Edelbrock models 1405 versus 1406 carburetors

-
Yes Hipo the final touch was the secondary early feed tube to be removed. I also drilled out the accelerator pump shooters to 0.8mm (0.036") and the bog is all gone. The secondary air valve was modified by drilling a hole of about 10mm in each weight to see if lighter was better but I inserted lead sinkers and peened them in to give them more weight. this did not make much difference so restored to its original weight.

Final list of mods on my 1406:

1) step #2 on the chart which gave me standard cruise and 4% power enrichment (.095" jet with.070" x .037" rod)
1a) drilled out the idle jets to 1mm (0.40") This fixed all the off idle stumble and cruise problems like surging etc.
2) drilled out pump shooters to 0.8mm
3) drilled another transfer nozzle closer to the early feed tubes
4) removed the early feed tubes.
5) secondary jets one step up to 0.098"

Cruise economy is great better than the Holley.
Response is all there. Very light on the pedal and vacuum advance is all O.K. with it..


Regards
Billy D...
 
Awesome thread, for knowledge,guys. Some old school tuning, nice work Bilbo & 65.
 
Hipo65 said:
.... What ended up totally ridding the bog was I pulled the secondary clusters removed the early feed tubes in the secondarys ( the small tubes) peened the main air bleeds smaller to about 1/2 the stock size to give stronger signal to the boosters. ....
Click to expand...

I have exatly the same secondary bog and an AEM wideband that shows total lean out when flooring.
I'm understand all in this tread exept "peened the main air bleeds smaller to about 1/2 the stock size", how did you do that?
 
Figured it out, but with an piano wire instead of peened to reduce the main bleeds...
 
So pulling out the early feed tubes you don't need to plug anything?
 
Bone stock 383 2bbl except Mopar M1 dual plane alu intake, 1405/1406 carb, HP exhaust manifold, 2 1/2 dual exhaust and blocked heatriser.
1468 accelerator pump, inner hole and 43 nozzle.
Ignition initial 10* and total 35*, ported vacum.

Now I've tried everything in this tread except "drilled another transfer nozzle closer to the early feed tubes" and stil got wot bog when flooring.
I've tried both an 1405 and 1406, same wot bog...
My O2 sensor lean out when flooring from cruise but if I'm a little gentler on the pedal I've got a little rich AFR around 12-13 at power and around 11-12 at wot so jetting should not be the problem.
I've tried add some weight to the air valve to make it open later (from 122g to 130g), no change.
I begin to suspect the blocked heatriser as when I do all my test it's around 50 degrees here.
I really appreciates if someone have any idea except "buy an Holly" or "600cfm is to small for an 383"
I'm running out of ideas...
 
On another board I'm reading about people having great success simply going to a stock 1405 set up with 1428 (.100) jets and 1451 Rods. Also stepping up to orange springs. I'm about to put a 1406 on my 73 charger so now a bit confused. I think I might start it at #23 and then maybe play with #19. Doing the 1405 set up doesn't put you anywhere on the 1406 chart let alone in the shaded area. Sounds risky. Does the fact that I'm deleted an EGR change anything in the calculations of tuning the carb??

Thanks!
 
As you can read I've tried both 1405 and 1406 and I get the same bog at wot no matter how I've jet/rod it to an acceptable AFR and I've tried every spring and ended up with the stiffest silver spring (8hg/in).
I get real good AFR in every situation except when I hit the pedal to the floor, then I get a lean out for a second that even stall the engine in some cases.
You can forget about the shaded area in the chart, every engine is unique and needs to be tuned to all the circumstances like deleted EGR, intake manifold, exhaust manifold etc.

I've now added more weight to the air valve counter weights, I'll get back with the result when I've tested...

I really appreciates if someone have any more idea...
 
