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Everything posted by carbking

  1. X2 on using the service manual! The sheets contained in the inexpensive repair kits are of the universal "one size fits all, is correct for none"! Jon.
  2. Ronnie - agree completely with you about the Q-Jet not being ideal for a tow vehicle. Jon.
  3. The adapter plates are wonderful inventions IF one has a strong right (or left) arm, AND a rabbit problem in one's garden They also may be used for a paper-weight (most of the time, probably not in Missouri during the tornado season ) Do the math. If one has an intake designed for an 800 CFM spread-bore, and one removes this carb, and with the use of an adapter, installs a 750 CFM Holley. Question? What is the effective CFM of the system??? Answer - less than 575 CFM!!!!! You have a maximum of 200 CFM on the primary (the manifold is the limiting factor). It is probably less due to eddy currents. You have a maximum of 375 CFM on the secondary (the carburetor is the limiting factor). It is probably less due to eddy currents. My guess would be about 180 on the primary side (less than the Q-Jet's 200), and 350 on the secondary side (less than the Holley's 375) for a total of 530 CFM. I will not argue that the Q-Jets are somewhat complicated. Each individual has a favorite brand, basically from familiarity. Having worked on most brands for more than 60 years, I have my opinions, but these are not truly applicable to this thread. Both square-bore and spread-bore carbs have their place, but NEVER with a spread->square or square->spread adapter plate. For the record, I have three collector cars/trucks: one totally original except for the factory high performance cam, one modified with dual square-bore carbs, one exceptionally highly modified with a racing spread-bore. Jon.
  4. 6-431 is a casting number and totally meaningless! By 1948, the identification is STAMPED (this is a recessed number/letter combination, NOT RAISED) on the top casting of the BBR-1. Orient the carburetor such that the fuel inlet is on your right. On the top casting you will read "Carter Carburetor manufactured for Chrysler" or something similar. The stamped identification is ABOVE the cast in wording. Once you have the identification, you can locate the correct rebuilding kit here: Jon.
  5. Matt - I am no longer building carburetors. Manufacture of carburetor rebuilding kits keeps me from fishing The first issue here is that installing a square-bore carburetor REQUIRES changing to a square-bore intake manifold. It cannot be successfully used with the existing manifold. Period. I am unaware of what manifolds may/may not be available for the 403. As to off-the-shelf new carburetors: Holley carburetors seem to be a favorite with many, but for some reason, Holley carburetors don't like me. Engine fires with new muscle cars (that I bought new and never touched the carburetor) and leaky Holley carburetors on three different vehicles all within 9000 miles prove this point! As to the e-clone, I cannot, in good conscience, recommend one. Period. But, Buick used 625 CFM square-bore carbs on the 401, and 425 in the 1960's before the spread-bore was designed. Both the Carter AFB and the Rochester 4-Jet as used by Buick. The 625 CFM square-bore are 250 primary, variable 375 secondary. Not sure 250 would be enough for the 403 for towing. It might be. There was also a 692 CFM Rochester 4-Jet, but I am only aware of two: the auto choke version was used on the 409 Chevrolet and is constructed from "verypricium". The other version (which I have, by the way) comes only with a manual choke. Conversion to an auto choke would require machine work. The 692 would be 313 primary, 375 secondary. Lots of things to consider: tire size, rear end ratio, total gross weight of both tow vehicle and towed vehicle, towing speed, and engine RPM at that speed. As I have posted many times, mathematics and physics are an enthusiast's best friends. Jon.
