I have a 1950 cadillac series 62, it has a later style (52-56) 4bbl intake. I needed to replace my carter WCFB because the mounting area had rotted out. I couldnt find a WCFB to replace it with but I got my hands on a stromberg aeroquad and it mounted up the same as the carter and with a little modification to the linkage seemed to work fine. My question is, the Carter had the vacuum advance hooked up to the front of the carb, and the stromberg doesnt have a hookup for that at all. The car idles fine (she needs some other things addressed before shes road ready, but i took it around the block and it ran as good as it did before). I've read the article on Vacuum advance 101, and one on eliminating the vacuum advance, but none of them seemed to have a clear cut solution for going from a carb set up for vacuum advance to a carb that isnt. "Sounds like you're not going to run vacuum advance so I'd set your initial timing at 12 degrees, limit the distributor's advance to 12 degrees (which is 24 at the crank) and you'll have 36 total. Any combination that gets you 34-38 degrees total is fine." That is a quote from an article called "hotrods eliminating vacuum advance" the caddy has a stock 331 to my knowledge, far from a hotrod, but does the same advice apply? or is there a better option for my scenario? I bought this car not running about a year ago and have slowly learned a lot from it, but I think I'm going to be selling it soon and dont wanna be selling someone a timebomb because I didnt get help figuring out the right way to complete this carb swap. thanks
Just hook it up to full manifold vacuum. Is there a vacuum port somewhere on the manifold? Don't worry about trying to use ported vacuum (above the throttle blades). Ported vacuum was used for emissions for smog motors that had less timing to reduce emissions. Vacuum advance is mainly to help economy but, can be used to add little initial timing at idle if need be. Need be is usually a larger cam with more reversion and less vacuum @ idle.
manifold va*** is the best in older cars . running advance is 2 fold it gives you better milage by increasing the torque ( higher combustion pressure) , and also makes the engine run cooler as the heat is put into the head ( with better water flow ) and exhaust stream instead of the cylinder wall .
It's possible the Cad won't like the extra ** degrees at idle. Sometimes idle quality isn't great with the extra ignition lead time. Or the exhaust will have a slight misfire sound to it. Or you may find that the engine idles too fast even when you turn the idle speed screw all the way out. If it runs great with full time manifold vacuum, great. If it doesn't, then what?
I don't see anywhere to attach to the manifold. You can see in these pictures that there's only one port on the manifold in the front and that goes to the bottom of the fuel pump. So I'm kinda stumped on how else I could run it, short of finding the correct wcfb, or eliminating it all together. Posted using the Full Custom H.A.M.B. App!
Also I did notice what might have been that misfire sound in the exhaust when it was idling in the driveway. Posted using the Full Custom H.A.M.B. App!
If the fitting on the intake manifold (in front of the carb) is full manifold vacuum you can cut this line and tee there.
Everyone has their own ways. My experience is with ported vacuum vacuum advance. I've seen lots of full manifold vacuum systems stock. Heck, the Japanese did it, too. Once throttle plate opens a little ported vacuum port will have nearly identical vacuum to full manifold vacuum port. Ported vacuum just turns it off at idle . ***uming carb is adjusted correctly--that's another story.
In order to work with what I've got, that seems like my best option, short of finding a good working Original carb. Posted using the Full Custom H.A.M.B. App!
I've drilled an extra hole before to add a port where needed. I've never drilled a hole for a ported vacuum port, though. Probably should look for another carb, then. Let's hope full vac will do the trick.
Are you sure the Stromberg has no fitting for either ported or manifold vacuum? I was thinking the Stromberg came from an era when almost all US cars had ported vac, Personally, if the WCFB had ported vac that is what I would try to use. Another choice would be an early Rochester 4barrel, same bolt pattern as the WCFB & definitely has a ported vac fitting. I strongly recommend that you retain the vac advane, I believe it will increase your gas mileage,maybe 3or4 mpg Greg
The only ports I saw on the stromberg were for the choke and the gas. That was it. I'm still hunting for the proper carb just in case. I'm starting to question if the manifold port to the fuel pump is worth tampering with. Posted using the Full Custom H.A.M.B. App!
Make sure you recheck initial timing as it will have moved quite a bit if you were using ported vacuum before the change.
Both Rochesters and Carters are readily available. All it takes is........cash. Cadillac during this period used a "choke modifier system". This consisted of a special choke cap with a machined hole through the center of the cap, a shaft extending through the hole, and an adjuster attached to the shaft (the other end of the shaft controlled the choke spring). The adjuster was attached to a piece of linkage which in turn was attached to an arm on the primary throttle shaft. The idea (from Cadillac, not from either Carter or Rochester) was to adjust the tension on the choke adjustment based on the throttle opening. It didn't work well, and most of these were removed by the dealership and a standard choke (not supplied by Cadillac) was installed at the first service (with or without the customers knowledge and/or approval)! The chokes were unique to Cadillac (Olds tried a similar unit on a couple of year); but neither the Cadillac or Olds units were ever available in the aftermarket. They were stocked only by Cadillac dealers or the Carter versions could be special ordered through Carter (then). Because of these unique parts which are virtually always either missing or broken, complete Cadillac 4-barrel carbs of this period are both difficult to find, and expensive when found; but they do exist. Take another look at the Stromberg for a 1/8 inch pipe plug or headless plug between the two idle mixture control screws on the throttle body. Jon.
Another possibility: If it is manifold vacuum that you require: MANY factory tripowers used by the various GM marques used a hollow carburetor mounting stud for manifold vacuum. The stud was approximately 5/16 inch longer than the standard stud, with the top 5/16 machined down to allow a vacuum hose to slip over the end. These should be readily available. I know they have been reproduced. And if you have a lathe, quite easy to make. We made dozens for our own use in restoring tripowers before they were commercially reproduced. Jon.
To the right of the adjustment screws, is that just a plug? Please tell me that's what I'm looking for Posted using the Full Custom H.A.M.B. App!
Thank god! I don't know how I missed that initially. I suppose I thought it was an adjustment screw or something. Well, we all learned something tonight..... That I'm an idiot haha. Thanks for all your help. Posted using the Full Custom H.A.M.B. App!
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