineers could control fuel delivery like they did... What is really neat is to read some of the early SAE papers on the subject! It is amazing... That is a video in itself... Andy

[@dougevans9867]

I’ve been drilling on metering blocks for years this takes me further for sure

[@ratgasgarage]

Glad I went back to this segment, I bought a fresh build 402 bbc with a t ram setup with 660s dp, I looked down the carb and saw step down boosters and drilled throttle plates, so I need more learnings here, thanks for putting this out brother 👍 RatGasGarage Rgg

[@UnityMotorSportsGarage]

I'm glad you enjoyed it Andy

[@MEC1955]

THANK YOU AGAIN Andy!!! for letting more secrets out...you're making all us Hot Rodders life easier!!The information is Invaluable!!!!

[@UnityMotorSportsGarage]

Thank you for watching! I'm glad you enjoyed it... Andy

[@cjbert6790]

Good video, you do have a great understanding of carburetors.

[@lautburns4829]

Andy this is great information,please keep it coming . All this research is much need because so many new Rodders need it.

[@UnityMotorSportsGarage]

Thanks Laut! I will keep them coming... Andy

[@jr78racer]

Thanks for the great tech, Andy!

[@JC-gw3yo]

I've read the Holley manuals, but you definitely take tuning a step further

[@UnityMotorSportsGarage]

Thank you! Andy

[@thomasleclair7418]

,,,,lookin forward to part 3 ,,the topics will be much needed................

[@herbscheit2061]

Andy thanku for the great info,you have a legendary mentor and Casper sounds so skookum!

[@UnityMotorSportsGarage]

Thanks for the kind words Herb! Yes I'm very fortunate to have DV as my mentor! Thanks for Watching Andy

[@aml3961]

Awesome information here and your other videos as well . I'm also a faithful follower of DV as well. .id like to make one comment about a statement you made here regarding a VS carb perhaps being a better selection for a tall rear gear and automatic tranny application. I was running a stock low end flat top piston 1969 350 . Aftermarket aluminium heads with 202 valves and 200 cc runners. A dual plane air gap on top . This is in a 66 chevelle with th350 transmission and a tall 336 rear gear At first I had a VS 720 demon on the engine. (An older BG one that they stopped producing in around 2013 I think it was) it ran well on that engine but I wanted to try something different. So I bought a holley 750 DP brawler. After putting that carb on the engine felt like it gained 30 torque and hp after some dejetting and reworking of accelerator pump jets and air bleeds BUT it had the exact problem you talked about here where because of the tall gearing along with an automatic I got a huge lean bog from off idle to WOT . I fought with it trying to get it right for months and tried everything single thing I could think of but I couldn't get it. I finally threw the towel in and went to a holley 670 VS avenger. I put that on there and yes it ran perfectly and about flawlessly with little to no tuning BUT the bigger 750 dp carb on that engine would woop the crap out of that avenger. I was disappointed. I finally said to myself screw this. Theres GOT to be a way to make the 750 DP work on this engine and gearing combo . And BTW I did have a wide band incorporated into this set up from the start . I put the 750 DP back on the engine and round 2 began . I still couldn't get the lean off idle to wot bog to go away . Tried a very wide range of squirters and what I found was that the larger squirters which provide a bigger initial shot of fuel but in a shorter duration than the smaller squiters was improving my lean bog issue but did not eliminate it . So that got me to thinking that the engine was responding in a positive direction as I increased the initial shot of fuel . How could I increase it even more in order to overcome this off idle to WOT bog ?? Well I thought there is only ONE THING I havnt tried and that was changing the installed 35 cc accelerator pump bladder to the available 50 cc bladder. I bought the 50 cc bladder along with the recommended armature kit along with it and installed that and BOOM !!!! THAT WAS IT !! I layed into that sucker and it stayed right with me. Never lost a step and that motor was GETTIN IT lol. Only problem i had then was getting it to hook because the thing came out of the hole so violent. 336 mind you I bought a set of mt et street and that solved that. What a feeling it was To do what EVERYONE said id never be able to do which was .... Get the 750 dp to run right on my 350 with auto tranny and 336 gear . Without a doubt that carb on that engine in that car would stomp any other carb on it. Well that's my long story lol I hope it may have opened your eyes to another angle and others as well. That's what it's all about. Lending what we've gained to others. Except for the guys around town who want to race me for money 🤣

[@barryc.1689]

Once again, Spot On! Andy. Thanks so much for putting together and presenting this information. Highly accurate and well presented. 👍👍

[@vrm86gt]

Great info as usual Andy!

[@mikef-gi2dg]

I am going to look at my carbs a new way thanks 4 part 1 and 2.

