To all those people who tell me " carbys are crap cos you just have to live with it being rich in one rpm and lean in another ". As a tuner with over 20 years playing with carbs I want to confirm this man has just passed on the secret to a clean flat air / fuel ratio trace that I achieve with a billet metering block and time on my dyno . I've had ignorant laptop tuners call carbs "No better than a monkey with a bucket".... this is a major part of teaching the monkey to dance.. If you are interested in carby tuning SUBSCRIBE..
www.grumpysperformance.com/emulsion8.jpg My favorite background. Doesn't have the hockey stick looking "spark timing" channel as the block in this vid does, but all other principles are viewable. I am thankful Bill Jenkins was so prolific in his later years - I learned a ton [I wish I learned earlier], and still wind up reading his posts from time to time. Its funny: at some point in life, we all wind up teaching. At a minimum, our kids & grandkids.
@@holleycarbshowtosadvice40y90 doing very well, God is good. Hope you guys are doing great. Helping many friends with the knowledge that you give. Thank you brother 🍻
I've been watching your videos to tune my Edlebrock Double Pumper - It's real. They made it. I like the way you describe the circuits in the carb. I just made my own PVCR based on your videos. They seemed to help a bit. I am about to get into tuning the bleeds on the emulsion well of the carb. My truck is limited to 4200RPM for now so I may not even need the high speed circuit.
If your talking about the edelbrock vrs becareful this carb is a 4 circuit carburetor tunes differently than a regular holley. Haven't had a chance to check one out yet. Good luck.
@@holleycarbshowtosadvice40y90 yes thats it! I will be tuning the fuel curves a bit next. I need to find out what emulsion plug relates to 4200 RPM on the metering block and then fine tune all the ones above it. I'm about to make a jet drilling fixture too.
The idle mixture screws can only change the fuel to the round holes . The transfer slot can only be changed by idle air bleed or idle jet change . The transfer slot comes in above the mixture screw. And runs off of the idle jet and idle air bleed .
You set up a holley basically two different ways for the idle circuit, one way if has a racing cam with low vacuum and another way if its stock. Watch my video.
What would be a good emulsion size bleed for a blow though billet metering block carb to start with? As always you one of the easiest to understand videos on the tube out there.
So Randy, if I understand corrrectly: we use the Main Jets to tune the W.O.T. AFR to be where we want it, but use the air bleeds to dial in everything below that?
No alot of times you will be close but your fuel curve might be rich at wot and you would change your lowest emulsion bleed hole on your metering block by 4 or 5 thousandths larger and lean it out. Now this is if your close with your tune.
hey Randy, great ved as usual, but I was surprised you advised us to go get a m.b. with 4 or 5 treaded holes instead of pulling out the drill and fixing the stock block. oh well after watching all your other vedios' I guess i can figure that one out
You can modify a stock block but only to a certain extent, most are two hole emulsion. Billet blocks have up to 5 holes and I usually use 4 holes. Some tuners use three. Hope this helps.
Great video and provides a lot of information that I think has been missing in different internet discussions. Having a problem with a 1000 cfm dp down leg boosters, and hoping to maybe get pointed the right way. 500 cid bbc. Demon body with Holley 5 hole blocks (6 if you count kill bleed). This is in a boat and it’s under load all the time. Idle and transition are okay but once on the mains it continues to lean out. Jets are 91/98 with 070 pvcr primary. Emulsion is: kill bleed 027 then 028/0/028/0/0. Main air bleed is 28. Floats are right. Frustrated with how much jet I’ve needed. Dangerously lean at peak torque (4700 rpm - 14.2). Was going to drop the main air bleed to 025 and work way up. Close up the emulsion too?
Tom are your emulsion 0s are they blocked with screw in bleed plugs? Also give me your high speed bleed size and how high is your float level. I'm guessing your venturi is 1.560 and 1.750 throttle plates. Let me know.
Hello Randy! I've watched several of your videos and have enjoyed all of them. I always reminded my students that carburetors many times take the blame for other engine problems, two common being engine timing and vacuum leaks. You're doing an excellent job. Keep up the good work! By the way, where in the south is your home base? I come and stay in central Alabama from Houston, TX several times during the year. May be I can stop by and visit sometime. Regards!
Great video i currently have an ATM 750 dp im tuning in my 428 Fe ive got the jets to give me 12-13 afr cruise now but it goes very lean when i left off the gas for a second before it goes back to the idle circuit 4 hole billet metering block has 4 holes the top 2 are wide open the bottom 2 are .020 from factory..
