The Stovebolt Site Forums The Shop Area Engine Shop Dual carbs not working correct! Please try to help!

Does anyone know the specs for the fuel pump used with one of these carburetors? Here is what I find for an Airtex 60239 (replacement fuel pump for Escorts that used one of these carbs):

Maximum Pressure Rate (psi) 7
Minimum Free Flow Rate (gph) 20 GPH @ 1800 RPM
Minimum Pressure Rate (psi) 5.5

Isn't that similar to the specs of an original/stock 235 fuel pump?

Wolfcub, I feel your pain.
I have a 55 second series 1/2 ton with a 235, 4-speed and Langdon's dual C/Ws on an Offenhauser intake with Fenton split manifolds. It took months for me to sort these carbs out before this Barrett Jackson (read: overpriced), jewel of a truck could even drive around the block. Have you noticed they push them on and off the podium?
These carbs are not [b]"NEW"[/b], they are [b]UNUSED"[/b]. There is a big difference!
They are an emissions carb, originally for a 1983 Ford Escort 1.6 liter, manual trans car.
They may have been sitting in warehouses for [b]30 YEARS[/b]1. The gaskets are dry and brittle, the rubber diaphrams are aged and the dissimilar metals, aluminum, brass and copper have corroded and suffered from electrolytic action due to oxygen and variances in humidity.
Poor quality control during manufacture means lots of casting flash and debris inside the carbs as well.
I would like to kill whoever staked the air corrector jets and emulsion tubes and it wasn't Tom. These are emissions carbs and it was done at the factory so end-users couldn't change jetting and kill the Polar Bears.
As a result, these carbs must be disassembled and cleaned meticulously, and the gaskets and diaphrams replaced. Tom may say he cleans them, but this is impossible due to the staking of the jets.
You will destroy the heads of the air corrector jets when you remove them because of the staking and the fact that they are 30 years brittle. Don't beat yourself up over it. I have a Weber jet screwdriver and it still happens. You will likely have to use small vise-grips to get them out. The idle jets will come out easier and survive.
The air corrector jets are .150 on the primary and .250 on the secondary, I have a source that I will try to find and post later.
The carbs are simple to disassemble and don't need to be soaked, just clean them with spray carb cleaner and the tube. All you have to remove is the top float cover and the float.
The universal part exchange number for these carb kits is: [b]15787CF[/b]. Any decent parts man can still find kits.
Since it is a Ford application (turn head, spit) I use Motorcraft kits. The Ford dealer number is: [b]E3PZ-9A586-W[/b].
The Motorcraft number is: [b]CT-1377-A[/b].
Bonus! They are currently on clearance at Rockauto for $11.00 each!
Float height and drop are very important. Specs are here: http://pages.suddenlink.net/churchill_toolboards/Langdons%20Carter%20Webers.pdf.
Fuel pressure is also important, 6 lbs is way too much. Regulate it to 3 - 3 1/2 max.
Another important issue I found due to the age of these carbs is that the O-ring that seals the idle mixture screws can be hard and not seal or grip the mixture screw tightly. This is critical because the screw don't have an external spring on them like most do to hold them in tension. If your O-rings are shot they can leak air, upsetting your mixture, or worse, vibration can make them turn out, richening your mixture. Until I rebuilt my carbs I couldn't figure out why my mixture settings were changing. I thought I was loosing my mind!
Also, with most carbs your baseline mixture setting is 1 and 1/2 turns out from seated. With these carbs it is 2 turns out according to WEBER.
Here is the link for the air corrector jets and other parts for these carbs. They are based on the WEBER DFT.

http://www.piercemanifolds.com/product_p/77501.250.htm

Pictured is the secondary air corrector, P/N 77501.250,
the primary is P/N 77501.150.
The Pierce Manifolds site has good info and good exploded diagrams of the DFT.
Good luck.

I'm sad for your frustration and problems you are having with this carb issue while at the same time I'm glad to see someone else having the SAME issue I had with these carbs which proved to myself I'm not crazy.

I rebuilt my 56 235 with duel fenton exhaust, duel fenton intake, hei carb and wires from Tom and the duel c/w webers from Tom. My 46 1/2t ran fine around the block a couple of times then started sputtering and popping upon down shifting and idles real rough.