[@UnityMotorSportsGarage]

I'm glad you enjoyed it Mike Andy

[@mikef-gi2dg]

@@UnityMotorSportsGarage Hey if you know DV, it's was smart on my part to partake.

[@jessewalker5413]

thank you for another great detailed video on holley carb tuning im getting real excited to start tinkering with my 600 vacuum secondaries ill be running on my tunnel ram 440 strip/street engine build that i can hopefully get finished and runnning for next year

[@patrickscahillii9365]

I always liked to Holley carb as I've been a mechanic since my teens and lots of people hated them, I always told them that they needed to take a little time and learn about the carb. Just like in school, apparently some people are better students than others.

[@UnityMotorSportsGarage]

You are right Patrick! Thanks for Watching Andy

[@PerformAlt]

Thank you for a great video with tuning tips for the vacuum secondary Holley. I have a 750 Mighty Demon vacuum secondary carb that I'm tuning on a 350 small block Chevy in a Chevy Luv pick up truck. You've given me a new direction to try and help eliminate a lean hesitation I'm having when I hit passing gear on my auto transmission.

[@8power857]

Hey good to see someone giving correct powervalve tuning advise for a change. Good work 👍

[@thomasleclair7418]

,,,,,,,,,,,,Thank you for dedication and hard work........I had to repair a friends [ BG 750 carb ] it had those screw in boosters and one came loose.....It should have been blue lock-tighted in place....Thanks for the info about Allstate carbs,,,,I will do business with them for sure.......Luv the TR-scoop on Casper and the 393 stroker....guess ya got a 3.875 crank in it......

[@gabrieldimarco9646]

Love your videos Andy, keep 'em coming.

[@UnityMotorSportsGarage]

Thanks Gabriel!

[@mikedeal8659]

Thanks Andy. I appreciate the time you put into this. I really enjoy the theory combined with real life examples (plus it always fun to see Casper run).

[@UnityMotorSportsGarage]

Thanks Mike! Andy

[@chrismedford6811]

Hey man thanks for the info, new on carbs myself. Getting my supercharger rotary going today an learned enough to hopefully get my fuel situation straight.

[@darneltyson6639]

More great info😅Thank u!

[@Lobo-tommy10]

Wow this is gold!

[@UnityMotorSportsGarage]

Glad you enjoyed it Tom.. Thanks for Watching Andy

[@bobganshaw364]

Excellent video, great job!

[@stephenwest798]

Thank you for sharing your knowledge with us, a lot of good info in this video. That hot humid weather is a killer on performance.

[@UnityMotorSportsGarage]

Thanks! YES hot humid weather is a big killer of performance! Andy

[@johnelliott7375]

I'm happy to see you are going to do more parts and series of videos on the carburator subject. Thanks for your help and your time with making this series to help us amateurs. Thanks again and I will share. Great Sunday to you and your family! Great up coming week to you! TTYL

[@UnityMotorSportsGarage]

Thanks John! There are many videos I plan on doing with these Holley Carbs... I hope you have a great week! Andy

[@johnelliott7375]

@@UnityMotorSportsGarage I hope you can do the same with your upcoming week Andy!

[@johnc7431]

Great video. I'm like a sponge I recently put a 302 together stock bottom in cam RPM manifold 650 double pumpe 2500 stall 373 rear end gears. Hole shot she bogs and then comes up on the RPMs trying to get rid of that bug do you have any suggestions.

[@UnityMotorSportsGarage]

John, it sounds like you need to up the accelerator pump squirter size to help cover the lean spot, you may have to try different pump cams. I will say that given the mild nature of your combo a vacuum secondary carb "could" work better.... I would still tweak the DP since you already have it! Hope this helps! Where does the converter flash to when you mat the throttle? Andy

[@bobcuomo5122]

Great video Andy !!!

[@alva1370]

Thank you for the knowledge Andy, I'm going to dig out a carb tomorrow and look at it in a completely new way.

[@UnityMotorSportsGarage]

I'm glad it helped you! Thanks for watching Andy

[@johnsalvaterra1355]

Thank you Andy! The video cleared up a couple of misconceptions I had. Nobody seems to play with the power valve other than the point of opening. So thanks for that info on sizing the openings. I also wonder when one might want a 4500 in place of a 4150.

[@MrTheHillfolk]

Haha don't even have a Holley but like to watch and think back on old situations I've been in, and finding the cure in this vid series. Darn it johnny , no wonder that old GTO ran like crap back in 89, it was the damn idle turned too high and getting into the transfer slots! Good stuff!

