WDO Carb questions

[Daves1940Buick56S]

I picked up another WDO 440S carb on E-Bay. It has all of the parts so I am going to use the choke linkages to get rid of my current Frankencarb and restore my original 440S to regular operation. But I also have decided that although the carb is pretty cruddy, it looks totally salvageable so I will probably get a kit from the Carb Shop and make it into a hot backup. But I really need to remove the choke and throttle plates to get it thoroughly cleaned out. So:

1. What is the screw size? I know I have to grind down the staked end of the old ones. I read somewhere that the choke screw is 3-48 and the throttle 4-40? Anyone know? Hopefully the Jon at the Carb Shop will have these.

2. The copper rivets (idle port plugs) above the idle screws. Anyone know of any good tricks for getting these out?

Cheers, Dave

[carbking]

Dave - both the choke valve screws and the throttle plate screws on the 440s are 3x48. The throttle plate screws change to 4x40 on later WD-0 carbs. And yes, I have these available.

Check the link and scroll down to T109-43 to see the "good trick" for removing the idle port rivet plugs.

http://www.thecarburetorshop.com/Carter_tools.htm

These can be made from a bar of steel if you have lots of time.

With no offense meant, draw a picture of how the throttle closes so you get the shaft and plates back in correctly. It is possible to install them incorrectly, but then the carb doesn't function correctly.

Jon.

[Daves1940Buick56S]

Thanks Jon! I will be getting in touch next week.

Cheers, Dave

[Dynaflash8]

Thanks Jon! I will be getting in touch next week.

Cheers, Dave

What I find interesting is that my books show the 419S started out 1939, then was replaced sometime during the year by the 440S, and before the year was over that was replaced by the 474S, which the books shows to be shared with 1940.

I have had two 474S carbs rebuilt by another carb shop and neither of them worked well, while a third one they did worked well on a different car among my collection. One of the 474S cars was rebuilt twice by that company and still doesn't work well. The current 440S in that car works well when the engine is hot, but not when the engine is cold. It is the third carb I've tried on that car and the other two didn't work well cold or hot. It makes me and my mechanic shake our heads. Maybe I can send one to the carb king. I haven't tried him before.

[carbking]

Dynaflash - carbking's focus has always been on the manufacture of kits first, and restoration of carburetors second. Current kit demand is at a 40-year high! That either says something about our kits or something about the number of cars being restored. But because of the kit demand, we are no longer restoring carburetors.

The WD-0 was advanced for its time, but not advanced compared to the later WCD carbs. Two major issues exist, both of which should be taken care of by a competant carburetor rebuilder:

(1) Casting warpage - the bowl casting warps where it fits against the throttle body, and the air horn warps where it fits against the choke cover. The bowl warpage causes a poor seal with the idle circuit resulting in a poor idle. The air horn warpage causes a poor seal with the choke, resulting in the choke staying on too long and an over-rich mixture for too long a period of time. Warpage is corrected by the use of heat (an oven) and pressure (special fixtures to hold the castings). Thicker gaskets are NOT the answer, and in fact, will make the warpage worse!

(2) Metering rod adjustment (one of the MAJOR changes in the later WCD carbs) - correct adjustment of the metering rods REQUIRES a special tool! Often, special carburetor tools may be made or other items substituted as substituting a drill bit for a float lever gauge; but not the metering rod gauge. It is calibrated to 1 thousanth of an inch!. Failure to adjust the metering rods with the special tool is just asking for poor performance. And there is no reason not to use the tools, as they are available, and not expensive.

Incorrect reassembly of the starting switch can also cause idle issues, but this is a very straight-forward assembly (there is a picture in the shop manual)!

Correctly rebuilt, the WD-0 WILL function well; just not as well as the later WCD. The key to getting the WD-0 to function is NOT to shop for the cheapest rebuilder; rather to ask how the rebuilder handles the casting warpage and adjustment of the metering rods. If the rebuilder does not tell you the metering rod adjustment is a "need three hands and a special tool" adjustment, look for someone else!

Jon.

[Dynaflash8]

Dynaflash - carbking's focus has always been on the manufacture of kits first, and restoration of carburetors second. Current kit demand is at a 40-year high! That either says something about our kits or something about the number of cars being restored. But because of the kit demand, we are no longer restoring carburetors.

The WD-0 was advanced for its time, but not advanced compared to the later WCD carbs. Two major issues exist, both of which should be taken care of by a competant carburetor rebuilder:

(1) Casting warpage - the bowl casting warps where it fits against the throttle body, and the air horn warps where it fits against the choke cover. The bowl warpage causes a poor seal with the idle circuit resulting in a poor idle. The air horn warpage causes a poor seal with the choke, resulting in the choke staying on too long and an over-rich mixture for too long a period of time. Warpage is corrected by the use of heat (an oven) and pressure (special fixtures to hold the castings). Thicker gaskets are NOT the answer, and in fact, will make the warpage worse!

(2) Metering rod adjustment (one of the MAJOR changes in the later WCD carbs) - correct adjustment of the metering rods REQUIRES a special tool! Often, special carburetor tools may be made or other items substituted as substituting a drill bit for a float lever gauge; but not the metering rod gauge. It is calibrated to 1 thousanth of an inch!. Failure to adjust the metering rods with the special tool is just asking for poor performance. And there is no reason not to use the tools, as they are available, and not expensive.

Incorrect reassembly of the starting switch can also cause idle issues, but this is a very straight-forward assembly (there is a picture in the shop manual)!

Correctly rebuilt, the WD-0 WILL function well; just not as well as the later WCD. The key to getting the WD-0 to function is NOT to shop for the cheapest rebuilder; rather to ask how the rebuilder handles the casting warpage and adjustment of the metering rods. If the rebuilder does not tell you the metering rod adjustment is a "need three hands and a special tool" adjustment, look for someone else!

Jon.

Thank you Jon, EXCEPT the 474S that refuses to work right was rebuilt by a place who is supposed to be one of the best, and it cost $350 (I thought that was expensive enough). The first time they put it together backwards, so they sent me another one, or I sent them another one and it worked well. This one they did over for free. It was wrapped in the cellaphane it came back in for a couple of years until the car was about finished and then installed. The car wouldn't run with it; kicked popped choked hot or cold. Tried all the right stuff and finally gave up and put another carb on it and it ran.