Stromberg WWC Carburetor question

Barry S

Member
FCBO Gold Member
Joined
Jul 30, 2018
Messages
174
Reaction score
408
Location
West Seneca, NY
Hello folks, I have a question that I hope this group can help with. My 67 Newport 383 has a Stromberg WWC 2 barrel carburetor. I rebuilt it last year and the car runs great. My issue is that after a day or so I have to pour some gas into the carburetor to get it to start. Once I do that it starts right up. I presume the gas in the bowl is draining down, and since there is no gas smell, I presume it’s draining down into the engine.

Is this a common issue? Should I put another kit in it?
 

Davea Lux

Old Man with a Hat
FCBO Gold Member
Joined
Mar 27, 2017
Messages
9,016
Reaction score
8,237
Location
Cornelius Or
In hot weather, these carbs would boil the gas out after the car was shut off. Check to be sure your heat riser is not stuck shut and overheating the carb. Otherwise, pump the throttle full open to close the choke on a cold engine and the car should start without having to prime it after 30 seconds or so of cranking.

Dave
 

CBODY67

Old Man with a Hat
Joined
Mar 27, 2011
Messages
7,778
Reaction score
4,879
Draining back? In order for that to happen, one of the soldered ball check seals in the main body would have to be leaking (as ethanol WILL erode that solder, with time). IF it was draining into the enigne, you would notice a strong raw fuel smell when you pulled the oil level dipstick out and smelled the oil on the end of it. NOT GOOD as fuel dilutes the motor oil, with other issues if left in that situation very long.

Back when the cars were "used cars" and "gasoline" had lead in it, Chryslers were known to have issues with fuel percolation in the float bowl, which caused hot re-start issues, but not quite as bad as you describe. Now, what we have would have been "super super winter gasoline" which is easier to vaporize than the old stuff was.

After you pakr it and it sits for a day or so, BEFORE you start it, remove the air cleaner and actuate the throttle lever. Look for the accelerator pump shot in the carb venturi area. Is it strong right up front, or does it take a bit of movement for it to start squirting? IF it does one long squirt, will it do another one? As you probably noticed in the carb rebuild, the accel pump feeds from the bottom of the float bowl. So two strong squirts means there is fuel in the float bowl, so the car should start after sitting (as the main jets also feed from the bottom of the float bowl).

For the record, the Chrysler-recommended starting procedure is (cold or hot) to depress the accel pedal about 1/3 of its travel as the starter is actuated. This lets the automatic choke do its thing while also having enough throttle for the engine to start as quick as it can. Which also means that the total ignition system should be in good condition, too. Trying to make one start as quickly as a modern EFI vehicle is not very possible, from my experiences.

On that or any Stromberg WWC 2bbl, do NOT crank down on the air cleaner wingnut, period!!!! Just snug it down and no more. Excessive torque on that wingnut will apply an upward force on the carb stud, which WILL warp the carb air horn such that the seal between the rear of the float bowl and the carb venturi area does not happen. Also, that same area is where the vac to keep the power valve closed travels between the carb main body and the air horn. So THAT vacuum also goes away and the carb runs on full "power" mixture all of the time, which means about 10mpg all of the time (from experiences in the early 1970s).

Sometimes, older vehicles had "character", such that no matter if everything was set to factory specs, they wanted something a bit different for best results. "A mind of their own"? SO . . . with everything set at factory specs, learn what makes the car work best and then exploit ot for your best results. In other words, don't try to make it do something it does not want to do.

Over the years, I've heard car enthusiasts cuss their (or a former) car up one side and down the other because the car would not do what THEY wanted it to do. Perhaps what THEY wanted it to do was not what the designers intended? So . . . learn what the car likes and what makes it feel good, as if IT is having fun, too. Things can be much more fun that way! BTW, Ford and GM products are this way, too, even the new ones.

Just some thoughts and experiences,
CBODY67
 

Sixpactogo

Active Member
Joined
Aug 22, 2015
Messages
279
Reaction score
243
Location
Wisconsin
Hello folks, I have a question that I hope this group can help with. My 67 Newport 383 has a Stromberg WWC 2 barrel carburetor. I rebuilt it last year and the car runs great. My issue is that after a day or so I have to pour some gas into the carburetor to get it to start. Once I do that it starts right up. I presume the gas in the bowl is draining down, and since there is no gas smell, I presume it’s draining down into the engine.

Is this a common issue? Should I put another kit in it?
I suspect your issue may be with the fuel pump bleeding back to the tank.
 

Gerald Morris

Senior Member
Joined
Mar 9, 2016
Messages
2,200
Reaction score
1,094
Location
Tucson
...