[@theshed8802]

I was getting worried when I saw part 2 of 2. I was expecting it to be part 2 of 7...and the other videos that you are talking about will probably get it there. Another great video Andy. One thing that I would like to say is that I always try to avoid using vacuum secondaries and spread bore carbys in situations where I need fine throttle control at higher RPM. I find that the square bore gives better control when trying to stay on the edge of traction exiting corners, looking to maintain a wheel slip or just hang under it. I'm looking forward to your future videos

[@rexwarrensr.9832]

Love your show dawg

[@boharris8179]

Been watching UTG had to come check out part 2

[@69JANKS]

Awesome Andy 👌🏼🏁

[@UnityMotorSportsGarage]

Thanks Brother

[@DragBoss351Cleveland]

Looking good Andy, Down to a science...

[@UnityMotorSportsGarage]

Thanks Tim! Just giving back what was given to me over the years Andy

[@DragBoss351Cleveland]

@@UnityMotorSportsGarage That is the key, give it back, and give others a hand...Thanks

[@markallen1413]

Really great info Andy, thanks brother 👍👍👍👍👍✅✅✅✅✅

[@UnityMotorSportsGarage]

Thanks, Mark

[@Streetfox5.0]

Good Video Sir! Alot good info. I like your truck Casper.

[@briansymonds-hf9fm]

Thank you for taking the time for these videos . I have a carburetor that goes lean at cruise speed 2600 to 3000 I keep getting told the low speed air bleed all that does is make it pig ritch at idle

[@skymit5519]

That’s was awesome, thanks

[@UnityMotorSportsGarage]

Thanks for Watching! Andy

[@jamesmarze9850]

Great video

[@UnityMotorSportsGarage]

Thanks James!

[@318willrun]

Great stuff as always !!!!!!! 👍

[@UnityMotorSportsGarage]

Thanks!

[@mikef-gi2dg]

I have read about these features/tricks hundreds of times. I have actually used a few of them over the years. I have a very mild 15/14 second drive in drive out SBC street car. Drive ability and ET consistency is EVERYTHING to ME. I have only used Holley 1850's because they are cheap and simple. I have gotten to know them fairly well, but it seems you have done things like change the boosters on an 1850, which I was told COULDN'T BE DONE. Plus mess with the AIR BLEEDS! how can this be? There seems to be tricks I never knew were possible!

[@UnityMotorSportsGarage]

Many of the newer 1850 style carbs now come with down leg boosters.. and adjustable bleeds! Andy

[@mikef-gi2dg]

@@UnityMotorSportsGarage What??? I didn't know that, going to start looking, got any model ##? Thanks you vids are easy to watch.

[@Comet-hn3gm]

Nice to see that you have been listening to Tuner and Mark Whitener. I too have been for the last 15 years or so.... 3450LB running best of 6.75 @101 with 395ci at about 3500 DA. Definitely could not have done it without help. This is on pump gas and drive it an hour there and back. Great Video !!!

[@UnityMotorSportsGarage]

Mark is pretty Sharp! That is pretty impressive times.... I sure hope I can my 4000lb Casper in the 6's.. Andy

[@vincentenk4449]

Thanks for sharing your time, effort, & knowledge! I'll STILL take carbs over EFI!

[@UnityMotorSportsGarage]

Thanks for Watching!

[@jaimie340]

Awesome video as usual. Would you consider doing a video on oil pressure and oiling system?

[@woodey028]

Nice video Andy. Not many people have the ability to chase that rabbit as far as you did. Looking forward to more good content. Please do a follow up video on spark plug reading. I like to check my plugs like religion. 👍

[@lynnrunningdeer7364]

A fun twist on the Theory of Relativity 😁.

[@bcbloc02]

Adjusting the power valve flow so it is actually feeding the power seems like the way it should always be done.

[@patrickscahillii9365]

P.S. Thank you for a MOST EXCELLENT VIDEO

[@UnityMotorSportsGarage]

Thank you Patrick Andy

[@johnshackelford6965]

Happy Halloween Scrow

[@chemgamer1419]

Hi Andy. Thanks for the vids! My friend told me to watch these because you guys know what you're talking about. He also told me to buy Dave Vizards carb book, which I did. Getting a LOT of good info from the vids and the book. However, I have a question about an issue that I’ve run across recently and cannot seem to find a solid answer to. I've only seen a couple of posts about it on line so I'm a bit skeptical about whether or not to believe what I'm reading. Here’s the issue. Directly below the transfer slot on secondaries of my Quick Fuel 4150 carb are 2 very small ports. These are different from the idle discharge ports that are below and just off to the side of the transfer slot. I've read on-line that these small ports are idle discharge ports for the 4160 carbs and that these need to be plugged if you have a 4150 because it’s a factory mistake and they will feed additional fuel, causing the engine to have a rich idle. I’ve only read this on line twice so I’m triple checking because I’m thinking the factory might have just left these discharge ports in the bodies so they could use the bodies for both 4150 & 4160 carbs. That they are just blocking the ports with the secondary metering block on the 4150 carbs, rendering the ports useless. I called the factory and they said they heard about it but could not provide an answer. Can you let me know what to do about these? I don’t mind plugging the holes but I just want to be sure. Thanks for any info!

