Help me understand Webers Tuning

[priobe]

Hello all,

I have decided to publish this thread to help me understand the tuning methods of 48 IDA.

I am hoping this thread will help accomplish the following:

1) Properly running motor
2) Correct fuel mixture
3) Properly burning plugs (Tanish Brown)
4) Low exhaust oder
5) smooth transition

This is my plan.

After syncing the carb and setting idle doing the following.

1. Setting the idle jet and holder as follows: 120 holder, 60 jet.

2. Set mixture screws 3 /4 turn on all carbs

3. Remove main stack jet holder

4. Start motor and monitor LM 1 wideband.

5. Let the motor reach normal operating temp. 190 degrees ( ford 427 FE)

6. Take the car for a drive only up to 2000 RPM or until motor shuts down.

7. Note the RPM where idle jet stack shuts down 2000 - 2500 RPM

8. Note the fuel mixture and behavior of motor until 500 rpm before what ever was noted when the circuit finishes

9. As an example if the intial jetting for idle circuit was correct then use a F-16 emulsion tube and the main jet value which is determined by the chokes. In this case 40mm choke X 4.1 will calculate to 165 (for a starting point).

Now our main jet circuits value is as follows 165 main, F-16 Etube.

10. Now install a air corrector which will be 40 more than the main jet. In this case 205. I will not pay much attention to the aircorrector at this time. The air corrector will come into play at higher speeds 4000 - up.

11. Now drive the car once again and monitor the transition and fuel curve on the LM1. Take note as to the behavior or the mixture starting from 2300 - 3500. If the mixture runs lean toward 2800 then move up the main jet to 170. If the fuel curve goes lean before 2800 and continues to stay lean then change emulsion tube and main jet.


Can someone help as to if my thought process is correct?

[priobe]

bump.............

[aks801]

Man, good luck! The ways of the Weber have always been a mystery to me, but that may have to change one day: I've really toyed with the idea of having a 428CJ topped with 48's.

I'm sure the resident Weber-heads will be chiming in for you before too long here.