How to Choose the Best Carburetor ?
#42
To have the quadrajet professionally restored/rebuilt is going to be a couple hundred buck + shipping+ a weekend of swapping parts. Which isn't really a problem. I just want to figure out what it'd be better off(in the long run) doing. Is the Edelbrock going to give me more performance if I rebuilt it? It appears to me, judging by the intake, and the bumped up timing, someone probably tried setting this car up to be faster than stock. There are a couple of stock looking cutlass's around, one of them in particular with a factory intake and carb, and I know personally his car won't chirp second gear. Where mine would, there has to be something different about them.
I guess what I'm asking, is performance wise, am I better off with the aftermarket intake and 1406 carburetor(re-calibrated or not) than a rebuilt quadrajet/oem intake? I don't want to waste time/money doing one, to find out I should have done the other.
#43
I would save the hassle of switching stuff out and spend a little more time tuning what you got. By the time you buy and intake clean it up get the carb rebuilt you will be in it more than what it would cost to set this set up correct.
#44
It was my understanding that he still has the stock intake?? I thought the carb, too.
So, we have added more volume to the intake but are using a smaller carb??
Again, guys, I did a reasonable comparison on a fresh engine with a point more compression, head work, headers, and 3.42 gears. The Performer was noticeably better. There simply is no way around the anemic compression.
One day, just for grins, I spent several hours driving around. 3.42 gears, no OD. I was astounded to find that seldom did I get above 2200 rpm. Throttle response and off-idle torque make a STREET CAR fun to drive. I'm tired of repeating myself, so I will stop posting in this thread.
JPC, I have a good 750 Q-jet that I don't need, PM me if you want it, Jim
So, we have added more volume to the intake but are using a smaller carb??
Again, guys, I did a reasonable comparison on a fresh engine with a point more compression, head work, headers, and 3.42 gears. The Performer was noticeably better. There simply is no way around the anemic compression.
One day, just for grins, I spent several hours driving around. 3.42 gears, no OD. I was astounded to find that seldom did I get above 2200 rpm. Throttle response and off-idle torque make a STREET CAR fun to drive. I'm tired of repeating myself, so I will stop posting in this thread.
JPC, I have a good 750 Q-jet that I don't need, PM me if you want it, Jim
#45
I thought I did everything right, and after putting in the new accelerator pump, the car runs like crap. It even stumbles a bit at ilde, and playing with the mixture screws and idle setting doesn't help. Maybe when I put the carb back together something wasn't right. I thought it might be sucking air, I sprayed carb cleaner around the outside of the carb looking for a leak but didn't seem to change anything.
I'm trying to figure out why someone would have put a small CFM carb and high rise intake onto the motor. It doesn't make sense. Is there any benefit at all of the 1406 600cfm carb over the OEM 700cfm Q-Jet? Secondly, is there any simple way to check to see if maybe this car is built up more than OEM? I have to take a valve cover off to fix the PCV valve oil leak, but I'm not sure if I can tell anything from looking there.
It was my understanding that he still has the stock intake?? I thought the carb, too.
So, we have added more volume to the intake but are using a smaller carb??
Again, guys, I did a reasonable comparison on a fresh engine with a point more compression, head work, headers, and 3.42 gears. The Performer was noticeably better. There simply is no way around the anemic compression.
One day, just for grins, I spent several hours driving around. 3.42 gears, no OD. I was astounded to find that seldom did I get above 2200 rpm. Throttle response and off-idle torque make a STREET CAR fun to drive. I'm tired of repeating myself, so I will stop posting in this thread.
JPC, I have a good 750 Q-jet that I don't need, PM me if you want it, Jim
So, we have added more volume to the intake but are using a smaller carb??
Again, guys, I did a reasonable comparison on a fresh engine with a point more compression, head work, headers, and 3.42 gears. The Performer was noticeably better. There simply is no way around the anemic compression.
One day, just for grins, I spent several hours driving around. 3.42 gears, no OD. I was astounded to find that seldom did I get above 2200 rpm. Throttle response and off-idle torque make a STREET CAR fun to drive. I'm tired of repeating myself, so I will stop posting in this thread.
JPC, I have a good 750 Q-jet that I don't need, PM me if you want it, Jim
I just had a bad acceleration from stop to WOT. If I can break the rear lose at 15mph, why can't I break it lose from a stop? At least I can say, I'm pretty confident it's a carburetor problem now.
Last edited by jpc647; April 9th, 2012 at 06:36 PM.