[@413x398]

Very enlightening video, Andy! Are you going to do a DIY booster swap vid at some time?

[@UnityMotorSportsGarage]

Yeah I will probably do that down the road!

[@johnelliott7375]

These videos are amazing and so informative on the tuning aspect. So much to learn and you are making it easier and in Leigh man's terms. Only thing that keeps me interested in keeping it analog instead of the new tech. Thanks for enriching my Sunday's. Take care and thank you for your time and your work as usual.

[@UnityMotorSportsGarage]

I'm glad you enjoyed it John!

[@johnelliott7375]

@@UnityMotorSportsGarageif I can learn how to do it get my vehicle going it is all I can ask for. Don't want to pay someone to do it for me. Thanks again and looking forward to the next one in your series. Plus I like to share your videos with people that I know with similar views that get use from them also.

[@donnatalielucasheimbigner7598]

You can also increase fuel economy in pick up trucks while pulling/hauling by putting a primary metering block from a carb with same size primary throttle bores as your carbs secondary bores. That info can be found in Holley's list info. You need to pull/haul with the vacuum gage & see what the value is at hard pulling. Add 1 or 2 to that value to select the proper size. If you aren't quite sure, go higher than you think to make certain you don't lean it out. You can drop your jet size by 2 or 3 at that point. I used an air/fuel ratio gage with an O2 sensor in my X pipe and read my plugs to fine tune it. I saw a jet type set up a number of years ago for the air bleeds as well as idle circuits & power valve restrictions but when I tried to get one the owner had died, his wife sold the company, & the new company quit making the kits. I can't remember what company it was now, but I did the same thing as you are here.

[@UnityMotorSportsGarage]

You are right! there is always exceptions to the rule Thanks for Watching Don Andy

[@andy347495]

Thanks for shedding some light on this stuff. I was wondering if you could give some insight or help on a issue I'm having getting my carburetor tuned. When I go to wide open throttle it starts out with a good AFR and then goes lean for a few seconds then richens back up as rpm's increase. Depending on what speed I start out at seems to determine how lean and how bad it stumbles before it comes out of it. Which I usually let off pretty quick when it's bad. The slower speed I start out at the leaner it gets. Im not sure if I need a lighter or stiffer spring for the secondary diaphragm or a different power valve. I know holley's literature says too light of a spring can cause lean issues because the signal to the boosters has been weakened and get enough fuel soon enough, but.... Since I am running a 600cfm holley on a stock truck 454 (was a TBI) is the opposite maybe true and I actually need to open the secondaries sooner to get fuel flowing through the secondaries? Could it be pulling a lot of air through the primaries? One holley techs told me I need I lighter spring while the other told me I need a stiffer spring. Idle vacuum is about 19 inches, I can cruise at about 15 and with light acceleration I can still hold 10 inches. I have a 8.5 power valve, that's the biggest I have. I have springs and a 10.5 power valve ordered. Also my truck is 6600 pounds, manual trans with a 4.56 rear end. Street driven and about 4200 rpm max.

[@ronbunker5778]

Your part 1, and 2 video on carbs is exactly the info I was searching for! Thanks for the great info and I have subscribed because I really like your videos and the concise explanations. Looking forward to your other content!

[@UnityMotorSportsGarage]

Thanks for the kind words Ron! I'm glad you enjoyed it... More to come! Andy

[@deerslayer5863]

Also like to see a in-depth edelbrock tuning series

[@UnityMotorSportsGarage]

I will probably get around to it... I deal with Holley's 95% of the time but the same things apply to the Edelbrock carbs you just have to go about it in different ways! Andy

[@cameronhedayat504]

Great info. Great video! Andy, as usual. I'm working on making my 660s work better on a tunnel rammed BBC

[@UnityMotorSportsGarage]

I used 1850 metering blocks on both the primary and secondaries on mine... I found that I really didn't need PV's on the secondary side as I could cruise around in the transfer slots... Thanks for Watching Andy

[@cameronhedayat504]

@@UnityMotorSportsGarage Cool! Thanks for the info. Andy. So I get 1850 primary blocks (to incorporate P/Vs)& stock 6224 secondary's. Another question. Have you seen-Tunnel Ram Tuning by Guy Papworth on Y/T? I like the way he positioned the air bleeds.

[@UnityMotorSportsGarage]

Cameron I have not... I will check him out! Thanks Andy

[@cameronhedayat504]

@@UnityMotorSportsGarage Yes. after watching it again. It's what you are talking about. The tip in. Is transfer slots only. Then the pumps squirt.

