Help - Dual carb dial-in on my 62 fury 440 Max Wedge Clone???

[Dk440]

Hey guys,
How do I syncronise the two 1405 carbs on my wedge intake? I had a "knowledgable" guy mess with them, after the engine stalled everytime I stopped for traffic the other day ( I guess I took off too soon, and drowned the engine ). He adjusted it to idle higher, but when I got back home and pulled the plugs, 4 were soaked in gas, so no wonder it had trouble idleing! I have changed the plugs and want to adjust the carbs my self, only I have not done it before.......! One would be fairly easy, I think.....but two??? I have tried to search the internet for help, but with little succes.

Please share your expertise! :thinker:

Thanks in advance.

Rolf

 

[eric383]

It sounds like 1 carb is either too rich or maybe has a sticky float. Check out the Edelbrock website and they have some great tuning tips for their carbs. Once you understand them it is a lot easier. Any idea what tuning changes have been done to the carbs? If you can, return them to stock specs and go from there. Right now I think the synchronizing is secondary. We've all been there and the learning curve can be frustrating.

 

[moparsteve636]

Yep! Check your jetting! X-rams like a staggered jetting also check the metering rods. Dan Dovorak Racing sells a carb synchronizing tool for the A.F.B! A handy tool to have on hand messing with the A.F.Bs!

 

[eric383]

X2 on that Steve. For a poor mans synchronizer you can take a piece of heater hose and listen to the sound of each carb as you tune it. When they sound the same you got it tuned. You just have to have an ear for it.

 

[Dk440]

I am at the very bottom of my learning curve, when it comes to carb adjusting/trouble shooting........! Unfortunately, I have no clue, as to what has been done to the carbs, and I do not know what cam the engine has, so I am a little bit lost. It obviously has a pretty radical cam and no choke, so it has trouble idleing when cold, and still tilts when hot - was told it was used to be taken to the track from time to time.
A basic question just to get started - I will try and look at Edelbrooks web site agian later, but first I just need to get something straigth..........The 2 Air/Fuel mixture screws on each carb - are they supposed to be in sync? At the moment carb1 is : Right screw 11/2 turns counterclockwise and Left screw 5 turns ccw. Carb 2 is: Right screw 2 turns counterclockwise and Left screw 4 turns ccw.........should they not be identical in order to run properly, or is it not that simple???:thinker:

 

[lewtot184]

you might have a fuel pressure problem. those 1405's use the small .093" needle and seat and don't like much over 5-6lbs psi. going to the .110" needle and seat would help some but isn't a cure for excessive pressure. the 1405 has the same throttle bore and venturi size as the original 3447's so i think the 3447 jetting is a good place to start. the factory jetting specs i have are .098" primary jets and .082" secondary jets for both carbs, no staggering. a .068"x.050" metering rod is recommended but edelbrock doesn't offer that size. a .068"x.052" or .068"x.047" should get you close. just adjust the mixtures screws to where the engine has the highest vacuum. another issue may be idle vacuum in gear. the 1405 uses a 5" orange step-up spring under the metering rod piston. if the engine vacuum in gear is close to 5" the rods may be lifting causing a rich condition. there is a 3" blue spring and a 4" yellow available. those engines came from the factory with a fast curve full centrifugal advance distributor. they had about 18 crank degrees in them and it all came in well below 2000rpm. i'm using a mechanical cam in one of my dodges (not a max wedge engine)that mimics the 413-426 stage one cam. i use a distributor with 18 degrees in it, fast curve, and about 18 degrees initial to get 36 degrees total to get good idle vacuum.

 

[rumblefish360]

It should be that simple as both screws turned out equally. Your on a cross ram? Or in line?

 

[Dk440]

It should be that simple as both screws turned out equally. Your on a cross ram? Or in line?

cross ram. It has been running fine for the past 2 years of ownership, so I think the carbs must be tuned right to begin with. I have a funny feeling, that it might be my own fault, after reading your replies. I took the air cleaners off and poured gas into the carbs manually for easier start after sitting for months.....if I poured in too much, I may have flooded the engine all by my lonesome.........!? But I still do not get the mixture screw issue! Could it bee, that the "knowlledgable" person, when adjusting the engine too idle higher, backed out the 2 screws to the left on each carb too much???? What are your thoughts on that???

