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Carburetor Issues and Another Question https://slantsix.org/forum/viewtopic.php?t=18749 |
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Author: | Desertrogue164 [ Sun Jul 23, 2006 2:38 pm ] |
Post subject: | Carburetor Issues and Another Question |
This is a long story so bear with me. 7 years ago I bought a 1972 Swinger with a 225 1bbl / auto. It had 73,000 showing on the clock at the time Iacquired it. It has been a good car, and another 70,000 miles later it still gets the job done. It hasnt been all perfect though. It has always had a tendency to stall occasionally , especially after being started hot ( such as stopping at the gas station or for coffee or doughnuts) It tends to do this right as Im trying to accelerate from a stop. As far as I could tell the car was all original when I got it. I bought it from its original owner. Attempted to adjust the idle mixture and the float level. Made sure there were no vacuum leaks. Played with the Ignition timing. Even bought a new carb. Still had the same problems. The car has been basically reliable though , so ive lived with it. But then I got greedy and decided to put a Carter BBD 2 bbl on it, along with Mopar aluminum 2 bbl intake. Both the carb and intake were free, so how could I resist? Then the real trouble started. After installing the new setup, it wanted to stall EVERY time I tried to accelerate from a stop. Couldnt get the divorced choke to work properly so I changed it to a manual choke. At least that made it possible to start the car cold on the first try, and keep it running untill it warmed up. It still likes to stall after I get it warmed up unless I keep one foot on the gas and one on the brake. I could turn the idle up more, but I dont want to beat on the transmission every time I put it in drive or reverse! Setting the float level high solved some of this. The worst problem is, when the car gets hot on a hot day, it will tend to stall out at idle and then flood out immediately. It is impossible to re-start, and raw fuel pours out of the carb all over the manifold! Sometimes I can open the hood and hear the fuel boiling inside the float bowl. I once had this very same problem with that very same carburetor (Carter BBD 2 bbl) on a very different application. The car was a 1958 Chrysler Windsor with a 354 polysphere V8. Same deal. Raw fuel pouring all over the manifold, and impossible to restart once stalled (however, with that car, it could be a cold day and still do it.) I replaced the carb on the Windsor and it did no good. Ive been through 3 such carbs on my Swinger. No good. One thing that I have noticed with all the Carter BBDs I have fooled with is that the accelerator pump is pitifully weak. Barely a trickle from a full pump of the throttle, as opposed to a Holley, strong steady stream with even the slightest throttle movement. (the 1bbl that came on the Swinger was a Holley) I have surmised that the Carter BBD is a piece of junk and that its designer should be , well lets say, dealt with harshly. Two different cars, two different engines, 5 different carbs, countless adjustments, same problem. Was wondering if the Holley II 2bbl would be better, I have a part number and the NAPA guy says he can get me one. Thoughts? As for my other question, Ive heard that 1972 was the last year for a forged steel crank on the 225. I have verified the engine in my car is original. The car was probuced in April of 72 at about the middle of the run. Any chance they put 73 engines in 72s? I hope not. |
Author: | DusterIdiot [ Sun Jul 23, 2006 3:01 pm ] |
Post subject: | No problem... |
The last year for a forged steel crank in the 225 was 1976 (but that year is a "split" year...some 1976 engines are Cast cranks...so far the 2 Feather Duster Engines I have from the 1976 model year are Forged cranks). You may want to rebuild one of those BBDs, look over the article on Super Sixing for known problems of the BBD. The Holley II is just a remanf. by Holley and may not solve the problem...you can get a Holley 2280 for it, but you will still have to "play with it to make things Jake"... There are other carbs you can put onthere depending on time and trouble and $$$. -D.idiot |
Author: | CStryker [ Sun Jul 23, 2006 3:22 pm ] |
Post subject: | |
First thought, how is your fuel line running? If it's running around the front of the engine like stock, you might wanna check out the fuel line mod. A search should bring it up. The drivability issues sound somewhat indicative of a vaccuum leak which seems (at least w/ my luck) to plauge these manifolds. I always have trouble getting it to seal where it bolts up to the block. Another area to check is where the EGR valve (or block-off plate, depending on your inclination) bolts up. You also say it is aluminum which introduces some other potential problems. Many of the e-beam welded ones leaked from the factory because of porosity in the castings. Furthermore they have a horrible tendency to crack in the floor of the manifold right underneath the carb, causing exhuast gasses to get sucked in. As far as the Holley II carbs, if you're going to buy a re-man carb, I've heard they might be your most likely way of getting a decent one, but I have no direct experience. As DI suggested, however, they're not that bad to rebuild if you're mechanically inclined at all. |
Author: | Jeb [ Sun Jul 23, 2006 6:12 pm ] |
Post subject: | |