[@UnityMotorSportsGarage]

@@cameronhedayat504 AED 6320 jet plates work great... You can use std Holley jets in the secondary side of 4160's Andy

[@byronnelson1556]

Some time maybe do blower application . I did use AFR gage on my blower applicaionmuchof what you have covered applies to blowers too. Byron

[@Redneckairflow]

I would like to see a video on plug reading and what to look for and what it means. There is alot of varying ideas on it on the internet and I'm not sure who is right and wrong

[@UnityMotorSportsGarage]

When Casper is up and going again, I plan on doing a video showing AFR vs plug color... It's pretty interesting to see... I know for me... in the past What I thought was good plug color was really fat! Thanks for Watching Andy

[@domstarkey7279]

I had a demon that the ide ones were gone I took two Pieces of the rubber off a wire then put two pieces of a wd 40 straw in side that an it ran killer lol you made me remember that when was talking about the straw fun the shit we do when where young an wanting to ride

[@kraschsclassics]

When you start with Mixed Up Boss please video every move you make when tuning. Wish you had done this with Casper. Ive started tuning my car and its usually make a change, test, document, then next day make another. When I'm satisfied with idle to cruise then it drag strip time for WOT.

[@UnityMotorSportsGarage]

I will do that this time around... Unfortunately I built Casper before I started KZbin.... That is how I did it the first time.. ALOT of trial and error but it pays off big in the end Thanks for Watching Steve Andy

[@donnatalielucasheimbigner7598]

Not to confuse people, but I have a pickup that needed a double pumper carb even though it weighs over 6000 pounds EMPTY. My engine is a HIGHLY modified Ford 400 & is good at squeezing fuel when cruising but needs a lot of fuel quickly while accelerating. The truck is '79 F-350 4X4 with a 4 speed and 4.10 gears. It can pull 25 - 30 mph small wheelies for a split second to put things in perspective. I had tried everything I could think of with a list 3310 750cfm vac sec converted to a 4150, but could never get it so the engine ran good across the entire range while driving normally, "hot rod" it a bit, & pull haul. I called Holley tech a few times & was not impressed. They couldn't tell me anything that I didn't already know or could easily find in print, including not have any real input as to try a double pumper. I didn't have a ton of cash & wanted an expert's opinion of what to try, but just didn't get any. I finally went with a list 4777 650cfm (my cam has great lift but tight duration & won't run above 5500 rpm) and converted to a secondary power valve by using the primary metering block from I think a list 4779 750 cfm carb (can't really remember at this point). It did take a lot of mods, but finally got it just right. I feel good at getting an average of 13mph with my driving habits. It can get a bit over 15 if driven really steady & super nice, but that isn't much fun & hard to do without cruise control. Also note that this was built & tuned in 1996 or 1997, so there are most likely a few things available now that weren't then.

[@stalegiverhaug2905]

I choosed a 650 cfm double pumper QFT, annular boosters on my CSB 350 with 6 speed manual transmission in my '34 Roadster that weights app 2750 lbs. Guess that should be a suitable setup? Airgap intake, tow. But then again - it probably gets rather hot under the hood in these cars. Not much space.

[@hippiemiller]

👍👍

[@vincebulwin8888]

Lot of good information there but I want to know about the tri-power that I have for 428 with a 4-speed wide ratio want to go to solid roller with it keeping the lift 525 and the lobe separation around 110 - 113 and gears out back keeping it around 3:25 3:30 and putting it down in a Maverick. What's your recommendations

[@UnityMotorSportsGarage]

Sorry Vince I just seen this post! I would try to find a cam with a Tighter LSA and smaller duration.. it would be more responsive.. sounds like a great combo! Thanks for Watching Andy

[@libertyjusticeforall6754]

Thanks again for another winning video! Learning Lots every time. How did u go about finding out the orfice size between jets and PVCR'S ? Formula?

[@UnityMotorSportsGarage]

Area is = 3.14 R2 Thanks for Watching Andy

[@libertyjusticeforall6754]

@@UnityMotorSportsGarage Thank you!!

[@libertyjusticeforall6754]

@@UnityMotorSportsGarage so after using a formula how do you go about sizing the Jets and orifices? You know that was how you know what size to use how do you figure it out?

[@UnityMotorSportsGarage]

@@libertyjusticeforall6754 Holley jets aren't measured in a dimension they are rated as a flow rate... There are charts on the internet that correlate them to size.. so like I stated if I find a 64 is best for lean cruise and 67 is best for WOT you take the size difference area and increase the PVCR'S by the Area that you came up with... Does this make sense? Andy

[@libertyjusticeforall6754]

@@UnityMotorSportsGarage got it, thank!!!!!👍👍👍👍appreciate your patience and time

[@davidcolegrove8818]

What color secondary opening spring did you find worked best in your application

[@ronnieb7408]

Do you have any tips or tricks for modifications of a holley for a blow thru style carb? What would need to be modified for a boost referenced power valve etc so that someone wouldn't have to dump 750 to 1000 bucks or more for the supercharger carbs.I know it can be done ..they have.I understand you're a nitrous guy so didn't know about for boosted applications.Thanks

[@richardmoerke9329]

Ok I get it! But what is a good to start a/f to start with ??? I think I have got it going down the road but wide open and all the in between stuff is killing me ! How you do this on the road. My wife is not happy trying to help me with this! LOL !!! You know what I mean.