 

[coloradodave]

Good info on this post but too technical for a beginner. First things first: Turn all the idle mixture screws CW until they are 'lightly' seated. You can mess up the seats if you turn them in too hard. Then turn ALL 4 screws CCW 2 turns. This setting will get it in the ballpark. Edelbrock's site and a set of owner's manuals (download from Edelbrock's site) will give you enough basic knowledge to get it running right. THEN you need to find a new "knowlegeable" guy who can actually help you. He was way off with those settings.
The best way is to do your homework and then tune it yourself. Asking here will help you but you need basic knowledge in order to be able to sort out the right answers from the wrong.
Wouldn't hurt to add a choke assembly to at least one of the carbs if you don't drive it often or if you do drive it when it's cold outside. The choke will also give you a fast idle for warming it up.
I run a crossram with 2 500 cfm Edelbrocks and it is very streetable if set up right. BTW, I run the stock jetting & metering rods. If it was running OK before and you didn't mess with the timing, leave that alone for now. PM me if you need additional help or have questions.

- - - Updated - - -

PS: The 'idle mixture' screws don't change the air/fuel ratios. They simply add more (CCW) or less (CW) of the mixture.

 

[Dk440]

Thanks Dave..........you hit bulls eye with that basic info - just what I needed for now!:hello2: I have downloaded the users manual from Edelbrooks web site, but at this point much of it could be written in Chinese for all I care.....too technical for a rookie like me! I will then do my homework, as you say, in order to step up a notch on my learning curve, and then also invest in the vacuum tool from Dvorak, as suggested by MoparSteve. Thanks for your help - once again!:notworthy:

 

[coloradodave]

Anytime. You really don't need the synchronizer at this point. With the engine 'off', snap off the linkage arm off each carburetor. Turn the idle speed screw (NOT mixture screw) on each carburetor CCW until it isn't touching its stop and the carburetor butterflies are completely closed. Then turn the idle speed screw on each carburetor CW until it hits its stop and another 1 full turn. Adjust the linkage arms so that they will snap on each carburetor without moving the butterflies. Now both carburetors are set equally for idle speed. After you start the car and warm it up (a good 10 minutes or so), if the idle speed is too low, turn each idle speed screw CW 1/4 turn until the engine is idling where you want it. Conversely, if the speed is too high, turn the screws CCW equally until the idle speed is right. There is no set speed for all cars (there are too many variables) but you want the carburetors to each be adjusted the same. Basically, it's where the car will idle in gear with an A/T, usually somewhere between 700-1,000 rpm.
Keep in mind in this post I'm referring to the single idle speed screws on each carburetor, NOT the dual mixture screws on each.
Down the road, after you become the guru of dual quad adjusting you can make the investment in the Dvorak sync tool (the old Uni-sync with an adapter for 4bbl. carbs) if you feel the need.

 

[dvw]

I'd start with the basics. Check the float level first very important. 2nd fuel pressure, no more than 6 psi MAX. 3rd, all idle mix screw out 2 turns to start. Warm up engine and loosen the metering rod covers. Have someone start the engine and put it into gear. Slide the cover to the side.the metering rod should be pulled down, not dancing or up at the top. If it's not down it needs a lighter spring. Last with a vacuum gauge turn all 4 mixture screws in or out 1/4 turn at a time until the highest vacuum reading is obtained. Make sure the timing has at least 15-20 degrees initial and 35-38 total. If not the distributor advance slots need to be modified. With this combo I have max wedges running and starting smoothly and getting 14MPG with a 3.55 gear.
Doug

 

[Dk440]

Anytime. You really don't need the synchronizer at this point. With the engine 'off', snap off the linkage arm off each carburetor. Turn the idle speed screw (NOT mixture screw) on each carburetor CCW until it isn't touching its stop and the carburetor butterflies are completely closed. Then turn the idle speed screw on each carburetor CW until it hits its stop and another 1 full turn. Adjust the linkage arms so that they will snap on each carburetor without moving the butterflies. Now both carburetors are set equally for idle speed. After you start the car and warm it up (a good 10 minutes or so), if the idle speed is too low, turn each idle speed screw CW 1/4 turn until the engine is idling where you want it. Conversely, if the speed is too high, turn the screws CCW equally until the idle speed is right. There is no set speed for all cars (there are too many variables) but you want the carburetors to each be adjusted the same. Basically, it's where the car will idle in gear with an A/T, usually somewhere between 700-1,000 rpm.
Keep in mind in this post I'm referring to the single idle speed screws on each carburetor, NOT the dual mixture screws on each.
Down the road, after you become the guru of dual quad adjusting you can make the investment in the Dvorak sync tool (the old Uni-sync with an adapter for 4bbl. carbs) if you feel the need.

