Thank you very much Randy and camera man, for sharing a wealth of experience with Holley carburettors. It's a great thing that you do passing on years of knowledge to the younger generations.
Excellent video. I watched the few you have and am using the imformation to modify an Autolite 4100 for use on a 302 with an aggressive Crower. Working on the transition circuit now, thank you!
That's a great old carburetor , I used to watch the fuel levels with the top of the carb off and the engine running, one of the few carburetors you could do that with , please dont do that not really safe,, just something I did years ago. Very good old carb. Good luck.
I truly thank you for all the input the content the knowledge in the time that you put into these videos they help us out a lot and I am very thankful to you you're very generous man for sharing your knowledge God bless you and your family
Great video. All your videos are great. Thanks. It'd be nice to find one that explains the emulsion jet tuning in-depth, I can't find anything on the topic. It's be especially nice because a lot of the new Holley performance/race carbs are coming with the 5 hole blocks (Ultra XP, Track Warrior, etc.) but that amount of tuning isn't really necessary for a street car and just causes issues. It's difficult to find advise on what to do, or how to modify/jet those blocks for a street car. I've scoured the internet to find recommendations and have actually spoken to Holley tech's about it, no one seems to have much advise. I spoke to Holley just the other day about it, the tech didn't know much, but I did get some spec's for the different carbs (750/850 Ultra XP, Track Warrior) which seem to use the same 5 hole blocks, Holley was able to let me know that they install the same bleed jet stack in all of them, which didn't surprise me... The stack from bottom to top is .029, blank, .029, .029, .029. I was told by a guy that knows Holley's pretty well to go with this stack for the street - blank, .029, blank, .029, blank, so basically a 2 hole system. Going to say a 2-hole system, I would imagine will change the HSB's on the top also..? Thoughts? Recommendations..?
@@holleycarbshowtosadvice40y90 That would be great! And I'm sure you'd get a million views because there's NOTHING out there! I've been scouring the internet for 3 days, not finding anything specific to Holley. I realize every engine is different, but a general idea of what each of the holes does from bottom to top and what hole size changes will do to a fuel curve would be great! Again, I spoke to Holley Tech, who was absolutely no help. Sad.
5:40 .... you started to talk about the different locations for the antisyphoning holes in metering blocks, does the location actually make any difference? For practice, i recently modified an early 1850 primary metering block by drilling out just the lower IFR and PVCR channels to accept 6-32 brass set screws that are blank to drill my own holes. All went surprisingly well and i plan on experimenting with it on a 770SA carburetor, but given the diifferent location of the antisyphoning holes, the 1850 is near the top like you have shown and the 770SA hole is inline with the booster opening, coincidently the same location on 3310 carburetors, will it even work or will i have to modify and reuse the original 770SA metering block?
I bought some aftermarket metering blocks and they have a .035" emulsion bleed in the idle feed restriction; at the top of the channel. With those, would it still be necessary to drill the main body and tap it for a bleed? The idle circuit hole on the top if the carb is .065". Thanks for great videos.
@@holleycarbshowtosadvice40y90 I was wrong in my thinking. The idle feed restrictor is fuel, not air. My original comment was based on thinking it was air. So, I WILL need to put an air bleed jet in the body for the idle circuit. I thought I was saving some work, but not. No problem, though, thanks to your videos.
Great videos, they have helped me understand how to tune carbs a little more. Can the air bleeds be modified on the secondary side? I think mine nees a little tuning. I've put the heaviest spring in the secondary Diaphragm, it helped, but hasn't fully fixed my lean spot.
They can, but usually you tune them last, Tune with jets or plates which ever you have and secondary diaphram springs , fuel level and don't over look ignition timing and advance. Hope this helps.
I sorry took so long , I usually clean them when rebuilding , but best way is with Guage pins and disassembled to know complete circuit is clean. Hope this helps.
Broke a tap in a main body trying to add acrew in air bleeds was years ago just playing. I still have the main body if I can get the tap out can I fill the air bleed cavity with jb weld and just drill the in weld?
Tore down a swap meet carb that I recently bought.... discovered someone drilled .035 holes straight through the idle feed restrictor holes straight into the bowl side of things. What is the reason someone did this? Thank you
Can't think of one good reason , probably was trying to richen up the idle circuit and drilled through the body, I would replace the metering block.Or you can try to repair it.
