carbking

Mark also requested a carburetor with an accelerator pump. Carter did offer a true accelerator pump on the BB series carburetor, which can be quite problematic for those not understanding how these things work. It is the one feature on these carburetors that I do not like. The Stromberg and Zenith carbs used vacuum pumps that only worked AFTER the engine had been started and engine vacuum was available. This (opinion) was much superior to the accelerator pump. The volume of the accelerator pump shot from these carburetors was maybe as much as 5 percent of that of a modern carburetor. For the most part, the benefit from an accelerator pump was largely in the mind of the operator! Beginning in late 1931, for use on 1932 models; single barrel carburetors from Stromberg (SF series), and Zenith (63 series) both continued the vacuum pump rather than an accelerator pump, but the output increased to maybe 20~40 (adjustable) percent of that from a modern accelerator pump. Jon.

I don't have a solution, but can maybe add some information that may (or may not) be useful. Stearns-Knight used only Tillotson carburetors on the 385. The first single barrel for the 385 was SP-1A, which was superseded by SP-15A. The first two barrel for the 385 was the VD-1A which was superseded by VD-1B. As Tillotson documentation is not the best of the carburetor companies, and these units were unique to Stearns-Knight, I have no flange mounting information. The largest engine to use the Carter BB series carburetor as original equipment was a 265 CID. Carter did suggest using the BB 289s on a 315, but we have proved that a larger carburetor works MUCH better! Carter produced the BB series in size 1 (2 3/8 on mounting centers), size 2 (2 11/16 on mounting centers), and technically size 3 (2 15/16 on mounting centers) carburetors. However, if one will look seriously at the 289s or 289sd (size 3), one finds that the internal venturi is the same as that used on the BB1A/BB1D (size 2), and the throttle body is tapered to fit a size 3 manifold. However from an airflow standpoint, these are size 2 carburetors. We found that replacing a 289SD on the Packard 315 with a Stromberg SF-3 (size 3 in both physical size, and airflow) yielded significant positive results. Looking at aftermarket carburetors from "the day", my records indicate only Schebler ever offered a replacement carb for the 385. This was a Schebler duplex model SX-274 to replace the 2-barrel. Personally, I cannot envision why anyone would ever wish to put a Schebler on anything except a numbers-matching showcar that came with the Schebler, and was never started. Neither Stromberg of Zenith (the two companies that offered the most aftermarket carbs) offered a replacement carburetor for the 385. Stromberg did toy with 2 different models for the single barrel (an M-4, and later an OT-4). Both were experimental only, and never produced. Interesting that both of these are size 4 carburetors. I do not have custody of the Zenith experimental files, but they did not offer a production unit. Stromberg didn't even do an engineering exercise on a replacement for the two-barrel. If one looks at updraft two-barrel carbs, one finds these were produced in varying quantities by: Johnson, Marvel (by far the most common, and least expensive), Penberthy (DV series), Schebler (S duplex), Stromberg (OO-2, UU-2, UU-3, UUR-2), and Zenith (105D, 105DC). Looking at these, only the Schebler, Stromberg UU-2, UU-3, and UUR-2, and possibly the Marvel from a Buick series 90 would be sufficiently large internally to feed a 385 at 4,000 RPM. Jon.

Gary - looks like what I need. Sent the company a request for quotation. Will see what happens. Thanks. Jon.

Gary nailed it on the aperature cards. Jon.

Thanks Padgett - I have downloaded the software, and will try it out. Sounds like just what I need for the Stromberg stuff. Again, thanks. Jon.

Thanks Dave, will consider this. Jon.

In the 1950's and 1960's, Stromberg Carburetor Company microfilmed their then existing drawings, parts listings, etc. I have been converting these to digital for years. The "A" drawings (8 1/2 x 11), "B" drawings (11 x 17), "C" drawings (18 x 24) presented no real difficulties other than time. The "D" drawings (24 x 36) are an entirely different story. The individual doing the filming, rather than raising the camera to accommodate the extra dimension; folded the drawings, and took several shots. Generally, a left and a right, but sometimes more. I have digitized the microfilm into JPEG files, but is there a stitching software available that is easy to use (I bring out the worst in any computer), and relatively inexpensive, that I can download on my computer and recreate these drawings by stitching the parts together. There are thousands, so do not wish to pay someone to do the conversion for me (there is little worth watching on the TV in the evening other than the western channel ). I also do not wish to use any of the online conversions, as uploading documents is time-consuming. Anyone have any suggestions of a software product that fits the above? Oh, and my platform is Microsoft Windows 7 Professional, and will remain so. For those who think I should convert to Windows 10, we have 10's of thousands of documents created in Windows XP. Windows 7 Pro has an XP emulator, but 10 does not; and the data files are NOT upward compatible. Along the same line as above. Carter used 80 column aperature cards. I have about 20,000 of them to convert to digital. Any ideas? Thanks in advance. Jon.