[@joeybenenati3992]

Can you do a video on Dominator carburetor

[@UnityMotorSportsGarage]

You will see Dominator videos here in the near future! Thanks for watching Joey Andy

[@huskynox1]

Great videos, but still didn't address one issue a lot of guys have using a DP for street/performance use, that issue being a rich spike when the primaries come online. I can't find a single video explaining why. Holley Tech is a waste of time.... DV's book doesn't go into this common issue either. Here's my experience.... I'm running a 445 (stroker) Ford FE with a moderate cam pulling 12 inches at idle (850rpm), 4-speed trans... I was running a 750 Ultra DP, which was very close out of the box, I only had to decrease the main by 1# (73 to 72), and increase the IFR by drilling (33 to 35) and change the PV to a 7.5 (from a 6.5), it wasn't perfect, but it was close (checking everything with MTX-L AFR gauge). I then bought an 850 Track Warrior because I wanted a bit more flow and to get rid of the choke housing. I liked the fact the 850 had fully adjustable metering blocks, but wow, this thing wasn't even close! "Horrible" is a good word that comes to mind :) I started messing with emulsion jet stacks (probably 15 different stacks), MAB from a stock 34 to a 40, PV upsized to a 7.5, main from a 86 to an 85, which got it to 'ok' performance, but the main thing I could never figure out was the major rich spike when the primaries came online at say 10% throttle, the AFR would spike to 11.0 with that initial 'high signal' and hold there until I increased throttle. If I increased throttle to say 12-15%, the AFR would go into the 12's, it was like a light switch... on/off, on/off, on/off with just a small throttle increase/decrease. I could never get rid of that. The staggered duration CompCams (230/236@50) likes 12.0 to 13.0 AFR, so I was shooting for 13 at cruise and 12-12.5 under load. I was told this is a common issue with the larger 1.75" blades and the step-down boosters, so maybe it can't be tuned out with the initial strong signal from the larger cubic inch motor..?

[@UnityMotorSportsGarage]

It sounds as if the transfer slots are too long and you are pulling fuel from both the slot and the booster Hope this helps Andy

[@huskynox1]

@@UnityMotorSportsGarage If this is the case, there's a flaw in the Holley design, which I'm coming to conclude. Like I said, you can find many, many forum threads that state the same issue I'm having with no resolve. And again, Holley tech has no answer. The only person that talks briefly about the issue is Patrick at Pro Systems carburetors. Sounds like buying a specifically tuned carb from Pro Systems is my/someones best bet. This isn't an advertisement for Pro Systems, but their prices are minimally more than a box stock Holley. IMHO - Holley should sell or at least advertise different calibrations for different motor sizes/builds. To say a 750 DP will be very close out of the box is very generic/deceptive. What if that 750 is going on a 350 or a 454, it's not just gonna be a simple main jet swap, it's going to be Air Jets, PVCR's, IFR's, emulsion jets, etc. 7 times out of 10, along with maybe never working because of a design flaw. Most Holley builders combine different throttle plates, with different main bodies, along with many other changes, basically parts bin engineering a correct carburetor. I've been building engines for over 30 years, being able to figure things out, normally, but this one got me! Again, like others have stated - your videos are great and cover most bases, but scouring the internet, emulsion tuning and issues like I'm having are not covered anywhere including DV's book. Thanks.

[@lynnrunningdeer7364]

Awe he said gals too😊

[@peggyparrow2059]

Did you put a balance tube between the vacuum pods ? That way they open at the same time.

[@UnityMotorSportsGarage]

Yes I did

[@slowridemodelcars1687]

Unity motor sports, question, stock 71 z28,original lt-1, 4speed, 373 gear,what carb would you recommend, a 650 double pumper or the original 780 vac sencondaries with a stumble off idle, thanks

[@UnityMotorSportsGarage]

That is a tough call... If it were me I would try my best to get the 780 to work since it is original but I feel that the DP would work amazing on that combo! If it has a stumble check the accelerator pump and make sure the pump arm it touching the linkage.. as soon as you move the throttle pedal you should see the pump nozzle shooting fuel.. you may have to go up on the squirter size... Hope this helps Andy

[@Mike62501]

Where did you buy annual boosters for the 660’s? Thanks in advance Mike

[@UnityMotorSportsGarage]

Allstate Carbs in NY can hook you up!

