Choosing a Carb
February 6th, 2019, 07:55 AM
#1
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Thread Starter
Join Date: Sep 2017
Location: Chicago
Posts: 95
Choosing a Carb
HI all - I am in the process of rebuilding a 455. This is going in my 72 cutlass vert. There is a 350 in there now.
The numbers that I am expecting are
-about 450hp and 400 something lb ft of torque.
Here are some of the additions....
J heads - ported and polished
10.1 Compression
-Bored over .30
-edelbrock performer intake
-Lunati voodoo cam - RPM Range = 2000-6000, Lift=.522/.539, Duration = 233/241, 280-3800 Stall, 3.42-3.73 gear
-Aftermarket Headers (Forgot the brand)
-Will get a 400 trans
I am in need of some carb suggestions. I've been searching all on here, but can't find a definitive answer lol.....I do see a lot of "Edelbrocks are terrible". What does everyone successfully run? Will I have to get some sort of plate to make a non-EB carb mate tot eh EB intake?
Please let me know your thoughts!!!!!!
The numbers that I am expecting are
-about 450hp and 400 something lb ft of torque.
Here are some of the additions....
J heads - ported and polished
10.1 Compression
-Bored over .30
-edelbrock performer intake
-Lunati voodoo cam - RPM Range = 2000-6000, Lift=.522/.539, Duration = 233/241, 280-3800 Stall, 3.42-3.73 gear
-Aftermarket Headers (Forgot the brand)
-Will get a 400 trans
I am in need of some carb suggestions. I've been searching all on here, but can't find a definitive answer lol.....I do see a lot of "Edelbrocks are terrible". What does everyone successfully run? Will I have to get some sort of plate to make a non-EB carb mate tot eh EB intake?
Please let me know your thoughts!!!!!!
February 6th, 2019, 11:08 AM
#5
Registered User
Join Date: Sep 2017
Location: St. Paul Minnesota
Posts: 4,243
Google Cliff Ruggles He will probably replace the power piston spring because your engine vacuum will be lower. From what I have read on this site, people have been well satisfied with his Quadrajet carbs. Good luck.
February 6th, 2019, 11:17 AM
#6
Running On Empty
Join Date: Jul 2018
Location: Earth
Posts: 20,107
Cliff
I might mention - you should probably call Cliff. Tell him what you are doing. He loves to talk and is very engaging - he enjoys talking it up & is happy to assist others.
I might mention - you should probably call Cliff. Tell him what you are doing. He loves to talk and is very engaging - he enjoys talking it up & is happy to assist others.
Last edited by Vintage Chief; February 6th, 2019 at 11:19 AM.
February 6th, 2019, 12:23 PM
#7
Registered User
Join Date: May 2018
Posts: 765
Are you going to dyno the engine or the car once complete?
I am interested to know the results.
Also, don’t forget to put a nice, high-stall converter behind that engine, as that cam will want a 3,000+ stall minimum to run good
as for a carb, my $.02....
Quadra jets can be tuned to run awesome, if you get enough fuel to them. Around 400hp is usually the limit of what every stock or upgraded fuel pump is capable of delivering to a small fuel bowl carb like a Quadra jet. The RobbMC fuel pump can supply much more fuel.
You “can” get a quadrajet to run well if you understand a wideband, and you know what metering rods, main jets, and real rod hanger letters to try... the biggest pitfalls are a small fuel bowl capacity and they tend to leak internally from the main well.
I personally like the smaller Holley Double-pump carbs for the reason of fuel capacity in the bowls... and they are rock-solid reliable and rebuildable. A cheap but fun carb is a 650cfm double pump or a 700cfm double pumper. If you buy a carb from a reputable builder or order one, you can get an 800cfm or 850cfm with annular discharge boosters to make it wonderfully responsive.
I can’t say anything bad about the E-Brock carbs, but they are more like tuning a quadrajet and I never found the performance sensation (seat-o-the-pants) as good as a well tuned Holley double pumper.
Also, my Holley double pump got the same mileage as a well tuned quadrajet on a 380-400hp 455 I drove for years....
I am interested to know the results.
Also, don’t forget to put a nice, high-stall converter behind that engine, as that cam will want a 3,000+ stall minimum to run good
as for a carb, my $.02....
