Lean Burn Q's

[NewportLover77]

I have a 77 Newport with a 400 four barrel. I have a couple maintenance related questions. I'm not entirely sure. The lean burn has been replaced / and bypassed with the Mopar ignition control module box (ECU).

Could you please let me know what new part numbers or requirements are for each of the following items? I'm a little clueless.



Ignition timing
spark plug gap
distributor
rotor
cap
coil
spark plug wires
spark plugs

 

[CBODY67]

It takes more than just an ECU to bypass/replace the system. That can depend upon IF the distributor has advance weights in it and a vacuum advance unit on it.

How much "timing" is in the distributor relates to the amount of initial timing.

Other settings, like spark plug gap and such, will not change. If a new distributor is installed, knowing how much timing is in it is important (mechanical advance, especially).

The carburetor mixture calibration should also change, as that was the OTHER part of the system. Or it can be replaced by a 650cfm Street Demon carb (looks and is basically an upgraded version) of the existing Carter ThermoQuad carb. With a complete electric choke mechanism and is a bolt-on situation. Just needs some adapter brackets for it to mate with the Chrysler throttle and kickdown rods.

If somebody has ideas of re-tuning the primary metering rods/spring, what might they be? @Davea Lux ?

Take care,
CBODY67

 

[Mr C]

Provided the motor is otherwise stock other than the LB delete, look up the stats for a 74 and you're in the neighborhood.

 

[NewportLover77]

It takes more than just an ECU to bypass/replace the system. That can depend upon IF the distributor has advance weights in it and a vacuum advance unit on it.

How much "timing" is in the distributor relates to the amount of initial timing.

Other settings, like spark plug gap and such, will not change. If a new distributor is installed, knowing how much timing is in it is important (mechanical advance, especially).

The carburetor mixture calibration should also change, as that was the OTHER part of the system. Or it can be replaced by a 650cfm Street Demon carb (looks and is basically an upgraded version) of the existing Carter ThermoQuad carb. With a complete electric choke mechanism and is a bolt-on situation. Just needs some adapter brackets for it to mate with the Chrysler throttle and kickdown rods.

If somebody has ideas of re-tuning the primary metering rods/spring, what might they be? @Davea Lux ?

Take care,
CBODY67

Thank you!

 

[NewportLover77]

It takes more than just an ECU to bypass/replace the system. That can depend upon IF the distributor has advance weights in it and a vacuum advance unit on it.

How much "timing" is in the distributor relates to the amount of initial timing.

Other settings, like spark plug gap and such, will not change. If a new distributor is installed, knowing how much timing is in it is important (mechanical advance, especially).

The carburetor mixture calibration should also change, as that was the OTHER part of the system. Or it can be replaced by a 650cfm Street Demon carb (looks and is basically an upgraded version) of the existing Carter ThermoQuad carb. With a complete electric choke mechanism and is a bolt-on situation. Just needs some adapter brackets for it to mate with the Chrysler throttle and kickdown rods.

If somebody has ideas of re-tuning the primary metering rods/spring, what might they be? @Davea Lux ?

Take care,
CBODY67

I apologize for any confusion I am new to the Mopar world. It appears that the previous owner remove the lien burn system by utilizing the Mopar electronic conversion ignition kit. I don't know the names of the parts but it appears to be a distributor, a wiring harness, a Orange ignition box, and a ballast.

 

[CBODY67]

I apologize for any confusion I am new to the Mopar world. It appears that the previous owner remove the lien burn system by utilizing the Mopar electronic conversion ignition kit. I don't know the names of the parts but it appears to be a distributor, a wiring harness, a Orange ignition box, and a ballast.

With that clarification of the kit used, just put the initial timing at about 10-12 degrees BTDC ans see how that goes. If it pings on acceleration, back the timing amount down a few degrees until it gets quiet.

Did the prior owner also change the carburetor, or modify it?

Thanks,
CBODY67

 

[NewportLover77]

With that clarification of the kit used, just put the initial timing at about 10-12 degrees BTDC ans see how that goes. If it pings on acceleration, back the timing amount down a few degrees until it gets quiet.

Did the prior owner also change the carburetor, or modify it?

Thanks,
CBODY67

Yes, it's an Edelbrock 1405

 

[CBODY67]

Then just check the initial timing and enjoy!

CBODY67

 

[mrfury68]

Sounds like the previous owner did it right.