VCCA Home Forums TECHNICAL - 1945 AND NEWER 1955-1957 Recommendation 4 BBL rebuilder?

Folks -

After about a 2 year hiatus, I am getting back to work on my '56 wagon. Long story....

It has 265 PowerPak with Powerglide. Came with a Rochester 4 BBL (and we already had the conversation about it should be a Carter, and figured out that the last few months of '56 production also offered the Rochester).

Engine and Trans are long since back from the rebuilders and machine shop, sitting waiting on me to get it together and finish. Time to make the carb new again, too. I was gonna do it myself, but have lost confidence.... I can handle Baby Grands and 490 Zeniths, but a 4 barrel is a little more intricate.

So, would anyone care to recommend a person or company that has done a 4 BBL rebuild and they are happy with the result? I care about appearance, but more interested having it RUN good (on "corn juice" gas at that).

The Rchester 4 barrel was not an early or late thing. It was a mixed production thing for power pac engines with Power Glide starting in 1956.
It is more simple than a Carter and performs in an equal manner. I have had both on various cars (since 1957) and have had no problems.
The fact that your 1956 has the darker aqua color indicates it is an early 1956. The later aqua was a lighter shade. Or my screen color could be off and yours is the lighter shade. Paint #710 early and #754 late.
The early 1956 210 also had the light colored vinyl trim on the bottom of the door kick-panel area and the late 210 had a darker color. Nice to know if you ever have the car judged and another 1956 210 is different from yours.

OK, that makes (more) sense. I seem to remember that the Shop Manual maybe only illustrates the Carter? Doesn't matter.

But I still need a quality rebuilder....

You can do this yourself!

With a little guidance, you will probably do better than most of the "rebuilders".

There is a factory patch to prevent stalling on hard turns. When the carb is apart, you need to check to see if it has been installed. If not, it needs to be installed.

To make it run well on corn gas, you need to modify both the idle and main metering circuits. To modify the idle circuit, using a set of orifice drills, measure the inner diameter of the idle jets (the two smaller tubes in the primary venturi cluster). Whatever the dimension, drill each idle tube 0.002 oversize. To modify the main metering circuit, simply increase the diameter of the main metering jets, both primary and secondary, by 0.002. You also need to install a leather accelerator pump. So far, no one has come up with a synthetic material that works as well in ethanol as the underside of a cow!

If this carb has the auxiliary airvalve, you SHOULD replace the spring. It doesn't come in any kit, you have to order it separately. The setting for this spring (not found in any service manual I have seen) is 1/2 turn past just touching closed.

If after reading the above, you still want to have it rebuilt by someone else, ask the above to any prospective rebuilder. If they don't know by now, use someone else.

And I no longer have time to rebuild carbs, please don't ask.

Jon.

Jon,
Since you no longer rebuild carbs, what are you doing with carbs these days ??

Bob. 2-22-2017

Bob - the problem (other than growing older) is the ethanol in the fuel. Our rebuilding kits are ethanol-friendly, and the demand for these kits is at a 45-year high! Still make the kits, and selling off the 100,000 +++ carburetors and tons of parts that we have.

Jon.

For the OP - you mentioned you had some concern about appearance. Depending on how deep is your concern, the following link may help:

http://www.thecarburetorshop.com/Carburetorfinishes.htm

Harsh carburetor cleaners WILL remove the chromate finish on the zinc alloy castings (if it is still present). If you have access to an ultrasonic cleaner, there is a very exotic cleaner available that does a reasonably good job of cleaning and will not hurt the finish. It is call "Dawn dishwater soap".

Jon.

Thanks for the update, Jon.

The Rochester 4 barrel is a simple carburetor. The instructions will come with Jon's kit. His kits may cost a little more but are of high quality.
If you need a Chevrolet instruction sheet I can supply on that was in a 1956 Service News>

I owe some answers here, and appreciate all the feedback. (Had some family show up for a couple of days, took up all my computer time.)

Jon, I sure wish you were still building carburetors for customers! You're clearly the guy I was looking for! I could probably muddle through it, but you start talking about "a set of orifice drills" - ain't got 'em. You talk about "factory patch to prevent stalling" and I am clueless.

Interesting about the leather accelerator pump. I only drove the car a little bit before I figured out the engine had to come apart (rings being the biggest problem - I needed an oil truck to drive along beside me...). But it would bog down real bad whenever I gave it any gas at all. So, I looked at the accelerator pump, and the mickey mouse rubber piston skirt in there had all fallen apart. I actually managed to find 2 original leather-skirted plungers, and put one in. But it didn't help, so the bogging down is being caused by something else. Which is why I wanted somebody that really knew these carbs to work on it.

Too bad you don't build 'em any more. Looking at your links, it sounds like you still do sell them, thought. Do you have a 7008737 set up to run on corn gas?

Gene, I didn't see your edited earlier post, about the color on the car. So, your screen color is off. Mine is a very late production (last couple of weeks). The turquoise is the later Tropical Turquoise (754), not the earlier Twilight Turquoise. And yes, original interior (still very nice) has the dark color lower panels on the doors, photo below.