Quadra jets can be tuned to run awesome, if you get enough fuel to them. Around 400hp is usually the limit of what every stock or upgraded fuel pump is capable of delivering to a small fuel bowl carb like a Quadra jet. The RobbMC fuel pump can supply much more fuel.
You “can” get a quadrajet to run well if you understand a wideband, and you know what metering rods, main jets, and real rod hanger letters to try... the biggest pitfalls are a small fuel bowl capacity and they tend to leak internally from the main well.
I personally like the smaller Holley Double-pump carbs for the reason of fuel capacity in the bowls... and they are rock-solid reliable and rebuildable. A cheap but fun carb is a 650cfm double pump or a 700cfm double pumper. If you buy a carb from a reputable builder or order one, you can get an 800cfm or 850cfm with annular discharge boosters to make it wonderfully responsive.
I can’t say anything bad about the E-Brock carbs, but they are more like tuning a quadrajet and I never found the performance sensation (seat-o-the-pants) as good as a well tuned Holley double pumper.
Also, my Holley double pump got the same mileage as a well tuned quadrajet on a 380-400hp 455 I drove for years....
Last edited by Battenrunner; February 6th, 2019 at 12:33 PM.
February 6th, 2019, 09:21 PM
#8
Oh no, not again...
Join Date: Jul 2018
Location: Sherwood Park, Alberta, in the Great White North
Posts: 359
Edelbrocks are only terrible because they're designed to work well on Chevy small blocks without any modification. You modify and re-jet one, it can be a good carb. I run the original version on a Buick, the Carter AFB. It works well for the application, but that's about it.
The Holley is a tuner's carb; you really have to know what to do with one because the working parameters change with barometric pressure changes. I could never get one to work for me, but others have. When working right, these would be the proper carb to boost power, however, you really have to know what you're doing with one. Mine always ran like a toilet, I have no idea to this day why. I used to run them on Ford FE blocks. The other thing about a Holley is that you have to have your ignition in perfect tune, if it backfires, it usually takes out the power valve, which requires surgery and gaskets. And, they like to drink. Here again, my experience with them hasn't been good; and yes, the carb was matched and supposedly jetted to the engine from the factory. It ran rich no matter what I did, and it iced up constantly.
So that leaves the venerable old Q-Jet. It was a very versatile carb, and depending on the application you can get some that are designed to 880 CFM, no way a Carter or the Edelbrock knock-off will get those numbers. The 1972 Pontiac HD version on their 455 is supposedly the best; can't remember the number for one of those. The versions they used on 1970-72 Olds 455 (particularly the 442) were also very good, as was the one on a Buick GS from the same period.
I've rebuilt and tuned a number of Q-jets on Buicks; I like them. But that's just my opinion. But they do have to be tuned for the application, you just can't slap one on and expect stellar results. There are a number of good books out there on how to tune them, if you're interested in playing they're well worth the read. If you decide to go with a Q-jet, avoid the very early ones, the 66 and early 67 models. They were garbage. The pre-1970 version maxes out at about 750 CFM, the later ones to about 880. The smogger carbs should be avoided as well.
So you have a couple of choices, and since you're doing mild mods to the car, IMHO the Q-Jet would be the preferred one.
The Holley is a tuner's carb; you really have to know what to do with one because the working parameters change with barometric pressure changes. I could never get one to work for me, but others have. When working right, these would be the proper carb to boost power, however, you really have to know what you're doing with one. Mine always ran like a toilet, I have no idea to this day why. I used to run them on Ford FE blocks. The other thing about a Holley is that you have to have your ignition in perfect tune, if it backfires, it usually takes out the power valve, which requires surgery and gaskets. And, they like to drink. Here again, my experience with them hasn't been good; and yes, the carb was matched and supposedly jetted to the engine from the factory. It ran rich no matter what I did, and it iced up constantly.
So that leaves the venerable old Q-Jet. It was a very versatile carb, and depending on the application you can get some that are designed to 880 CFM, no way a Carter or the Edelbrock knock-off will get those numbers. The 1972 Pontiac HD version on their 455 is supposedly the best; can't remember the number for one of those. The versions they used on 1970-72 Olds 455 (particularly the 442) were also very good, as was the one on a Buick GS from the same period.
I've rebuilt and tuned a number of Q-jets on Buicks; I like them. But that's just my opinion. But they do have to be tuned for the application, you just can't slap one on and expect stellar results. There are a number of good books out there on how to tune them, if you're interested in playing they're well worth the read. If you decide to go with a Q-jet, avoid the very early ones, the 66 and early 67 models. They were garbage. The pre-1970 version maxes out at about 750 CFM, the later ones to about 880. The smogger carbs should be avoided as well.
