Re: IML: Choke Heater Stuff...
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Re: IML: Choke Heater Stuff...



The oil pressure gauge thing is interesting, but I really don't think you need to go there. The constant power wouldn't be a problem if you compensate for it by adjusting the tension on the choke spring. The housing can be turned to either lean out or richen up the mixture during warm up. That is what you really need to be concerned about. That adjustment can go from a very tight choke, to one that will barely close at all. You should be able to find a "happy medium". It is very good how these things can get us thinking...
 
Paul W. 
 
-----Original Message-----
From: therichardsonfamily@xxxxxxxxxxx
To: mailing-list@xxxxxxxxxxxxxxxx
Sent: Mon, 15 May 2006 15:36:40 +0000
Subject: Re: IML: Choke Heater Stuff...

I agree that this may not be that hard to hook up.  Your mention of your FMC hooked to the oil pressure sending unit turned the light bulb on for me!
 
I would guess that the electrical current needs to be variable in relation to the engine temp. - so that the higher current produces more heat in the thermal coil, which causes the choke to slowly open more.  The Carquest guy thought that just a switched 12V power source would do the trick - but I wouldn't think that would give the thermal coil a variable current to change the choke position slowly, it would be a constant current only - not related to the engine temp.
 
That's why a connection to a gauge that has a variable current directly related to the engine temp. would enable the changing choke position.  (I guess that only works if the sending unit DOES actually send a variable current to the gauge as the temp. changes - does anyone know the theory behind sending units and gauges?)
 
With your connection to the oil pressure gauge - that would indicate that with LOWER oil pressure there would be a higher current to the gauge?  (or the opposite?)  The thermo coil recieves it's info from the fact that the oil pressure drops as the engine warms?  I would think a link to the water temp. would make more sense but, I'm no engineer.
 
I hope that others on the site are not tired of this discussion - I I am learning a lot with every e-mail.  Thanks everyone - where's the expert?
 
Dan Richardson
 
-------------- Original message --------------
From: randalpark@xxxxxxx
I'm thinking that you can be creative and make this work. As long as you connect it to a power source that only flows when the ignition is on, it should work. The housing is adjustable to increase or decrease the spring tension, usually indicated by and arrow and the word "LEAN". This means that turning the housing in the direction of the arrow will cause the choke to open easier (or sooner), while going the opposite way will make it take longer.
 
If you don't want to play with this, there is probably another choke spring housing that will fit, and which would rely on engine heat. The easiest type to fit would be one that employs heat from the exhaust manifold through a tube. I believe that kits for this might be available and would be called a "Choke Stove". The stove clamps to the exhaust manifold, while a tube carries heat to the choke spring.
 
These types of issues beset hot rod and custom car guys all the time, so the solutions for them are varied, plentiful, and usually high quality. One draw back would be that it has been many years since cars have been made that way (carbuerated), and most hot rodders these days don't create "little duece coupes" with big V-8's, but rather little Susuki's with a spoiler and a loud exhaust tip. Still, I think that there are hobby mag's out there that can offer information. Try typing something into the web. You might be surprised.
 
Paul W. 
 
-----Original Message-----
From: Daniel Richardson <TheRichardsonFamily@xxxxxxxxxxx>
To: mailing-list@xxxxxxxxxxxxxxxx
Sent: Mon, 15 May 2006 06:52:26 -0500
Subject: Re: IML: Choke Heater Stuff...

Thanks Paul:
 
Actually, that might be the key to this mystery?
 
Here are my thoughts - maybe this choke set-up uses an electrical current to heat up the thermal coil that opens the choke valve as the engine heats up.  So... perhaps the electrical connections go to a gauge sending unit - as the engine warms, more current goes to that gauge to make the gauge read at a higher level? - that increased current to the thermal coil would also make it open the choke more??
 
If I was an engineer trying to solve the choke release issue, that would be an obvious design I would try.
 
Now, that begs the question.... does anyone have this choke disk on their Mopar?  If so, where do the terminals connect?  Or, if Chrysler never used this set-up, where can I purchase the 1- Well type choke set up, 2- a new vacuum choke pull-off, 3- the proper linkage?
 
Thanks everyone for your help,
 
Dan Richardson
 
----- Original Message -----
Sent: Sunday, May 14, 2006 6:39 PM
Subject: Re: IML: Choke Heater Stuff...