My records suggest the 1922 Maxwell would have used an Eagle carburetor for domestic models, and a Zenith T4X for export models. I have never tried to make an Eagle carburetor run. The Zenith T4X has a very thin cast iron throttle body surrounding a zinc alloy (pot metal) venturi that "grows" with age; thus cracking the cast iron. From observation, about 90 percent of those found are cracked (the other 10 percent WERE cracked, and repaired)! Another disadvantage to the T4X is you must compete with the Henderson motorcycle crowd, as the Henderson also used a T4X. The Tillotson model X was an aftermarket "imitation carburetor" for use on the models A and B Ford. The question about compression is not in my area of expertise, but as a "rule-of-thumb", I use 12 times the compression ratio for my own use on pre-1930's vehicles. Hopefully, an engine specialist will give you better information. Jon.

Ed - someone revived this thread, and I again read your comments. Years ago, had a gentleman with a 1931 Cadillac V-12 with absolutely "toast" Johnson carbs (Dr. Goodpliers had worked on them several times) who was not independently wealthy (probably should not have had a 1931 Cadillac V-12). He did not wish to apprenticeship his first-born to acquire a set of Johnsons, and asked what options he had. While it may sound like heresy to Cadillac owners here, I knew there was no way he was going to fix it correctly; and suggested either turning the intakes or fabricating new ones to use Carter W-1 574s from a 1946~1948 Chevrolet. He called back a few weeks later, thanking me. He didn't tell me how he mounted the carbs, but said the engine developed a LOT more power, better driveability, and more than doubled the fuel economy! Of course, this is the proverbial "apples to oranges", as his Johnsons were horrible. Jon.

The first 3921s carbs came with the 170-839s choke housing assembly. Sometime during production, 170-839s was discontinued, and superseded by 170-911s. Either will fit and work on the 3921s carburetor. The Master Parts Index does not specify the exact date of change (this would be on the original drawing, and no offense meant, only necessary for an exact numbers-matching car, so not going to look it up); nor the reason for the change (this information may or may not be available on the original drawing). Jon

1963 Jon

I also am surprised by these figures. Perhaps a torque wrench reading in pounds-feet is less accurate at lower values. Perhaps a torque wrench reading in pounds-inch and then converting to pounds-feet might yield differing results. Jon.

The choke housings are different. 3503s - 170-785s 3921s - 170-839s (superseded by 170-911s) Sorry. Jon

(1) Mill the remaining projection from the outside of the choke cover (2) Machine a custom brass fitting on your lathe. The fitting should have the correct male thread on one end, and a small shoulder to fit against the outside of the choke cover. On the inside of the shoulder, the fitting is tapped to thread into the choke cover. The fitting should have approximately the same inner diameter as the original. The very inside end should be milled on either side to have a slot that will hold the spring. The threads that thread into choke cover should be approximately 1/8 inch too long (standing proud of the cover on the inside by 1/8 inch). (3) Tap the choke cover for the same thread as you used on the fitting (4) Machine a brass nut 1/8 inch thick with the same thread. (5) Assemble the fitting into the cover, and secure with the nut. (6) Re-install the spring (7) Re-install the cover on the carburetor. The inner clocking will be off; although this can be corrected by only threading the last 1/8 inch going through the cover, rotating the fitting until the correct clocking is obtained, and then secure with the nut. I prefer to have the cover threaded. Some items are made of unobtainium or verypricium and must be fabricated. If you found two on ebay, then this item made not be one that deserves this amount of fabrication. Jon.

Also, make certain, the spring is activated by heat the same way. Have not tested all of the Rochester chokes, but Carter made some that were wound the same way; but uncoiled in opposite directions when heat was applied. Jon.

No, they won't all fit, but most of the ones with the male fitting on the outside of the choke will fit, and can generally be adjusted to work. Jon.

Just for the record, my older vehicles like the cold a LOT better than the new electronic marvels like it. The newer cars with all the live sensors drain the battery in this cold in a couple of days if not started. Jon.

West - check the "rich - lean" direction arrows to start with; then check that the inside "slot" is "clocked" the same as yours. Of course, you can always ignore the original setting by number of bars, and just set the choke, but if trying to keep original, then clocking is important. There are other differences in the lettering that probably is no longer important, but I have had some very "intense" customers over the years. The springs also have a different coil length to control the timing, but again, one can generally adjust for this. Automatic chokes were one of the "cash cows" for the carburetor companies. Change the clocking 2 or 3 degrees, change the part number each year; and EVERY dealer would order 2 of each at the beginning of the model year! Jon.