The Carter BBD is a good carburetor. Way better than a Holley 2280. I agree with the ofther guys in that you may have some issues with the fuel line routing. What kind of carb to intake gasket are you using. The thick one is the correct one. I have a BBD on my Duster and I love it. Way better than the crappy Holley 1945 it came with. |
Author: | Reed [ Sun Jul 23, 2006 6:29 pm ] |
Post subject: | |
Here is my diagnosis. I like the BBD. When the throttle shaft bushings aren't worn it is a great little carb that is simple and reliable, when set up properly. The symptoms you describe sound like a combination of two things: (1) the fuel line overheating, and (2) a vacuum leak (wait, keep reading) First, to the fuel line re-route trick- change to a rubber fuel line and run it up over the valve cover instead of around the front of the engine. Second check the choke pulloff diaphragm to see if it still holds a vacuum. This sounds like a large part of your flooding and stalling problems. Third, make sure that the BD you have is either a slant six specific BBD or that the linkage piece for the choke butterfly is correct for a slant six. The V-8 BBD can be made to work on a slant sx, but the location of the eyelet where the manifold heated choke spring rod attaches is different between the two. Using a V-8 piece on a slant six without other modifications will result in a improperly functioning choke mechanism. Fourth, make sure the vacuum advance pod on your distributor will hold a vacuum. Fifth, bypass the OSAC valve (if so equipped). Sixth, go through your current BBD and make sure everything is set properly. Float level, choke pulloff, accelerator pump stroke, and especially the metering rod setting. Reman carbs are notorious for not being set anywhere near correct from the factory. If you want, I will happily adjust your BBD for you if you pay for shipping. To me it sounds like you have several differnt problems working toether to bring your slant sown. What is your idle vacuum reading? |
Author: | SlantSixDan [ Sun Jul 23, 2006 8:03 pm ] |
Post subject: | |
Yep, everyone responding here is on the right track. The BBD is an excellent carb design. Most variants of the Holley 2bbls (2280 or 2300) don't approach BBD driveability and response/reliability without extensive and very specialised modifications (there are exceptions). If the accelerator pump shot on your carb is weak, it's because the pump is worn out, improperly assembled/missing parts, or incorrectly adjusted. If you are buying 'remanufactured' carburetors, you are only buying an endless carburetion headache for yourself. Holley II is a brand of 'remanufactured' carburetor. Using a V8 BBD is possible on a slant, but not without choke lever modification. Your symptoms, which persist despite a complete induction swap, suggest a fairly serious vacuum leak, so you will need to do some careful assessment and diagnosis of all vacuum-operated accessories (power brakes...?) and all manifold sealing junctions (including the EGR valve area, the intake-to-head junction and the intake-to-carb junction). Some links to get you pointed in the right directions: Fuel line mod Electric choke kits Another (clever) electric choke installation on a V8 BBD used on a slant-6 BTW, this Mopar 2bbl intake you installed...was it the Mopar Performance sandcast aluminum intake, or was it a factory aluminum intake? |
Author: | Desertrogue164 [ Wed Jul 26, 2006 6:47 pm ] |
Post subject: | |
The fuel line re routing sounds like the next logical step. Ive used a see through fuel filter for years (with the old induction as well) and have always noticed how the fuel percolated inside of it. A vacuum leak could be a possibilty though I doubt it, I did have some trouble with this at first and had to re install the manifolds to get it right. I used copper spray a gasket to coat the manifold gasket and it seemed to work well. I tested for leaks by setting the idle mixture lean and using starter fluid (to see if the engine would speed up or smooth out when I sprayed it at all the joints.) The engine will idle well at 500 rpm. As I stated previously, the hesitation, stalling problem was about 95% solved by raising the float level and advancing the timing. ( Reading a Haynes manual had given me the faulty information that the timing was supposed to be set at TDC, but now I know better.) Im sure that if I could just get that accalerator pump working right, I would be roasting the tires. My main problem now , has the symptoms of vapor lock, mainly because it only occurs when the engine is hot on a hot day. The manifold is the aftermarket Mopar Performance M1 unit, not the factory installed manifold. From what Ive found on this site regarding manifolds, I guess Id say I was really lucky to have found one of these manifolds for free. The friend I got it from bought the car it was installed in just to snatch out the /6 and stick a 440 in it. He builds a lot of Mopars, but is only interested in big blocks. |
Author: | SlantSixDan [ Wed Jul 26, 2006 8:17 pm ] |
Post subject: | |
EGR...? |
Author: | dakight [ Thu Jul 27, 2006 5:36 am ] |
Post subject: | |
Quote: Another (clever) electric choke installation on a V8 BBD used on a slant-6
Dan, that link brought up the HEI conversion thread. A quick scan through it revealed nothing about a choke.
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Author: | SlantSixDan [ Thu Jul 27, 2006 6:47 am ] |
Post subject: | |
Whoops, yeah, sorry 'bout that. I've fixed the link (click "reload" then click the link again) |
Author: | dakight [ Thu Jul 27, 2006 7:36 pm ] |
Post subject: | |
Ah... I remember seeing that setup before. I may look into doing that myself when i get to that point. |
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