I just got an edmunds dual carb manifold for my 47 Kaiser. Its a split manifold each carb will run 3 cylinders It is made for 2 bolt single barrel carbs. My question is what are my options for carbs what carbs will fit this manifold and what carbs do you guys recomend. It a 226 flathead straight six. Im already running an edmunds high compression head. Thanks<!-- / message -->
Some useful info gathered over the years. Don't overcarb! Good luck if you stick to single holers, but here is some info on the 2bbl.s http://www.4secondsflat.com/Carb_CFM_Calculator.html Stromberg, 97; Had a 31/32 venturi dia. and 155cfm rating. 48; Had a 1 1/32 venturi dia. and 170 cfm rating 81; Had a 13/16 venturi dia. and 125 cfm rating. The Chandler-Grove/Holley cfm's.... The model 92 is rated at 142 cfm. The model 94 is rated at 155 cfm. The model 8BA is rated at 162 cfm. The model ECG is rated at 185 cfm. The Stromberg 97 was used in '36 thru '38 Ford cars and in trucks in '36 and '37. It replaced the 48 model due to complaints from customers concerning poor mileage and winter drivability. One reason was the 48 has only a single knob on the ****erfly shaft for the accelerator link to connect to, and this was a problem that the 97 corrected. The 97 has two knobs... one for winter when more of an initial shot of fuel is needed to prevent an accelerator flat spot and one for summer driving. The 97 has a 0.969 inch venturi and is rated at 150 cfm. They came with a 0.043 main jet and a #63 power valve (or high speed jet as they were sometimes called). The main jets are sized according to the diameter of the hole. Thus a 0.043 jet is bigger in diameter by 0.002 than a 0.041 jet. The power valve is sized like numbered drills. Thus a #63 power valve has the same diameter hole as a #63 drill bit. This means that a #63 power valve has LARGER holes than a #61 power since numbered drill bits get smaller as the number increases. Main jets are drilled to within 0.002 inches of the desired size. Then they are reamed to the final diameter. This is because drilling leaves an egg shaped hole to some degree and reaming leaves a round hole. I've found that a change in jets seldom exceeds 0.003 inch (unless you're running alky or nitro). Power valves seldom change more than 3 numbers. Float level is adjusted wet. Measure 15/32 inch to the GAS level from the top of the float. This is done with the engine running but swinging the air horn ***embly aside. This has caused lots of fire because of sloshing of fuel and the presence of sparks on the armature communtator quite close to the front of the carb. These carbs were designed to be run with a max of 2-1/2 psi of fuel pressure. The stock Ford fuel pump could often make 3-3/4 psi. The design of the float system isn't as well designed as the Chandler-Grove/Holley carbs and the excess pressure overwhelmed the needle ***embly. Thus flooding the carb and dumping raw gas onto the engine, and in the proximity of the sparking armature. This gave Strombergs a bad rep. All that is needed is to use a fuel pressure regulator and set if at 2-1/2 psi and it won't happen. I set the float level dry at 5/16 inch. This is measured 1/4 inch from the front of the float and from the top of the float to the top of the float chamber (no gasket). If it runs fine (and 90% do), I don't mess with them. If it stumbles on acceleration or acts lean, I will set the fuel level with the engine running. One advantage the 97 has over the Holley (I'll just call them Holley instead of Chandler-Grove/Holley from here on) is the ****erfly arrangement. Strombergs fit much better and don't stick coming off idle anywhere like most Holleys do. The biggest reason I like Strombergs is their power valve arrangement. It's all mechanical and is operated mechanically by the accelerator pump. Whereas the Holley is vacuum operated. The Holley is designed to open at 7 inches Hg (mercury). Most flathead engines in good shape running a single carb may make 18 inches Hg at idle. Change to dual carbs and the vacuum is about 12 inches Hg... probably less if you're running a cam. At 5000 feet elevation, 10 inches Hg is about all you can