i was just wondering if any one knew if the rochester 4gc was the only available 4 barrel offered from the factory. I thought i had read somewhere they offered a carter as well. ive been fighting this 4gc for some time. just thinking of maybe trying a differnt carb. i tried a holley for a while but getting the hydra-matic to dance with it was a pain and never worked right.
Cads had both. In fact the Rochester was the replacement for the Carters because they were considered a better piece. Isn't the 55Olds a big base? I know the 53's were small base. If it is u could go to another GM car with the same base and make some linkage. Also they all share the same gasket sets so if your base is good a later 64-65 Rochester body and top could straighten yours out..good luck.
That's a good idea. Never thought about switching my baseplate to a newer (64-65) Rochester Sent from my iPhone using The H.A.M.B. mobile app
Yea the linkage song and dance is a bit daunting to set up I'm sure Sent from my iPhone using The H.A.M.B. mobile app
I found a chart listing '55 Super 88 as having a Carter wcfb. Not sure if that would be pertinent to your situation, but here's the chart: http://www.thecarburetorshop.com/Koldsmobile2.htm What are your carb's symptoms? There are some people on here like carbking who often will chime in to help people with Rochesters. I've been wrestling with 4gc's for a few years, have had luck and like them. (In fact that chart is from carbking's site, I believe, his store)
Thanks for the chart clunker. I've gone through the carb with a kit from mikes carb parts a while back. Ran pretty good at first then It started stalling as u hit the gas. The acc pump had come apart. Fixed that and ran pretty good. Then got another stall off idle the other day. Looked today and the pump is fine but not getting any gas from the squirters when I hit the gas. If I'm real easy on it off the line it will stumble through the the idle until the main circuit picks up then it runs fine. Any help is appreciated Sent from my iPhone using The H.A.M.B. mobile app
Do you have the correct check ball in the pump well? There are 2 balls in the kit the small one fits the pump well.
WCFB Carter? I see it on the chart but I've never seen a Carter carb on any 55 Olds, only Rochesters. The only problem I had with the Rochesters was temporary flooding on a hard left turn and I've had a bunch of 'em. Maybe rough idle due to worn throttle shafts or bores? I have a buddy with a new Rockester for a '53, 303 he sold. Has the carb left over but I don't know how much different it is from a 55 carb..
Just resolved the same exact problem on some 4gc's, (stumbling at accelerating from stop), by ignoring the prescribed float height, and raising it by a lot to increase fuel level in bowl, (1/4" or more), then readjusting all the idle and jets. Had tried a lot of things first to no avail. I'm no carb expert, just play one on tv, but I think that the accelerator pump bores were not getting completely filled, (dual quad set up and it was happening to both carbs), so unless I jammed on it it didn't seem to be getting a healthy squirt. My theory is that the new float needles and seats were somehow not letting the bowls fill to spec despite the floats themselves being set to exact factory specs. So there wasn't a healthy squirt at the top of the bore. Other kits I've used on 4gc's came with special instructions to readjust floats differently to accomodate new design for needles and seats (actually lower), but these kits came with no such instructions so I had gone with stock float height adjustments. The motor has "0" problems with stumbling now after that adjustment, and doesn't seem to run rich at all. I have also had those new accelerator pumps fall apart in the bore, so I try to use old ones by reviving them in seal reviver, seems to work. Try adjusting the float level significantly higher. Can't hurt to try it, won't cost you anything, all I can tell you is that it seemed to work for me. Or perhaps something is happening that is preventing bowl from filling all the way since you say it was previously running ok. Maybe someone else will also chime in with different hypothesis. I also think you might have trouble with the tv rod if you try to stick a Carter on unless it has the exact carb and correct throttle shaft hardware for your application, you could buy 20 cores and each and every one will have different plates on the ends of the throttle shafts, so the tv rod would not have the correct geometry. It may be better to try and get the original Rochester carb to work. That being said, I reworked a dual quad manifold from a '55 Caddy with correct Rochester 4gc's to work with the tv rod on my '60 Caddy by measuring the distance from "pivot" locations of start and end point (7 o'clock to 12:00 noon) from the throttle shaft plate to tv rod hardware on the original stock single carb, then fabricating a plate that mimicked the action, then mounting it on the new carbs and attaching the tv rod to it. The jetaway Hydramatic works fine with this new plate, so I'm sure you could adapt anther carb to work. (Sounds like you already have done this) Good luck
Thanks again clunker. I'm gonna try to raise the float level. I have the correct check ball in. I thought maybe it got stuck in its bore maybe. Gonna take the carb off tonight and see what everything looks like. I had also set my floats to the factory spec. Yea I ran a Holley for a little while and had to figure out the TV rod deal out fabbed up some brackets. It worked ok. But decided to go back to the Rochester I figured it probably worked well when new so I wanted to try and make it right. Again thanks for the help Sent from my iPhone using The H.A.M.B. mobile app
Had the same problem with my 54 olds accelerator pump kept coming apart terrible stumble. Put a 56 olds carb on have not had any problems since.
Took the top plate off the carb today. The acc pump had come apart again. Only thing I've been able to figure out is that the plastic part of the acc pump was getting hung up on the return spring. Maybe letting the pump go to far into the bore. I wound the spring pigtail a little tighter so it wouldn't be able to slip past to the rubber part of the pump. So far so good. Sent from my iPhone using The H.A.M.B. mobile app
Nice, hope that does it for you. Don't know why, but I keep having the repop pumps fall apart in the bores too.
Yea I hope it holds together too. I also raised the float level while I had the top plate off. Sent from my iPhone using The H.A.M.B. mobile app
Hesitation can be caused by many things (not all of them carburetion); check the vacuum advance, and the initial timing. Lots of just plain wrong accelerator pumps (generic cheap kits with too great an interchange). Too long, too short, wrong diameter, wrong style, etc. Leather accelerator pumps last MUCH longer than modern rubber, neopreme, fluro-elastimer, or anything else that doesn't come from the underside of a cow! The problem with the turns has a factory "fix" that is documented in various service bulletins, both from the carburetor manufacturers and the car manufacturers. It involves a small amount of machine work to the carburetor housings, and the insertion of a brass vacuum sleeve. Once done, problem solved. Jon.
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