73Charger318 said:
On another board I'm reading about people having great success simply going to a stock 1405 set up with 1428 (.100) jets and 1451 Rods. Also stepping up to orange springs. I'm about to put a 1406 on my 73 charger so now a bit confused. I think I might start it at #23 and then maybe play with #19. Doing the 1405 set up doesn't put you anywhere on the 1406 chart let alone in the shaded area. Sounds risky. Does the fact that I'm deleted an EGR change anything in the calculations of tuning the carb??

Thanks!
Click to expand...

When I read your answer/question more carefully I think the 1406 would work perfect on your 318, but where in the chart you would end up depends on many factors, the deleted EGR might change versus if you did'nt delete it, but it must be tuned by running it to see where in the chart you should be going, the best thing is to start with 1406 standard tuning and go from there.
Standard 1406 would give you 0.0023 opening in the jet for cruise and 0.0051 power opening (main jet minus rod thickness in inches)
#19 would give you 0.0028 opening in the jet for cruise and 0.0061 power opening
#23 would give you 0.0025 opening in the jet for cruise and 0.0056 power opening

Standard 1405 would give you 0.0030 opening in the jet for cruise and 0.0053 power opening, wich is 0.0007 richer in cruise and 0.0002 richer in power compared with standar 1406 setup.

On my 383 0.0028 gives me an AFR about 14-15 at highway cruise wich I'm pleased with, but 0.0053 is a bit rich in powermode for my 383, that gives me an AFR about 11.
At 0.0040 or 0.0045 in power mode gives me an AFR about 12-13 and works better on my engine, so I'm way out of the shaded area.

Good luck and I hope you dont get the famous bog but I thing the 1406 air valve works better on a smaller engine.
 
Zwap said:
When I read your answer/question more carefully I think the 1406 would work perfect on your 318, but where in the chart you would end up depends on many factors, the deleted EGR might change versus if you did'nt delete it, but it must be tuned by running it to see where in the chart you should be going, the best thing is to start with 1406 standard tuning and go from there.
Standard 1406 would give you 0.0023 opening in the jet for cruise and 0.0051 power opening (main jet minus rod thickness in inches)
#19 would give you 0.0028 opening in the jet for cruise and 0.0061 power opening
#23 would give you 0.0025 opening in the jet for cruise and 0.0056 power opening

Standard 1405 would give you 0.0030 opening in the jet for cruise and 0.0053 power opening, wich is 0.0007 richer in cruise and 0.0002 richer in power compared with standar 1406 setup.

On my 383 0.0028 gives me an AFR about 14-15 at highway cruise wich I'm pleased with, but 0.0053 is a bit rich in powermode for my 383, that gives me an AFR about 11.
At 0.0040 or 0.0045 in power mode gives me an AFR about 12-13 and works better on my engine, so I'm way out of the shaded area.

Good luck and I hope you dont get the famous bog but I thing the 1406 air valve works better on a smaller engine.
Click to expand...

Great info, thanks! So don't do any tuning off the car? I thought it might be easier do just do it before installing but you're probably right. I should see how it runs with the standard setup and tune from there. Would be great to hear from anyone that's using the 1405 setup on the 1406 and see what sort of air/fuel mixture they get.
 
The thing you could do before installing is to check the float levels wich is very important to get the tuning right.
Of course it's easier to change jets before you installing but if you leave the .098 main jet and .095 sec jet in you still have a lots of easy tuning possibilities just to change rods (and perhaps springs).

Here's an chart over wich jet opening you can get with .098 main jet, the first nubmer 14XX is Edelbrock partnumber for the rods:
 

Attachments

  • Jet Rod chart (98).JPG
    119.1 KB · Views: 297
YES!!!
No more bog when flooring!!
What solved my bog was to open up the blocked heat crossover, then I had to re-tune the jets and rods wich result that I could jet a little bit leaner than with blocked crossover.
Smaller nozzle (from 43 to 31) and outer pump hole, otherwise I got the opposit rich condition when acceleration.
Perfect! No more lean out when flooring, perfect AFR all over.
I did suspect that the crossover should affect the AirFuelRatio but not that much.
 
You must log in or register to reply here.
-

Back
Top