Automatic Choke

[depmike38]

:confused:My carb is at Pony being re-worked and I've got a problem I need to get ahead of before it gets back. The choke was changed to electric by my friend because the original owner for some reason had moved the heat tube from the intake manifold to the exhaust manifold by drilling a hole in the exhaust manifold.(Brilliant) According to the tech at Pony it probably ruined the carb about ten minutes after the raw heated exhaust hit it. When he got the car the original choke system had been disconnected and blocked off and since it wouldn't work off the intake changed it to electric so it would at least have a choke. I'm assuming that there is a heat tube built into the intake that is clogged or carboned up. Is there a way to fix this without pulling the intake and if I'm going to have to where can I source a gasket set?

[Don Henschel]

Just try blowing compressed air through it and see if air blows through and rust and dirt comes out. Check and see if your heat riser valve in your exhaust manifold (passenger side manifold) is stuck open which will cause the heat tube in the manifold to not get as hot as it should. I don't think this should be a problem as my heat riser valve plate was cut out with a torch before I got the car, and my choke works very well. I got the tea pot as well.
P.S. I'm glad you posted this as I went out to see what kind of a setup this is and sh*t :mad: I discovered a bit of coolant on my lifter cover plate below the intake! Time to try retorqing the intake or lifting it and replacing the gaskets:(

[Don Henschel]

Just to clarify! Blow through the heat tube fitting (that goes to your choke)on the intake, and see if rust, dirt, etc. comes out the other side. Some times the passage cracks or burns through or gets rust in it. You put a new carb on and it gets contaminated from this. The old FE's and other models with the heat tube through the exhaust manifold had a steel pipe which would burn through or crack. I don't know whats in the intake on these. A casted in passage or a pipe somehow installed in the intake (directly below the carb in the crossover runner in the manifold itself). As for the carboned up crossover passage, Like Barry mentioned in another thread, when the exhaust heat riser valve is cold (and if its working-not gutted out or removed all together, or stuck open) you should see exhaust coming out one tailpipe only, and when the valve opens, out of both pipes. Like I said my choke opens properly, with no stalling, flooding, not too fast or slow with the heat riser gutted out with a torch. Good luck with the rebuilt teapot. I rebuilt mine myself, with very good results. No flat spots, flooding, leaks etc. I'm quite happy with this weird looking carb, and the only problem was with a sticking needle and seat years after I rebuilt it from rotten gas in the tank.

[Nick DeSpirito]

There are two heat tubes in the intake. They are rounded on each side but triangular in the middle. I'm pretty sure they were made of steel. I replaced both when I restored my car. I remember using a punch to get the old ones out and pressing in the new ones. I happened to find a guy by the name of Benji Perugini in Florida that was restoring a Mark II. He made new ones for the car he was working on and decided to make and sell kits for other Mark II owners that included the brass elbow that connects to the choke housing This was around 1993 and I have no idea how to contact him to see if he is still making them. Does anyone know of a source for these in case someone needs them?

[Barry Wolk]

Mine doesn't have the choke tube coming off the exhaust manifold like I've seen on other cars.

http://i244.photobucket.com/albums/gg18/barry2952/_N4U1883_1-001copy.jpg

[Chuck Lutz]

I looked at mine and only have one tube and it looks to be copper with webbing over it. It's loose and just slips into a hole.

[Don Henschel]

You won't have it off the exhaust manifold. Its directly below the mounting base of the carburator on the intake. There is a cross over port through the middle of the intake tube where your exhaust is diverted through when the heat riser valve closes. If you lift your air cleaner you will notice an elbow on each side of the intake just below the carburator. A pipe up to the choke (the hot air) and on the other side a pipe going up to the housing on the carb (fresh filtered air in)where the air cleaner sits on.

[Don Henschel]

Just looked in the Factory shop manual. And they show the heat tube in the intake. And like Nick mentioned it looks like it should not be to hard to replace (intake probably will have to be removed?). If you have the manual its on page 181 in the fuel systems section. Certainly a very wise investment is this shop manual! You cant have too much information on hand for one of these orphans!