@@holleycarbshowtosadvice40y90 can you do a video on metering block interchangeably? I have a few blocks laying around from various carbs I've torn down over the years. They all bolt up physically but some of the passages/orifice sizes are different obviously and in different spots on the block. I dont know how to make them compatible for a specific application. Basically let's say I wanted to use a block off an 1850 and use it on a 4781 or something along those lines. Thanks for the input
? About a 4500 holley dominator does it have to have a power value in the front of the meter block or can it be blocked off like the one in the back I'm having problems with it trying to leave off the line
A two circuit 4500 will usually run a power valve and should in the primaries some three circuit 4500s will also use pv but alot of the three circuits 4500s want use a power valve with the intermediate circuit, basically the three circuit 4500 works well for racing they are a bit rich at launch but work well for racing, but will use more fuel. Some of your great carb builders make 4 and 5 stage 4500s and they work well if you can afford one. Hope this helps. Bud I'll try to help you but I'm not sure if your talking about a stumble off the launch, if your strictly racing start with your distributor and lock your timing out, and tune from there.let me know.
An engine with a racing cam , creates low vacuum so usually its best to set the idle circuit up completely, now with out a racing cam you could play with the bleeds.hope this helps.
I need help. Holley 6213 q-jet double pumper 800 CFM, No transfer pump tube. Wrong metering blocks. Primary has 6343, 450 cfm with zero Air bleed holes main well. Rear 4779 750 cfm no power valve. Since this carb had dual power valves the rear metering block is wrong. I was going to install a 1850 primary and 4781 secondary. What is your recommendation ? Thank you.
Don't have any information. Try calling holley and ask size of power valve circuit restriction and try to get jet size, if no info on jet size , you have to work with the jet size , and those metering blocks sound ok.
I’m no , stranger to a Holley and always enjoy immensely your tech videos Randy , thanks very much .
You are most welcome
Thank you very much Randy and camera man, for sharing a wealth of experience with Holley carburettors. It's a great thing that you do passing on years of knowledge to the younger generations.
Thank you .
Us old guys too!
You know carbs are still being made, sold, and used right? It's nowhere near dead or forgotten tech
Excellent video. I watched the few you have and am using the imformation to modify an Autolite 4100 for use on a 302 with an aggressive Crower. Working on the transition circuit now, thank you!
That's a great old carburetor , I used to watch the fuel levels with the top of the carb off and the engine running, one of the few carburetors you could do that with , please dont do that not really safe,, just something I did years ago. Very good old carb. Good luck.
I like how you say that finding your tune is like R&D - that's what it feels like 🍻
Saxon thanks as always.
I truly thank you for all the input the content the knowledge in the time that you put into these videos they help us out a lot and I am very thankful to you you're very generous man for sharing your knowledge God bless you and your family
Thank you and God bless you .
Great video quickfuel ss models come with metering blocks that have screw in everything also air bleeds. They are expensive !
Absolutely!
I've read book after book on holley mod. and tune but it never come together like you bring it together. Thanks for sharing your knowledge.
Your welcome.
Great video. All your videos are great. Thanks. It'd be nice to find one that explains the emulsion jet tuning in-depth, I can't find anything on the topic. It's be especially nice because a lot of the new Holley performance/race carbs are coming with the 5 hole blocks (Ultra XP, Track Warrior, etc.) but that amount of tuning isn't really necessary for a street car and just causes issues. It's difficult to find advise on what to do, or how to modify/jet those blocks for a street car. I've scoured the internet to find recommendations and have actually spoken to Holley tech's about it, no one seems to have much advise. I spoke to Holley just the other day about it, the tech didn't know much, but I did get some spec's for the different carbs (750/850 Ultra XP, Track Warrior) which seem to use the same 5 hole blocks, Holley was able to let me know that they install the same bleed jet stack in all of them, which didn't surprise me... The stack from bottom to top is .029, blank, .029, .029, .029. I was told by a guy that knows Holley's pretty well to go with this stack for the street - blank, .029, blank, .029, blank, so basically a 2 hole system. Going to say a 2-hole system, I would imagine will change the HSB's on the top also..? Thoughts? Recommendations..?
I will do a video, thanks.
@@holleycarbshowtosadvice40y90 That would be great! And I'm sure you'd get a million views because there's NOTHING out there! I've been scouring the internet for 3 days, not finding anything specific to Holley. I realize every engine is different, but a general idea of what each of the holes does from bottom to top and what hole size changes will do to a fuel curve would be great! Again, I spoke to Holley Tech, who was absolutely no help. Sad.
After all these years the air bleed/main well picture is now clear. Oh boy!
You know Mike i was the same way about connecting rod length ( rod ratio ) when I finally under stood it.
Thanks for posting Randy,but you didn't leave the information on the kit in the description.Thanks again.
tim rayburn there is no kit just buy what you need on eBay
Tim I got mine from Amazon I will list it soon .
Sharon S @ 5:24 he says "here's the tap and the drill made for this,it comes in a kit.I'm gunna leave a description for this in the description."
