Holley Carburetor Tuning Tricks

[@Adrenacyde]

Another great upload. Hats off to the cameraman too! A good Team.

[@holleycarbshowtosadvice40y90]

Thank you.

[@MattsRageFitGarage]

I have learned so much from your videos lately I've taken my cars I've driven for years that have run pretty well to running rivaling my EFI car as far as throttle response and performance. I've commented about this car before, but the 1850-5 on my galaxie ran pretty well, but once I put the afr gauge on it I've been tweaking on it pretty good using the knowledge I've learned here although it in the cold it would occasionally have a slight off idle stumble no acc pump adjustment or cam would tune out. I had to go .002" larger on the IFR jet and I relocated them to the top position and that made a huge difference in throttle response and still has a good afr of around 12.5-13.5 when cruising and accelerating on the transfer slot circuit. It also got rid of my problem of the engine wanting to quit when kicking it down off the highest idle cam or wanting to quit when I put it in reverse when it's cold no matter how I had the choke pull off or high idle RPM set. Been tweaking on the PVCR's now and it's no longer dumping excessive amounts of fuel when the power valve opens and it just runs great. Keep on making the videos!

[@holleycarbshowtosadvice40y90]

My friend you are doing great.

[@woodey028]

Love this information. Thank you for sharing Randy. I just put together a 500" 440. Has a QFT 950. And my afr is in the 10.0:1 range. I'm going to follow this advice and tune it properly. She's a mean mopar.

[@holleycarbshowtosadvice40y90]

Just don't go to lean and thanks for watching.

[@20havenfun08]

Thank you so much... I'm retired, don't get to do much anymore... but watch all your videos.

[@holleycarbshowtosadvice40y90]

Thanks Mike I really appreciate it.

[@tonydee761]

Great stuff Randy, thanks for educating us & showing us some of the racers secrets.

[@holleycarbshowtosadvice40y90]

Thanks and your welcome.

[@broke_dongle]

Thanks!

[@holleycarbshowtosadvice40y90]

Thank you.

[@donstieben3939]

Such great info for new tunners

[@holleycarbshowtosadvice40y90]

Thanks Don.

[@polara1974]

Great vídeo as usual!!! Will love to see a vídeo on Mopar Six Pack and tunning tricks. Greetings from Argentina!!!!

[@holleycarbshowtosadvice40y90]

One of my favorite cars was the cuda, I came up in the best of times with camaros, Cudas and mustangs, there was some power on the street, those were the days. If I can run across a six pack or a tri power I will definitely do a video. Thanks for watching.

[@robertjohnson3550]

Good video,I like how you break things down keep it coming

[@holleycarbshowtosadvice40y90]

Thanks Robert

[@beyondtheapexracing]

You have really helped me understand this carb a lot more, I really appreciate it, I’ve been chasing a stumble when accelerating but my accelerator pumps are adjusted and working as they should, what I noticed is the gasket between the edelbrock performer intake and throttle plate does not completely cover the front a rear ports, could this create a vacuum loss in that area and lead to my issue? I’m not sure which gasket I should get, I also have a wood spacer there as well

[@holleycarbshowtosadvice40y90]

If its not completely sealing that could cause your hesitation, just remember the accelerator pump may need a larger nozzle. Hope this helps.

[@ford351cleveland]

Hello Randy thankyou agin for the video i unfortunately do have a conflicting question as in your fuel mileage and tricks video part one at 7:42 you said start with the idle fuel restrictor first and then start with the idle air bleeds but, in this videos its diffrent. I am Not hateing or calling you out, would just like to know what to do first as i already changed me idle fuel restrictor but not the air bleeds... Thankyou again for the videos they are a great help. Ps...if one does not have a idle air bleeds can you stack carb base gaskets or use diffrent thicknesses of cat gasket as this will cause less signal on car slowing down fuel flow vianthe Air route ? Thank youn Randy

[@holleycarbshowtosadvice40y90]

Always start with your transfer slots first , and then go to your idle air bleeds and tune and last if you need to restrict your ifr, but remember when you lean your idle fuel restrictor your leaning idle and most of all the transfer slots, if you lean it to much you'll get into a stumble or a lean spot. I don't understand your question about stacking gaskets and the air bleeds. You can write me back on that. sorry for the confusion. Hope this helps.

