This is not a Drag Race Question, help is appreciated

John Lang · 02-06-2016, 05:36 PM

Anybody have any experience with 500cfm Holley #0-4412-1, or 0-80583-1 or o- 4412BKX-HP Holley, 2bbl carbs ? Is there any performance to be gained from one to the other ! This is for a IMCA race car ! Sorry to post this on a Drag site but in my area of the country there's no one to ask ! Thanks,..John

FED 387 · 02-06-2016, 06:12 PM

4412 carb is the same as a 80583 with the following exceptions--- 4412 is a street carb & has machining done to allow for choke mechanism-pressed in air bleeds--- steel throttle plates and shafts and other things done---the 80583 was designed as a race carb only---it has no machining done for choke mechanism/rods----screw in air bleeds---- stainless throttle plates and better quality steel throttle shafts etc..---4412 can be used for racing a 80583 was designed only for racing--- hope this helps FED 387

John Lang · 02-06-2016, 07:28 PM

FED ! There is another 4412w/BKX-HP ? Got any ideas on that ? By the way thanks for the info ! I'm doing one of these carbs for a friend, and trying for the most bang for the buck, so to speak !...John

jcw31 · 02-06-2016, 08:28 PM

John had some exp with 4412 guage legal,used vdl,pro sys and box stock jetting was between 71 to 73 pv was 6.5 to 8.5 both sideways and forward mount , manifold and spacer made a diff.Not so much as to who did carb.

dmir55 · 02-06-2016, 10:26 PM

The 4412s is the best of the original castings. This was the number on the first run of the 4412's. Every time Holley made another run the castings seemed to flow a little less. I don't know about the newer 500's. Never had a chance to work with them. I suppose the rules cover them but what about the 650 Holley two barrel. they really work and I have found them on Ebay now and again. Bob Oliver is the best I have worked with on any Holley 2 or 4 barrel. A few more things. Use the 35cc accelerator pump. When you use the 50 cc pump it fattens the engine up so much it takes the whole straightaway to clean it up. Use the anti pull over shooter. EVERY circuit in the 4412 is trying to work at speed. Main circuit, idle, transition slot and the shooter. Try a 2.5 power valve, it will give you a high speed lean out. If you are doing your own carb I hope this helps. Happy motoring!

FED 387 · 02-07-2016, 12:59 AM

John-- the 4412bkx has had the choke air horn removed, uses different down leg boosters and has had the screw in air bleeds repositioned further towards the side of the carb to improve air flow--- if you can use a 6425 Holley 2 bbl carb they are rated @ 650 CFM not 500 like the other 2 carbs-- you will definitely need to utilize a anti pull over nozzle make sure you double stack the washers and use a washer top & bottom on the nozzle might need to use a solid screw instead of the hollow one-- Holley makes a anti pull over kit don't remember the part number but I'll get back to you on that- you might have to work on the accelerator pump area too-- I use a small Honda valve cover grommet sanded down to about 3/16 inch and use JB Weld to epoxy it to the pump gasket to hold it in place then fit the return spring over it-- you only need that pump for the first shot about 1/3 then let the carb do its thing--- probably plug the power valve up too--- it's all trial and error

FED 387 · 02-07-2016, 01:21 AM

Sorry there --is no kit just the nozzles and they come in about 6-8 different sizes-you might also need to drill a small hole in the nozzle to act as a vacuum break---You might need to change float bowls too if you have the one with the flapper in it---you will need to get one that has a check ball in the bottom of where the accelerator pump mounts instead of the bowl that utilizes the rubber flapper--- that rubber flapper tends to vibrate and can actually act as a accelerator pump by allowing fuel to be pumped thru the circuit when you do not want fuel coming out of those nozzles.

John Lang · 02-07-2016, 03:37 PM

You guys are incredible ! Thanks for the help ! I'll let you know what's going on with this !..John

jcw31 · 02-07-2016, 03:58 PM

The vdl came with a 35cc pump, the stock 4412 50cc, the baker was 50.cc never had a problem with it being too rich off the turns. these were guage legal with choke tower.Some had a tiny bleed hole in the metering block above the jets for pullover.Some were run without pv and jetted around 76.

02-06-2016, 05:36 PM	#1
John Lang Member Join Date: Oct 2003 Location: Sheboygan Wi Posts: 391 Likes: 0 Liked 6 Times in 2 Posts	This is not a Drag Race Question, help is appreciated Anybody have any experience with 500cfm Holley #0-4412-1, or 0-80583-1 or o- 4412BKX-HP Holley, 2bbl carbs ? Is there any performance to be gained from one to the other ! This is for a IMCA race car ! Sorry to post this on a Drag site but in my area of the country there's no one to ask ! Thanks,..John __________________ John Lang 365 STK, SS