Thanks
5:40 .... you started to talk about the different locations for the antisyphoning holes in metering blocks, does the location actually make any difference? For practice, i recently modified an early 1850 primary metering block by drilling out just the lower IFR and PVCR channels to accept 6-32 brass set screws that are blank to drill my own holes. All went surprisingly well and i plan on experimenting with it on a 770SA carburetor, but given the diifferent location of the antisyphoning holes, the 1850 is near the top like you have shown and the 770SA hole is inline with the booster opening, coincidently the same location on 3310 carburetors, will it even work or will i have to modify and reuse the original 770SA metering block?
I believe it will work i would give it a try. Let me how it turns out.
I bought some aftermarket metering blocks and they have a .035" emulsion bleed in the idle feed restriction; at the top of the channel. With those, would it still be necessary to drill the main body and tap it for a bleed? The idle circuit hole on the top if the carb is .065". Thanks for great videos.
As long as the idle mixture is not to rich your ok.
@@holleycarbshowtosadvice40y90 I was wrong in my thinking. The idle feed restrictor is fuel, not air. My original comment was based on thinking it was air. So, I WILL need to put an air bleed jet in the body for the idle circuit. I thought I was saving some work, but not. No problem, though, thanks to your videos.
Great videos, they have helped me understand how to tune carbs a little more.
Can the air bleeds be modified on the secondary side? I think mine nees a little tuning. I've put the heaviest spring in the secondary Diaphragm, it helped, but hasn't fully fixed my lean spot.
They can, but usually you tune them last, Tune with jets or plates which ever you have and secondary diaphram springs , fuel level and don't over look ignition timing and advance. Hope this helps.
can you plz do a video on ajustable air bleeds with air bleed jets
When I can, got alot promised out already.
My 650 vs have blocked air bleeds, sealed brass ports , don't want to drill and tap, just need to know the best way to clean them? thanks Jim
I sorry took so long , I usually clean them when rebuilding , but best way is with Guage pins and disassembled to know complete circuit is clean. Hope this helps.
Broke a tap in a main body trying to add acrew in air bleeds was years ago just playing. I still have the main body if I can get the tap out can I fill the air bleed cavity with jb weld and just drill the in weld?
I have never tried that, its worth a shot as long as your sure of the bleed size. Let me know how it turns out.
Tore down a swap meet carb that I recently bought.... discovered someone drilled .035 holes straight through the idle feed restrictor holes straight into the bowl side of things. What is the reason someone did this? Thank you
Can't think of one good reason , probably was trying to richen up the idle circuit and drilled through the body, I would replace the metering block.Or you can try to repair it.
@@holleycarbshowtosadvice40y90 can you do a video on metering block interchangeably? I have a few blocks laying around from various carbs I've torn down over the years. They all bolt up physically but some of the passages/orifice sizes are different obviously and in different spots on the block. I dont know how to make them compatible for a specific application. Basically let's say I wanted to use a block off an 1850 and use it on a 4781 or something along those lines. Thanks for the input
? About a 4500 holley dominator does it have to have a power value in the front of the meter block or can it be blocked off like the one in the back I'm having problems with it trying to leave off the line
A two circuit 4500 will usually run a power valve and should in the primaries some three circuit 4500s will also use pv but alot of the three circuits 4500s want use a power valve with the intermediate circuit, basically the three circuit 4500 works well for racing they are a bit rich at launch but work well for racing, but will use more fuel. Some of your great carb builders make 4 and 5 stage 4500s and they work well if you can afford one. Hope this helps. Bud I'll try to help you but I'm not sure if your talking about a stumble off the launch, if your strictly racing start with your distributor and lock your timing out, and tune from there.let me know.
Do you have to do all of these modifications at once or can you just change the main body air bleeds?
An engine with a racing cam , creates low vacuum so usually its best to set the idle circuit up completely, now with out a racing cam you could play with the bleeds.hope this helps.
6-32 is fine, 6-24 is course threads.
Thanks
I need help. Holley 6213 q-jet double pumper 800 CFM, No transfer pump tube. Wrong metering blocks. Primary has 6343, 450 cfm with zero Air bleed holes main well. Rear 4779 750 cfm no power valve. Since this carb had dual power valves the rear metering block is wrong. I was going to install a 1850 primary and 4781 secondary. What is your recommendation ? Thank you.
Give me some time, I'll try to find some information . It has been a long time since i have worked on a spread bore holley, great carb.
Don't have any information. Try calling holley and ask size of power valve circuit restriction and try to get jet size, if no info on jet size , you have to work with the jet size , and those metering blocks sound ok.
Ehere do you get the bleeds
Just about any speed shop. Some fastener companies sell 1/8 " cup plugs. Hope this helps
After all these years the air bleed/main well picture is now clear. Oh boy!
You got it.