[Ian Cowie]

Don, why would you say "You won't have it off the exhaust manifold".
As mentioned and shown in pictures, both Chuck's and my car clearly have the choke copper line covered in webbing coming off the passenger side exhaust manifold. I was thinking that someone added that to my car but now seeing Chuck's has exactly the same thing ... why the different routing?

http://photos.cowco.net/albums/uploads/vehicle/56Lincoln/Engine_2.JPG

[Nick DeSpirito]

Ian,

That set up is not stock. Your heat for the choke should be obtained by the heat tube in the intake manifold with an elbow directing it into the choke assembly. (maybe you're right about it being only one tube in the intake. It's been so long ago since I did it, it's hard to remember. ( I don't know why I thought there was 2 tubes although, knowing myself, I probably ordered a spare and it's in my garage someplace). I had my intake off the car when I did the replacement. I did it on the work bench at my mechanic's shop.

Barry,

You probably have the original set up. There should be an elbow going from the intake to the bottom of the choke assembly. BTW, your A/C lines in that shot look amazing. The old authenticity manual stated they were black, so I painted them black. Your's bring back to mind my Army days when we had to polish every exposed copper line in the latrines with Brasso. : )

[Don Henschel]

Mine is a late model 56 with the Holley. I used to have a 59 Ford with a 332 FE and it had the hot air tube down to the exhaust manifold with a little vent pipe for cold air in curled towards the firewall (lousy setup where dirty air could be sucked in!) They later moved this intake to the carburator air filter mount on the carb. My 50 Merc. sedan has the hot air tube going down to the intake very similar to my Continental.

[Don Henschel]

This is what I have, and I would think you should have it to. Maybe your tube in the Intake cracked or burned through and they figured it would be simpler to install in the exhaust?? I myself would just get some stainless tubing and replace whats in my intake. My climate is not a warm as you guys down in the south (no, we don't snowmobile in summer or have genuine Saskatchewan Sealskin on our car seats etc. LOL) but my choke still works very well without the heat riser. Even the factory automatic choke on the Holley on my Merc (now thats a strange looking carb!) works very well without ever missing a beat within the 25+ years I have owned it

[Don Henschel]

:o:oJust noticed Chucks picture! This almost looks like it could have been an aftermarket or factory changeup (for cold climates as mine wont get as hot when the heat riser opens up)or quick fix. Who knows with these cars???
To busy trying to figure out how to upload a picture and didnt notice yours! Sorry! Mine is like Barry's and Chuck's and whats in the picture.

[Don Henschel]

I looked again! What ever it is looks factory and or meant for that engine. Is that a square raised part of the manifold, or is there a small shaped housing sitting on top of the manifold? I would say this would give you a great deal more heat to your heat tube. Maybe a northern cold climate option or factory campagn add on for nasty winter conditions.:confused: People actually drove them in winter when they were new, not like us pampering them now:p!

[Nick DeSpirito]

Don,

Thanks for the shop manual scan. That is exactly how it is. You're right. The ones to the exhaust manifold are aftermarket.

http://www.markiiforum.com/attachment.php?attachmentid=78&d=1251737762

You can see in the illustration, the tube in the intake and the little elbow and tube that directs the heat into the choke housing in which the heat acts on the thermostatic spring.

[Chuck Lutz]

Just to close the loop here on the exhaust maniford tubing saga...
I was looking through all the posting since joining the forum yesterday and found the articile and photos posted by Nick on the Gate car. That car, too had the little sheet metal box (in a different location and shape than mine) on the manifold. So I would guess that it's either 1. and after market, 2. a 1956 "hey guys, let's try this" on the fly at the factory or dealerships or 3. maybe it came out in a service bulletin.