I blocked carb A with a plate, no difference. Blocked carb B no difference. Put on one Rochester BC and it ran perfect.
I sent the carbs back to Tom and he cleaned them for free. I followed his instructions, new metal truck filter, ran the fuel in a glass bowl for debris before hooking up the carbs etc. Ran the truck around the block a couple of times and the SAME problem again. I took off both carbs, put on two Rochester BC I got free off stovebolt and the truck runs perfect. The webers are now on the shelf.

I really think it's the luck of the draw. Some CW are good out of the box from Tom and some are not. I've seen other posts on cw carbs with mixed revues. I hope you can solve the problem and post your solution for reference.

^^^^^thank you both for your informative replies!^^^^^^^^

As i wait for my new carbs from tom to arrive i still think im going down the wrong road. Something tells me I am going to have this same fuel issue.....but i could be wrong. Reading like crazy for the last week i have found so many who are happy with a 4small 4 barrel manifold that allows them to use a more current carb that has jets readily available allowing them to make adjustments easily.

The 2 old carbs i have from tom now are going to be my test units. When it comes to jetting will changing the top air jet to a larger hole and keeping the main bottom fuel jet lean out the mixture ? would it not allow more air into the mixture?

I installed a pressure regulator and will set it to 3psi for the 2 new units being installed.

I will order some of the rebuild kits right away so i have them on hand. thanks for the info.

Quote:

"As i wait for my new carbs from tom to arrive i still think im going down the wrong road. Something tells me I am going to have this same fuel issue.....but i could be wrong. Reading like crazy for the last week i have found so many who are happy with a 4small 4 barrel manifold that allows them to use a more current carb that has jets readily available allowing them to make adjustments easily."

End quote.

Wolffcub - if you wish to go with a 4 barrel, that is certainly your choice; however:

There are many older carburetors for which calibrations are available. These would include, but are not limited to the following:

Carter - W-1, WA-1, YF
Holley - 1904, 1920
Rochester - B
Stromberg - B
Zenith - 28, 228

Should you go with a 4 barrel, you basically have only 2 choices:

Carter - AFB part numbers either 9400 or 9410 (scarce and expensive)
Holley - 390 CFM (part number unknown)

One other suggestion:

We have found the dial type pressure regulators available from your local auto parts store that sell from 24.95 to 39.95 to be exceptionally useful if you have a strong right arm, and a rabbit problem in your garden.

If you are going to use a regulator, get one of the good Holley units that are in the ball park of $100. each.

Another option other than the regulator is a return line.

Jon.

Just got to thinking maybe I should mention some of the other older series carbs for which parts are either not readily available, or the carbs are difficult to use in multiples. I will use the letters "P" or "M" to designate which of the above in the list.

Autolite (P,M)
Carter BBR (P,M), BBS (P,M), W-0 (P)
Holley 1908 (P)
Rochester H (P), M (P,M)
Stromberg A (capital P), E (P)
Zenith 20 (P), 23 (P)

Please note that these units are pre-1974 which is my area of expertise. I can offer no insight on 1 barrel carbs made after 1974; other than to offer one reason why we used 1974 for a cut-off date in our business is the fact that virtually all carbs made after that date (and some earlier) were designed for smog emissions and many were deliberately designed to make "tampering" (the EPA's term for recalibration) difficult.

Jon.

Jon, thank you for those last 2 posts, very informative and will go into my reference folder...would be nice if we could do that for individual post vs. the whole thread. In any event, thanks again for taking the time to share with us.

I got the new carbs yesterday and installed them last night. Relocated all fuel line further away from the block to keep it cooler. My existing runs were just above the intake and exhaust ports. It is now about 5" above that at carb level and runs across the engine bay near the rear. Installed a 1-4psi fuel regulator as i have got lots of recommendations to do from here and other forums. Will try setting it at 2.5-3 psi for the first try.

Should have it running later today. I will post up what happens.

Think that the ignition system not working correct in terms of not enough voltage or not sparking right can cause this? Weak spark possibly?