These guys do amazing work. Will retrofit for "corn gas" too. Have used them more than once and are the gonto guys for local clubs too.

http://www.customrebuiltcarbs.com

Thanks, Jaw33.

Well, we've made it to New York to the Central Meet and back home in the '56 wagon just fine, and now the biggest issue I have to deal with is the carb. (Or the carby, as they say Down Under, I like that better.)

So being a PowerPak / Powerglide car, I have the Rochester 4-Jet instead of the Carter Carby.

I need to say up front that I am NOT a carburetor guy, at least not 4 BBL. I can handle the 1910's Zeniths on a 490, or the simple 1 BBL Carters and Rochesters in the 20's to early 50's. but when we get up to 4 venturi, I get nervous and easily confused.

So it was rebuilt in April by Custom Rebuilt Carburetors as recommended here, in Middlesex, NJ. It was very pretty, and very expensive. I got very little detailed information from them, just that everything was renewed, and (supposedly) set up to run on corn-juice gas.

During this touring last week, everyone who followed me any distance told me that I made a lot of black smoke whenever we went up a long hill, or I accelerated hard. And I could FEEL that things were not right. This also happened on the long rides on the Interstate coming and going. Our group cruised at about 60 mph - but whenever I needed to push on it above about 50 mph (in other words, whenever the secondaries were called on) instead of a surge of power, it kind of struggled and bogged down instead of accelerating. And that would correspond to the black smoke observed by others.

Before leaving, I did set up the idle mixture with the vacuum gauge (got to about 17 at the best), and idling at around 500. Choke is working well.

It seems to me that the secondaries are not working as they should. Where do I start? Could be not enough float level? Could be metering jets are not right? What should the jets be? I have been told earlier here to "open them up .002" on both primaries and secondaries - but I don't know if that was already done by the rebuilder or not. The car runs and idles very well at lower speeds, very smooth. I do get black soot when it starts up, though. Anxious for any input on how to proceed.

I would not fool around with the jets. The stock jets worked perfectly well in my 1957. The "front" jets should be stamped 48 and the rear 46. I would suspect the float setting for either.
I have never changed any of the settings for using ethanol and have never had any problems.
To be honest I would contact the rebuilder before doing anything.
I always found the early 265-283 engines ran best with an additional 6 to 8 extra degrees of timing advane. With it my '57 Power Pac can still run regular grade with no pinging.

Call the rebuilder and ask to speak directly to Phil. Nobody else. He's the owner. They will be able to advise what to do. Excellent shop that does dozens and dozens of classic carbs for many makes and clubs locally. Even did a full resto and manufacture of broken parts for our 34 Ahrens Fox Fire Truck. They will get it tuned in for you.

Jeff

I will try that tomorrow Jeff, thank you. Gene, I am also well advanced and have no problems in that area. This is pretty clearly about the secondaries either not working or not working properly.

This problem is resolved. I did not talk to the rebuilder. Rather, I finally got some "shop time" today, and so I studied what was actually going on with the carburetor (and especially linkages), and also studied the Service Bulletin that describes the Rochester 4-Jet.

What I found after puzzling with it all for a while was a linkage issue. The secondaries were not opening at all. There is an air pressure activated butterfly valve above the actual throttle butterfly for the secondaries, so you have to hold that open to see what is going on with the actual throttle valves. And they didn't open under any conditions.

So studying the linkage, I gradually came to understand that there is a "tang" that is held by a "notch," by the choke linkage cam, until the choke is fully off - then, that tang has to ride up over the cam which allows the secondaries butterflies to open. This was not happening. So with some gentle bending of the tang, I got it so it could follow the path it is supposed to follow.

Road test results were dramatic! No more black smoke and stumbling - but a HUGE improvement in power and response at 60 mph. In other words, now I have a 4 BBL instead of a choked 2 BBL... Now, it works like it is supposed to. Tomorrow, I will do some fine tuning adjustments, but I am confident that the problem is identified and fixed.

When you get to know your car you can tell when the choke is hot and open because then when you floor it you can hear the air rush as well as feel the added power.
Glad to hear you found the problem. A good rebuilder would have checked this during bench assembly.

So ChevyGuru.....in response to ChevGenes comment and innuendo that the rebuilder was no good....can you confirm if the linkage you referred to was part of the rebuild or not? I have no skin in the game so to speak but this rebuilder has done a huge amount of excellent work and has a national POSITIVE reputation as a result. Just curious if the linkage problem you found was truly a mistake by the rebuilder as some are jumping to or was it linkage that was no given to the rebuilder as part of the manifold/choke/throttle linkage assembly? Thanks for clarifying for us.....

Jeff

To make sure the rather complicated linkage is properly adjusted is part of the rebuild process. Also easy to test when the carb. is on the bench.

The linkage was on the carb when it went to the rebuilder, as shown in the most recent photo above. Very honestly, I'm not going to blame the rebuilder for this. The carb came back in May, I believe. And although of course it was set aside and only handled a few times, it was on and off repeatedly as the engine was built up. And the adjustment to the tang was a only few thousandths. So it could well have been bumped that far when I was building it all up. Might well have been set up perfectly when it left their bench. No blame or complaint from me, just glad to have figured it out.