[depmike38]

The tech at Pony carbs told me that if the carb itself gets the heat and fumes directly out of the exhaust manifold it would ruin the carb in short order. He said that the cars that have a line going to the exhaust manifold are not drawing out of the manifold but are either using an enclosed tube or a heat sink type plate but that the Continental's manifold is not that type. I guess I'll remove the intake and repair it if I can't clear it on the car. By the way I have access to the intakes off of a pair of 57 Premieres. Any possibility that they are the same as the 56?

[Barry Wolk]

This is what I've garnered from the Mark II encyclopedia. There were lots of choke updates. None of them included running a pipe from the exhaust manifold to the carb. In fact, they were quite emphatic that exhaust gasses were no NEVER enter the carb. The result would be lots of carbon deposits and an inoperative choke.

It helps to understand the way that the warm-up system on the car works. The first step is the thermostatically controlled damper on the passenger side exhaust. The operation of this valve is essential to the system working properly. It basically senses underhood temperature, not the temperature of the pipe. Leaving the hood open to test will give you a false reading.

Check to see that the damper is closed when the engine is cold. The spring is easy to install backwards, defeating the operation. The circle on the axle of this valve is actually weighted. It rotates when the bi-metal spring relaxes as it warms up.

The valve is designed to create hot exhaust back pressure when the engine is cold. There is a passageway underneath the carb, cast into the intake manifold. It connects two ports in the heads that connect to the exhaust passages. Gasses, like water and electricity, follow the path of least resistance. Blocking one exhaust manifold forces that bank's exhaust back through the passages, under the carb to help vaporize condensed gas, through the other head to warm it up and out the driver's side exhaust pipes. If it were not for the crossover pipe in the exhaust, there would be nothing coming out of the passenger side tail pipe. This is why there's a plume of steam coming out just the driver's side, for a time, when it's cold.

As the space under the hood warms up the engine has reached a proper temperature where gas no longer condenses on the cold manifold surface the valve is allowed to open under the offset weight of the damper. This allows exhaust to flow out of bot sides equally.

The book spoke of two tubes on the carb. Neither of the two tubes are to hook up to exhaust gasses. What they do hook up to is a tapered tube that passes through the hot exhaust gas chamber beneath the carb. Internal porting draws air from within the carb, through one side tube, through the tube in the exhaust chamber, up through the other tube and into the choke chamber, moving a bimetal spring. The hot air is then drawn back into the air/fuel mixture. Exhaust gasses were never intended to pass into the carb under any circumstances.

It looks like the tube with the box on the manifold is a logical fix instead of drilling out the tube in the exhaust passage. The tube would pick up hot air through the box on the manifold and pass it through to the choke mechanism directly.

Does the hose from the manifold pass through some type of heat exchanger, or right to the choke? If it went to a heat exchanger, that would be more complicated, but it would work.

[Chuck Lutz]

Just to be clear.. on my set up the copper tube only passes through the sheet metal box (I'd call it a bit of a heat exchanger) and DOES NOT go into the manifold or suck in exhaust. It was suggested today that it might be a type of heat sink using the copper to conduct heat to the carb. I'm at a bit of a loss because I don't know where the other end is connected. I'll find that out soon.
There's a Mark II on Ebay right now for sale. It's pretty beat but one of the photos shows the same sort of set up.
I did have a fleeting thought. I understand that the cars came with both Carter and Holly carbs. Could one or the other use this set up?

[Don Henschel]

It probably just pokes into the housing where the heat collects (kind of like an oven), and the air enters through the small space between the manifold and the box. Exactly the same way as a pipe running through the flow of exhaust heating the OUTSIDE of the pipe with your clean air flowing through the INSIDE being heated up and then sucked into the choke thermostat housing of your carburator to heat up the bi-metalic spring with engine vacuum. The exhaust manifold is the pipe in this version with the air oosing into the box through the gap between the box and the manifold. A cruder simpler design than the pipe running through a drilled passage and the choke would get hot air whether the heat riser was working or not. Maybe this is factory! There are too many of these critters popping up for it not to be. Kind of like whether or not your engine has a Holley or a Carter carb, or a spin on or a cartridge filter. Nowadays we can cheat and stick a modern electric choke thermostat on for heat.