So you have a couple of choices, and since you're doing mild mods to the car, IMHO the Q-Jet would be the preferred one.
February 7th, 2019, 08:28 PM
#10
Oh no, not again...
Join Date: Jul 2018
Location: Sherwood Park, Alberta, in the Great White North
Posts: 359
If I got my stats wrong, fine, correct them. My memory isn't what it used to be. If you feel that my comments about a particular carb are wrong, then tell me why they're wrong. I'll be the first to admit I'm an idiot if I'm wrong.
I'm basing my comments on my experience, so in some cases it may be subjective, and I get that. I state that. I happen to like Q-jets and have rebuilt dozens successfully, same with Carter AFBs because they were the main carb used on a Nailhead Buick. I stated my bias against Holley, and admitted that I could never get one to work right. No one brought up the illustrious Rochester 4GC, another complicated wonder that is tough to get right, primarily because most of the kits seem to be too generic and cheaply made. I could never get a needle to seat properly. And, I did the WCD on the 53 Olds; which is the forerunner to the AFB. The AFB (and by virtue of being a virtual copy, the Edelbrock "performer") are easy to build and can be re-jetted and played with if you know what you're doing. So how is that wrong?
I'll be the first to admit that I don't know much about the current crop of Edelbrock Holley knock offs, but the older Performer design I do know a fair bit about because I've overhauled a lot of them. Most of them on SBC. On Buicks they run like toilets, they can't get enough air through. They aren't recommended for BBB or any other big block.
As for the power valve blowout protection, that's news to me, I won't argue it. Fine; the last time I wrecked a Holley was about 20 years ago, and I went through 3 power valves. They came from Napa, they claimed to be an improved design, but they were garbage all the same. So who knows. I just know that everything I tried didn't work, and that thing had to be tampered with every time the sun went behind a cloud, I just couldn't get it to idle, and it would fall over itself when you stepped on the gas, almost if it had a built in vacuum leak. Maybe I had a dog, but it was a clean dog, and after a session on a laping table a flat one so that wasn't the problem. Anyway, after I sold it, the next owner burned it to the ground. At any rate, after that one and then playing with a few 2 bbls on Fords, I was totally turned off Holley and will avoid one to this day.
Quite frankly, I've never seen a Holley on an Olds; that could just be because there aren't many Oldsmobile tuners up here. Most I've seen are running 4GCs, Q-jets or AFBs. Here again, subjective and based on my experience, nothing more.
Last edited by Nailheadcanuck; February 7th, 2019 at 08:32 PM.
February 8th, 2019, 12:00 AM
#11
Registered User
Join Date: Nov 2008
Location: Central Fl
Posts: 7,971
Edelbrocks are only terrible because they're designed to work well on Chevy small blocks without any modification. Wrong. The carb has no idea what make of engine it's on. They're jetted for a particular engine size and hp range, NOT the make of engine, just like every aftermarket carb is. You modify and re-jet one, correct it can be a good carb. Your opinion I run the original version on a Buick, the Carter AFB. It works well for the application, but that's about it.
The Holley is a tuner's carb; you really have to know what to do with one because the working parameters change with barometric pressure changes. All carbs change with changes in the baro, every single one. So does EFI, the injector pulse width will change with changes in the baro as well. I could never get one to work for me, but others have. When working right, these would be the proper carb to boost power, however, you really have to know what you're doing with one. There are lots of books on how to tune Holleys as well. Mine always ran like a toilet, Did you ever buy a wideband air/fuel meter to see what was happening? I have no idea to this day why. Then the answer is no. I used to run them on Ford FE blocks. The other thing about a Holley is that you have to have your ignition in perfect tune, if it backfires, it usually takes out the power valve, already addressed that which requires surgery and gaskets. And, they like to drink. Here again, my experience with them hasn't been good; and yes, the carb was matched and supposedly jetted to the engine from the factory. Again did you ever check it with an air/fuel meter? It ran rich no matter what I did, and it iced up constantly. You had other issues that you overlooked
So that leaves the venerable old Q-Jet. It was a very versatile carb, and finicky. Did you know that changing the fuel pressure by just 1 pound effects the entire fuel curve? and depending on the application you can get some that are designed to 880 CFM, they never made one from the factory that was that big. no way a Carter or the Edelbrock knock-off will get those numbers.The 1972 Pontiac HD version on their 455 is supposedly the best; can't remember the number for one of those. The versions they used on 1970-72 Olds 455 (particularly the 442) were also very good, as was the one on a Buick GS from the same period.
