captjim

Re-install the stock intake. Sell the RPM and E-brock carb, use the money to get the Q-jet rebuilt by a pro.

jpc647

I can't seem to find out the CFM rating of a OEM 7042250 carb. I've seen 700cfm and 750cfm from different sites. One guy had one for sale here a few months ago listed as a 750cfm. If that's the case, I'm really wasting my time with this edelbrock carb. If factory the car came with a 750, and I'm trying to use a 600, it'll never run right? Unless I have wrong information, which I might.

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.

coppercutlass

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.

captjim

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

jpc647

This is sort of what I'm thinking. While I already have a 7042250 carb and OEM intake, the cost of rebuilding and restoring the carb is almost as much as a new carb. Plus the cost to sand and or bead blast the intake to get it ready for paint. Then I need to find an Air cleaner from a GM HEI 350, buy a new air filter, and find/buy the heat tube and bracket that connect to the air cleaner. Changing it all back to stock is going to cost a pretty penny. I'm hesitant to do it, to find out it's still not right.

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.

Please do not get upset. A lot of my last post, I was simply thinking out loud. The car ran pretty well when I first bought it. I don't know if there has ever been any engine work done to it, but I have to assume their has. On Saturday after a day of playing around with the car when it was "almost running perfect", I could break the rear end free at 15mph, and from a stop, rolling onto the throttle from a stop the car was chirping second gear. Please correct me if I'm wrong, but I do not see how a stock OEM 180HP/275hp motor could be doing this.

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.

jpc647

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?

coppercutlass

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.

captjim

There isn't any, other than perhaps ease of tuning.

coppercutlass

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.

jpc647

PM sent.


Thanks for the information. I've looked into rebuilding the quadrajet, and it's way too expensive. I can buy a reman for less than I can have one completely rebuilt for. It looks like I'll buy the rebuild and calibration kit for the 1406 at this point. I still have to figure out a way to clean the intake. It doesn't look very nice at the moment. Don't want a fresh clean looking carb sitting on the old dirty intake.

rocketboy

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.

jpc647

Thanks for the input. I'm not looking to rebuild the motor for quite a while. To me, thats a long term investment and I'm not sure how long I'm going to have this car. I want performance, but with drive-ability. I don't really have the time required to swap out motors either. I know where there is a 70 455 out of a 98, I don't know if thats a low compression motor or not, but I don't want my car to be down for a month while I tackle the project.

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.

jag1886

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?

Rickman48

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!

captjim

Pretty arrogant remark. I certainly have seen one. I also made a performance based comparison, which nobody seems to recognize. Fine. For the record, I never said the intake was causing the problem, just that it was a bad match for this combo.

jpc647

When I bought the car in 2008, it ran perfect, except for a slight hesitation in the mid range. Which I can say is probably because my 1406 has not been calibrated, but it was so minor, it wasn't worth taking it apart. So yes, it used to run right. I've probably put 4,000 miles on the car since I've had 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'll do this. Thanks for the advice. I know I have a leak somewhere in the carb now, since after I took it apart the car idles poorly. But I'll check for stretch. Thank you for the suggestion.

And you're right. Without recalibrating the carb, it is a bad combination. It did work, and work pretty well. It's not right, but I'll re-calibrate it at this point, simply because it'll be half the price to go back to OEM.

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.

pistonpop

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!

coppercutlass

did you use a constant hot 12v source for the distributor. The voltage drops after it warms up with the stock resistor wire. HEI needs constant 12 .

MDchanic

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

pistonpop

I did not install the HEI distributor but I'll check. The car was running great?

Thanks for your help.

pistonpop

How can i tell if the stock wire was used and what do I install if it is stock?

MDchanic

Measure the voltage at the power wire to the HEI with the car running.
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

jpc647

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?

MDchanic

Ah, the Italian tune-up.

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

jpc647

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.

pistonpop

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

coppercutlass

I did the italian tune up last week and spun a rod bearing . What i thought was a bad water pump turns out to be the beginings of a spun bearing.

jpc647

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.

MDchanic

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