[Don Henschel]

I did have a fleeting thought. I understand that the cars came with both Carter and Holly carbs. Could one or the other use this set up? I thought about that right away and checked the members serial numbers. Yours (C2287) should have a Holley and mine is a very late 56 (K3391) and has a Holley. Ian Cowie (C2280) should have a holly. Barry's on the other hand is alot older and has the same setup as mine.(3418) I believe is the first 57 plus or minus 1. And close to this number would have the Carter (correct me if I'm wrong). Chuck and Ian check your intake on each side below the carburator mount point and check and see if your manifold is drilled and whether it looks like there were brass elbows installed at one time???? Take a picture if you can (with the air cleaner lifted off). I would like to take a picture on mine but someone stole my camera at work. I guess we are flogging this saga to death but I guess it is something for the authenticity manual and curiosity.

[Barry Wolk]

I think it's great information.

Come to think of it, my buddy's '57 has a tube going to the exhaust. For those that have it, does the tube go all the way through the manifold? It would work as a hot air intake that way as it would just heat the air in the tube and not let exhaust gasses through.

[Nick DeSpirito]

Barry,

I don't think (but I don't know for sure) that they would actually drill a hole in the exhaust manifold. My thinking is that it just picks up heat from it to relay to the bi metal spring in the choke assembly. I'm pretty sure that they are just clamped onto the manifold.

[Chuck Lutz]

Ok, here's a sketch of how mine is arranged. Again, it may just be a thermal conductor to the carb. I find that the manifold gets pretty hot, pretty quickly.

[depmike38]

Well everyone I have a carb on the way back to the tune of $608:eek:. It seems that in the course of numerous rebuilds every type of patch job imaginable had been done and I'm probably fortunate the car didn't burn to the ground. At any rate John at Pony said that whoever had tried the straight into the exhaust manifold trick had fried not only the choke assy but had all but burned out the housing it attached to so I would imagine that the little box that's on top of some of the manifolds is most definitely just giving the choke a heat source to draw from. He did however have the name of a couple of places that he thought were able to supply the manifold tubes. One was The Lincoln Farm and the other was a place called Mainly Convertibles so I'll try them and see if they can help.

[Shelly Harris]

My automatic choke is causing very hard starting and poor accelleration when cold. Looking in the choke control unit I see that those moving discs are all rusted up with sections actually eaten away and missing. The coil still looks good on the cover. Meanwhile, although the carb works ok when the engine's warm, it's 50 years dirty and has at least 66K, or 166K miles on it. Since I don't have a car for show, but rather to drive like I stole it, I'm leaning towards sending the carb out for a rebuild with instructions to install an electric choke control. Make sense? Or should I replace the automatic choke control with stock -- (which I discover is not easy to find parts)?

[Barry Wolk]

Electric. If mine stopped working, that's what I would do.

Can't enjoy them if they're not reliable. Can't make them reliable if you don't drive them.

[Don Henschel]

Ok, here's a sketch of how mine is arranged. Again, it may just be a thermal conductor to the carb. I find that the manifold gets pretty hot, pretty quickly.

Just a hollow pipe with vacuum sucking hot air from the oven on your manifold, nothing more and nothing less. Unscrew it from your choke housing & blow on it. I guarantee you will hear air hissing from that box. Did you check to see if your manifold is drilled? I'm curious. Those pipes dont burn out that fast. This wizzwazz is quite common from what you guys are saying.

[Don Henschel]

Don't worry Shelly. You would be absolutly amazed what fits newer and older Holley carburators from one model to the next. That diaphragm (secondary control) If my memory serves me correct was used well up into the 80's and beyond for an example. The choke vacuum piston etc (the guts in that thermostat ) are found in newer ones.

