The Stovebolt Site Forums The Shop Area Engine Shop Carter YF carburetors

Based on what I read from all of your answers to my Rochester carb question. I guess I'll forget the Rochester idea, and buy a Carter YF carb instead. My engine is a 235 from a 1962 truck. I assume that there are lots of different Carter YF carbs. Before I start looking for one, can you guys give me any more specific info regarding which version, or which number, or any other helpfuI info. I don't want an automatic choke.

Contact Jon Hardgrove at the Carburetor Shop.

He'll fix you up with the correct YF model carburetor as well as the proper kit to rebuild it.

573-392-7378 Mon-Tue 9:00am-12:00pm, 1:00pm-4:00pm Central Time

He determined that the carb on my truck was actually set up for a Willys Jeep and put me on the right track to the exact carburetor I needed.

It can be complicated to explain.

After 1950, Chevrolet switched from Carter to Rochester. Carter made carburetors to replace the Rochester (aftermarket or OTC).
Whether a Rochester or a Carter, both are 50+ years old and both are subject to significant wear.
This is where a professional restorer is needed if you want a well behaved carburetor.
Carburetor rebuild kits are for carburetors that have little wear.
Many choose to find a carburetor, install a rebuild kit and fingers crossed that the wear is not too bad (works good enough).
Right now we are at the crossroads of experimenting with EFI kits. They have not yet be proven reliable (it takes many years to find out).

In 1960, GM started using the low profile carburetor air horn design on trucks.
It requires a center bolt to hold the air cleaner to the carburetor. Previous designs used a clamp to compress around the carburetor throat.
In 1960, Carter also switched to the center bolt design.

If you go by the Carter recommendation (attachment) you would purchase a YF 3211s but this is an automatic choke carburetor.
I like the YF 2100s manual choke but beware it is made for the older style air cleaner.

great info, thanks

In my opinion the YF3211S was one of the best carburetors made for the 235...but if you're married to the idea of a manual choke the only option you have with the 3211S is to use one of the aftermarket adapters (turn auto into manual). Those adapters work, but honestly speaking they are not my first choice. The YF3211S came out in 1957 and it did have the central shaft air cleaner retaining bolt. With the 235 made from 1959 forward, you need to understand things changed. This might mean using a carburetor made for 1956 and older engines won't work quite as well. What changed? Specifically smog and air pollution were getting more attention and GM took steps to make the 235 more efficient. They adopted a new camshaft which produces more torque at lower rpms...thus using less fuel and particularly helping make the engine more efficient in heavy traffic situations (think bumper to bumper). The 1956/57 camshaft makes the 235 produce torque of 210 but at 2400 rpm. The 1959 cam makes it produce 217 at 2000 rpm...more or less a return to the 1953/54 Corvette numbers of 223 at 2000. If you're using a different camshaft, then all bets are off on this idea, however. If you study the YF3211S, you'll see the metering rods were designed to make it run leaner than the 2100S. The 3211S returned to a 2 step metering rod (don't really know why), and both the economy position and the power position are larger than the 2100S...meaning they take up more room in the main jet which was the same size in both. My theory was that the Carter folks (also pressured with lowering emissions) returned to the 2 step rod so that the 3211S would remain in the economy mode longer...thus reducing fuel consumption and keeping the 235 in that zone longer. If it were me, I would leave the manual choke mechanism in place and have an auto-choke...in other words just let the manual choke exist for appearance sake. If you're using a later model 235 in your AD pickup, you've abandoned the idea of keeping it 100% original anyway. Around 1964 or 1965 I was looking at the same decision. A mechanic in the village where we lived told me "use the auto-choke. Those things are going to do their job better than you and that's one thing you don't have to worry about."

I am constantly watching for new old stock (NOS) or close to NOS Carter carburetors. They're getting harder and harder to find, however and very expensive. I have a very nice YF3211S at this time but no YF2100S models.

It should be noted that the page posted by buoymaker is a SALES page. Sales pages list ONLY those units in current (in this case 1964) production.

When I did my list several years ago, I pulled prints for each of the carburetors, and used the application guide on the print.

Easy to see from the sales list that several carburetor numbers of carburetors no longer in production have been pulled from the list. Other numbers have expanded application year ranges from that listed on the prints.

I have compared this sales list to my list, and have updated my list to include the expanded year applications, while still retaining the discontinued units. Also, there are newer numbers that came after the sales list was printed in 1964 that are included on my list.

Carter YF carburetors produced for Chevrolet

Note that the sales list also includes type YH (Corvette, and turbo Corvair), BB-1 updraft (C.O.E. a.k.a. "double duty" trucks), early 2-barrel, and early 4-barrel applications. I can add these items, if the readership thinks them necessary. I originally did not, as it makes for a bulky list, and didn't really think many on this forum would have an interest.

Jon

Jon G.

I do not KNOW why Carter returned to the two step rod, but GUESSING testing may have shown that the 216/235 had insufficient torque to maintain the vacuum for the mid-range step on the metering rods, and that the 3-step rods were simply additional expense for these engines. Again, this is a GUESS!

As far as smog emissions are concerned:

That company with the same name as a famous country and western singer from Tennessee pioneered smog emission testing; building a laboratory in southern California that employed quite a few folks about 1960. By 1964, this company had a viable working smog emission system (obviously not to 2022 standards, but a beginning).

The California legislature was sufficiently impressed to create smog emission legislation to take effect with the 1966 model year; NOT that they were interested in smog emissions, RATHER that they figured the legislation would REQUIRE AMC, Chrysler, and GM to also build laboratories in southern California, employing more folks. Oh, and the legislation was written so that the other company's results, were not applicable, requiring they continue their laboratory!

The Feds implemented smog emissions in 1968.

I will now get off my soap box, other than to state my personal opinion that the car companies, with the consumer footing the bill, really did a good job in spite of the various government requirements. I feel that if there was NO legislation, public opinion would have created sufficient pressure on the car companies once the first system was in production; and smog would have been reduced by a significantly greater amount much quicker, and MUCH cheaper than with the legislation!

Jon

I agree, Jon G. With government interference, the companies only do what they have to do. If the Feds had stayed out of it, consumers would have pushed for it sooner. I think the same is true for safety items like seat belts and air bags.

Air bags were available a few years before they were compulsory as an option & hardly anyone bought them. The public didn't want them till Madison Ave. told them they do.
George

ps I know this is political but I didn't start it.

Running a shop in California in the days of random roadside smog testing roadblocks made C.A.R.B. (California Air Resources Board) a 4-letter word! We did make a pretty good bit of pocket change converting road draft tubes to closed PCV systems, which was another CARB bright idea. The parts stores stocked conversion kits for most cars, and a universal kit that could be adapted to the oddball cars that didn't justify producing a drop-in setup.
Jerry