#46
Copper,
Any idea what else, or how else I can tune what I have? I would have to guess at this point I probably have a vacuum leak somewhere. Probably when I took the top of the carb off, maybe it didn't seat right when I put it back. I'll buy another top gasket(not sure if they can be re-used). Or maybe the ported or unported vacuum line I swapped, maybe there is a crack in one of them. Other than those two things, I have no idea what else to do.
Still wondering what the benefit of a 1406 carb is, over say a quadrajet. Been doing a few searches and a lot of people don't like the quadrajets, a lot of people have problems with them bogging and such. They don't seem like the best carb. But they would have been a 700cfm carb, and now my car only has a 600cfm carb. This has got to add to my fuel problems, right? Am I overlooking something?
Any idea what else, or how else I can tune what I have? I would have to guess at this point I probably have a vacuum leak somewhere. Probably when I took the top of the carb off, maybe it didn't seat right when I put it back. I'll buy another top gasket(not sure if they can be re-used). Or maybe the ported or unported vacuum line I swapped, maybe there is a crack in one of them. Other than those two things, I have no idea what else to do.
Still wondering what the benefit of a 1406 carb is, over say a quadrajet. Been doing a few searches and a lot of people don't like the quadrajets, a lot of people have problems with them bogging and such. They don't seem like the best carb. But they would have been a 700cfm carb, and now my car only has a 600cfm carb. This has got to add to my fuel problems, right? Am I overlooking something?
#47
My first ever combo on my cutlass had a massive vacuum leak but oddly it affected nothing I fixed it and all it had was imrpoved idle . Make sure the holes on the carb mounting pad don't go all the way down I have encountered this before and it was the issue I had with mine. The quadrajet is good the edelbrock is good. The quadrajets have their pros and cons as do the eddy's make sure the idle isn't too lean. It's really hard to diagnose since I'm noit driving the car I usually will drive it mess with it drive it again etc. Make sure you make all your adjustments at running temp.
#49
The edelbrock is very easy to tune becasue you coulf easily go back to stock settings and it is more forgiving than the quadrajet. The quadrajet is a very complex carb compared to holley or the edlebrock but when tuned right it will out perform them both . I like simplicity so I run the e brocks and now a holley.
#50
The edelbrock is very easy to tune becasue you coulf easily go back to stock settings and it is more forgiving than the quadrajet. The quadrajet is a very complex carb compared to holley or the edlebrock but when tuned right it will out perform them both . I like simplicity so I run the e brocks and now a holley.
#51
I personally have never liked those carbs for any kind of performance. if at the end of the day you are more interested in performace, then keep the rpm intake and by a holley 600 db and save yourself a headache, and save up some money and rebuild the motor with flat top pistons and a bigger cam, headers,a stall converter, and at least a 3:55 gear or lower. but if at the end of the day you dont care about all out performance then put the motor back stock with the cast iron intake and q-jet and leave it alone. either way you will be better off than you are now. the other way you can go is find a 68,69, or 70 455 preferabaly out of a toronado just not a low compression one and put it in and leave it stock even with the gears you have now and it will suck you in the seat and fly, bone stock and all. it just depends on what you want.
#52
I personally have never liked those carbs for any kind of performance. if at the end of the day you are more interested in performace, then keep the rpm intake and by a holley 600 db and save yourself a headache, and save up some money and rebuild the motor with flat top pistons and a bigger cam, headers,a stall converter, and at least a 3:55 gear or lower. but if at the end of the day you dont care about all out performance then put the motor back stock with the cast iron intake and q-jet and leave it alone. either way you will be better off than you are now. the other way you can go is find a 68,69, or 70 455 preferabaly out of a toronado just not a low compression one and put it in and leave it stock even with the gears you have now and it will suck you in the seat and fly, bone stock and all. it just depends on what you want.
My only choices at this moment appear to be re-calibrate my carb to run with the RPM intake, or swap everything over to OEM setup. To swap it over to OEM(probably better of the two choices), I need to find some parts. I need a 4bbl HEI air cleaner assembly, the heat riser tube and bracket to mount it to the manifold. I can't seem to tell if the heat tube's and brackets will be the same between 72 and HEI equipped cars. Otherwise I have the change out the distributor too, and I really don't want to convert back to points.
Probably going to end up rebuilding/recalibrating the 1406 as it seems to be the cheaper, and less hassle free option of the two. Otherwise I'll end up with a bunch of used parts that I'll spend countless hours trying to clean and make look good, and I probably won't be happy.
#53
Still not sure what to do about my intake situation. I know it "can be used", but I almost think I might have a better performing car if I swapped out the RPM to the OEM one. That I just don't know. It's a lot of work to change and intake to lose any performance.