I also did get a HEI system. I will try the new carbs first without the new HEI installed. I need to take a closer look at it anyways because the inner reluctor teeth are hitting the outside pick up ring. No quality control here boys!

Before you adjust your linkage back off the idle speed (Not mixture) screws so they are not making contact with the cam.
Then, slowly screw them in until they JUST make contact, then turn both of them exactly the same amount, about 3/4 turn. This will give you a base idle but more importantly you will know that both carb throttle plates are open equally so each carb is flowing the same amount of air. Then hook up your linkage.
When it's running, whenever you adjust one idle speed screw you must screw the other in or out the same amount, this will keep the carbs synchronized so you get equal flow to each cylinder.
and ensure that one carb is not doing more work.

Another thing I forgot to mention about Langdon's C/W kits is that the stainless socket head bolts he supplies to mount the carbs to the adapters are too small of a diameter. They don't "square up" the carbs on the spacer, they allow too much fore/aft and side to side movement, not ensuring that the carbs are exactly centered over the adapter bore and gasket. When I got my truck one of the carbs was offset towards the valve cover and the other was offset towards the driver's side. When I took the carbs off I could see in the imprint on the gasket that the oval hole in the gasket didn't correspond to the throttle bores.
Get yourself some stainless 5/16 by 1 and 1/4 long bolts, washers and nuts. They fit through the carb base holes snugly as well as the slotted holes in the adapter. There is still a little play in the adapter holes so just eyeball it closely and center both carbs equally.
I hope it turns out well for you.

Every time I see one of these multi-page posts from people trying to make a multi carb system work, I'm reminded how intelligent the original designers were when they chose ONE carburetor for stovebolt engines.
Jerry

Yesterday was a good day.

I installed the carbs as I noted t posts ago and got the truck back up and running. I forgot to mention that i also split the carbs for a clean out prior to installing them. I found a little debris in on of them and found that both of them had a metal build up around the idle mixture screw right at the tip. Looked like some sort of pigtail drilling debris around the tapered tip of the screw. The tips were fine and were not damaged. I also re-plumbed the lines and kept them further way from the block this time so they don't get so hot.

After getting it running and warmed up i rechecked the timing to see where i left off. Currently set at 12deg and vacuum is 17in. Everything seemed fine with the distributor and was advancing during revving. Checked all the new fuel line connections and set the regulator pressure to 3psi. Went back and forth setting the idle mixture and rpm and timing till everything was ok. Final readings were, 500 rpm, timing still 12 and vac 17.5 ish.

With my AMA card in hand and the tow truck number read on speed dial i got in a took her out for a boot. First thing i noticed doing neighborhood speeds is the engine was smoother than before. Got to the back paved country roads and tested out my new lead shoes. Its a completely different truck ! It pulls hard compared to before. Way more torque. When in third (final) and cruising at 1500rpm you mash it and she just gets up and goes. Still nothing to brag about but 100 times better than before.

The harsh smell of gas during acceleration is little to none compared to before, and when costing in gear it almost never spits and backfires now. At higher rpms the engine is smoother and does not want to jump out of the chassis and onto my lap. It still has a slightest feeling that it wants to go harder when you just let off the throttle when accelerating hard. I will play with the timing using the octane selector now for easy adjustments and see what else i can squeeze from it. Parking in the garage the only smell i got from it was from the header wrap burning from playing so hard and a bit from the top valve cover breather, the smell of gas to me was not present in my garage anymore.

I should probably install the HEI setup i got sooner than later before i go taking all the time to play with timing and then change out the system and have to do it again.

[IMG]http://i96.photobucket.com/albums/l170/mazdacub/1949%20Chev/IMG_1836.jpg[/IMG]

[IMG]http://i96.photobucket.com/albums/l170/mazdacub/1949%20Chev/IMG_1837.jpg[/IMG]

[IMG]http://i96.photobucket.com/albums/l170/mazdacub/1949%20Chev/IMG_1834.jpg[/IMG]

Pictures look good, very clean install.

Glad its finally working out, when you get some time, pull the first set apart so we can see whats in them.

Now go drive the wheels off it, the HEI can wait a while!