I've rebuilt and tuned a number of Q-jets on Buicks; I like them. But that's just my opinion. But they do have to be tuned for the application, you just can't slap one on and expect stellar results. There are a number of good books out there on how to tune them, if you're interested in playing they're well worth the read. If you decide to go with a Q-jet, avoid the very early ones, the 66 and early 67 models. They were garbage. The pre-1970 version maxes out at about 750 CFM, the later ones to about 880. The smogger carbs should be avoided as well.
So you have a couple of choices, and since you're doing mild mods to the car, IMHO the Q-Jet would be the preferred one.
The Holley is a tuner's carb; you really have to know what to do with one because the working parameters change with barometric pressure changes. All carbs change with changes in the baro, every single one. So does EFI, the injector pulse width will change with changes in the baro as well. I could never get one to work for me, but others have. When working right, these would be the proper carb to boost power, however, you really have to know what you're doing with one. There are lots of books on how to tune Holleys as well. Mine always ran like a toilet, Did you ever buy a wideband air/fuel meter to see what was happening? I have no idea to this day why. Then the answer is no. I used to run them on Ford FE blocks. The other thing about a Holley is that you have to have your ignition in perfect tune, if it backfires, it usually takes out the power valve, already addressed that which requires surgery and gaskets. And, they like to drink. Here again, my experience with them hasn't been good; and yes, the carb was matched and supposedly jetted to the engine from the factory. Again did you ever check it with an air/fuel meter? It ran rich no matter what I did, and it iced up constantly. You had other issues that you overlooked
So that leaves the venerable old Q-Jet. It was a very versatile carb, and finicky. Did you know that changing the fuel pressure by just 1 pound effects the entire fuel curve? and depending on the application you can get some that are designed to 880 CFM, they never made one from the factory that was that big. no way a Carter or the Edelbrock knock-off will get those numbers.The 1972 Pontiac HD version on their 455 is supposedly the best; can't remember the number for one of those. The versions they used on 1970-72 Olds 455 (particularly the 442) were also very good, as was the one on a Buick GS from the same period.
I've rebuilt and tuned a number of Q-jets on Buicks; I like them. But that's just my opinion. But they do have to be tuned for the application, you just can't slap one on and expect stellar results. There are a number of good books out there on how to tune them, if you're interested in playing they're well worth the read. If you decide to go with a Q-jet, avoid the very early ones, the 66 and early 67 models. They were garbage. The pre-1970 version maxes out at about 750 CFM, the later ones to about 880. The smogger carbs should be avoided as well.
So you have a couple of choices, and since you're doing mild mods to the car, IMHO the Q-Jet would be the preferred one.
Based on all your statements I would regard you as a carb rebuilder, not a tuner. You don’t make mention of any jetting changes based on reading plugs, your O2 info or anything of the sort. You even admit not knowing why something ran so rich etc.
I hope this helps to substantiate my earlier statement. Thank you.
Last edited by cutlassefi; February 8th, 2019 at 05:19 AM.
February 8th, 2019, 06:06 PM
#12
Oh no, not again...
Join Date: Jul 2018
Location: Sherwood Park, Alberta, in the Great White North
Posts: 359
Yes it does, thank you.
And, you're right, I've done more rebuilding than tuning. As for Edelbrocks not doing well on Buicks; yes, CFM is CFM, but we've found that unless properly jetted, the Edelbrock out of the box will not keep up to the needs of the Buick and will level off on the top end and fall on its face. Even jetted, the upper end performance isn't quite there as compared to a Q-jet. The Buick is very particular about air to fuel ratio and doesn't respond well to just having more gas pumped into it, it wants a lot of air. They're surprisingly easy to flood out and don't run worth a hoot rich. (Yes, all engines are particular) The bigger secondaries and being a spreadbore really help, I would imagine the same would be true for an Olds big block. The SBC is the most common engine application out there, so it only makes sense that Edelbrock will set the base tune for an SBC since most customers do not know how to tune and will just put it on straight out of the box.
