The Stovebolt Site Forums The Shop Area Engine Shop Rochester vs Carter

I noticed in perusing the plentiful data to be found on the excellent Carburetor Shop website that it looks like the Rochesters replaced the Carters in Chevy trucks about 1950, but from 1965-1967 a few Carters re-appear. Then from 1968 on it is all Rochesters with a few Holleys sprinkled in. Is that the case, and, if so, what is the re-appearance of the Carters attributable to?

Thanks

In 1923, Chevrolet went out for bids for carburetors. One of the provisions of the bid, is that Chevrolet would be allowed to build a certain percentage of their needs themselves.

From all I can read, Carter was the only company that would comply with that provision.

So Chevrolet started buying Carter carbs exclusively about 1925 (before this, a number of different brands were used, to include Detroit Lubricator, Holley, Marvel, Stromberg, and Zenith).

Chevrolet used only Carter carbs through 1949.

In 1948, Chevrolet asked Carter for a major redesign of the W-1 being used by Chevrolet.

In 1949, Rochester started producing "carburetors" (the model AA used by Oldsmobile, and thankfully discontinued after 2 years).

Since Rochester is a division of GM, GM required Chevrolet to start using the Rochesters in 1950 on both the 216 and 235. After the redesign, and then 1 year only sales, Carter was less than happy about this development; and started making aftermarket type YF carburetors designed as a bolt on replacement for the Rochester B. Many folks (including me) feel the Carter YF is vastly superior to the Rochester B.

I do not know why O.E. Carters were sprinkled into the mix from in 1965.

Jon

Thanks Jon very interesting

Strange things happen, as you well know. Carter built some Rochester Quadra-jets over the years.

A lot of the muscle cars & performance cars of the mid-60s used Carter AFB 4 barrel carbs. The 4gc Roch. were not good for that & the square bore carbs worked better then the spread bore for high performance.

George

I remember reading on this site many years ago, the ABCs of carburetors, and it’s stuck with me.
Now I have more knowledge on the topic.

In the mid 1950s, Cadillacs came with Carter WCFB 4 bbl carbs or Rochester 4GCs. It wasn't an option or anything, you got whatever you got.

I can only assume that Rochester couldn't meet the production requirements so Carter supplied some. It seems to be about 50/50 with the Cadillacs.

Does the question pertain only to Chevrolet 6 cylinder engines, or are you asking about v-8's as well?

My post only considered the sixes. If V-8's are also in consideration, then there is more to the story.

Jon

I was only referring to the 6 cylinders. Thanks for all the feedback!

I used to attend GM/Rochester classes at the GM training center in Memphis as part of the annual instructor upgrade training required by the Tennessee vocational/tech system. A Rochester field engineer told us that a certain percentage of QJ production was required to be sublet to Carter by the feds to prevent GM from being prosecuted on "restraint of trade" regulations. That was in 1967 when the QJ was a brand new design.
Jerry

This is all very fascinating. I really like learning the history of these things.

Hey Jerry. So what do think is the best carb. for the 235. And can you also direct me to a forum that has some information about HEI distributes. Thanks

There's a website that goes somewhat into detail about a HEI conversion for a Stovebolt distributor, but I can't in good conscience recommend it to anyone. The author has "borrowed" heavily from information I gave him, without attribution, and presented it as his own research. I'm working on a way to install a GM pickup coil and reluctor in an OEM distributor, and locate the module elsewhere, but I don't have a working prototype. When (if) that happens, I will gladly share the results of my research without trying to profit from it.

I believe a Carter YF carburetor designed for an AMC/Jeep 232 cubic inch inline six from the mid-1960s should be compatible with a Chevy 235, and those carburetors were manufactured around 20 years later than the Rochester B. I see "rebuildable cores" on Ebay pretty frequently, at fairly reasonable prices.
Jerry

Thank you Jerry, Well sir if you don't recommend it I believe I will pass also :-). and thank you for the Carter YF info. By the way I put all new exhaust valves on my 848 head and truck is doing great. My son did all the heavy lifting lol but we did it , all your advice was a really big help thank you and God bless

The "big cap" HEI that GM used on the 230/250/292 sixes can be modified pretty easily to fit the 216/235/261 engines by changing the depth it plugs into the earlier block, and installing a bronze drive gear on the ones used for the 216 and pre-1954 235 engines with the forged steel camshaft. Personally, I think that setup is ugly enough to make a freight train take a dirt road, and it must be used with a conversion to a 12 volt electrical system on the 1954 and earlier trucks. The 'Pertronix" electronic ignition conversion comes in two versions- - - -the ones that have already failed, and the ones that will quit soon.
Jerry

Lol I hear you loud and clear :-). Hope your doing well