Resistance wire removal or replacement.

If installing an electronic ignition system the resistance wire most likely has to be removed or bypassed. There are several ways to do this and the solution depends if you have the 1963/64 4-speed Hydra-Matic transmission or the 1964 3-speed Turbo Hydra-Matic transmission. There is also a Ignition Power Relay supplied by PerTronix but that will not be discussed in this thread.

If your car is equipped with the 3-speed Turbo Hydra-Matic the easiest way is to remove the resistance wire from the coil and secure it or remove it completely. After that take a new fresh wire and connect it to the switch on the transmission downshift. The pink wire going from the ignition switch on the dash to the switch, is the same wire the resistance wire is connected too. So just connect to that pink wire and you are home-free.

If your car has the 4-speed Hydra-Matic life is a bit more tricky. So now its time for some pictures and explanations.

1. The red arrow is pointing to the brownish resistance wire. It is normally taped together with the yellow wire (starter solenoid) and the green wire (temp gauge). 2. At the yellow circle the wires will go three ways and you have to open this up. 3. The blue circle is showing the wires going through bulk-head into the cock-pit.

Here is the device on the bulk-head partly removed.

Here is all opened up and as suggested by Jason Edge you should be able to carefully pull out the resistance wire and free it from the pink ignition wire. (Red arrow is pointing to the resistance wire)

However on my car it was not possible to pull trough the hole in the bulk-head and I had to do the job inside the instrument panel. To facilitate the job I removed the dash and the steering column lower cover. Found the connection between the two pink wires and the brownish resistance wire.

Removed the tape. (Hard to focus with the phone camera)

Connected the two pink wires (the ignition switch and the fuse box) with the new wire to the ignition coil. If you have a Turbo Hydra-Matic you will have three pink wires here instead of two, as the third wire is going to the transmission downshift switch.

When this job is done you have to secure it all again and pay attention to protection of the wires.

Here the new red wire is connected to the plus on the new ignition coil together with the yellow wire from the starter solenoid and the wire from the electronic ignition. The green arrow is for the green wire to the temperature gauge.

After this new rotor, distributor cap, spark plug wires and spark plugs. Remember that you might have to increase the gap size on the spark plugs as you now will have a hotter and cleaner spark. Depending on plugs used you might have to increase distance to 0,035-0,040".

When all is set and done. Start your car. Run it until normal working temperature and do a complete ignition timing adjustment as per 1964 Cadillac Shop Manual page 12-17 to 12-18 (I don't have a 1963 Shop manual so don't know the pages in that book).

Good luck

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We have discussed three different ways to set and run our engines timing. 

1) the factory/shop manual way, 5 degrees initial timing at the harmonic balancer, a ported timed vacuum signal to the vacuum advance that adds 10.75 degrees and the mechanical/centrifugal advance that adds another 10 at it's maximum. This 25.75 total degrees advance at max vacuum and what ever rpm the mechanical advance max's out at (I don't have the book in front of me) as has been stated many times if the car does not perform properly with theses parameters then you need to look elsewhere for your problem. For example, worn distributor, carburetor worn or dirty, vacuum advance can is junk, plug cap rotor wires, points to name some but not all the possibilities. 

2) adding 1 to 6 degrees to the initial timing, everything else stays the same with the factory set up but this will add to whatever the total timing is at any given point of the timing curve. For the uninformed a timing curve is a mapped out ignition timing chart showing what the timing would actually be at given rpm and vacuum signal. Think stock broker trying to sell you some stocks and showing you a graph of how much the stock went up over the years. This will add some low end power but you may sacrifice high end power and could get into starting problems if to much damper timing is added. There is a trade off as always. 

3) keeping the factory set up but moving the vacuum advance signal to a manifold vacuum. This also has advantages and disadvantages. This will alter the factory curve at the vacuum advance since the throttle plates are no longer controlling the vacuum signal to the vacuum advance. Your starting timing will only be 5 degrees so it will make starting easier but once started you will have full vacuum advance at the distributor for a total of 15.75 degrees advance while idling. You will also have full vacuum advance any time the throttle is only part way open at any rpm as this will cause high manifold vacuum. With a ported vacuum it would not be full vacuum.

