carbking

The 1956 Pontiac dual-quad option was for use on production cars. Rejected in favor of tri-power (although Carter provided prototype dual-quads to Pontiac for testing) in 1957; and of course the troublesome fi debuted in 1957. The Super Duty (race only) Catalina's did have the dual-quad option in 1962 and 1963, but they fit only the Super Duty heads, not production heads. Jon.

As far as value is concerned, one used to be able to acquire auction results from the various auction companies. Take these with a pound of salt, as some cars which are listed as sold actually may have been "trades" among friends to make the price look better, and then sell at a later date at a higher price. I didn't read where you mentioned this, but since the car still has the original fuel injection system my guess would be the car is VERY low mileage! It has been a long time since a few Pontiac club members asked us to reproduce the necessary service parts to rebuild the Pontiac fi units. From what I remember, maybe 50 percent of the 1957 service parts were the same as Chevrolet; but less than 25 percent of the 1958 parts interchanged. We never did make up the kits. Too expensive. Too bad the 1956 dual-quad package was one year only. Jon.

Note the adapter between the Zenith carburetor and the intake. The original carb used on the model 75 was a Penberthy "cross-flange" carb. Drawing a straight line between the two mounting bolts on a cross-flange carb will result in a line in the orientation of fender to fender (can be seen in the picture on the manifold). Drawing a straight line between the two mounting bolts on a straight-flange carb will result in a line in the orientation of bumper to bumper (can be seen on the Zenith carb in the picture). Thus the necessity of the "flange adapter" pictured. My records show the model 75 used a 249 CID engine, similiar to the model 72 (export) also a 249. The model 72 used a Stromberg OX-2 carburetor, which like the domestic model 75, was a cross-flange. The original Penberthy is quite scarce (zinc alloy - pot metal, and cracked to pieces). Once you get the engine running, you might consider looking for a Stromberg OX-2 which could be calibrated specifically for the 249 CID engine, and the adapter could be eliminated. The Stromberg OX-2 is mostly brass. Jon.

How about Abbott, Stearns, and Elcar? Jon

I misunderstood your first post. When you mentioned the 100 miles on it, I assumed engine, and you meant carburetor. Suggestion: buy some test equipment. I would suggest any enthusiast working on older vehicles needs a minimum of 3 items of test equipment. These are: (1) Timing light (2) Compression testing gauge (3) Dwell/tach combination meter Since your engine has 100k plus miles, I would suggest (especially on a Ford 6 of this period - been there, done that!), that your backfire is much more likely to be a burned/stuck intake valve. We burned a couple by 60k miles on a 1960 Ford 223 6-cylinder that Dad bought new. A compression test would verify/deny this long distance diagnosis. The compression test is quite easy to accomplish. I would also suggest the acquisation of a factory shop manual for your car. In the meantime, Motors/Chiltons aftermarket manuals have lots of useful information, and are relatively inexpensive. As a general rule, engine running issues should be approached as: (1) compression (2) ignition (3) fuel And when purchasing test equipment, I personally (OPINION, others may/will differ) believe good, used made in the USA equipment from the 1960's and 1970's is vastly superior to the offshore stuff currently available new. Jon.

The Edsel 6 should have a one-barrel Holley carb. The range on the adjustment screw is from 0 ~ 1 1/2 turns. Beyond 1 1/2 turns, no change. Also, this screw only controls the mixture at idle, nothing beyond idle. In the years of production of the Edsel, the mixture needle would be the older short taper needle. It was not until 1968 when smog emission demanded more precise tuning that the long taper needles were regularly used. I have not seen in this thread the age of the gasoline. If the gasoline is old, then issues may arise especially with a cold engine. Once the engine is totally up to normal temperature, the issues may diminish, or even disappear. The fact that changing the screw is showing effect may simply be that the engine is warmer rather than any actual change from the adjustment. I would suggest checking the age of the fuel (anything over 6 weeks is suspect, especially on a new engine). And as others have mentioned, I would check the timing, both at idle and at higher RPM, to make certain the distributor advance unit is functioning. Jon.