You are correct in that the engine compartment itself generally doesn't make enough heat, fast enough to open a fully closed choke. Some of us have adapted our cars to require less heat (necessarily due to failing choke pull off mechanisms), but that is not the ideal. Running the heater hose up against the housing can help, but with our '50s and '60s cars, only when the heater is on. The choke must be fully closed when the car is cold in order to start easily. The speed of the opening is dependent on the type of car, and the climate. My 1980 FMC Linc. T.C. feeds to power to the choke spring through the oil pressure sending unit! I guess they thought it would match up to the required amount of current needed to open the choke properly. When the oil pressure sending unit failed, I had a heck of time figuring out what was going on with my choke, not that I planned to drive the car with no oil pressure. The trouble was, once I realized that the car had o.p., I still couldn't run it because the choke wouldn't op en until I replaced the sending unit. This was only true on this model car that came with the H.O. engine option.
 
That part isn't Imperial related, but since you brought up the question of a power source for your choke heater, it is interesting so I thought I would mention it.
 
Paul W. 
 
-----Original Message-----
From: Daniel Richardson <TheRichardsonFamily@xxxxxxxxxxx>
To: Imperial Club <mailing-list@xxxxxxxxxxxxxxxx>
Sent: Sun, 14 May 2006 15:50:01 -0500
Subject: Fw: IML: more carb questions

Paul & Brian & others:
 
I think that it is an electric-thermal choke set up.  The local Carquest guy said I should run the terminals to an ignition switched power source.  The 12V helps heat the thermal spring to open the choke as the engine warms up?
 
Maybe that makes sense - there probably isn't enough heat next to the carb to back the choke off as the car heats up?  (otherwise, why have the thermal spring in the intake manifold?)  Inside the disk is a piston connected to a vacuum source on the carb, that pulls on the choke as well - that would work like the diaphragm choke pull-off.
 
The 1967 FSM does identify the 4327 as an HP 440 Auto Trans. carb.  But, it makes no mention of any other choke set up for Chrysler except the "well type".  In the kit, it shows applications to some GM engines as well - perhaps this carb came off a GM, or maybe the Dodges or Plymouths had this set up, or maybe this is a late '67 year-end issue?
 
Regardless, now the question is where exactly do the terminals connect to?  If anyone could advise, that gets me a little closer.
 
Regarding the springs, I only noticed the springs on the throttle linkage in the FSM.  It seems that the carb itself needs a spring somewhere - maybe not but, I can't figure out how everything operates as it sits now.
 
Thanks for the help,
 
Dan Richardson
300L w/ the heart of a '67 Imperial
 
 
 
 
----- Original Message -----
Sent: Sunday, May 14, 2006 10:29 AM
Subject: Re: IML: more carb questions

I am no carb expert, but the terminals that you describe sound like connections for an electric-thermal choke pull off. I have this on several of my other cars from GM and FMC. There is a disc in the housing that heats the choke spring, activating choke opening during warm up. Imperials from the '60s usually had a spring mounted in the intake manifold that heated up and pulled a lever to open the choke. You should be able to make this work.
 
Paul W.
 
-----Original Message-----
From: Daniel Richardson <TheRichardsonFamily@xxxxxxxxxxx>
To: Imperial Club <mailing-list@xxxxxxxxxxxxxxxx>
Sent: Sun, 14 May 2006 09:33:43 -0500
Subject: IML: more carb questions

Hi everyone!
 
I'm rebuilding a Carter 4327 to go on the '67 Imperial 440 I have in my 300L.  Any carb experts out there?
 
In the FSM, it identifies that carb application as a non-CAP, High Performance.  A-OK with me.  The carb has a choke set-up that is not shown in the FSM - at least I don't think so.  (the FSM refers only to a "well type" choke - that's the kind that hides in the intake manifold, right?)  This choke is a disc, just a bit smaller than a snuff tin, mounted on the carb right where the vacuum choke pull off would be.  It has the thermo-coil in the housing and also a piston that seems to act as the vacuum choke pull-off.
 
The rebuild kit shows this choke set-up on the diagram - still A-OK.  One question is - what are the two electrical terminals on the outside of this choke housing, disc looking thing for?  Do they need to be connected to anything for the choke to operate correctly?  Or, are they test leads for the mechanic to check choke operation?
 
Also, I am missing the choke connector rod (I might find one in the basement) and I am not sure where it attaches.  To the slotted bracket or to the hole on the choke rod?
 
Lastly, I have no springs pulling on any of the carb linkage (except throttle rod and throttle return).  In trying to figure out the operation of the primaries & secondaries, it seems that there should be something pulling on something else.
 
Wow!  Way too detailed - and yet way too vague!!  Is there a Carter doctor in the house?  Or anyone that has a rebuild book that can advise of the way chokes and springs work?
 
I know this is a tough one!!!  Thanks,
 
Dan Richardson
300L with the heart of a '67 Imperial inside


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