Carb for 1956 Cadillac

[gatech1956]

So I had some work done today at a new shop and  was told something interesting. I’ve had the wrong carb on my car and apparently my linkage is all out of whack because of it.  I guess that would explain why I have been underpowered at times I just thought my transmission needed to be inspected.

Anyway, where is the best place to get a correct carb? Should it be Rochester or carter?

[2danreed]

What carb is currently on your car? My '56 sedan had a Rochester (they came down the line with either Carter or Rochester). I rebuilt the stock Rochester and it continued to run quite well for the next 15-plus years without a problem. My only experience with a Carter is on my current 1964 Cadillac. I've only had this '64 for a bit under a year, but the Carter was easy to adjust using the shop manual and it too runs well. Sorry I can't tell you where to buy a replacement carb for your '56, but I know every season here in southeastern PA I see vendors selling plenty of carburetors.

[carguyblack]

Both Carter and Rochester were available that year. I've only had Rochesters on my three 1956 Cadillacs but the folks who helped me fix these things always said that the Carter was more desirable and easier to set.

[gatech1956]

What carb is currently on your car? My '56 sedan had a Rochester (they came down the line with either Carter or Rochester). I rebuilt the stock Rochester and it continued to run quite well for the next 15-plus years without a problem. My only experience with a Carter is on my current 1964 Cadillac. I've only had this '64 for a bit under a year, but the Carter was easy to adjust using the shop manual and it too runs well. Sorry I can't tell you where to buy a replacement carb for your '56, but I know every season here in southeastern PA I see vendors selling plenty of carburetors.

I am not completely sure what is currently on. The issue is that this carb doesn’t have the right components for the transmission Rod. The carb only moves a small amount. The shop had a 58 and there’s a lot more play by comparison

[J. Gomez]

Maybe posting a picture or two of what you have and how it is setup can help identified the type of carb you have.

There is also a possibility that the previous owner place the correct year carb either 4GC or the WCFB  but the throttle base is from a different model. Most of other GM models share a similar throttle base to the manifold but the throttle linkage are totally different for each.

The throttle base at the intake is the same for either the 4GC or WCFB  but the linkage from the plates and the carb bowl side are different. The TV-rod and the throttle rod to the dash relay are the same for either carb.

If you check the Service Manual you will notice the difference linkages at the throttle primary valve to connect the two rods.   

Good lucak..!

[fishnjim]

You have to know the "VIN" number for the proper motor sequence as they changed carbs by lots.
Here's the list and check your sequence number for the "right" as manufactured number carb.   The Rochester will have a triangle tag on it(6 digits), the Carter(4 digits maybe a letter) will be stamped on the base.
I suspect that there's a lot more to this story, than what you were told...   

One can make any carb "work", it just takes a little know how and a few parts.   
These early vacuum idle carbs are not easy to work on and often changed for a later AFB.  Nothing wrong with that and if properly set up will work just fine.   The problem is a lot depends on how well the motor functions as to how well the carb works, so you get in one of those loops chasing problems not caused by the carb.   Advance that forward 60 plus years and a whole host of new issues arise from age and changing fuels etc.

["Cadillac Kid" Greg Surfas 15364]

Wouldn’t a 1956 Carter be a “WCFB”?
Greg Surfas

[J. Gomez]

Wouldn’t a 1956 Carter be a “WCFB”?
Greg Surfas

Oops you are correct is a '56 not a '57  , corrections made 

[gatech1956]

Here’s a picture of the carb

[Caddy Wizard]

Looks to me like regardless of whether that is the correct carb or not, the TV rod is adjusted so far to the end of its travel in one direction that when you mash on the gas, the TV rod will only go halfway because the TV linkage in the transmission will reach the end of its travel. So I am guessing that you can only mash the gas halfway down and you can only get the carb throttles halfway open.

Try an experiment.  Have someone mash the gas pedal for you as far as they can and see if the throttle is opening up all the way.  Then remove the cotter pin and disconnect the TV rod from the carb and repeat the test.  Note the difference.