get with a single carb and most are in the neighborhood of 8 inches Hg! Just touch the throttle and the vacuum drops to near zero in a hurry in all of them. When the power valve opens it changes the fuel/air ratio from 14.5 : 1 to 12.5 : 1. This was designed to provide fuel enough to run a 250 cubic inch engine wide open. Just imagine what happens when you're running dual carbs. That's right.... it enriches the system enough to run a 500 inch engine!!!! Think about 3 of them.... 750 inches! No wonder the plugs show rich and the car won't rpm like it should. Changing main jets won't affect this either since it's all vacuum controlled. The only fix is to replace the vacuum power valve with one that operates with less inches of vacuum.... or plug the holes to make the power valve inoperable (an old trick we tried). Jerre Jobe of Vintage Carburetion in Calif. has them in stock if you're so inclined. Keep in mind that if your engine backfires just one time, it'll likely blow the neoprene in the power valve.... so you should order a couple of changes for each carb. One advantage the Holley has over the 97 is main jets. Holley is still making jets for their OHV carbs and they are the same as used in the older Holleys. However, no such luck with Strombergs. And you have to have a special jet wrench to change them. The power valves are not made anymore either. Flathead Jack and others still offer main jets. Power valves can be soldered shut since there is only a single orfice. I redrill with a pin drill using the drill size I want some distance away from the solder. Not the best solution, but sometimes we can't have everything the way we'd like. Something that may be of help to you. I always remove the throttle base to check the fit of the ****erflys. I hold them up to a light. If I can see light around them, I loosen the 4 tiny screws holding the ****erflys about a turn or so and hold the throttle tightly shut while I tap on the end of the shaft with a screwdriver handle and tap inside the throttle bores. This usually centers things and gets rid of the gap around the ****erflys. Tighten the screws on the ****erflys while you continue holding the throttle shut tight. Whenever you can see light around them, the multi-carbs won't idle down and will probably stick coming off idle. Single carbs aren't affected much if they show light around them. A big advantage Strombergs have over Holleys is the three straight slotted screws that hold the main body to the throttle body. They can all be reached with a screwdriver from the top. The Holley has the front straight slotted screw come up from the bottom. When I use Holleys, I replace the front screws with bolts. Reason being is I bolt the throttle bases tightly on the manifold and connect the linkage between them loosely. Then I install the rest of the carbs. After the carbs are synchronized, I tighten the linkages up. Now if I have to work on the carbs, I don't disturb the throttle bases. I remove only the main body and air horn as one piece. When I'm through rebuilding the carbs or whatever I'm doing, I reinstall them on the undisturbed throttle bases. Thus I don't have to re-synchronize them.
Two Carter 574s carbs work well on the Chevy stovebolts. They bolt to the 216 manifold and provide enough fuel for a mild 235 without over carbing. I don't know the specs for your motor but should be close enough. You'll get a lot of opinions here so if you think you'd like more info on these PM me and I'll spill the beans. Terry
It should be the top left intake #1717 above Measure the bolt holes on your stock carb. It's possible that the intake was designed to just add another stock carb. If so then you know what you are looking for. If your carb won't fit the dual intake, make a cardboard pattern of the bolt holes and the opening to help in your search. I doubt that you will find anyone with personal experience on multiple carbs on a 47 Kaiser. In most cases there is no need for altering the carbs. On dual carb systems each carb feeds 1/2 of the engines needs at any particular time. The jets were designed for the air flow through the carb and probably are just fine.