I'm sure the intake has nothing to do with your problem, I know most of the people telling you the intake is too large have never seen one of these intakes out of the box the intake ports are almost 3/4" smaller than the stock intake, which should increase velocity not slow it down.
I still haven't read that you have pulled the dist cap and made certain the mech advance isn't worn out or stuck and have you checked the timing chain for stretch.
I only bring this up because all the years I worked as a mech I would say 90% of time when a customer came in saying there new carb wasn't working right it was something else.
I'm also curious as to how many miles your engine has on it, you did state (now the car doesn't run right) as if the car did run right at one time. Did it?
I'm sure the intake has nothing to do with your problem, I know most of the people telling you the intake is too large have never seen one of these intakes out of the box the intake ports are almost 3/4" smaller than the stock intake, which should increase velocity not slow it down.
I still haven't read that you have pulled the dist cap and made certain the mech advance isn't worn out or stuck and have you checked the timing chain for stretch.
I only bring this up because all the years I worked as a mech I would say 90% of time when a customer came in saying there new carb wasn't working right it was something else.
I'm also curious as to how many miles your engine has on it, you did state (now the car doesn't run right) as if the car did run right at one time. Did it?
#54
I also tend to agree with the timing chain being stretched, and it's not too bad to check!
Remove your distributor cap and turn your crank pulley back and forth until the rotor moves.
Over 2 inches is unacceptable, and only gets worse as the engine warms up!!!
And I believe your cam was ground retarded, for GM's 'appearance' to help air pollution - don't know if advancing would help or not!
"Chain looked good" and falling apart upper gear are a couple of different things!
Remove your distributor cap and turn your crank pulley back and forth until the rotor moves.
Over 2 inches is unacceptable, and only gets worse as the engine warms up!!!
And I believe your cam was ground retarded, for GM's 'appearance' to help air pollution - don't know if advancing would help or not!
"Chain looked good" and falling apart upper gear are a couple of different things!
Last edited by Rickman48; April 13th, 2012 at 04:23 PM.
#55
Still not sure what to do about my intake situation. I know it "can be used", but I almost think I might have a better performing car if I swapped out the RPM to the OEM one. That I just don't know. It's a lot of work to change and intake to lose any performance.
I'm sure the intake has nothing to do with your problem, I know most of the people telling you the intake is too large have never seen one of these intakes out of the box the intake ports are almost 3/4" smaller than the stock intake, which should increase velocity not slow it down.?
I'm sure the intake has nothing to do with your problem, I know most of the people telling you the intake is too large have never seen one of these intakes out of the box the intake ports are almost 3/4" smaller than the stock intake, which should increase velocity not slow it down.?
#56
I'm sure the intake has nothing to do with your problem, I know most of the people telling you the intake is too large have never seen one of these intakes out of the box the intake ports are almost 3/4" smaller than the stock intake, which should increase velocity not slow it down.
I still haven't read that you have pulled the dist cap and made certain the mech advance isn't worn out or stuck and have you checked the timing chain for stretch.
I only bring this up because all the years I worked as a mech I would say 90% of time when a customer came in saying there new carb wasn't working right it was something else.
I'm also curious as to how many miles your engine has on it, you did state (now the car doesn't run right) as if the car did run right at one time. Did it?
I still haven't read that you have pulled the dist cap and made certain the mech advance isn't worn out or stuck and have you checked the timing chain for stretch.
I only bring this up because all the years I worked as a mech I would say 90% of time when a customer came in saying there new carb wasn't working right it was something else.
I'm also curious as to how many miles your engine has on it, you did state (now the car doesn't run right) as if the car did run right at one time. Did it?
I drove the car a lot the first year, and not so much since. I've played with the mixtures screws a couple of times, but not much else. I haven't checked the mech advance, as I have no idea how. I did replace the module at one point, and I noticed the springs/weights of some sort in there, but I didn't disturb them. The odometer reads 43,000, not sure if it's 143, or 43.
I also tend to agree with the timing chain being stretched, and it's not too bad to check!
Remove your distributor cap and turn your crank pulley back and forth until the rotor moves.
Over 2 inches is unacceptable, and only gets worse as the engine warms up!!!
And I believe your cam was ground retarded, for GM's 'appearance' to help air pollution - don't know if advancing would help or not!
"Chain looked good" and falling apart upper gear are a couple of different things!
Remove your distributor cap and turn your crank pulley back and forth until the rotor moves.
Over 2 inches is unacceptable, and only gets worse as the engine warms up!!!