Excellent descriptions I´ve seen. On my carb I have 4 threaded holes so I can fiddle with them. They don´t have any bleeds in them though but they are all open and drilled to 28 thousands from the manufaturer. One thing I´de like to know is if I open one to say 35 thousands, will the lean effect be the same in all positions albeit in a different area och the fuel curve? Is there any kind of typical reference how much effect on AFR a certain change in hole size make? E.g a change in 5 thousands will result in x.xx i AFR?
There is so many factors, not just changing emulsion bleeds but also you have to figure in hsab size and then the type of booster your using. I can tell you the holley xp ultra 750 has a great fuel curve. Hope this helps
Emulsions... 2 works, sometimes 3. But on the issue of billet metering blocks, never use all 4: gotta play with combinations, and that goes well with an AFR gauge to test across load conditions. One of the funny things about emulsions is by introducing more air, fuel drawn to the booster can increase [to a point] because for the same vacuum signal there is less mass to lift - velocity of fuel delivered increases. The air bleed is the baseline for this function: it determines the minimum signal booster has to develop for fuel to be drawn. Generally, main air bleed is the dead last thing I fool with because most the time... I got something wrong somewhere else.
hey Randy, love your videos. Is there a way I could contact you about my Holley issue that I’ve been chasing for a year now. I have rebuilt it 3 times and still same problem! Thank you
I'm trying to run an AVS2 on my 350 sbc and it its just a pig. I cant get this stupid thing to run right and i am going to go to my 750 holley carb and to my single plane intake. The Avs2 is just backfiring from the low idle on 1 cylinder and it is driving me nuts.
Normally you are right but it is possible with the right combination. A lot of things come into play like the engine breathing capability, the right size carb and the right carb modifications, this can be the difference in winning and loosing.hope this helps
The air bleeds work backwards the smaller the bleed hole it will richen the fuel mixtture . And just the opposite within .a bigger bleed hole the leaner it will be. Hope this helps.
I have a quickfuel 650 brawler dp and i have set the fuel curve flat on half throtlle. When i ooen the secondaries(full throtlle) my fuel curve goes from 2000-2500 rpm starts at 10 afr and only goes to 12.7 at 3500 rpm to max rpm and stays in 12.7 afr. I wanna change the low rom 10afr to 12.7 afr . Can i do this with just putting bigger emulsion jets in on the lower place? Do i have to do this on the primary and secondary metering block or can i just do it only on the secondary metering block? Do i need to go bigger on emulsiin jet to lean out this rpm range? Thanks for the vid
When you open the secondaries your afr is going to be rich with a dp then it goes to 12.7 through max rpm, if you want a more flat fuel curve you may want to go with a vacuum secondary but you can lean your carb but don't use your emulsion, when you have steady afr from 3500 to max rpm your emulsion is working properly. Maybe try .002 larger secondary high speed air bleed or jetting secondary leaner. Hope this helps
@@holleycarbshowtosadvice40y90 Can I adresse this low rpm rich mixture a little bit with putting my total timing from 3000rpm to 2500 rpm? Will it clean it out a little bit?
When you go to wot it'll go rich from the accel pump and popping open the secondaries until you gain some rpms the 12.7 is the fuel ratio, a holley vacuum secondary has no rear accelerator pump and the secondaries come in slow, so the mixture curve is much more flat. Hope this helps
@@holleycarbshowtosadvice40y90 yes i tested this and so i put full throtlle at 1500 rpms and so the pumpshot is burned and afr is 11.5 but when i come back at 2500 rpm the afr goes back to 10 and lower
Well now. I have been struggling to visualize the mail well action as rpm rises, and how the air enters. As rpm rises, the level in the main starts to drop, as it drops it uncovers and air bleed, and air is drawn in. I think I got it.
Was hoping to hear more about the highspeed air bleeds. In a nutshell, having an issue on my 680qft 4160 where theres not enough overlap between the transition and the mains, goes dead lean from about 1800-2500. Hearing conflicting info on which way to go with the bleeds.. bigger / more air flow helps lift the fuel and bring mains in sooner but will lean it, but also hear smaller will give stronger signal and bring mains in sooner. Currently with 61 idle bleeds it fills the gap enough to run, but the transition is rich untill 1500 where it will lean out to 15-16:1 until 2500 it will start richening up again. 28s in the high speed, with 68 jets, fully on the mains - 3k rpm- im back to 12-13 but starts gradually leaning back out as rpms climb.