  6. I came to this thread late. I first read the then last part of the thread talking about Q-Jet rebuilders, which is when I jumped in, and recommended Cliff. Just read the entire thread, and it appears towing is the major issue. In 1981, my Dad bought a Winnebago with a 454 Chevrolet engine, and the 800 CFM Q-Jet. The Winnebago, when loaded and towing my van to swap meets, would gross 15,000 pounds plus. Trying to use the speed control was an exercise in futility in the mountains of Pennsylvania on the way to Hershey. The engine simply did not have the power to pull the grades in high, as the cruise control would not engage the secondary except under WOT, in which case the transmission would downshift and the engine would overheat. Manual driving had the same issue and would also cause the engine to overheat. Dad and I finally got frustrated, and Dad asked me what to do? I told him the wrong style carburetor was on the engine for towing. He said, in no uncertain terms: FIX IT (there may have been some other words used, but fix it is a literal translation) So I ordered a different intake manifold (square bore) from Offenhauser. And "married" two genuine Carter type AFB carburetors. I took a Carter 4760s (750 CFM) as the base, and replaced the manual choke with the electric choke, throttle arm, and fast idle mechanism from a Carter 9635s. At the same time, I plumbed fresh air to the snorkel on the air cleaner. Result: PROBLEM SOLVED! Driving the exact same route at the same cruise speed from Eldon, Missouri to Hershey. Pennsylvania the following year, the travel time decreased from 20 hours to 18 hours! Fuel economy changed from 6.1 MPG to 6.9 MPG (13 percent INCREASE). And the temperature gauge never moved from the center climbing the grades! So why did a slightly smaller carburetor make this huge difference?? It is important to understand the difference between the design of a spread-bore carburetor (the Q-Jet 800 CFM), and a square-bore carburetor (the Carter AFB 750 CFM). Instead of looking at total CFM, look at the PRIMARY side CFM: 200 on the Q-Jet versus 375 on the AFB. The Q-Jet is a total of 800 (200 primary plus a variable 600 secondary). The AFB (the one I used) is a total of 750 (375 primary plus a variable 375 secondary). The extra 175 CFM (almost double) was sufficient to feed the engine under most conditions, plus the AFB could go the WOT without the transmission downshifting. If one looks at many large engined trucks, one finds that a TWO-BARREL carburetor is used, rather than a four-barrel; which is where I got my idea. Just food for thought. Jon.
  7. Cliff does have a significant backlog, but that is simply a testament to the quality of his work! There are others that can rebuild these carbs for stock applications; but if the application is going to be non-stock, then live with it until you can live without it while Cliff is redoing it. The other possible solution, since you have the book on order, would be wait until the book arrives, then give Cliff a call. Tell him exactly what you are wishing from the application. He offers the same level rebuilding kits on these last model carbs as do I on earlier ones. And he will give you excellent advice. See what he recommends, and if you feel comfortable with any necessary machine work, order what he suggests. Just remember that so many carburetor rebuilders have gone out of business, and if you find one that will give you 48 hour turnaround, THERE IS A REASON! Jon.
  8. When one wants increased performance from a late model Rochester Quadrajet, one calls Cliff Ruggles of Cliff's High Performance. Period. Cliff wrote the second book on Q-Jets (the first was by Doug Roe). Call him. Tell him what has been done to the engine, and what you want, then LISTEN (remember the old E.F. Hutton commercials)? I have read lots of books in 60 years of working on carburetors. Cliff's ranks as the number one as far as being "user friendly", and among the top three, period. Plus, you don't have to have an advanced degree in mathematics to understand what is written. Jon.
  9. Ed - "perfect" - agree. But not all enthusiasts have access to the dyno and the 5-gas. Technology is a wonderful thing, in the hands of those who understand it. But an experienced tuner with more conventional tools can get very close; in most cases, close enough so the "seat of the pants" meter shows no change This is what I was trying to show in explaining the sensitivity of the float setting. Lots of money can be saved on buying parts by simply testing. Jets can get expensive, especially in a multi-carb environment. Jon.