I have very little experience with Webers, so one can decide if the following has any applicability to the Webers: When we were still restoring zinc alloy carburetors made in the USA in the 1930's, it was not uncommon for a fiber washer gasket surface to requiring "facing" due to deterioration of the zinc alloy base metal; in order for the fiber washers to seal. I have not seen this issue on post WWII US-produced carburetors by the major brands. European carburetor makes other than Weber (ie Solex and British Zenith) used a zinc alloy in the 1950's and 1960's that was much WORSE than that used in the USA in the 1930's! Again, I have very little experience with Webers. Jon.

It would not seem to be the case, but there are MANY DIFFERENT of these things. New old stock is best, and probably quite expensive if you find the correct one. Good used is second best, and somewhat less expensive, if you can find the correct one. Repairing what you have would be the next choice. The brand new powder cast versions have no rigidity, and will not hold up, other than as paperweights. Both of the ones you picture are fixable. Jon.

How much torque is too much torque depends on the diameter and pitch of the threads, plus the material with the female thread. For Webers, I don't know; but would suggest you contact the factory. I am going to offer a different opinion to some of those already expressed in this thread: (1) For fuel use, fiber washers are superior to nylon washers (they crack). (2) Unless told to do so by the manufacturer, NEVER use a sealant around fuel (or learn how to rebuild the carburetor(s) ) Personal and professional opinion - anytime the carbs are removed, the sealing washers should be replaced with new. Figure out the diameters and the thickness, and order a box of them from McMaster-Carr. Jon.

What you show is what was/is used. Yes, it can be problematic. A little corrosion on the zinc threads, an impatient "mechanic" and the fitting is cross-threaded. Have seen many choke housings that were damaged. Different "fixes" can be tried: rethreading the end with a die, cutting off the end if too much metal has been removed, then rethreading, there even used to be a brass fitting that could be screwed into the zinc (self-tapping threads) with new threads for the regular fitting. This fitting repair was the darling of some of the least expensive commercial carburetor rebuilders, and was generally good for one time use, then totally ruining the choke housing beyond repair. Yours looks like there is sufficient metal left to cut off the end, and touch up the threads. Jon

Mark - give me a call during normal telephone hours. Jon.

You guys just had to bring up the cow magnets!!! I am indirectly partially responsible for the great cow magnet fiasco! My apologies.A lot of years ago, got a call from a gentleman in Texas that had rust issues in his fuel and was going to take the car to the Pate show in a couple of days for sale, and could I overnight a rebuilt carburetor to him today?Well, the answer was no, but: I told him about the Carter Magna-trap. This was a magnet with a special shape to fit into a Carter glass bowl fuel filter. I have told many enthusiasts about this, and suggested one of the refrigerator magnets like your better half uses to stick honey-do jobs to the refrigerator.He told me he had a dairy farm, and had several of the cow magnets (cows are stupid, they will eat just about anything, including baling wire....oops, showing my age again ). If you feed one of the magnets to a cow, the wire doesn't pass into the entire digestive tract (you city folks, use Google, not about to get into the digestive system of a bovine ) He would make a loop in the fuel line and tape three of the magnets to the loop, hopefully to stop the rust from passing into the carburetor.About 3 days later he called, and he was laughing so hard, it took about 15 minutes for him to repeat the story. Seems everyone that looked at the engine asked about the cow magnets. After the first few, he started with a story that he continued to embellish as the day wore on. The final story was the magnets created a flux field, supercharging the fuel molecules, and giving almost non-Newtonian power and fuel economy!Well, you guessed it. P.T. Barnum scores again! This even made the Johnny Carson show (remember the "headlines" segment)? Over 300,000 cow magnets were sold in the southwestern United States within a month. Every supplier was sold out, and had back orders.Here is a link to a picture of the Carter Magnatrap that I placed on my website:http://www.thecarburetorshop.com/Carter_Magnatrap.jpgAnd now you know "the rest of the story" Newspaper story: https://www.washingtonpost.com/arch...noredirect=on&utm_term=.19601413ca5dJon.

I do not know what may have been printed for service in some of the O.E. shop manuals such as Waukesha, Hercules, or American LaFrance; but Stromberg did not print such a manual. Stromberg printed 2 pages in their service manual which contain: one cut-a-way drawing (not exploded), adjustments, parts numbers, and a picture of all the parts. Stromberg placed the parts on a white sheet in an order in which they took up the least amount of space, and took the picture. No physical proximity of parts intended. As far as the brass screw headed or hex headed plugs are concerned: Remove the zinc alloy parts (the venturi), the float, and all springs. These are parts that would be ruined by heat. Now heat the casting in an ELECTRIC toaster oven just as hot as you can get it. Remove the casting from the oven, and heat the cast iron AROUND the plug with an acetylene torch (propane isn't sufficiently hot) until starting to show red. Do this for all of the plugs. Return the casting to the toaster oven, and heat as hot as you can get it. Turn off the oven, and allow the casting to completely cool. DO NOT QUENCH. Remove the casting from the oven, and remove the plugs. Jon.