Ok the smaller air bleed will pull more fuel and earlier. Now there is ways to help your problem, try raising your float level slightly and install a smaller high speed air bleed , you could try annular boosters which has a better signal but they are expensive. Hope this helps. One other thing that can cause this problem is if your idle fuel restrictor is to small it can feed the idle mixture circuit and starve the transfer slot .
Ive already been playing with the IFRs and wasnt doing anything for me other than making the transition even richer and the idle mixtures a pita to set. Currently i have .034 IFRs and im 5/8 out on the idle mixtures (4corner). Going from 71 to 61 idle bleeds really helped as far as drivability, but now have weirdness at idle with cascading idle and the whole transition being rich. Will drop the high speeds from 28s to i think i bought 23s@@holleycarbshowtosadvice40y90
I sent you a message about my 950 HP running too rich at cruise 2300 to 3200 RPM big duration cam would l benefit from the billet plate, l have a 73 primary jet and a 3.5 PV. The engine is a 455 Buick it made 656 hp 600 ft lb torque
Do you have a video which addresses baseline jetting specs for typical builds. Examples: Say mild 350 with a Holley 600 VS Street/Strip Set Up 350 Holley 750 VS Street/STRIP 383 Holley 750DP ?
Авто/Мото
To all those people who tell me " carbys are crap cos you just have to live with it being rich in one rpm and lean in another ". As a tuner with over 20 years playing with carbs I want to confirm this man has just passed on the secret to a clean flat air / fuel ratio trace that I achieve with a billet metering block and time on my dyno . I've had ignorant laptop tuners call carbs "No better than a monkey with a bucket".... this is a major part of teaching the monkey to dance.. If you are interested in carby tuning SUBSCRIBE..
Thanks , you know those guys that are always talking about a carb being junk. They don't know how to create a fuel curve.
One of the best descriptions of air bleed operation that i have seen. Simple and clear. Very well done.
Thank you.
If you go missing, we'll all come looking for you like a bunch of Rambos!!!! Can't let this much knowledge disappear!!!
Thanks Elliot lol , I'm sure I pissed some people off but they will get over it.
Thank you for these videos! It’s helped me more than anything else to get my 500” Mopar just right for any type of driving.
Glad I could help Joe.
Awesome stuff! Thank you Randy!
Any time
Best on RUclips.
Thank you.
Thanks
You should do a video tuning a carb on an engine
Maybe later.
Very informative channel. Keep up the good work.
Thanks
Well done again.
Thanks Tim
Thank you , love your videos:)
Thanks
Metering block were confusing before I milled into one to SEE wtf was going on
I’m a very visual learner and it helped
Absolutely
www.grumpysperformance.com/emulsion8.jpg
My favorite background. Doesn't have the hockey stick looking "spark timing" channel as the block in this vid does, but all other principles are viewable.
I am thankful Bill Jenkins was so prolific in his later years - I learned a ton [I wish I learned earlier], and still wind up reading his posts from time to time. Its funny: at some point in life, we all wind up teaching. At a minimum, our kids & grandkids.
Great video ! Thank you 😁
Glad to help
Yes sir! Miss your content Randy. Always helpful 🍻
Thanks my friend, hope your doing well.
@@holleycarbshowtosadvice40y90 doing very well, God is good. Hope you guys are doing great. Helping many friends with the knowledge that you give. Thank you brother 🍻
Great video keepem coming
Thanks
thanks again
Anytime.
I've been watching your videos to tune my Edlebrock Double Pumper - It's real. They made it. I like the way you describe the circuits in the carb. I just made my own PVCR based on your videos. They seemed to help a bit. I am about to get into tuning the bleeds on the emulsion well of the carb. My truck is limited to 4200RPM for now so I may not even need the high speed circuit.
If your talking about the edelbrock vrs becareful this carb is a 4 circuit carburetor tunes differently than a regular holley. Haven't had a chance to check one out yet. Good luck.
@@holleycarbshowtosadvice40y90 yes thats it! I will be tuning the fuel curves a bit next. I need to find out what emulsion plug relates to 4200 RPM on the metering block and then fine tune all the ones above it. I'm about to make a jet drilling fixture too.
best vids on the planet...!!!
Thank you.
2 thumbs up as usual, thank you for your time
Glad you enjoyed , thanks mike.
The idle mixture screws can only change the fuel to the round holes . The transfer slot can only be changed by idle air bleed or idle jet change . The transfer slot comes in above the mixture screw. And runs off of the idle jet and idle air bleed .
You set up a holley basically two different ways for the idle circuit, one way if has a racing cam with low vacuum and another way if its stock. Watch my video.
good vid.
