Replace Choke Tube or Install Electric Choke?

[Michael Stinson]

My mechanic has sourced a choke housing and new internals.  As you might expect, the choke tube is damaged and or clogged.  My options are to either replace the choke tube, or my mechanic recommends changing over to an electric choke.  

Please advise what is involved in replacing the choke tube:

• Where to source, part number, etc.
• What EXACTLY is involved in replacing the choke tube?   
• What is involved in converting to electric choke?   I think the Rochester carb was refurbished at some point, so the plan at this time is to keep it. I doubt it was completely rebuilt, as the mess in the choke housing would have been addressed at that time.  But I don't know for certain. 
  If we convert to electric choke, any recommendations for brand/ model? 
• If we convert to electric choke, what else needs to be done to ensure it operates correctly?   

The more details the better.  Please explain like I am 5 years old.   I welcome email and phone calls to discuss in detail.  

Thanks everyone in advance. 

[Dennis P. DiBari]

Hi Michael,

     That internal choke tube is quite a delicate operation.  For my 64 - Series 62, the coolant has to drained, the carburetor removed, and the intake manifold taken off.  Once the manifold is carefully removed, the internal tube and coiled spring must be CAREFULLY drilled/tapped out.  The caveat is the possibility of cracking the intake manifold.  They are hard to find for our cars.  If it is taken out, the new tube (about 10 inches long) has to be carefully tapped through the intake manifold - flush with both sides.  If this is successful and the new choke pipe is hooked up, you must have a good working heat riser on the driver's side exhaust.  They work in tandem to heat the choke manifold.  I have not dealt with the electric choke on my car.  If fact, I went to an external choke stove to heat the choke, as my internal tube is clogged.  Hope this helps.

Dennis DiBari

[Michael Stinson]

Thanks for the info Dennis.  I will pass this along to my mechanic. 

[Dennis P. DiBari]

Mike,

     You are welcome.  Hope it helps.

Dennis DiBari

[Patrick Westphal]

My recommendation is to switch to an electric choke. I don’t have a brand or model number for you as mine came with the Edelbrock carb when I replaced it. Anyway the power to the choke needs to come from the ignition which has 12 volts on it when the key is in the on position. If you are going to run a wire directly to the ignition switch in the car be sure to add an it line fuse to that wire. 

[Frank Murch]

You know advice is worth what you pay for it.  I am charging you nothing for this.  The edelbrock carb 1406 is what is on mine. It is electric choke.  It has larger secondaries and my intake is cut with larger holes to deal with this. The airclealer is edelbrock.  I have the original intake and carb on the shelf, but the Edelbroch releases some power, and runs smoother. It is also more serve-able.  

[CHRIS CARLSON]

I have installed an electric chock on my 4GC Rochester carb. I also installed Olson intake gaskets with the exhaust cross over blocked. I have electric chock stats on hand for the Rochester , you can also purchase them from Mikes Carburetor . If your car has the turbo hydromatic  the kick down switch that mounts to the base of the throttle plate on the carb has a hot wire and you can tie into that wire to provide power to the electric chock. I removed the hot  wire from the plastic connecter removed the old end, stripped the wire back a small amount took my new wire for the electric chock and twisted them  together crimped a new end on the wires reinserted it into the plastic connecter and connected it back to the kick down switch and the new wire runs behind the carb to the chock stat, its nice and clean looking .

[Michael Stinson]

Thanks for the reply Chris.  This sounds like a good approach to addressing the performance issue while retaining as much originality / authenticity appearance in the engine compartment as possible.  Did you actually replace the intake manifold or just replace gaskets and block off the cross-over?  Is the cross-over to/from the heat riser on the driver side?  Does the choke tube have to be removed from the passenger side intake, or just blocked off?    What are "choke stats"?  Do you know what brand or model of electric choke you installed?  Thanks again.  

[CHRIS CARLSON]

Michael, You would remove the intake manifold and replace the gaskets with the block off style gasket, or you could use regular gaskets and just cut a piece of tin and place over the exhaust crossover port on each side. I also removed the heat riser valve on the exhaust manifold and replace that with a laser cut steel blank I believe I purchased from Russ Austin. You purchase  an electric choke stat from quadrajet parts.com they have two versions one for the l-shaped connector which requires to buy a pigtail wire to go on it that locks on the terminal that's what I generally use. Or you can purchase one with just a common Spade connector that pushes on the end. If you go to quadriparts.com they have a section for Rochester 4GC carburetor parts. I connected the tube from the intake back to the choke housing so it looks pretty original other than the electric wire going to the choke. 

[Logan Robb]

I am in the process of swapping over to an Edelbrock 1406. Take a look at my profile to see my progress so far. My Page - 63/64 Cadillac Website