[@ford351cleveland]

@@holleycarbshowtosadvice40y90 Hello Randy oky will do it in the order you said idle air bleeds first and the idle fuel restrictor second. Mabye add a highlighted comment in the other video just telling people the idle air bleeds first and not idle fuel feed restrictor just my thoughts Regarding the stacking gasket question... am i correct in saying that chenge the idle air bleeds one is change the signal on a carb?... i unfortunately do not have acess on idle air bleeds screws to do the modification as i do not live in the usa and my v8 shop does not carry them in stock and if they need to order them it wil take up to 6 weeks to arive or I could do it at a much bigger cost via courier. If i am correct on that changeing idle air bleeds changeses signal can i not just rasie the carb by adding gaskets or a small spacer this wil have the same effect on the air bleeds ? Or am I missing something ? Thankyou Randy for answering not only my questions but also other subscribers questions I realy appreciate your knowledge and your effort on sharing it with us

[@holleycarbshowtosadvice40y90]

No bud that won't work, you have to change the amount of air entering and emulsifing with the fuel in the transfer slot.

[@ford351cleveland]

@@holleycarbshowtosadvice40y90 thankyou very much for the info have a great day Randy

[@jamesunderdal8976]

I've never even heard anyone mention the idle air bleeds before that's some new information for me.

[@holleycarbshowtosadvice40y90]

A good way of leaning your idle circuit.

[@claytonstoolbox]

Does using those stainless flush fitting, throttle blade screws rather than the old brass screws that stick out the other side, improve flow much? How do you keep the flush fitting throttle blade screws from backing out since you cant stake them?

[@holleycarbshowtosadvice40y90]

Yea the button head screws do give you a small increase in cfm, but they work better with thinned throttle shafts for a worthy increase in cfm. I use the blue loctite on the button head screws never had a problem.

[@philduckett7593]

Hi Randy; new to channel, good stuff. I have a boat (new to me) with twin '94 454XL crusader engines with R84050 (4011) marine carbs. One works ok, other floods out when rpms drop below 1200rpm. Its been rebuilt twice (by someone that supposed to know what they're doing) no difference. Float level is set right, lowered it some more, no change, float valve swapped out, seat looks good, no joy. Swap carbs, problem follows carb, so not fuel pump. What might put too much fuel in when trying to get to idle? Thanks

[@holleycarbshowtosadvice40y90]

I need to know if fuel is coming out of the vent tube and or the boosters and is the fuel level correct. Now if all this is correct then remove your carb and the throttle plate from the main body and check the gasket, the wrong gasket will block the outer idle circuit holes, this happens alot. Let me know. Hope this helps.

[@claytonstoolbox]

What technique do you use to tune/jet a carburetor for racing without a AFR gauge? Plugs, smell, ect. They did it years ago, I haven't found much detailed information on this. Thnx

[@holleycarbshowtosadvice40y90]

Look up Steve tech on you tube , reading spark plugs properly. Best video I've seen.

[@richardrudd8055]

Randy, do I adjust my transfer slot on the primary AND secondary butterflies since I have the 4 corner adjustment screws or only adjust the front primary transfer slots?

[@holleycarbshowtosadvice40y90]

Set your primary side transfer slots correctly, your secondary transfer slots should not be exposed, let me know if your idle air bleeds are changeable and the size,all four corners. I'll try to help you.

[@BlueSilverado]

Make a transfer slot opening video for both primary and secondary

[@holleycarbshowtosadvice40y90]

The primary transfer slots are the only ones exposed there is no need to modify the secondaries . Hope this helps.