Dwight - I followed the link on ebay, but was unable to read the tag number. What follows is OPINION (mine) and others may/will have differing opinions. Virtually any Zenith is superior to virtually any Marvel, period. Having said that, some Zeniths are much better than others for a number of reasons. Many (not all) of the modern Zeniths (current production) have no power circuit (power valve) to enrich the mixture under wide-open throttle application. This is normally not an issue for "parade" vehicles, or vehicles normally driven in moderately flat terrain. Those that tour will want the better Zeniths with the power circuit. Should you need parts, we make rebuilding kits for virtually any Zenith, clear back into the early 'teens; but for those carbs made prior to WWII, other parts may/may not be available, and the kits are hand-made, thus expensive. The two series before WWII for which most parts are available are the 63 series and 263 series. ALWAYS check the identification (tag) number to find the series. If the carb is a universal (designed for aftermarket, not original equipment), jetting is somewhat more forgiving than for O.E. carbs. If the carb is an O.E. carb, we have found a good rule of thumb is the "donor" engine should be within +- (plus/minus) 3 percent of the "donee" engine. Example: if one has a 250 CID engine, 3 percent of 250 is 7 1/2. So one could reasonably expect good results using a carburetor from an engine within the range of 242 1/2 to 257 1/2 CID. Not saying a carb outside the range won't work, but it might require more tuning. If you acquire a new-old-stock Zenith with an accelerator pump: Zenith used brass pumps (not leather) in most updraft applications. AT LEAST 90 PERCENT OF THE NEW OLD STOCK CARBS OF THIS TYPE THAT WE HAVE DISASSEMBLED HAVE A STUCK PUMP!!! EXPECT IT! Not a problem if you have patience. Once the pump is unstuck (assuming you don't damage the pump freeing it), it will work fine. However, if you damage the pump in freeing it, chances are a new pump is constructed from either unavailablium or verypricium! If you have access to an ultrasonic cleaner, place the entire carb in the cleaner for about 30 minutes (plain water) BEFORE you attempt to disassemble to free up the pump. Run the heaters at about 165 degrees F. So far, knock on wood, has worked for us every time. And if you tear out the gears in the rear end from all the extra power you now have, don't blame me Jon.

Easy question, very long answer. If you are looking for the least expensive very good carb, then a Carter YF from a late 1960's Ford truck with 300 CID 6 would be the way to go. If you are looking for the best replacement regardless of cost, then an aftermarket Zenith 228BV12 or a Stromberg BXV-3, BXOV-3 or BXUV-3 would be the way to go. The above are carburetor types, and you need to determine exact models for your displacement. There are others. If you have additional questions about this, 573-392-7378 (9-4 Mon-Tues central time). Jon.

The Stromberg "D" series carbs were Stromberg's first attempt at a downdraft carburetor. As such, the "D" series carbs basically used updraft technology on a carb that sat on top of the intake, rather than below. The single barrel DX-3, was superceded by the DXR-3 (the "R" meant revised), which in turn was superceded by the DXC-3. The "X" meant cross-flange, and the 3 meant S.A.E. size 3. The DD-3 (the double letter meant two-barrel) was superceded by the DDR-3. Stromberg freely acknowledged all of these carbs had problems, and when the "E" series came out, Stromberg offered "E" series replacements for all of the "D" series original applications. The DXR-3 would have been replaced by an EXV-3, which in turn would have been replaced by a BXV-3. The thing to remember is that there were many different EXV-3's and BXV-3's. The trick is to do one's homework as to internal venturi size and/or engine displacement; and choose a replacement unit that has the proper airflow for the engine in question. Simply looking for an EXV-3 or a BXV-3 is basically hit-or-miss. By the way, repair kits do exist for the DXR-3, but the special tools would have to be fabricated; unless one finds a rebuilder that has done one of these in the past, and already solved the special tools issue. Jon.