4) has not been discussed but the other way to adjust timing curve is to change the mechanical advance springs to decrease or increase the amount of timing given at different rpm's.

It seems I lost half my post trying to edit it. 

There is no right or wrong way to set timing. The factory set it for best engine performance, longevity, fuel mileage and emissions. It was also based on what they knew 50 years ago. Today the opinions on how to do timing are like belly buttons, everyone has one. They are not all wrong and they are not all right, some ideas add low rpm power and some add high rpm power. The best way to adjust the timing on a fifty year old distributor is to have it checked and setup on a distributor machine. 

Also adding timing to compensate for other engine problems is not the reason to fiddle with it. It's always best to make the car run properly at the factory settings before looking to boost performance through more timing. This includes making sure wires, plugs, rotor, cap, points and vacuum advance canister are all in good woring order.

Do your research and make your own decisions based on what you learned. Every change has a list of advantages and disadvantages know them all before attempting those changes.

My way works for me but may not for you. Good luck and enjoy these big beautiful cars.

Do clean and lightly grease the weights in the the dist cap under the rotor so they work freely and correctly
Sometimes over lokked when doing basic maintenance
I changed my springs in 2006 and they were available from Advanced Auto locally Then (USA )


I am of the belief but not positive, that adding to the timing at the harmonic balancer will add low end power and moving to manifold may increase high end power. I'm not an expert so more research is needed. Jason has posted one link that would be helpful reading. There are many other sites that offer insite to this also. 

When I installed the fitech fuel injection system the instructions stated that they provided a ported vacuum source for those who prefer to run factory vacuum signal. They did not recommend one way or the other. The system also provides for a completely locked out distributor with a computer controlled timing curve. Use can use many inputs to set it up and it will monitor everything. The timing is a set curve that is not adjusted by the inputs. You are just able to monitor inputs and make adjustments based on them.  I decided to keep the factory setup for ease as it's a lot of work to make it jive with the petronix ignition.

Do we have part numbers on the dist vacuum advance units so we can know if the correct one has been installed when it was replaced ?


At most cruising speeds you will see 2000 rpm's. So we will have 10 degrees centrifigal advance. Add the factory recommended 5 degrees at 480 rpm's set by the distributor position and measured at the harmonic balancer. This totals 15 degrees at 2000+ rpm's. The variable is the vacuum advance. At cruising speeds with a steady throttle you will have 20 inches of manifold vacuum. If you have a factory ported vacuum signal to the vacuum advance you will have considerably less vacuum signal as the carburetor ported vacuum port is partially blocked by the throttle plates. The ported signal obviously can not be more than the full manifold vacuum but it can be considerably less giving less timing. Now if you have your vacuum advance connected directly to the manifold you will have 25.75 degrees of timing most of the time.  This is exactly what is happening with the timing. About the only time ported and manifold timing totals are the same is at wide open throttle. 

Your ability to understand advance timing and simplify its explination at cruising speed of 2000 Rpms is very helpful to my understanding of the subject
A bit of your brilliance comes thru in being able to simplify a subject
Mostly the varience in the way the vacuumm advance works is the issue based on the vacuum port you choose to use on the Edelbrock carb --ONLY !

The Edelbeock replacement for the stock carb has a --special feature --that allows you to use - one of the --TWO -vacuum ports --on the carb while blocking the one not being used
The stock carb --does not have this feature available ( only ONE vacuum port ) and cannot do this

By following the directions that come with the Edelbrock carb and the techs you are told to use the --manifold vacuum port --on their carb
Using that vacuum port on the Edelbrock has the effect of adding more advance timing thru the Entire RPM range ( and keeping the timing a higher number while cruising ) while still only having the stock --total advance -- still be the same 25.75
This will have the effect of increasing HP and low end torque --increase gas mileage and run the engine a bit cooler as all timing advance does ( with limitation on the gasoline octane being used )