  10. I have had a number of queries concerning rejetting of carburetors this week, some from this forum, some from others. Enough to start a thread. Re-calibration is often misunderstood. Remember from "carburetion 101", a carburetor is a device for metering and mixing fuel AND AIR! Virtually all carburetors, at least those produced in the last 90 years, have air bleeds (a.k.a. air jets) as well as fuel jets. Thus changing a fuel jet from 0.055 to 0.053 may have a different result, even on carburetors of the same make, type, and venturii diameter, if the air bleeds are significantly different. This should always be considered, thus one should speak of recalibration, rather than re-jetting. Typical reasons why enthusiasts recalibrate, in the probable order of requirement: (1) THERE ARE OTHER ISSUES, COMPRESSION, OR IGNITION, CAUSING THE ENTHUSIAST TO THINK THE CARBURETOR IS AT FAULT!!!!! I have stated "tongue in cheek" for many years, that the older updraft carburetors are much more reliable than modern downdraft models. Why? Because the updraft is not the first item the enthusiast sees when he/she opens the hood, and is more difficult to remove; thus causing the enthusiast to look at other issues first! (2) Living, or moving to, a different altitude. Because of the lower density of air at higher elevations, engines calibrated at lower elevations will run rich at higher elevations. Using Carter as a baseline: sea-level to 4000 feet, standard calibration; 4001 to 6000 feet, one size lean calibration, 6001 to 7000 feet, two sizes lean calibration. In general, Carter made no recommendations about 7000 feet except for off-road or military vehicles. (3) Using a different from stock carburetor, or carburetors. This can be a great waste of both time and money, if the carburetor(s) are significantly either too large (venturii) or too small for the engine. So - if one thinks recalibration is in order, how does one proceed? Well, that grumpy old Missouri hill-billy normally has jets for MOST older carburetors available at a price. BUT Before you call the old grouch, go back and revisit "carburetion 101". There are several factors that can cause the correct carburetor to run rich even with the correct calibration. (1) Excessive fuel pressure. This issue has been beat to death, but modern "new" fuel pumps are less than reliable in their output pressure (another thread rightly suggested that fuel pumps produce flow, not pressure; however, when the output flow meets resistance to that flow, an "output pressure" will exist). Virtually all carburetors produced in the USA since 1935, and many before, have suggested operating/maximum pressures, which should not be exceeded. (2) A fuel valve with orifice that is larger than that designed by the original engineers. This may be because of inexpensive "one size fits all, is correct for none" rebuilding kits; or it may be the old bigger is better syndrome. Those interested in performance may decide that a racing fuel valve will work on the street - IT WON'T! So if you really believe you need different jets, and are really to part with your hard-earned money - NOT SO FAST. ALL carburetors are extremely sensitive to bowl fuel level (today, commonly called float setting). In yesteryear, many carburetor companies would specify the actual FUEL level at a certain measured fuel pressure. As a general rule deviation from the correct setting by 1/16 of an inch will cause a deviation of one calibration size (lean or rich, depending on which direction is the setting deviation). The enthusiast can USE this fact as a "forecasting" tool. If one deliberate resets the fuel level, as a test, not as a final setting, one can determine if this recalibration is actually going to be beneficial WITHOUT parting with one's cash. So, again assuming that one is going to recalibrate; if the test shows improvement, but not to the level of that desired, order the SECOND calibration size, rather than the first. EDIT: I should have included these pictures as to how fuel level was set: The device was affixed to the bottom of the bowl, and the fuel level in the eyeglass would match the fuel level in the bowl. Jon
  11. Although it is true that both the 1934 NAsh and the 1934 Auburn 12 used type Stromberg EX-32 carburetors, so did 35 other makes of cars and trucks. It was a very common single barrel of the time. Even though both are type EX-32, they are totally different, and not interchangeable. And just for the record, while the Nash carb is not at the same price level as the Auburn, it would be in the top 10 of the 37 makes. If you really want the least expensive price, you might try for some of the truck models. Jon.