[@derekdoble4438]

Do you mind me asking which wideband air/ fuel ratio meter you went with for a carbureted engine?

[@UnityMotorSportsGarage]

I use a Fast dual channel wideband .. Thanks for Watching Andy

[@Redshedcycle]

I really loved this video! But you can tell me this stuff all day and I still won’t know where to start without some verbal direction. I’ve got a carb I really need help with on a stock HO 305 in my SS Monte Carlo. If you are willing to help me please email me! Thanks for the video!

[@danielbeiersr3642]

I have a Holley 800 cfm, dual feed double pumper spread bore carb. Are there annular boosters and trick parts kits available for this carb

[@UnityMotorSportsGarage]

To be honest I don't know.. I have never seen any boosters for the spreadbore stuff... You might try Allstate Carburetor Thanks for watching Andy

[@danielbeiersr3642]

Thanks for replying

[@jaco5187]

Hi Andy. I have a 68 Mustang with a 289 and aftermarket T5. I'd like to rebuild the engine and stroke it to a 331. I also want to go multi-carb, 3x2 or 2x4. Would that be too much carburation?

[@UnityMotorSportsGarage]

No, I don't think it would be too much I ran two 600 Holley's on a mild 306 and it did really well.. on a 331 combo multiple carbs would be alot of fun! Thanks for Watching Andy

[@jaco5187]

@@UnityMotorSportsGarage Great. Thank you. Edelbrock makes a 2x4 manifold, the XF-8. I'd love to put that on it.

[@barneymiller7894]

Any thoughts on the new Edelbrock VRS 4150 carbs? They look to have pretty much all the features of a good custom Holley plus longer venturi, im just curious what someone who knows a bit more about carbs has to say

[@UnityMotorSportsGarage]

Stay Tuned... I will have a video dropping this weekend about them! Andy

[@barneymiller7894]

@@UnityMotorSportsGarage Awsome 👍

[@davidleonard8369]

Hey Andy, what's your opinion on standard vs window type power valves. Do they really flow more fuel or do the channel restriction holes pretty much negate the presumed flow advantage of a window type power valve.

[@UnityMotorSportsGarage]

The four window power valves do offer more flow. I would say for 80% of folks the two window valves work fine! They are a must when using E85 because of the needed increase of fuel flow through the carb.. if I have a choice I will use the high flow valves! It would be neat to actually do a flow test between the two... Andy

[@davidleonard8369]

@@UnityMotorSportsGarage thanks Andy. I have always used the window valves just because I figure that if fuel flow of the power enrichment circuit needs to be altered then the power valve itself will not be a factor. Other than the opening point.

[@erongli6681]

Can you modify my carb for best all around? Stock 69 351w with weiand stealth intake and holley 80457-2

[@derekdoble4438]

Great videos Andy but there is so much to take in between video part 1 and part 2 idk where to start. Lol Do you mind me asking where to start for just a street towing application I have a 1977 E350 1 ton dually van/ truck with a bone stock 8.5:1 compression 460 that I'm making into a ramp truck car hauler. I'm having trouble with the stock autolite carb and so I purchased a used (4160 i believe) 600cfm holley street avenger carb with vacuum secondaries and has the ford kickdown lever for the c4/c6 that I'm swapping on there to replace the autolite with a TD2199 adapter/egr delete spacer plate. The holley carb came from Florida and the main jets are H55 and the secondary meter plate has 39 stamped on it and looks to be a 30cc accelerator pump and I can't make out the numbers on the power valve. So I guess what I'm asking is how would you tune a single holley carb for a 14,000lb truck at its heaviest at 1000ft elevation?

[@derekdoble4438]

The jet size H55 seems small but I don't know what they had this carb on if it was on a 289 or 302 or something but was thinking of swapping it out with 64 to start with

[@UnityMotorSportsGarage]

One question I have, what is the List number on the carb?

[@derekdoble4438]

@@UnityMotorSportsGarage On the choke horn it has 80457-2 then under that it has 1640

[@UnityMotorSportsGarage]

It should have 66 jets in it stock... Start from there and it came with a 6.5PV. If you towing with it primary I would use a 8.5PV to bring extra fuel in sooner under load... You may need to experiment with it and maybe even try a 10.5... I would use the stock accelerator pump nozzle to start out as well... Hopefully this will get you in the ballpark Thanks for Watching Andy

[@derekdoble4438]

@@UnityMotorSportsGarage thanks so much for the reply. I'll have a baseline to start with since I'm rebuilding the carb and going through it. One last thing do you have any thoughts or opinions on a secondary metering block conversion kit part# 34-6s or should I stick with the the #39 metering plate?