Its a split manifold each carb will run 3 cylinders If it has individual ports (like the Ford 226 shown), or only siamese on some cylinders, it can be effectively split 1-2-3 and 4-5-6 as long as the 3 & 4 cylinders do not share a port. However, if it has all 3 intake ports siamese (like the Dodge 230 shown) it can't - because the manifold split tries to separate the 3-4 cylinder pair - and has to use both carbs to feed the entire engine (rather than 1 carb feeding 3 cylinders). Why is this different? Because (despite the "CFM calculators", which was developed for V8 use) the number of cylinders connected to a carb greatly affects how much CFM they need. All 6 cylinders need about 1.1 × the CFM indicated, which if using 2 on a common manifold, each can be 55% of the calculated flow rate (total 110%). On the other hand, for each "set" of 3 cylinders to use 1 carb, it should be about 2.2 × the calculated CFM of the 3 cylinders, which is much larger than above. Examples: 226" @ 80% VE and 4,500 RPM by the conventional formula is 235.4 CFM. Correct this for 6 cylinders: 235.5 × 1.1 = 259 CFM. Divide by 2 to get size per carb: 130 CFM each. Now, split into 2 groups with no "sharing": 226 ÷ 2 = 113", × 80% @ 4,500 RPM = 117.7 CFM. Correct for 3 cylinders: 259 CFM each.
Also keep in mind when trying to use the 4bbl cfm calculator that 2bbl carbs are flowed completely different so you really cant use those formulas . Standard 4bbl carbs are flowed at 1.5" of hg. whereas the 2bbls are flowed at 3" of hg. . Something else to keep in mind when you start isolating runners that don't share a common plenum you can have an "ir" effect which will require you to run a larger then typical carburetor in regards to the cfm.
As others have posted, what size carburetor to run will depend on the design of the manifold. What brand, model, etc. can depend on a myriad of variables. This article may/may not help, but it may start you thinking: http://www.thecarburetorshop.com/Dual1barrelcarbs.htm As posted by Terry, two Carter model W-1 number 574s work very well on a Chevrolet 235, which is very close in displacement to your Kaiser. Tommy - could I get a photocopy of any of the pages in your Edmunds manifold catalog pertaining to Pontiac? I would be happy to pay for them. Jon
Click on my name and Email me so I can send it to you. You don't show an Email address or a PM address.
Tommy - you don't show an email either. Our email address is listed on the "Contacts" page of www.thecarburetorshop.com. Thanks. Jon.
Lots of good technical info above. If you decide on a twin two barrel set up, Barry Grant offers a "modern" version of the Stromberg 97 for about $400 each. From a galloping horse, it pretty much resembles a 97, but has all modern internals. If you want a more authentic look, and a little less expense, Speedway offers a repop Stromberg 97 for about $300. Supposedly, many of the problems of the orginal 97's has been corrected. For even less expense, Vintage Speed has a rebuilt Rochester 2G starting at about $200 each. It comes even with a very cool "hot rod" finish. Good luck!
Miller91 quote "The Chandler-Grove/Holley cfm's.... The model 94 is rated at 155 cfm. " Just to avoid any possible confusion on the 94's.... there were 4 companies that made 94's between 1936-1957, and they range from a rating of 135 CFM to 190 CFM . It's important to start off with two of the same for a dual carb set-up. Terry
Ya thats the one. My stock Carter W-1 carb fits just fine and i will probably run two of them after checking if the jetting is the same. I have one with a automatic choke and the other has no choke will this hurt the engine if i run them that way? Should i run chokes or no chokes with dual carbs? Ive had dual carbs on vws. Kadrons and Dellortos i know how to adjust carbs to run the same but they didnt have chokes. Another question does anyone know if a Kadron (solex) carb has the same bolt pattern as an american carb? It just looks the same and im curious.
Your Email comes back so here it is full size. Sorry for it being so large but this way anybody that wants to save it or print it can easily read the text. This was scanned from a 1955 Newhouse catalog. My experience with dual carbs for a hotrod is that a choke is not necessary. I did hook up the manual chokes on two 97s just for ****s and giggles but I never used them. That is ***uming that you are not rushing around in the morning trying not to be late for work. 2 pumps of the pedal with 2 accelerator pumps alway was enough to get her started easily. You may have to let her warm up some in bitter cold weather but it was never a problem for me.
If it hasn't been mentioned above;most street inline engine will have run smoother at lower speeds if the manifold is a log type ora divorced manifold having a large balance tube between the 2 or more sections
The Jalopy Journal