[@Darrenlawrence89]

That info is very helpful ,,, I got my qft metering plate all set up with adjustable air bleeds and I did restrict the ifr. In certain gears on freeway depending on throttle position il get a lean spot ,, and if I get on it it will bog a little bit and be fine I’m thinking it’s the transfer that you explained ?🤔

[@holleycarbshowtosadvice40y90]

I always get my transfer slots correct first and then work with the air bleeds next and last if need be the ifrs. Try this method and see how it works for you. Hope this helps.

[@Darrenlawrence89]

@@holleycarbshowtosadvice40y90 will do , thank you ,,,

[@Darrenlawrence89]

@@holleycarbshowtosadvice40y90 is a 10-32 air bleed possible for the idle circuit on top of carb? And can a sae drill bit be used instead of a #21 ? Only asking to cut down on time waiting for parts

[@Darrenlawrence89]

Sorry for all my questions , Does the transfer slot work coming off part throttle cruise ? Or only off idle ?

[@holleycarbshowtosadvice40y90]

Yes the transfer slots work partly at idle but mostly between coming off idle and part throttle,if your thinking of installing screw in air bleeds make sure you have enough metal around the bleed area, some casting have enough for a 10-32 bleed and some dont, a 6-32 will work but you can only drill it so big usually around .070 to maybe .075 thousandths is about the max and sometimes thats enough. Now the 6-32 works fine on the high speed air bleeds because the hole is half the size of the idle bleed. Hope this helps.

[@philarmbrust2626]

Do I need the equalizer tube on a Holley or can I epoxy them shut , thanks

[@holleycarbshowtosadvice40y90]

If your talking about the fuel transfer tube yes you really need it, there is a way to modify it for dual fuel inlets but its alot of work.

[@michaelgiglio1571]

Randy, i f i open the airbleeds should i still drill holes in the front butterfly to close the transfer slots enough or would the two changes be tomuch for street and stip. Mike

[@holleycarbshowtosadvice40y90]

Michael I always start with my transfer slots first , if my cam is dropping the engine vacuum to low then I will drill the butterflies to get my transfer slots correct and then I will finish tuning the idle circuit with air bleeds first, always remember when you change your idle air bleed to readjust your idle mixture. Hope this helps.

[@michaelgiglio1571]

@@holleycarbshowtosadvice40y90 Randy, good work mate. Your segments are helping us tune the best carby ever made. I always use a 750,s on 302,s or 351 clevelands. no smaller. Tnx

[@holleycarbshowtosadvice40y90]

Thanks Mike.

[@eastendcustoms777]

what will cause the idle air screws turned all the way in with the transfer slot set , the engine will cont running with no change what could cause this engine should idle down or stall thank u

[@holleycarbshowtosadvice40y90]

Any unmetered fuel , like a power valve leaking , or an idle air bleed stopped up, there are some holleys that have a reverse idle system, turning the mixture screw out leans it and turn them in for rich. Hope this helps

[@leftturn13]

Got 377 sbc running 10/11 on afr gauge at cruise. 14 afr at idle. 750 brawler carb. What is best way to lean at cruise . Tried changing pv with no change.

[@holleycarbshowtosadvice40y90]

Work with your Main jets first.

[@crimthegrim]

i have a question for you! i have yet to find the answer to it, so on some 4150's street avenger/ truck avenger for example they have the front throttle blades are different from the secondary's gold color different numbers on them as well i was wondering what the differences are ? they fit in the same sized hole but they are numbered different colored differently is there a reason?

[@holleycarbshowtosadvice40y90]

I have no idea, I have called holley about simular things with no answer. Sorry.

[@lods7185]

On a 4 corner idle carb how does a secondary T slot affect idle? Can it be open to much as well?

[@holleycarbshowtosadvice40y90]

The secondary transfer slots should not be exposed, if they are exposed the idle speed is set to high. Balance your idle speed between the primary and secondary. Hope this helps.

[@salvatoregiovanni8967]

When do we ever get to see Randy’s face?

[@holleycarbshowtosadvice40y90]

Maybe one day lol.

[@broke_dongle]

Thanks!

[@ford351cleveland]

Thanks!

[@holleycarbshowtosadvice40y90]

Your welcome