My guess would be that, since he posted the pictures, he doesn't have a tag. Jon

David - glad you enjoy the posts. The Packard Air Valve carb is an early Detroit Lubricator Design (about 1905), so it was WAY ahead of its time. But the model 51 was designed in the late 1920's and is a more efficient design. There was a lot of knowledge gained from 1905 to 1928 in the design of carburetors. There are many issues which can effect the idle on the P.A.V. carb, but the two most common: (1) fatigue of the idle spring (2) wear in the bushing area of the air valve shaft (resulting in the air valve not seating) The spring is still available in rebuilding kits, but the supply is limited. The wear in the bushing area has to be machined. An issue which no one really likes to talk about is cost. About 40 years ago, we had both the springs in the P.A.V. carb reproduced (approximately 100 springs) to put in the kits. We still have a few left. Less than 100 sales in 40 years! This demonstrates the demand for these parts. Same is true for the model 51 vane support (there are several different, by the way). We had a retired independent machinist reproduce these for us. He enjoyed puttering around his shop, and really made quality parts; but he passed to his maker many years ago, and have found no one to take his place. With these low production precision parts, the initial cost for production run numbers and the payback is really an issue. Another issue is understanding. Mentioning the Detroit type 51 is somewhat similar to mentioning a modern Rochester Quadrajet. It is a TYPE of carburetor, not a specific carburetor. Restorer32 mentioned buying a Graham carb to get a bowl, and then discovering the bowls were quite different. He certainly isn't the first, nor will he be the last. There are many different Detroit type 51 bowls. Most of these "automatic" carburetors are controlled by a tensioned spring (or in the case of the P.A.V., 2 springs). Replacing the tensioned spring (if one can find the specifications to reproduce the spring, even new old stock ones have fatigued) will generally improve the performance of the carburetor. Jon.

West - you are both right and wrong! The 1929 Packards through March used the Detroit Packard Air Valve Carb. The Johnson model R was used from April through July, and they WERE retrofitted with Detroits. I have NEVER seen a complete useable Packard Johnson model R. The Detroits were fitted beginning in August. Jon.

David - about 40 years ago, a gentleman in the Northeastern US did a really quality reproduction of the early brass bowl, but these bowls have not been produced for at least 31 years. The wooden patterns are still available, if anyone wanted to again reproduce these bowls. I am not going to do so. Jon.

Just for the record, the 1929 did not have the bowl vent (this one doesn't). When the bowl vent was introduced in 1930, the throttle body gained a raised boss for machining for the brass fitting for the bowl vent. The Packard Service Letters suggested modifying the earlier (1929) carbs, and the throttle body was drilled, but without the boss. This one has not been modified. The early 1929 bowls were bronze. The late 1929 bowls were diecast (as is this one) with the two machined holes in the air intake for the arms of the flame arrester (as is this one). Detroit Lubricator made "running changes" in their carbs. We have identified 29 different Detroit Lubricator model 51 carbs used on Packard alone in the years 1929~1932 FOR DOMESTIC MODELS. There are additional different models which were used on export cars. I have never attempted to document these. Several other models were used by Graham and Cadillac. I have identified the Cadillacs, and most of the Grahams. For those of us that did not grow up in a Graham dealership, trying to decipher models in this time period generally results in a large headache For those interested in the application, the last three digits in the stamped number on an original bowl cover were the identification number. Kind of a moot point today as the bowl covers have been reproduced (blank) and then stamped by the hobbyists. What I believe is a complete list by year and month can be found on this link: http://www.thecarburetorshop.com/Kpackard.htm Back to the 6 character stamped code on the bowl cover: the letter is the month the carburetor was produced (A=January, B=February, etc.), and the first two digits are the last two digits of the year of manufacture. Thus: the code A-30753 would be identification number 753 produced in January of 1930. From the link, this was used on a 1930 Packard 726 or 733. I actually started a book on these carburetors, but was too busy with running the business to ever finish the book. Jon

David - the one on Ebay appears to have a 1929 throttle body, and a late 1929 bowl. The pictures are not sufficiently clear to really draw other conclusions. And no, it isn't mine. Jon.