[Chuck Lutz]

NO, that's what had me confused. (as you get to know me you'll find I confuse easily). The manifold isn't drilled. I was out driving tonite and came back to see just how warm the copper tube was. OUCH... it gets hot.
But I did get a bit of schooling from Jack Rosen this afternoon. As soon as I mentioned the tube from the exhaust header he stopped me. He said he's seen lots of them "thanks to JC Whitney". Seems that when the heat tubes from the intake throught the carb rotted out, the choke advance failed badly. As a "cheap fix" the tube and sheet metal box thingy was marketed as the thing to do. He quickly followed with the parts that HE stocks and sells to replace the rotted one in the carb/intake. This seems to support the "after-market" conclusion Barry suggested earlier.
As for drilled exhaust manifolds with the tube, one might conclude that either someone just got that wrong as the installation proceedure or a concept of "if a little is good, a lot is better" drilled them into the manifold.
In my drive around tonite it seemed that my car ran better and knockless when before warming up and rougher when it got warmed up. Strange, but as they say.. "it's not the destination but the journey".. buckle up if you have them.

[Don Henschel]

"Thanks to JC Whitney" "Now you know the rest of the story" as Paul Harvey put it. Mine still after all these years still works great. The setup on my 50 Merc is exactly the same on the intake, same place, same design. It works very well to. I guess I'm lucky that it didnt burn through.

[Nick DeSpirito]

Well everyone I have a carb on the way back to the tune of $608:eek:. It seems that in the course of numerous rebuilds every type of patch job imaginable had been done and I'm probably fortunate the car didn't burn to the ground. At any rate John at Pony said that whoever had tried the straight into the exhaust manifold trick had fried not only the choke assy but had all but burned out the housing it attached to so I would imagine that the little box that's on top of some of the manifolds is most definitely just giving the choke a heat source to draw from. He did however have the name of a couple of places that he thought were able to supply the manifold tubes. One was The Lincoln Farm and the other was a place called Mainly Convertibles so I'll try them and see if they can help.

I got one from them last year, but I chose the "show Finish". Ran me $450.00+ $225.00 core charge = $675.00. I had to replace the accelerator pump piston cup. They put in a blue Neoprene? one in which developed a tear after two months (and not that much driving) and I was getting a hesitation on taking off from a red light. Found a guy in FL. who made a leather one. Hesitation problem solved.

[Barry Wolk]

Please post contact info for piston plunger.

[Don Henschel]

I think it comes in the rebuild kit? http://www.carburetor.ca/carbs/kits/CK410.htm
I think I got my kit from Jack. If you look around you can find NOS. Do a search for part numbers and start checking out swap meets.

[Barry Wolk]

There's nothing wrong with the rest of the carb. If it ain't broke, don't fix it.

[Ian Cowie]

My feelings exactly Barry ... the only problem I am having is the stumble. So $600+ for a rebuilt carb is not necessary and ain't gonna happen.

If my only problem seems to be the power piston, is it possible to replace without a total rebuild? Is the leather just that .... a piece of leather? Can one simply cut a new one from a piece of leather, wet it, form it, and install?

Ian

[Nick DeSpirito]

Barry,

I didn't do the job. I explained what was going on to the head guy at Hibernia when my car was there and he had one of the techs pull it apart and that's when I found out about the cup. They're the ones that found the guy to make a leather one. I will call and see if they will give me the info on the guy that made it.

[Nick DeSpirito]

http://www.carburetor.ca/carbs/images/kits/small/sCK410.jpg

It looked like that blue thing in the center of this picture. It was rubbery and flexible.

[Barry Wolk]

Need a microscope to see that blue thingy.

[Nick DeSpirito]

http://www.carburetor.ca/carbs/images/kits/fullsize/ck410.jpg

[Don Henschel]

There's nothing wrong with the rest of the carb. If it ain't broke, don't fix it. But you need the plunger seal? I agree if it aint broke, but spare parts are nice to have. I keep odds and ends left over from when I rebuild my carbs "incase sh*t happens". It's always nice to have little things cluddering up the garage such as generator brushes, carb. kits etc. for a quick and usually a lasting repair.