The up side of this is --a new carb is always a Nice thing to have -- but while installing a new Edelbrock carb you not only have a new carb but the ability to change the stock advance timing curve thru the entire RPM range to increase the engines overall performance
This feature is a real PLUS in performance and is not duplicated by just rebuilding a stock carb and replacing it
This make installing an Edelbrock carb a --better idea -than it was before this discussion ( the are the performance people )

I choose to run 8 degrees of timing at my dampner ( harmonic balancer ) on the pump gas available at the pump today ( 3 degrees more than stock of 5 degrees )
That gives me a total advance of 28.75 --i choose to use
Both Clovis and Kevin have come to the same conclusion themselves completely independent of my own choice using the 28.75 which i find interesting thru a little experimentation

Clovis -has just suggested he is going to try --10 degrees of advanced timing --on his dampner but he is working with the Fiteck fuel injection intake system which is very different than our carburetor intake system but does allow him a lot of -- electronic feed back -as to what is happening when his system is doing what it does which he is able to covey back to us regarding engine performance
This information is not available to anyone with the stock carb intake system and should help all of us understand more of what is going on inside our engines

Doing this is not for everyone - so do what you are comfortable with --always


Thanks Tony, but let me be clear on one thing, I am not a ignition expert lol. I'm only posting observations of what's going on with our timing. I also do not have an opinion of either vacuum source to use. Both manifold and ported vacuum signals will work fine and the opinions on the internet, of which is better, are limitless. I had a vacuum gauge tied into my system before switching to the fitech fuel injection and now it allows me to monitor pretty much everything going on under hood. My thoughts are that the ported vacuum will give better fuel mileage and manifold vacuum will give slight performance gains. This is with the stock preset timing at 5 degrees. A way to add some low rpm performance is to add a few initial or preset degrees. If the pedal is smashed to the floor from a standing position, and the vacuum hose is connected to either source, the response will be the same and timing totals equal. This is with factory set 5 degrees. Hence the reason I chose adding more initial/preset timing with a ported signal. This is the easiest and cheapest way for me to add low rpm performance and adds timing where the other two vacuum sources do not, and that is real world testing. I kept adding one degree at a time and did some pedal smashing. I could have kept going but stopped when I was happy. I remember you telling me at the time to go easy lol. I am comfortable with the fitech to continue experimenting with timing. This will be done with performance and fuel economy in mind. One of the cool things the fuel injection allows is exhaust temperature monitoring.  This allows leaning out without burning a valve or piston top. Another observation is intake air temperature. I have seen it at 128 degrees and it wasn't an extremely hot day. I will be addressing that with a cold air intake before timing and fuel economy testing progresses.

Tony one last thought on your previous posts of removing the masticated splash shields and higher temp thermostat. Obviously removing the slash shield could allow cooler air into the engine compartment. You can't test intake temps but it is a possibility.  I've also been doing some research into engine temps and performance gaines. Dyno testing seams to support your theory that a hotter thermostat will produce better performance. I've talked to a performance engine builder and he stated 210-230 degrees for a peak performance engine. Things that make you go hmmmmmm?

Funny you say that about the temps being run on dynos are in the 200 degree plus range as performance feed back cannot be questioned with that king of testing and feed back
In speaking with the auto store counter guy he told me all the new cars run in the in the 200 plus range today which was a --Big Surprise --to me

Not sure myself --but the fuel injection and other advancements in engine technology ( using a lot of metal alloy engine parts ) may be the underlying cause for the increased need for higher engine running temps
( better to atomise the fuel mixture in the cylinders ?)
Most of my adjustments are things i feel --in the seat of my pants --and and make the engine just feel a bit more responsive and not as scientific as any dyno or running against a time clock would be
I did find that changing from the 195 degree termistat to the 180 now my engine temp has reduced 10 degrees at the temp sending unit on a inferered heat gun But about all i can say about that until i use the car more to see what i think about the change
I do remember feeling the 429 ran a tad better going from the 180 to the 195 in my past change out
Being in Florida running 10 degrees cooler could be a good thing but keeping an open mind to see what i see and feel about the change


Tony with this new information I think you can go back to saying "termistat" with pride. Pmsl



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