And I believe your cam was ground retarded, for GM's 'appearance' to help air pollution - don't know if advancing would help or not!
"Chain looked good" and falling apart upper gear are a couple of different things!
The rebuild kit, and the re-calibration kit will be less that $100.
To rebuild/restore the Q-jet is $110. Then I need to bead blast the intake, another $50. Then I need an HEI Air cleaner, which is going to be toasted, so I'll need to paint it, and buy a new rocket 350 sticker. Another $50. Then I need the air tube, and the bracket and the gasket thing, probably $75. So it's $100 to fix the edelbrock, or $285 to go back to OEM.
I just wish the last guy just had the Q-Jet rebuilt, instead of going aftermarket. It would have been cheaper for him, he already had everything...
But I digress. I'm not sure how much work I'll get done on the car this weekend with finals coming up. But we'll see.
Last edited by jpc647; April 13th, 2012 at 08:33 PM.
#57
Here is my Edlebrock Carb issue
I have a 71 olds Cutlass S 350/350. I replaced the carb about 5 months ago, (the holly carb on it was shot) ,with a 4B, 650 CFM, Edlebrock 1806 and Edlebrock 7111 intake and fairly new HEI distributor from Summit. I purchased the car in October 2011.
The car ran much better with this new carb for some time, (for 4-5 months), About 4 weeks ago I was driving it and learched forward from a dead stop and hit the brakes hard and the car stalled. Then it started stalling frequently when I came to a stop that night. Then it seems now when I drive it runs fine but after about 30 min, when it gets around 195 it stalls every time I stop?
So I called Edlebrock and did some internet research and found others with this problem. I was given the below recommendations and did the following; I took off the air horn removed the needle and seats/springs and air mixture screws, adjusted the floats to top out at 7/16" and drop no more than 1", dried up all the bowls, cleaned everything with carb cleaner and blew it all out with a can of air, put it all back together with a new air horn gasket and new gas filter. The car started right up, waited until the stat opened and reset the mixture screws to its highest vacuum with a gauge and set the idle at 700 RPM.
After the car got hot the RPM dropped a bit and the car stalled!? I do not know the fuel PSI but intend to borrow my friends gauge tomorrow since these carbs like 5 to 5.5 PSI only. I did notice the fuel pump vent was capped and there is no vacuum hose from the vapor canister to the carb. I am not totally convinced it’s the cab. I might also change the fuel pump? And I am thinking of hooking back up the venting?
Any suggestions/coments? HELP!
#59
I responded to this question on your other thread.
It may be easier for you and the rest of us to keep track of responses if they are all on the same thread.
- Eric
It may be easier for you and the rest of us to keep track of responses if they are all on the same thread.
- Eric
#60
#61
#62
It should be about 12V.
If it's 7 to 9V, then the resistor wire is connected, and you need to run a 10 or 12ga wire from the heavy pink wire that comes out of the ignition switch to the HEI.
- Eric
Last edited by MDchanic; May 18th, 2012 at 09:40 AM.
#63
After all the checking and tinkering I still came up with nothing, until tonight.
I was coming home from a local cruise night, and after being frustrated that tinkering with the car hadn't yielded any real results, I decided to hammer on it at 70mph. After a few seconds I buried the speedometer and then some. I just kept it there. After probably a solid minute or two I decided to let off before I blew the motor. Maybe this was stupid, but oh well.
I got back into town, about a mile from my house, going about 20-25mph, and a light changed to yellow. I nailed it, and MAGIC happened. My car actually really took off. I got a solid chirping of the tires and the car roared to life. I was shocked. I pulled over to a stop shortly there after and took off WOT. Car peeled out and took off like it used to.
Now my question. The car may tentatively be fixed. But what was/is wrong. It's imagine it's something to do with the secondaries. I mean they were definitely open during my all out run. Is this something I should look into further? Over the next few days, I'll drive the car and see if it really is fixed, but after my all out run up to 130ish mph, what could have changed? I've gone WOT many many times trying to fix it, and nothing. Are the secondaries needing of adjustment? Could they be not closing all the way or something? They definitely open all the time when the need is there.
Just looking for ideas here. Eventually I'll have the OEM parts to put back on, but I was really surprised tonight. What could an all our run at WOT for 2 minutes have fixed?
I was coming home from a local cruise night, and after being frustrated that tinkering with the car hadn't yielded any real results, I decided to hammer on it at 70mph. After a few seconds I buried the speedometer and then some. I just kept it there. After probably a solid minute or two I decided to let off before I blew the motor. Maybe this was stupid, but oh well.