Followed your tutorial, Dave and with 1 full turn + 1/4 on the single idle screw on each carb ( and the 2 ccw turns on the 4 mixture screws of course ) it idles fine around 900 rpm........but, when I put it in drive with the foot on the brake it frequently struggles and drops to 500 rpm!?:angry9: Also, if ( still in drive ) I rev it a little bit, it revs up fine, and then drops to the point where it allmost stalls on me - I then tap the gas gently, and it comes back again.....??? Sticky float, maybe? The weather is awfull to night, and the next couple of days dont look to get much better, so I have not been able to take it for a test-drive and see how it performs. But it seems clear, that something is not quite right. I wish I had all the suggested equipment, but I dont, so I have to invest in everything, if to stand a chance of fixing the problem, and make good use of all the great info: Fuel pressure gauge, vacuum gauge ( Dvorak ), timing gun etc.............!:tearyeyed: Will keep you posted.

 

[coloradodave]

When the weather clears, turn in the idle speed screws to raise the idle RPM up to 1,000-1,050RPM AFTER the engine is fully warmed up, which is 10-15 minutes of running and 180* or better on the temperature gauge. The gauge that Dan Dvorak sells is only for synching the idle speed of each carburetor. What will be more beneficial to you at this point is a simple vacuum gauge. The air/fuel mixture in the max wedge manifold has to travel a fair distance from the carburetors to the intake ports. The idle and low speed will be somewhat erratic till the manifold gets hot. The vacuum gauge is easy to use and will help us help you to diagnose the issues you're having. There are many other variables, including timing, distributor advance rates, converter 'tightness', gas quality and age, etc.
I'd also like to know if this is a new problem and if so, what happened to the car just before the problem showed up.
Hang in there. Have you tried to find a good shop that builds hotrods or races 'American Iron' in Denmark?

 

[Dk440]

It is a new problem - started last week! I have driven the car 3 times after sitting in my garage all winther. The only thing I have done to the car is I have changed the engine oil + filter, and after the first drive, changed a leaking valve cover gasket, and now also the plugs, but nothing special! 2 first drives were fine, but last tuesday was hell! It misfired/backfired thru the carbs when cold ( has never done that ) and stalled when stopping for traffic in Drive, but would fire right back up and idle, when in neutral. I had to keep my foot on the gas whenever I came to a stand still in Drive, in order to keep it "alive"!?
I do know a guy, who owns a MOPAR-shop and dragraces everything with a Chrysler logo every weekend - he can help me for sure, but I just hate it, when I cant fix it myself, and have to pay someone to fix it as a result of my incompetence!:angryfire: But I am leaning more and more towards that solution....................

 

[dvw]

It is a new problem - started last week! I have driven the car 3 times after sitting in my garage all winther. The only thing I have done to the car is I have changed the engine oil + filter, and after the first drive, changed a leaking valve cover gasket, and now also the plugs, but nothing special! 2 first drives were fine, but last tuesday was hell! It misfired/backfired thru the carbs when cold ( has never done that ) and stalled when stopping for traffic in Drive, but would fire right back up and idle, when in neutral. I had to keep my foot on the gas whenever I came to a stand still in Drive, in order to keep it "alive"!?
I do know a guy, who owns a MOPAR-shop and dragraces everything with a Chrysler logo every weekend - he can help me for sure, but I just hate it, when I cant fix it myself, and have to pay someone to fix it as a result of my incompetence!:angryfire: But I am leaning more and more towards that solution....................

Did you check the metering rod position? This is a HUGE part of diagnosing AFB carb problems. If they're not functioning correctly nothing you will do will tune it.
Doug

 

[Dk440]

Did you check the metering rod position? This is a HUGE part of diagnosing AFB carb problems. If they're not functioning correctly nothing you will do will tune it.
Doug

I will do so, when I get a spare moment - and an extra pair of feet to assist me! ;o) But thanks Doug - I will dig inn to the carbs shortly and see, if I can find anything out of the ordinary.

 

[Dk440]

Removed the 4 idle/mixture screws and blew into each hole with an airgun. Also cleaned the points in the distributor, and now it runs fine!!!:grin:

Thanks for all your help - fantastic, as allways!

 

[Rolling Thunder]

Glad to hear