Joe

Nice. Multiple carbs always look good. Most people can't even tune one carb, much less two or more. Even some "experts" don't know everything. I've worked with Holley, Carter, and Quadrajets, plus Mikuni and others. Lots of information on these on the web now, so a person can learn a lot with a little homework. They aren't as scary as they look.

Good luck with the rest of your project.

Congratulations!
When these carbs are clean and set up right they work really well on the inline Chevy. Glad you got it sorted out.
What kind of HEI setup did you get? Large cap or small?
I recently installed a performance large cap setup on my 235 and it made an amazing improvement over my Mallory dual point.

Your truck looks great!
You have done an incredible job with it. So much attention to detail, routing of cables and hoses, rear discs, rear sway bar with poly bushings. Very impressive!

How about some details regarding your power steering conversion?
The pump and alternator mounts and brackets are different from what I've seen before. Yours are MUCH cleaner and look almost factory. Why don't you start a new thread about it with pictures and details so it doesn't get lost in this carb discussion. I'm sure many here would appreciate it, I certainly would.
You've done great work.
I'm in Calgary, maybe we'll meet up at a show in Red Deer some time.

The HEI is the small unit. I made a bracket to hold the coil yesterday that will bolt in the original coli location.

[IMG]http://i96.photobucket.com/albums/l170/mazdacub/1949%20Chev/HEICoilBracket.jpg[/IMG]

Later today im installing the PCV valve and line. I designed and made the power steering and alternator bracket system. I still need to modify the top bracket design so its not so long and it will curve to follow the alternator pivot center. I saw a kit a guy made before to hold a pump and alt but it required a modified head bolt and still with the braced back it looks like it wobbles when running. I was actually thinking of cutting up a bunch of kits if others want it. It all bolts to existing hole locations and lets you independently adjust the tension for the alt or pump without loosening the full system.

Im thinking 2 of these would look nice on it.

http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&docid=QZoj7QkOzuSknM&tbnid=2WlTiVrZe4SqvM:&ved=0CAcQjRw&url=http%3A%2F%2Fclassicbroncos.com%2Fforums%2Fshowthread.php%3Ft%3D163458&ei=hxIbVLXmDYmryAT6ooLICg&bvm=bv.75097201,d.cWc&psig=AFQjCNG8wSAyLHuIAUExt9iX1TK3Iu5Xag&ust=1411146652570691

Glad to hear your having success...now get out there and drive it like you stole it! We'll have to do another cruise before the snow arrives for good.

Sooner then later....i have a feeling the snow is almost here. Im printing some carb adapters so I can use that carb sync tool you have. Its handy having a 3d printer at times!When we meet up we can test them out.

That's a handy toy for sure. I was at IMTS(International Manufacturing Technology Show)in Chicago last week and they were 3D printing an entire car. Don't have printer myself but do have this.

Here's mine after four years. Second shot. These are on a year round daily driver only vehicle in Virginia. We have milder winters here and 90+ degree temps in the summer. These run well when dialed in. Nothing exceptional about how they were set up, just be careful with Teflon tape or paste, that can give you fits.

so by dialed in what exactly you referring to as the only adjustment is idle speed and idle mix. Or did you actually change jets? Been driving like crazy today and it still feels like its a tad bit rich mid throttle. Wish there is a way to delay the secondaries to test out a few things.

This should do the trick for the carb sync tool. Will print one up tonight and test the fit.

[IMG]http://i96.photobucket.com/albums/l170/mazdacub/1949%20Chev/CarbTop.jpg[/IMG]

Wolffcub, where do you intend to run the hose coming from the PCV valve?