[Nick DeSpirito]

The carb base gasket is wrong in that picture. I sent for one (actually, I remember now that Pony sent it with the carb) and I got one like that and couldn't use it because the two holes on either side were exposing the fuel passages underneath the carb. I wound up buying gasket material and making my own.

[Don Henschel]

My feelings exactly Barry ... the only problem I am having is the stumble. So $600+ for a rebuilt carb is not necessary and ain't gonna happen.

If my only problem seems to be the power piston, is it possible to replace without a total rebuild? Is the leather just that .... a piece of leather? Can one simply cut a new one from a piece of leather, wet it, form it, and install?

Ian It was just a kit I posted not a $600.00 carb. You can get simpler ones without the set screws for less. If your carb needs minor repairs just rob the little goodies out of the kit.

[Don Henschel]

The carb base gasket is wrong in that picture. I sent for one (actually, I remember now that Pony sent it with the carb) and I got one like that and couldn't use it because the two holes on either side were exposing the fuel passages underneath the carb. I wound up buying gasket material and making my own. The last one I got from Jack and worked OK. Sometimes you will see extra holes on the gasket,but when you lay the gasket on the flat surface of the intake they get dead ended as well with no harm done. A spare gasket is a good thing to have around in case you have to lift the carb to repair a small glitch, such as a paper seal that shrinks with time and weeps alittle bit and requires a retorque.

[depmike38]

At least I had a core or it would have been an $800 carb. I did spend the extra for the plated finish since it's supposed to hold up better but I hope they live up to their press clippings as I've never spent this much on a carb before.

[Don Henschel]

The good news is unless the throttle shafts and bushings are worn, or if you want it plated, in most cases with the kit mentioned above properly installed, you can bring your carburator back to new condition with few issues. With your core you also have spare parts should anything get broken.

[depmike38]

I was told that the time the choke was hooked up directly to exhaust heat had burned almost through the housing the choke assembly attaches to and it had a piece of linkage on it from a different carb. The choke part doesn't surprise me and I already knew about the linkage. They replace all the wear parts but you're right that the shafts and bushings were probably all right. I am a bit concerned with the problem Nick experienced with the power piston. Hopefully it was just an aberration or if a vendor problem or they've corrected it by now. I was just real leery of this carb as almost without exception the rebuilders caution about a potential fire problem if it's not re-worked properly(I'd never built or seen one of these) or if the car has a timing problem. They all say to make sure you carry a fire extinguisher but I do that anyway. Oh well, it's on the way back so we'll see.:D

[Don Henschel]

As for fire problems if you let things get tired (like I mentioned after being told if it aint broke dont fix) and gaskets start to weep or drip, give your carb a tune up with a fresh set of gaskets and seals. Most people that I have run across complaining about automatic chokes not working dont maintain the carburator. A carburator with weeping gaskets totally caked full of dust, with linkages sticking because of this. These carbs are quite simple to work on if you take your time with some patience you can get them to work without problems. Things are better now for information than they used to be (you can download an entire repair manual of the net in a few minutes!). For all the hassles I run into way up here for getting parts I recondition as much as I can myself. Variations of these carbs are common on other Fords. As for fires, loose fittings, leaking gaskets, and hoses should be fixed (I have my MarkII in my attached garage with a walk in door straight into my house. If a VERY small leak starts I smell it right away and I don't put up with the stink! I fix it. My parents almost lost their house because their early 80s van caught on fire. NOT DUE TO A FUEL PROBLEM! A lot of Fords during the late seventies throughout the eighties were bad for fires starting from the steering column. My parents van was one of these. Yes I diconnect batteries in all my cars I don't drive on a regular basis! Mice can even cause problems with wiring. Whos had problems with these nasty little beasts in their Marks?