I got back into town, about a mile from my house, going about 20-25mph, and a light changed to yellow. I nailed it, and MAGIC happened. My car actually really took off. I got a solid chirping of the tires and the car roared to life. I was shocked. I pulled over to a stop shortly there after and took off WOT. Car peeled out and took off like it used to.
Now my question. The car may tentatively be fixed. But what was/is wrong. It's imagine it's something to do with the secondaries. I mean they were definitely open during my all out run. Is this something I should look into further? Over the next few days, I'll drive the car and see if it really is fixed, but after my all out run up to 130ish mph, what could have changed? I've gone WOT many many times trying to fix it, and nothing. Are the secondaries needing of adjustment? Could they be not closing all the way or something? They definitely open all the time when the need is there.
Just looking for ideas here. Eventually I'll have the OEM parts to put back on, but I was really surprised tonight. What could an all our run at WOT for 2 minutes have fixed?
#64
... [W]hat was/is wrong... Is this something I should look into further? [A]fter my all out run up to 130ish mph, what could have changed? Are the secondaries needing of adjustment? Could they be not closing all the way or something? What could an all our run at WOT for 2 minutes have fixed?
Another old trick that sometimes works is pouring a glass of water into the carburetor while holding it at high idle - don't pour too fast to as not to bend a rod. It's sure cheap enough.
- Eric
#65
Haha, I like that.
Thanks for the input. I'm going to take the car out again tonight and I'll see if it's actually fixed. I got pretty excited yesterday, but there aren't too many places I can "safety" (without endangering others) bring my car up that fast, so if I had to do it a couple of times to "free something up" I might be out of luck for a little while.
I have no effin' idea. We can all speculate about opening up the secondaries, blowing out the carbon, or whatever, but the fact of the matter is that, in some cases, this works, and has worked for many years.
Another old trick that sometimes works is pouring a glass of water into the carburetor while holding it at high idle - don't pour too fast to as not to bend a rod. It's sure cheap enough.
- Eric
Another old trick that sometimes works is pouring a glass of water into the carburetor while holding it at high idle - don't pour too fast to as not to bend a rod. It's sure cheap enough.
- Eric
#66
I would use a spray bottle and spray into carb it's safer and effective. I just did it to my friends 69 mustang and boy did the black crap come out! We also added Zmax fuel additive with a full tank it seemed to help a lot! Good luck hope your problem is gone for good!
John
John
#68
Well the Italian Tune up wasn't a fix. I ended up having problems for a few more weeks.
I was at a cruise night a few weeks back talking to a gentleman about my problem, and he saw my fuel filter was before the fuel pump. He explained in his experience, that causes a restriction. I moved the fuel filter up after the pump, and out of my driveway I laid down 111' feet of rubber. It'd say my fuel delivery problem is fixed.
My only problem now, is a short, off idle bog. Its real quick, and only if it's a hard start. If I drive normal, no problem. Half throttle up to Opening of the secondaries I have a small bog. Not sure if it's too much gas, or not enough. Moved accelerator pump up and down, trying to eliminate that, to no avail.
Sometimes the trans doesn't downshift like I feel it should. If I'm doing 30-35 sometimes I feel like the trans should jump down into second, but it doesn't unless you stand on the accelerator.
I was at a cruise night a few weeks back talking to a gentleman about my problem, and he saw my fuel filter was before the fuel pump. He explained in his experience, that causes a restriction. I moved the fuel filter up after the pump, and out of my driveway I laid down 111' feet of rubber. It'd say my fuel delivery problem is fixed.
My only problem now, is a short, off idle bog. Its real quick, and only if it's a hard start. If I drive normal, no problem. Half throttle up to Opening of the secondaries I have a small bog. Not sure if it's too much gas, or not enough. Moved accelerator pump up and down, trying to eliminate that, to no avail.
Sometimes the trans doesn't downshift like I feel it should. If I'm doing 30-35 sometimes I feel like the trans should jump down into second, but it doesn't unless you stand on the accelerator.
#69
If the bog is immediately after opening the secondaries, then you may have to tighten up the secondary air flap spring a little bit.
There's a tiny Allen screw that anchors the tiny spring up high on the passenger side.
I can't recall the exact adjustment procedure, but you can look it up without much trouble.
If the secondary air flaps wait a little bit longer before they begin to open, it may cure your bog.
- Eric
There's a tiny Allen screw that anchors the tiny spring up high on the passenger side.
I can't recall the exact adjustment procedure, but you can look it up without much trouble.
If the secondary air flaps wait a little bit longer before they begin to open, it may cure your bog.
- Eric
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