  12. When the Rochester Q-Jet came out in 1965, it had several "teething" problems: (A) internal dashpot (fixed in 1966) (can be fixed by professional rebuilder, if he/she wishes) (B) "umbrella" fuel valve (mostly fixed in 1967) (can be fixed with an available kit) (C) press-in well plugs (fixed in 1968 as mentioned by Joe above)' (can be fixed by professional rebuilder, if he/she wishes) (d) (small d) float pin placement (novice rebuilders could break the casting plus not ideal for high performance work) (fixed mostly by 1971) And an on-going issue, like virtually all "modern" carburetors, an aluminum throttle body that normally requires primary bushings to be installed after some 50k~80k miles. Overall, a wonderful street carburetor that can also easily be adapted to straight-line racing. Jon.
  13. I forgot to mention (senior moment? ) that floats may also be machined from Balsa wood. Again, the float must be sealed after the arm is affixed to the float. Jon.
  14. Model airplane dope, or POR-15 may be used to seal a NEW (never been placed in fuel) float. We were unsuccessful when we experimented trying to re-coat a used float. I am unaware of a brass float for this application, although we have a few left for earlier Marvels (replacing Marvel 30-504). We started machining Marvel floats from the closed-cellular polynitraphyll foam maybe 30 years ago. The reason: we could find no source for natural cork in quantities that were economically reasonable. The cork we could buy was "recombined" cork. Recombined cork was the scraps of natural cork from those who used the natural cork, ground, and a filler added to glue the crumbs together. IT DOESN'T FLOAT! We suggest to our customers that the foam float SHOULD be sealed, after the float arm is installed on the float. Jon.
  15. The U5 is a later carburetor. The serial number (yes, in that era carburetors were serial numbered) 223631 follows the U-5. The record of first usage of the Zenith type U in my database is 1921. Kelly-Springfield started using the type U in 1923, again, according to the information in my database. The U-5 would not bolt to the 1916 intake manifold. Is it possible your truck has been repowered? We do offer a rebuilding kit for the U-5, but it is one that is made to order, and we are currently swamped with orders. Seems we stay that way most of the time. Phone number is in my signature. Jon.
  16. From the pictures, it appears that the governor is a "sandwich" governor. That is, the governor is "sandwiched" between the carburetor and intake manifold. We have no information on governors this early, and very little period. The Zenith documentation indicates that Kelly-Springfield used a Zenith type L-4 carburetor. Difficult to tell from the pictures, but the carb doesn't look to me like a type L; more like a type O. In any event, the type and size will be cast on the side of the carburetor. Often, this identification is on the side closest to the block, and the carburetor must be removed to see the identification. "Clean out kits" (gaskets, fuel valve, fiber washers, body screws) are probably available if you are not in a hurry, but will not know until the exact type of carburetor is known. Once you can see the identification (in letters and numbers about 5/16 inches tall), it will appear as a letter (or maybe two) representing the type of carburetor, followed by a number representing the size. Example "L4" supposedly original, or "O4" which the picture resembles. The numbers on Zenith carburetors do not correspond directly to an S.A.E. size, but do IF you make the correction. To get the S.A.E. carb size from the Zenith number, subtract 3 from the number. Thus an L4 would be an S.A.E. size 1. An O5 would be an S.A.E. size 2, an L8 would be an S.A.E. size 5. The following information is copied from an article on my website: Carburetor sizes – 1 barrel The Society of Automotive Engineers developed standards for carburetor physical sizes. The more common sizes found on automobiles are listed below. Bore size is listed as approximate, as some carburetors were much more efficient than others. Nominal ½ inch or 5/8 carburetor, center to center 1 13/16 on mounting bolts, bore size approximately 13/16 inch. Nominal ¾ inch or 7/8 inch carburetor, center to center 2 ¼ on mounting bolts, bore size approximately 1 1/16 inch. Nominal 1 inch carburetor, center to center on mounting bolts 2 3/8, bore size approximately 1 3/16 inch. (Often referred to as size 1). Nominal 1 1/8 inch carburetor, center to center on mounting bolts 2 3/8, bore size approximately 1 5/16 inch. Nominal 1 ¼ inch carburetor,center to center on mounting bolts 2 11/16, bore size approximately 1 7/16 inch. (Often referred to as size 2). Nominal 1 3/8 inch carburetor, center to center on mounting bolts 2 11/16, bore size approximately 1 9/16 inch. Nominal 1 ½ inch carburetor, center to center on mounting bolts 2 15/16, bore size approximately 1 11/16 inch. (Often referred to as size 3). Nominal 1 ¾ inch carburetor, center to center on mounting bolts 3 5/16, bore size 1 15/16 inch. (Often referred to as size 4). Nominal 2 inch carburetor, center to center on mounting bolts 3 9/16 inch, bore size approximately 2 3/16 inch. (Often referred to as size 5). Get the identification from the carburetor, and I can probably give more specific information. Jon.