Cadillac used Johnson on 1932 and 1933 8 cylinder. The 12 and 16 cylinder did use Detroits in 1932 and 1933. The first Detroit on a Cadillac 8 cylinder was 1934. Jon.

Unfortunately, sufficiently common for me to put a blog on the issue on our troubleshooting page: http://www.thecarburetorshop.com/Troubleshooting.htm#Fuelleak The fuel fumes while running are probably coming from a different place. This should be addressed. Jon.

Maybe one of the Caddy guys will respond, but it looks like a 1932~1933 carb to me. Jon.

Ed (or Tom if you and Ed make a deal) - don't put it in penatrating oil! Take the carb as far apart as you can. Get the floats out. Now place the lower section of the carb in an ELECTRIC oven (a toaster oven works well). Heat it up to 500 degrees if the oven will go to that; let it "bake" for 15 minutes or so, and just turn off the heat. After it completely cools, do it again. Now after it completely cools, try the penatrating oil. The only thing you will hurt on the AFB is the springs, and they are available. CAVIAT: this is not a "one procedure works on all carburetors". It does work on the AFB's. Jon.

Tom - just got your email. In 1963, Buick also used Carter AFB carbs. MOST (not all) of the AFB carbs have the identification number stamped on the edge of the mounting flange between the left-most idle mixture screw and the choke housing. And even the ones which are not stamped are reasonably easy to identify. Might be another solution along with looking for a tagged Rochester. Jon.

Bernie - the issue you describe COULD be caused by the use of the wrong accelerator pump. Many of the Rochester carbs had a pump with a check ball in the pump thimble. The purpose of this check ball was to allow the escape of air which was caused by percolation of the fuel in the bottom of the pump well. Many of the aftermarket (read cheaper) pumps did NOT include the ball. If the ball is not present (some don't use it) but should be; as the fuel percolates, pressure is formed in the bottom of the pump well. Since the air would be on top of the fuel, the fuel (over some period of time) is forced out of the pump well through the pump squirter, REDUCING the amount of fuel available for the pump shot when the pump is activated. Thus, the pump will work perfectly when the engine is not running, but the first squirt when running will be weak. A second squirt should work normally. Jon.

The "missing tag" carburetor presents a problem for the owner as well as for those of us that manufacture and sell parts. Generally, the reason the tag is missing is that at some time in the carburetor's life, it was rebuilt by a commercial rebuilder. The commercial rebuilders "grouped" several carbs together under one "sales" number, and removed the tag so an informed customer would be unaware of what the customer was actually buying. With the tag missing, the odds of the carb being correct for the application are maybe 1 in 10!!! Some of the "cut-rate" commercial rebuilders would even sell carbs from different makes (the conversion of Pontiac to Chevrolet is common with Q-Jets, even though the Chevy is side inlet and the Pontiac front inlet) As Rochester used about 40 different accelerator pumps in the 4-Jet carbs, the odds are not good. We suggest that the customer look for a tagged original carb to rebuild. Then he/she knows the carb IS calibrated specifically for the application (not some generic calibration), and that parts ordered would fit. Jon.

Carter showed three different size 6 cylinder engines used in 1950 by Studebaker in their trucks: 169 CID - Carter BBR-1 633s 226 CID - Carter BBR-1 606s 245 CID - Carter BBR-1 606s (early production) 245 CID - Carter BBR-1 777s (late production) The BBR-1 was not one of Carter's better carbs. As only 4 screws hold the airhorn to the bowl, the airhorn tends to warp, allowing seeping all of the time, and a leak when cornering. This may be corrected during a rebuild by straightening the casting using heat and pressure. The BBR-1 is also susceptible to fuel pressure (the BBR-1 doesn't like much pressure); but if the castings are not warped, there is a reason for the leak. Find the reason (virtually ALL used castings you find will also be warped) for the leak and rebuild what you have. Jon.

Try this link: http://www.thecarburetorshop.com/Fuel_valves.htm Jon.

Since you wish to keep the original Marvel updraft, I would go very easy on performance modifications (ie increased compression) to the engine. The Marvel does not lend itself well to re-calibration. Jon.