Carb tuning help Edelbrock

[mbartell]

I've been doing a ultra low budget build for my Buick. I've hunted and collected parts for years, finally got it all together and running, and I need some advice on getting the carb closer to working well. Right now it bogs off idle.
The build?
231 bored 1st over, stock compression dished pistons .030? (It's been 9 years)
Cam is an "RV cam" that I found for $50
Intake is Weiand 7541
Carb is Edelbrock 1406
1"spacer to try and increase velocity because of the too big carb and open plenum.
Hooker headers
Torque converter- Who knows what stall, out of a friend's Camaro when he upgraded.
TH350 non lockup.
stock 82 regal 2.41 rear end.

 

[WarWagon]

What are you intending to do in this car with the stock 2.41 ratio rear gear?
Being all engine or NA this sounds like a bad recipe.
Questionable low stalling torque converter,
Unknown "RV" cam (probably 204/214) with a 600cfm carb on the single plane intake with an additional 1" spacer. That is overkill on a stock headed NA v6 especially with highway gearing.
I'm going to say you have a lazy vacuum signal to the boosters in your 600cfm carb and it's not drawing fuel correctly.
That intake manifold has very short runners and it suffers down low with velocity, adding the spacer just make worse.
Loose the spacer, and you can try disconnecting the secondary linkage on carb and run it as a 2bbl on the big intake trying to help signal to the carb boosters. Or: Run a 500cfm carb on that intake or other option: run the factory 4.1 intake or the Edelbrock dual plane manifolds with the 600cfm carb.
If you could find out what the unknown parts are it will help with what direction should go and more solid advice.

 

[charlief1]

Loose the eldelcrap carb. Go with a spreadbore design which can either be a holley or Q-jet. That will give you the bottom end you need and the top end that you want. The spacer will work with a spreadbore design but will kill you with a squarebore design line the edelcrap. The 241 gears need to go and you need a converter with a known stall speed. Something like a 2600 to 2800 stall speed.

 

[mbartell]

I like to drive on the highway. I don't race, it's not for 1/4 mile. Just want to cruise around town, get on the highway and drive cross country. Think about mileage, what makes an engine run happily. If I was racing I'd "just" put in a V8.
I've read Doug Roe's book on quadrajets, and what they take to tune. They actually are a lot like edelbrock, and have worse support, that's why I didn't go with the quadrajet. The factory 4.1 intakes are getting cheaper, when you can find them, but I haven't seen a good one in several years.
2 reasons I have the intake spacer- 1 To increase velocity to try and make up for the gigantic open intake. 2 So the electronic choke will clear the brace that holds the alternator and AC compressor. You can kind of make it out in the first picture.

I've tried all 3 settings on the accelerator pump, and they stall the same. If I'm really gentle, it will get past the stumble and accelerate really well. Sounds awesome, too. I've heard that edelbrock can help, but I'll need to hook up a vacuum gauge and the tach to figure it all out.

 

[No disintegrations]

How does it sound in neutral? If driving and you slowly floor it what happens? ( cruising and over 1 second time go from cruise throttle to full). I'd guess as said above that the signal is weak because those are intended for v8 size engines and need some work to be happy in a smaller engine. What does edelbrock say? And I've run both the 1405 and 1406 on a 302 Ford truck and it ran excellent.

 

[charlief1]

A taller plenum will increase velocity, but if the throttle openings are large, it won't happen until it's above 3 grand. Edelcrap will tell you to switch to a 390 cfm, which will do the same as a spredbore will do. The difference is that the spreadbore will give you the bottom end you want with a top end that's not choked off.

 

[WarWagon]

The dual plane intake with the 2.41 gears would be a good combo, engine will build torque earlier with a strong vacuum signal for the bigger carb. Leaving it as it: Most likely going to have to run that 1406 carb fat in idle transfer circuit and perhaps get the low speed circuit also fatter to help the engine pull fuel. And the redundant statement: that intake has really short runners and is not happy at lower rpms.
Lots of help will find you here.

 

[ek02]

I have used every type of carburetor on various N/A Buick V6's over the last 39 years. The Q-Jet works well with a setup like yours. I have recently used Edelbrocks. On a 3.8, the 600 CFM did not respond well. I went to a 500 CFM and it ran very well. I bought the tuning kits for each carb and fooled with jets, metering rods, and springs until they ran right. I recently went to a Thunder Series AVS 650 CFM Edelbrock on my 274" stroker with GN1 heads and roller cam. It was perfect right out of the box on air/ fuel ratio, and with adjustable secondary's, it pulls much harder than the 600CFM. If you go to a 500 CFM, I would get the Thunder series. All that being said, if you stick with the 600 you have now, pull the top off and make sure the metering rod pistons are moving freely. A very likely cause of off idle bogs. You can buy the tuning kit and go to heavier springs under the metering rod pistons to correct a bog. Different metering rods have an effect also and come with the kit as well as jets. A tuning book comes with the tuning kit. Your electric choke carb is set up for low emissions and is probably pretty lean. Make sure your vacuum advance is working and hooked to manifold vacuum. Make sure the advance weights are moving freely in the distributor and set timing at 16-18 degrees (factory specs) with the vacuum advance disconnected. These distributors have very little advance in them. If that converter is a factory stock V8 converter, the stall speed is less than the stock V6. I had one once and response was really bad. Your combo will not be fast, but it should run correctly when everything is right.

 

[cruzn57]

if you use a 4 hole spacer, not one big hole, it will increase vac signal,
1406 are noted for heat transfer "after shut off" so they need a spacer/ heat insulator.
get as much initial timing as the motor will tolerate, to reduce lag, or bog.
check the accel pump squirter visually, the rod should be in the hole closest to the carb, for max shot.
you may require a larger (bigger hole) squirter.
the engine will only draw as much air as it needs, so to big of a carb slows down the velocity/ signal.
for drivability, you CANNOT beat the edelbrock, yes , its similar to a q jet,, and much. much better than a holley!

 

[mbartell]

I haven't been able to check vacuum while accelerating- sick toddler and a pre schooler makes it hard to get any garage time.
It is a 4 hole spacer, and the holes closely match the carb and the plate I made for the intake (One reason it was cheap, there wasn't a carb plate on it.) The distributor I have is a vacuum advance one with a 5 pin module, not hooked to a knock sensor or anything. What kind of advance curve do I want ? All in at lower RPM?
Could I make a divider of some sort to take up volume inside the intake to make the engine better suited for low end?

 

[mbartell]

There is nothing coming out of the accel. pump squirter- I think I found the problem!

 

[ek02]

That will do it. The pump rubber may have shrunk if it sat for any amount of time. The pump is available by itself or in the rebuild kit.