Thank you
What would be a good emulsion size bleed for a blow though billet metering block carb to start with? As always you one of the easiest to understand videos on the tube out there.
I sorry I don't do blow through carb stuff.
So Randy, if I understand corrrectly: we use the Main Jets to tune the W.O.T. AFR to be where we want it, but use the air bleeds to dial in everything below that?
No alot of times you will be close but your fuel curve might be rich at wot and you would change your lowest emulsion bleed hole on your metering block by 4 or 5 thousandths larger and lean it out. Now this is if your close with your tune.
hey Randy, great ved as usual, but I was surprised you advised us to go get a m.b. with 4 or 5 treaded holes instead of pulling out the drill and fixing the stock block. oh well after watching all your other vedios' I guess i can figure that one out
You can modify a stock block but only to a certain extent, most are two hole emulsion. Billet blocks have up to 5 holes and I usually use 4 holes. Some tuners use three. Hope this helps.
Great video and provides a lot of information that I think has been missing in different internet discussions.
Having a problem with a 1000 cfm dp down leg boosters, and hoping to maybe get pointed the right way. 500 cid bbc. Demon body with Holley 5 hole blocks (6 if you count kill bleed). This is in a boat and it’s under load all the time. Idle and transition are okay but once on the mains it continues to lean out. Jets are 91/98 with 070 pvcr primary. Emulsion is: kill bleed 027 then 028/0/028/0/0. Main air bleed is 28. Floats are right. Frustrated with how much jet I’ve needed. Dangerously lean at peak torque (4700 rpm - 14.2). Was going to drop the main air bleed to 025 and work way up. Close up the emulsion too?
Tom are your emulsion 0s are they blocked with screw in bleed plugs? Also give me your high speed bleed size and how high is your float level. I'm guessing your venturi is 1.560 and 1.750 throttle plates. Let me know.
Hello Randy! I've watched several of your videos and have enjoyed all of them. I always reminded my students that carburetors many times take the blame for other engine problems, two common being engine timing and vacuum leaks. You're doing an excellent job. Keep up the good work! By the way, where in the south is your home base? I come and stay in central Alabama from Houston, TX several times during the year. May be I can stop by and visit sometime. Regards!
I'm in jacksonville fl. , let me know if your ever in this area. Thanks for watching.
Great video i currently have an ATM 750 dp im tuning in my 428 Fe ive got the jets to give me 12-13 afr cruise now but it goes very lean when i left off the gas for a second before it goes back to the idle circuit 4 hole billet metering block has 4 holes the top 2 are wide open the bottom 2 are .020 from factory..
Thats not unusual especially with a manual transmission.
When you say wide open, do you mean you removed upper 2 air bleed screws?
Excellent descriptions I´ve seen. On my carb I have 4 threaded holes so I can fiddle with them. They don´t have any bleeds in them though but they are all open and drilled to 28 thousands from the manufaturer. One thing I´de like to know is if I open one to say 35 thousands, will the lean effect be the same in all positions albeit in a different area och the fuel curve? Is there any kind of typical reference how much effect on AFR a certain change in hole size make? E.g a change in 5 thousands will result in x.xx i AFR?
There is so many factors, not just changing emulsion bleeds but also you have to figure in hsab size and then the type of booster your using. I can tell you the holley xp ultra 750 has a great fuel curve. Hope this helps
Emulsions... 2 works, sometimes 3. But on the issue of billet metering blocks, never use all 4: gotta play with combinations, and that goes well with an AFR gauge to test across load conditions. One of the funny things about emulsions is by introducing more air, fuel drawn to the booster can increase [to a point] because for the same vacuum signal there is less mass to lift - velocity of fuel delivered increases. The air bleed is the baseline for this function: it determines the minimum signal booster has to develop for fuel to be drawn. Generally, main air bleed is the dead last thing I fool with because most the time... I got something wrong somewhere else.
There must be a hundred different ways to design a fuel curve everybody to their own, good luck .
hey Randy, love your videos. Is there a way I could contact you about my Holley issue that I’ve been chasing for a year now. I have rebuilt it 3 times and still same problem! Thank you
Yes I'll get back tomorrow.
Whats your email address? I'll email you my phone number.
I'm trying to run an AVS2 on my 350 sbc and it its just a pig. I cant get this stupid thing to run right and i am going to go to my 750 holley carb and to my single plane intake. The Avs2 is just backfiring from the low idle on 1 cylinder and it is driving me nuts.
Well I hope you figure it out. If I can help let me know.