For the record, the Chrysler-recommended starting procedure is (cold or hot) to depress the accel pedal about 1/3 of its travel as the starter is actuated. This lets the automatic choke do its thing while also having enough throttle for the engine to start as quick as it can. Which also means that the total ignition system should be in good condition, too. Trying to make one start as quickly as a modern EFI vehicle is not very possible, from my experiences.
Interestingly enough, by 1983 they advise drivers of 1 barrel Holley 1945 /6 Lean Burn engines to just floor the accelerator ONCE before starting to set the electric choke.
On that or any Stromberg WWC 2bbl, do NOT crank down on the air cleaner wingnut, period!!!! Just snug it down and no more. Excessive torque on that wingnut will apply an upward force on the carb stud, which WILL warp the carb air horn such that the seal between the rear of the float bowl and the carb venturi area does not happen. Also, that same area is where the vac to keep the power valve closed travels between the carb main body and the air horn. So THAT vacuum also goes away and the carb runs on full "power" mixture all of the time, which means about 10mpg all of the time (from experiences in the early 1970s).
YEP! I'm sure all 3 of my Stromberg WWCs have warped air horns. I have a couple Carter BBDs also. Would these be any less prone to this malady?
Sometimes, older vehicles had "character", such that no matter if everything was set to factory specs, they wanted something a bit different for best results. "A mind of their own"? SO . . . with everything set at factory specs, learn what makes the car work best and then exploit ot for your best results. In other words, don't try to make it do something it does not want to do.
Sho' 'nuff! After 50+ years of people diddling them up, PLENTY of irreversible mechanical scars, bends, scuffs, scratches et al have occurred, so the physical properties of the system change accordingly. I've started negotiating work with Toostoned's most reputable Mopar oriented machine shop. Let's see what this old fellow can do with some of my horde!
Over the years, I've heard car enthusiasts cuss their (or a former) car up one side and down the other because the car would not do what THEY wanted it to do. Perhaps what THEY wanted it to do was not what the designers intended? So . . . learn what the car likes and what makes it feel good, as if IT is having fun, too. Things can be much more fun that way! BTW, Ford and GM products are this way, too, even the new ones.

Just some thoughts and experiences,
CBODY67
Good advice. If one wants modern performance, get a modern car.
 

CBODY67

Old Man with a Hat
Joined
Mar 27, 2011
Messages
7,778
Reaction score
4,879
I suspect your issue may be with the fuel pump bleeding back to the tank.
Ok, so the fuel inlet in the carb is on the top of the float bowl, where the needle and seat reguilate the flow. Certainly, for a while, the fuel filter will be pressurized, but probably not for very long (never have measured it, but probably maybe about 15 minutes, with no pressure by the 30 minute mark?), so that fuel pressure will probably migrate back to the tank, but not siphon fuel from teh float bowl, I suspect. Still, unless it has evaporated, there should be some residual fuel in the fuel lines and filter to the carb.

As the fuel pump usually is at the lowest point in the fuel line system, fuel in the tank should keep the fuel lines filled and ready for action.

So, perhaps some diagnostics need to be done.
1) After letting the car sit as normal (a day or more), not started or driven, unhook the fuel pump feed rubber line and see if fuel runs out. Of the rubber line itself and/or the fuel pump. Recover the fuel from the fuel pump to see how much volume is there.
2) Then unhook the fuel pump output line to the fuel filter and carb. See how much fuel runs out of that line as to volume.
3) Operate the carb accel pump to investigate how much fuel is squirted from the accel pump squirter on the first pump. Then the second pump. IF any air comes out, too.
4) Now that the presence, or lack thereof, and amount of fuel at each of those locations, put everything back together securely, put the carb on the top step of the fast idle cam (would need to remove the air cleaner and manually close the choke plate fully with the throttle opened a bit in our warmer weather).
5) Check the engine oil level on the dipstick and smell the oil to see if it might smell of fuel
6) With the trans in "P", start the car, paying attention to crank time in seconds. This will indicate how long it might take for it to start with dry pump-to-carb fuel lines. Record this time. Once the engine starts, jab the accel pedal to allow for normal fast idle speed. Then you can drive the car as you normally do. Once driven for about 20 miles, park it as normal.
7) Next time you drive the car (a day or so later), using 30-40% accel pedal position, record how many seconds it takes to start and run. Hopefully, this time will be less that the test with the dry carb fuel lines.

Two side issues, make sure you have the correct type of gas cap on the car. How old are the fuel line rubber sections at the tank, at the rear of the stub frame, the section going to the fuel pump, and on both sides of the fuel filter. Ethanol'd fuel dries out the rubber from the inside of the hose outward, until the outer rubber layer will drop off revealing the fabric reinforcement layer of the fuel line.

The 7 steps might seem a bit hokey, but until you troubleshoot and see what's there, you might not fully realize what might need to be done and to what. OR speculation can run wild with all sorts of "fixes" offered up.

Hope this might help with diagnosis,
CBODY67
 

Barry S

Member
FCBO Gold Member
Joined
Jul 30, 2018
Messages
174
Reaction score
408
Location
West Seneca, NY
To all who replied, THANK YOU for your expert advice! This is the most awesome forum of experts!

We're making a last minute trip to Raleigh so I won't be able to try the suggestions here for a couple of weeks. When I do I'll report back with updates on what I found.

Again, THANK YOU!
 
Top