[J. Gomez]

It looks to be a correct Carter WCFB carb and throttle base.

A few add things;

The throttle return spring pointing forward and it seems to be a heavy duty type. I believe the return spring would be the same for either Carter or Rochester (someone with a Carter can chime in) and it is a lighter gauge and mounts backwards at the spark plug wires support bracket, the one that mounts at the ignition coil side. I do not see one on your picture.   

The TV-rod is all the way in as Art mention as well, is that the maximum that can be pushed inwards towards the firewall until it stops?    Not sure is the throttle shaft is position correctly, again someone with a Carter would be best to validate.   

[Caddy Wizard]

The TV-rod is all the way in as Art mention as well, is that the maximum that can be pushed inwards towards the firewall until it stops?    Not sure is the throttle shaft is position correctly, again someone with a Carter would be best to validate.

Jose, according to the picture I think the TV rod is adjusted all the way OUT, not IN.  That means that before you step on the gas, it has already used up some of its travel...

[cadman56]

If memory serves me correct, that TV rod  should be adjusted towards the transmission increasing the distance between the transmission and the carburetor primary shaft.
I always adjusted mine back towards the transmission just short of pushing the primary throttle plates open.  Gave great power, up shifts per the book and down shifts.
I agree, have someone push all the way down on the gas pedal and see if throttle plates are opening all the way.

[J. Gomez]

Jose, according to the picture I think the TV rod is adjusted all the way OUT, not IN.  That means that before you step on the gas, it has already used up some of its travel...

Art, sorry I was referring to the rod trunnion and the adjusting nuts on the TV-rod which are place all the way in the threaded TV-rod on his picture.   

Normally the trunnion would be about 1” or so from the front of the threaded rod when the adjustment is made and the TV-rod is pushed toward the rear until it stops.

[chrisntam]

Perhaps the gentleman could undress the car a bit (remove the air cleaner) and then take a pic of the carb and post it.  Maybe pics from 3 or 4 angles...

[gatech1956]

I will try to post more pictures later.

Jose, are you saying I have some components missing?

Art, I agree the rod is pushed too far up which is what the mechanic explained to me. He said based on the carb where wasn't a way for him to adjust the rod further back. You may know this mechanic. He is part of peachstate classics, recommended by the peach state CLC.

[J. Gomez]

I will try to post more pictures later.

Jose, are you saying I have some components missing?

Art, I agree the rod is pushed too far up which is what the mechanic explained to me. He said based on the carb where wasn't a way for him to adjust the rod further back. You may know this mechanic. He is part of peachstate classics, recommended by the peach state CLC.

From the limited view on your posted picture it seems the spark plug wire holder which is behind the carb and bolt under the ignition coil bracket is MIA.

If you have the Service Manual handy you can see the holder under Section 8 page 8-1.

I’m not too familiar with the layout with the Carter carb (if yours is a Carter ) since I have a Rochester, but I believe that both share the same arrangement with the throttle return springs. The only heavier spring is at the throttle relay (you can see it under Section 12 page 12-2) and the lighter spring is place at the carb throttle and connects to the spark plug holder.

Maybe someone with a Carter can share some pictures on their layout for your reference.   

I recall a previous older post from a ’56 member which had an issue with the adjustment of the TV-rod his problem was the rod had drastic bents which cause a similar condition as yours. Something to check in your situation.

[gatech1956]

Here are some other angles bear with me while I get the air cleaner off

[J. Gomez]

Well is confirmed it is a Carter you can see the name stamped at the bowl next to the ignition coil.

Buuut what type of choke is that there are no modifier rod from the thermostatic housing down to the lever. 

I think you have several issues around that area with several missing/wrong pieces, hope you can get them straight with the local tech.   

Good luck..!

[gatech1956]

Interesting observations. Speculating here but do you think this a carb that was supposed to part of the dual carb setup found on eldorados?