So if you have 2x4 and never see more than 6500 are you ever gonna touch the bottom bleeds
Normally you are right but it is possible with the right combination. A lot of things come into play like the engine breathing capability, the right size carb and the right carb modifications, this can be the difference in winning and loosing.hope this helps
On those jets increase size for more fuel ?
The air bleeds work backwards the smaller the bleed hole it will richen the fuel mixtture . And just the opposite within .a bigger bleed hole the leaner it will be. Hope this helps.
Now if your talking about fuel jets they work , the bigger the more fuel flow, the smaller the less fuel. Hope this helps
I have a quickfuel 650 brawler dp and i have set the fuel curve flat on half throtlle. When i ooen the secondaries(full throtlle) my fuel curve goes from 2000-2500 rpm starts at 10 afr and only goes to 12.7 at 3500 rpm to max rpm and stays in 12.7 afr.
I wanna change the low rom 10afr to 12.7 afr .
Can i do this with just putting bigger emulsion jets in on the lower place? Do i have to do this on the primary and secondary metering block or can i just do it only on the secondary metering block?
Do i need to go bigger on emulsiin jet to lean out this rpm range?
Thanks for the vid
When you open the secondaries your afr is going to be rich with a dp then it goes to 12.7 through max rpm, if you want a more flat fuel curve you may want to go with a vacuum secondary but you can lean your carb but don't use your emulsion, when you have steady afr from 3500 to max rpm your emulsion is working properly. Maybe try .002 larger secondary high speed air bleed or jetting secondary leaner. Hope this helps
@@holleycarbshowtosadvice40y90
Can I adresse this low rpm rich mixture a little bit with putting my total timing from 3000rpm to 2500 rpm? Will it clean it out a little bit?
When you go to wot it'll go rich from the accel pump and popping open the secondaries until you gain some rpms the 12.7 is the fuel ratio, a holley vacuum secondary has no rear accelerator pump and the secondaries come in slow, so the mixture curve is much more flat. Hope this helps
@@holleycarbshowtosadvice40y90
yes i tested this and so i put full throtlle at 1500 rpms and so the pumpshot is burned and afr is 11.5 but when i come back at 2500 rpm the afr goes back to 10 and lower
Well now. I have been struggling to visualize the mail well action as rpm rises, and how the air enters.
As rpm rises, the level in the main starts to drop, as it drops it uncovers and air bleed, and air is drawn in.
I think I got it.
Yes you do, nobody wants to give this information up. Have a good one.
@@holleycarbshowtosadvice40y90 If releasing these secrets causes you to wind up on a milk carton....I will demand an investigation.
Was hoping to hear more about the highspeed air bleeds. In a nutshell, having an issue on my 680qft 4160 where theres not enough overlap between the transition and the mains, goes dead lean from about 1800-2500. Hearing conflicting info on which way to go with the bleeds.. bigger / more air flow helps lift the fuel and bring mains in sooner but will lean it, but also hear smaller will give stronger signal and bring mains in sooner. Currently with 61 idle bleeds it fills the gap enough to run, but the transition is rich untill 1500 where it will lean out to 15-16:1 until 2500 it will start richening up again. 28s in the high speed, with 68 jets, fully on the mains - 3k rpm- im back to 12-13 but starts gradually leaning back out as rpms climb.
Ok the smaller air bleed will pull more fuel and earlier. Now there is ways to help your problem, try raising your float level slightly and install a smaller high speed air bleed , you could try annular boosters which has a better signal but they are expensive. Hope this helps. One other thing that can cause this problem is if your idle fuel restrictor is to small it can feed the idle mixture circuit and starve the transfer slot .
Ive already been playing with the IFRs and wasnt doing anything for me other than making the transition even richer and the idle mixtures a pita to set. Currently i have .034 IFRs and im 5/8 out on the idle mixtures (4corner). Going from 71 to 61 idle bleeds really helped as far as drivability, but now have weirdness at idle with cascading idle and the whole transition being rich. Will drop the high speeds from 28s to i think i bought 23s@@holleycarbshowtosadvice40y90
I sent you a message about my 950 HP running too rich at cruise 2300 to 3200 RPM big duration cam would l benefit from the billet plate, l have a 73 primary jet and a 3.5 PV. The engine is a 455 Buick it made 656 hp 600 ft lb torque
You might, but its according how close you are now. These high horse power engines don't like running lean so be careful.
When l remove my plugs they are always close to dark brown they used to come out black
Sounds good.
Do you have a video which addresses baseline jetting specs for typical builds.
Examples:
Say mild 350 with a Holley 600 VS
Street/Strip Set Up 350 Holley 750 VS
Street/STRIP 383 Holley 750DP
?