[@canabox7112]

You know your shit Bro

[@UnityMotorSportsGarage]

Thanks Cana... I've had a great teacher... David Vizard Andy

[@andy347495]

Can you have the same symptoms with a secondary diaphragm spring that is too light or to heavy?

[@UnityMotorSportsGarage]

Do you mean a bog? If so yes if the accelerator pump isn't delivering enough fuel to cover the lean spot of the primaries....

[@andy347495]

@@UnityMotorSportsGarage its not a bog when you initially give it throttle, It will take off then stumble. The afr gauge starts off at about 12.5 for a couple seconds then go to about 16:1, that's when I can feel the stumble. It seems to be more prevalent when the vehicle is under a load starting off at slower speeds. At higher speeds the stumble isn't as drastic and comes out if it and richens back up to 12 or 13:1.

[@UnityMotorSportsGarage]

@@andy347495 based off of what you said it does sound the accelerator pump is not supplying a long enough shot... Might need to go to a play around with different squirters/cams and or add a 50cc accelerator pump. Block off the port to the vacuum pot to rule out any secondary action... Get the primary side dialed in and go from there

[@andy347495]

I should add that I went down two sizes from stock on the secondary diaphragm spring and it got worse. Then, I went to the black spring to see if it would get better. It seems like it's a little better with that one. My idle vacuum is 19 and I have the 10.5 power valve in.

[@andy347495]

@@UnityMotorSportsGarage ok, thanks a lot Andy.when you say vacuum pot do you mean the the secondary diaphragm?

[@centralbears3010]

Are you going to Shady Side in NOV? SEGA Races?

[@UnityMotorSportsGarage]

I plan on being there watching and maybe making some videos Andy

[@centralbears3010]

@@UnityMotorSportsGarage Mickey Jordan here. i hope to get a chance to meet you there. Bring that casper.

[@andy347495]

I'm wondering if I'm understanding something correctly or at least on the right track of thinking. I went from a smaller power valve number to a larger power valve number. Before I did this my AFR would not drop below 12.5 when under light acceleration when just cruising down the street. Now witj the bigger power valve, when I accelerate slightly vacuum drops as expected and the the afr will drop to 11.0 now. My theory is, before the power valve change there was more air moving when it opened and therefore it wouldn't richen up so much. Now, with the bigger power valve it is opening sooner and there is less air causing a richer condition. Am I close to understanding what's going on? Is it more accurate to say the air is moving faster vs saying there is more air?

[@UnityMotorSportsGarage]

By going to a higher PV number it will richen the circuit sooner... The smaller the number delays the opening... Does think make sense... It sounds like it needs to be leaned out at cruise (main jet) and the PVCR'S opened up slightly... You want a lean cruise 14-15 AFR and mid 12 to high 12's on once the PV opens

[@andy347495]

@@UnityMotorSportsGarage yeah, that makes sense. Are you saying my post is correct?

[@UnityMotorSportsGarage]

I don't think its so much of a difference in how much air is being consumed... Because if you think about you have three major things happening... Air being drawn into the carb / intake manifold is dropping and the engine is demanding more Air/Fuel.... You are just trying to time the carb to deliver the proper air fuel at the given time the engine wants it...

[@UnityMotorSportsGarage]

I don't know if any of that makes sense... I've worked 14 hrs today...lol Andy

[@andy347495]

@@UnityMotorSportsGarage yeah, it makes sense. my power valve is actually opening sooner now since I went up on the number. That is why my afr richens up with less throttle than before. So in other words, since I have so much vacuum (19-20 inches) at idle, because of the 6.5 power valve I had to use such big jets to keep the afr rich enough when opening the throttle to accelerate a small amount. I do have a vacuum gauge routed into the cab.

[@jontrudell7529]

My God the amount of Time you must have into that truck is got to be Absurd

[@lynnrunningdeer7364]

Hey, are you okay?

[@jontrudell7529]

CARB CULT LEADER UMS!!! 😆

[@jorgegomez4608]

I have David Vizard carburetor book And the little red Holley book Back in the day, along with the Holley carburetor book by Dave Emanuel also Old only the David Vizard book Comes close to what you Explaining but you should now Write your own book Which ties them all In together keep it Coming. The carburetor That made me go back to The drawing and thank God for those books Is my 1050 dominator With a 3 circuit system On street have to run One step hotter plugs Lean out the second circuit Idle feed restriction to 76 With 78 primary jet and 5.5 pv 90 jet secondary 495 Pontiac Solid roller that 4500 should In your future video My motor loved it

[@johnshackelford6965]

Steve Magnante Max Wedge stock cam Emperor Palpatine Production

[@ronsmith7739]

Big problem !!!!!! You never say whether the power valve is open or closed !!!!!!!!!!!!!