Yes, I've found that Q-jets can be a mess with fuel pressure issues, My last Q-jet was an early one on a Nailhead Buick, it killed 3 brand new Chinese made knock-off fuel pumps, and on the 4th one (an old US made one) gas was just blowing past the needle and seat retrofit and spraying everywhere. I put the original AFB back on and haven't had a problem since, but I haven't taken that Q-jet apart yet to figure out what went wrong with it. Possibly the needle and seat that was used in place of the original and faulty umbrella design; it was also probably a cheap kit thrown into it.(It changes what you can do with the float) It was completely overhauled and totally refurbished and re-anodized by a "professional" carb rebuilding company at a ridiculous cost to me. (Q-jets were supposedly his specialty and I gave him a very rare one that had sat in a wrecker's yard in the open to overhaul) I'm still a little too pissed-off to go look at it, I'm still tempted to just kick it across the driveway instead. As for that company that built it, they've uprooted themselves and moved to the US, so no warranty, just $700 wasted.
I had a fairly good book on the Holley and I still don't know what was wrong. I did check plugs and jetting, it was supposedly correct for that engine. (Stock Ford 390) Could have it been worn out? Possibly, didn't have the equipment to verify it. The only thing I narrowed it down to was thermal expansion on the throttle shaft bores causing an intermittent vacuum leak. And I didn't have an air/fuel meter then, I do now.
At any rate, thanks for clearing that up and I'll shut up now.
And, you're right, I've done more rebuilding than tuning. As for Edelbrocks not doing well on Buicks; yes, CFM is CFM, but we've found that unless properly jetted, the Edelbrock out of the box will not keep up to the needs of the Buick and will level off on the top end and fall on its face. Even jetted, the upper end performance isn't quite there as compared to a Q-jet. The Buick is very particular about air to fuel ratio and doesn't respond well to just having more gas pumped into it, it wants a lot of air. They're surprisingly easy to flood out and don't run worth a hoot rich. (Yes, all engines are particular) The bigger secondaries and being a spreadbore really help, I would imagine the same would be true for an Olds big block. The SBC is the most common engine application out there, so it only makes sense that Edelbrock will set the base tune for an SBC since most customers do not know how to tune and will just put it on straight out of the box.
Yes, I've found that Q-jets can be a mess with fuel pressure issues, My last Q-jet was an early one on a Nailhead Buick, it killed 3 brand new Chinese made knock-off fuel pumps, and on the 4th one (an old US made one) gas was just blowing past the needle and seat retrofit and spraying everywhere. I put the original AFB back on and haven't had a problem since, but I haven't taken that Q-jet apart yet to figure out what went wrong with it. Possibly the needle and seat that was used in place of the original and faulty umbrella design; it was also probably a cheap kit thrown into it.(It changes what you can do with the float) It was completely overhauled and totally refurbished and re-anodized by a "professional" carb rebuilding company at a ridiculous cost to me. (Q-jets were supposedly his specialty and I gave him a very rare one that had sat in a wrecker's yard in the open to overhaul) I'm still a little too pissed-off to go look at it, I'm still tempted to just kick it across the driveway instead. As for that company that built it, they've uprooted themselves and moved to the US, so no warranty, just $700 wasted.
I had a fairly good book on the Holley and I still don't know what was wrong. I did check plugs and jetting, it was supposedly correct for that engine. (Stock Ford 390) Could have it been worn out? Possibly, didn't have the equipment to verify it. The only thing I narrowed it down to was thermal expansion on the throttle shaft bores causing an intermittent vacuum leak. And I didn't have an air/fuel meter then, I do now.
At any rate, thanks for clearing that up and I'll shut up now.
February 9th, 2019, 01:08 PM
#14
Registered User
Join Date: Feb 2017
Location: , CA
Posts: 406
Cliff
I might mention - you should probably call Cliff. Tell him what you are doing. He loves to talk and is very engaging - he enjoys talking it up & is happy to assist others.
I might mention - you should probably call Cliff. Tell him what you are doing. He loves to talk and is very engaging - he enjoys talking it up & is happy to assist others.
February 9th, 2019, 02:05 PM
#15
Running On Empty
Join Date: Jul 2018
Location: Earth
Posts: 20,107
I've clicked on it six times from three different devices and it still takes me to https://cliffshighperformance.com/
I doubt you received a spam virus. Your AV software, IMO.
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