02-06-2016, 06:12 PM	#2
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,349 Likes: 325 Liked 280 Times in 150 Posts	Re: This is not a Drag Race Question, help is appreciated 4412 carb is the same as a 80583 with the following exceptions--- 4412 is a street carb & has machining done to allow for choke mechanism-pressed in air bleeds--- steel throttle plates and shafts and other things done---the 80583 was designed as a race carb only---it has no machining done for choke mechanism/rods----screw in air bleeds---- stainless throttle plates and better quality steel throttle shafts etc..---4412 can be used for racing a 80583 was designed only for racing--- hope this helps FED 387

02-06-2016, 07:28 PM	#3
John Lang Member Join Date: Oct 2003 Location: Sheboygan Wi Posts: 391 Likes: 0 Liked 6 Times in 2 Posts	Re: This is not a Drag Race Question, help is appreciated FED ! There is another 4412w/BKX-HP ? Got any ideas on that ? By the way thanks for the info ! I'm doing one of these carbs for a friend, and trying for the most bang for the buck, so to speak !...John __________________ John Lang 365 STK, SS

02-06-2016, 08:28 PM	#4
jcw31 Junior Member Join Date: Jan 2013 Posts: 82 Likes: 0 Liked 2 Times in 2 Posts	Re: This is not a Drag Race Question, help is appreciated John had some exp with 4412 guage legal,used vdl,pro sys and box stock jetting was between 71 to 73 pv was 6.5 to 8.5 both sideways and forward mount , manifold and spacer made a diff.Not so much as to who did carb.

02-06-2016, 10:26 PM	#5
dmir55 Junior Member Join Date: Jul 2014 Location: northern Minnesota Posts: 64 Likes: 0 Liked 0 Times in 0 Posts	Re: This is not a Drag Race Question, help is appreciated The 4412s is the best of the original castings. This was the number on the first run of the 4412's. Every time Holley made another run the castings seemed to flow a little less. I don't know about the newer 500's. Never had a chance to work with them. I suppose the rules cover them but what about the 650 Holley two barrel. they really work and I have found them on Ebay now and again. Bob Oliver is the best I have worked with on any Holley 2 or 4 barrel. A few more things. Use the 35cc accelerator pump. When you use the 50 cc pump it fattens the engine up so much it takes the whole straightaway to clean it up. Use the anti pull over shooter. EVERY circuit in the 4412 is trying to work at speed. Main circuit, idle, transition slot and the shooter. Try a 2.5 power valve, it will give you a high speed lean out. If you are doing your own carb I hope this helps. Happy motoring! Last edited by dmir55; 02-06-2016 at 10:41 PM.

02-07-2016, 12:59 AM	#6
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,349 Likes: 325 Liked 280 Times in 150 Posts	Re: This is not a Drag Race Question, help is appreciated John-- the 4412bkx has had the choke air horn removed, uses different down leg boosters and has had the screw in air bleeds repositioned further towards the side of the carb to improve air flow--- if you can use a 6425 Holley 2 bbl carb they are rated @ 650 CFM not 500 like the other 2 carbs-- you will definitely need to utilize a anti pull over nozzle make sure you double stack the washers and use a washer top & bottom on the nozzle might need to use a solid screw instead of the hollow one-- Holley makes a anti pull over kit don't remember the part number but I'll get back to you on that- you might have to work on the accelerator pump area too-- I use a small Honda valve cover grommet sanded down to about 3/16 inch and use JB Weld to epoxy it to the pump gasket to hold it in place then fit the return spring over it-- you only need that pump for the first shot about 1/3 then let the carb do its thing--- probably plug the power valve up too--- it's all trial and error Last edited by FED 387; 02-07-2016 at 01:00 AM. Reason: spelling

02-07-2016, 01:21 AM	#7
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,349 Likes: 325 Liked 280 Times in 150 Posts	Re: This is not a Drag Race Question, help is appreciated Sorry there --is no kit just the nozzles and they come in about 6-8 different sizes-you might also need to drill a small hole in the nozzle to act as a vacuum break---You might need to change float bowls too if you have the one with the flapper in it---you will need to get one that has a check ball in the bottom of where the accelerator pump mounts instead of the bowl that utilizes the rubber flapper--- that rubber flapper tends to vibrate and can actually act as a accelerator pump by allowing fuel to be pumped thru the circuit when you do not want fuel coming out of those nozzles.

02-07-2016, 03:37 PM	#8
John Lang Member Join Date: Oct 2003 Location: Sheboygan Wi Posts: 391 Likes: 0 Liked 6 Times in 2 Posts	Re: This is not a Drag Race Question, help is appreciated You guys are incredible ! Thanks for the help ! I'll let you know what's going on with this !..John __________________ John Lang 365 STK, SS

02-07-2016, 03:58 PM	#9
jcw31 Junior Member Join Date: Jan 2013 Posts: 82 Likes: 0 Liked 2 Times in 2 Posts	Re: This is not a Drag Race Question, help is appreciated The vdl came with a 35cc pump, the stock 4412 50cc, the baker was 50.cc never had a problem with it being too rich off the turns. these were guage legal with choke tower.Some had a tiny bleed hole in the metering block above the jets for pullover.Some were run without pv and jetted around 76.