  17. Carburetor icing is more often the result of the carburetor being adjusted too rich. If the venturi is too small, the carburetor will run rich. Jon.
  18. You can always try tapping further into the hole, and using a longer screw; but if that fails (opinion) the heli-coil is the best option. Jon.
  19. Everyone has their own method. I use an empty mustard squeeze bottle that I fill with fresh fuel, and fill the carburetor bowl through the bowl vent. Or, in the case of various lawn & garden tractors, tillers, weed eaters, etc., that have sat all winter; a small psssst of starting fluid. Jon.
  20. This actually makes the issue worse! You are pumping fuel from the bowl as the fuel pump is trying to fill the bowl, but not enough to cause the engine to start. Jon.
  21. Garry - the issue now becomes "which UUR-2 is the repop"????? Stromberg made at least 102 different type UUR-2 carburetors. Without referring to the prints, I can think of at least three DIFFERENT bowls, and four DIFFERENT bowl covers. They are NOT interchangeable. There at least two different styles of large venturii. Not trying to throw cold water on your parade, but without knowing EXACTLY what you have, impossible to answer your question. Try to get the exact part number for the repop you purchased from the repopper, and then maybe. Otherwise, your local carburetor restorer that has knowledge of these carbs, and a machine shop is your best answer. Jon.
  22. Have never tested the Offie against an original Buick 2x4. As a general rule (opinion), the Offies of this period were the best of the aftermarket intakes, at least for performance street use. General rule number 2: the aluminum aftermarket intakes lost weight, and power, when compared to original. However, dual quads, when properly set-up WILL out-perform a single quad, and are WAAAAAY better than the eye-candy tripowers. As to the ebay link (not mine, I wouldn't sell them that cheap) being stupid prices; try putting a set together using current production "stuff" that will perform as well for less. Jon.
  23. I have quite a few Carter carburetors for Chevrolet, some original equipment, others the popular YF replacements. These are cores that I planned to rebuild, but way too busy to rebuild, even my own carburetors. So offering these for sale as is, with one of our major rebuilding kits.Some of these are actually rebuilt by someone else, some are used cores. All will be sold as cores, with the major rebuilding kit. Some of these I have more than one. Once I sell out of a number, I will not be acquiring more. All will have throttle and choke shafts which turn freely, nothing is seized.Prices listed below include postage to all addresses in the 48 contiguous United States. When comparing prices, remember that our 100 percent USA major overhaul kits are approximately $80~85, and postage is going to be in the $20~25 range, so take these into account.W-1 carbs:420s - $300.574s - $325.Also have many earlier W-1's which are totally restored, and priced accordingly. CALL on these.YF carbs:756s - $250.787s - $250.788s - $350.789s - $300964s - $250.965s - $225.966s - $350.2100s - $400.965s - new old stock in original Carter box - $400.MasterCard/VISA accepted without penalty.Trades: NO carburetors, cars, or car parts wanted (with 150,000 carbs, I just don't need more ) Will consider trades for U.S. gold and silver coins. No other coins or anything else considered.Here is a link to my website showing applications of the YF carbs: (9-12, 1-4 Mon-Tues central time).Jon.
  24. Please consider this ad as ended, the book is now on Ebay. Jon.