Wolffcub, here are some web sites that might shed some light on your carbs:

http://www.carburetion.com/Weber/adjust.htm
http://www.scuderiatopolino.com/UserFiles/TuningofWebercarburetorsrev2.pdf
http://www.webercarbsdirect.com/v/vspfiles/images/Weber%20Trouble%20Shooting%20Guide.pdf

Thanks for the info. Having a blast driving the truck now. Run out of gears way too quick now, hit third way too soon. Need something with OD of slightly change the rear end ratio. 3000Rpm to do 60mph. I plan to hok the PCV to the intake manifold vacuum port. Currently the post supplies the vacuum for my brake booster but i was going to try and T it and try the brakes and PCV like that. I have a feel I might run into power brake issues after due to the vac levels going too far down. The carb has 2 other small vac ports on it that are not used, EGR vacuum signal port and venturi vacuum signal. Wonder if i can use one of those and not have to touch my power brake setup. Was also thinking about possibly installing it to the under side of the air cleaner plate but it would unfortunately be inside of the element thus possibly getting the carb all dirty.

actually scratch that last port (venturi vacuum signal) that's not the same as whats shown in this manual

https://docs.google.com/file/d/0B85S9Twi0dSUY2NuYWRGa2pOVjg/edit?pli=1

If you look back at one of my pics i have a port right at the bas of the carb. I will take a look at one of my busted units and see where it goes. I think it might be a direct vacuum port right below the butterflies.

Connecting into the brake booster line will not be a problem. Vacuum is vacuum, and it all comes from the manifold regardless of where you connect. The PCV should not be connected to a ported vacuum source. The valve itself will control the flow. Also make sure you have a fresh air source to purge the crankcase, whether it be a line from the rocker cover or crankcase to the air cleaner, or a filtered oil fill cap. You need a "loop" for the PCV air to flow through and purge the crankcase. The PCV system only flows a few CFM of air at most (4-6 CFM max. as I recall).

I currently have a breather oil cap on the valve cover. I will then consider changing it to one with a nipple and connect it to the bottom plate of my air cleaner setup. If i do it that way the fresh air into the valve cover can be filtered.

"If i do it that way the fresh air into the valve cover can be filtered"

wrong, any line from the valve cover to the air cleaner will be drawing air out of the valve cover

Bill

Thought they all worked that way.

http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&docid=PY5ojDU34y2CGM&tbnid=pjC4mvW9q0tBXM:&ved=0CAcQjRw&url=http%3A%2F%2Fwww.strutpatent.com%2Fpatent%2F07431023%2Fengine-pcv-system-with-venturi-nozzle-for-flow-regulation&ei=20wcVOvwNcaWyAS5_oKQDw&bvm=bv.75774317,d.aWw&psig=AFQjCNG3Yt0SPfqDrXpgrHR5pBnfteay0A&ust=1411227225158489

what if i connect it to this? Will it work better?

[IMG]http://i96.photobucket.com/albums/l170/mazdacub/1949%20Chev/0900c15280051bbd.jpg[/IMG]

Wrong Bill, most of the OEM's use a fresh air line to the air cleaner. The PCV is drawing air from the crankcase under manifold vacuum and the crankcase fresh air is drawn from the air cleaner. The "vacuum" your thinking of in the air cleaner is very, very minimal in inches of water.

sorry Wood, a line as wolf suggests from the oil fill hole to the air cleaner will be drawing air from the valve cover, NOT putting fresh air into it, regardless of how a correct PCV system functions

Bill

Bill, you are definitely wrong...you don't know what you are talking about on this one. Why would it be working in millions of vehicles if it were supposed to be your way? The vacuum draw on the PCV valve is hundreds of times stronger than the negative pressure created in an air cleaner!

Rather old technology, isn't it TC?

I am not suggesting using that technology. That diagram simply and clearly shows the routing/flow of the gases in a stock GM system used in many trucks over many years.

Please post other photos of factory diagrams of other types of PCV routing for an assembly described in a post above. That would be more helpful than saying "you don't know what you are talking about on this one. Why would it be working in millions of vehicles if it were supposed to be your way?".

Thanks,

Hi TC,

I just meant that it has been around awhile (longer than I thought). It is still in use today.

Woodswarrior: There are many times that "WE" (Red 58,for one), don't agree. There are more times than I can count,that he's,(Red 58)'s helped me out of a pickle! We're all "Bolters" here,correct? It's nice to have people that TRY to help,even if you don't agree with what they're saying. PLEASE try and be POLITE!! B.T.W... Thanks for the info.,on the PVC set-up.I'll route it that way. Sugar gets you way more flies than vinegar. THANKS!!