1937 Ford Pickup

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Thanks Pops. Today after groceries and cleaning in the shop for a while I found a new way to get confused and dumbfounded. I decided to rebuild the swap meet Holley carb I picked up. All went well enough till I got to the automatic electric choke. I don't understand why or how the vacuum circuit works. There is a "piston" with a small ballish thing with a little tit on it inside of it. The piston is hollow and is in a chamber that has manifold vacuum to the bottom end. The other end is open to the choke heater which vents to the air horn. It doesn't make sense that vacuum can be drawn though it. [S[S:confused:. Has anyone dealt with this? I can't find any info on this on the web or on Holley's web sight.
 
Pictures as requested. The screwdriver points to the vacuum port that runs to the bottom of the chamber. It connects to a passage that runs to the bottom center of the carb. The brass cylinder had the little shiny piece inside it, the pin on it looks cut or broken. I'm thinking I may plug the vacuum port and try it with just the electric choke heater. If that doesn't work I will just run it with a choke cable.
 

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That steel line coming off the side goes to a plate that sits on the cross over on the intake or exhaust manifold depending on how long it is.
The port you are showing pulls heated air into the choke housing to heat the coil spring to open the choke butterfly.
If you have an electric choke cover then, you don't need the heat riser tube but, if the provisions are there then, use it.
The brass piston is the vacuum pull off that opens the choke butterfly a small amount so the engine doesn't get flooded with gas until it warms up.
The odd lookin piece is an anti-blowback check valve incase the engine spits back through the carb.
 
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I read your last posts quite a few times to get it sorted out in my mind. OI explained the automatic choke very well. I think the part that was throwing you off, Kenny, was that the vacuum system isn't applying the choke, it's pulling it off after the engine starts up. The bimetal 'spring' in the black plastic cap, is what closes the choke.
Automatic chokes work alright when they work and when they're set right for the conditions, but I prefer a mechanical choke so I know what's happening out there at the carb.
 
Thanks guys. The hose to the left of the choke heater housing is rubber and goes to a tube at the top of the air horn. the brass cylinder that is the choke pull off. It can't be moved in any direction by vacuum because there is a hole clear through it. To act as the pull off it would have to move down ward under vacuum in order to allow the choke to open. In order to move upward and close the choke it would seem it needs a spring under it. As it is now it will suck manifold vacuum through the choke housing from just below the air cleaner base right to the bottom of the carb. Is it possible that there are parts missing from the pull off? Maybe a piece of linkage, a spring and possibly part of the anti blowback check valve? I'm not trying to start an argument. just trying to understand what I have going on. If I understand properly I can plug off the vacuum and try to set the choke so that it is open enough when cold to help start it and it will open as the spring heats up electrically. Thanks for the help.
 
You are correct in your thinking.
When you set the choke without a pull off just don't set it too tight or it will flood the engine.
 
I think I found out a little more info. I looked up choke pull off adjustment on you tube. In the video you can see the anti blowback check valve is supposed to be connected to the lever inside the choke heater chamber. On mine the rod from the check valve to the lever has been cut. This will keep the end of piston from being sealed. It looks like I have to seal that vacuum passage and rely on just the spring or use a manual choke with a cable. I do have a manual setup on an old 390 cfm carb. This may be the way to go.
 
Got the motor in the truck fired up today. It sounded good with just the headers on it. Didn't run it very long. I don't have coolant in it and didn't want to get it too hot. The hood hinge came in in the middle of last week. After attaching it to the hood and getting it mounted I cant get it to line up anywhere near right.[S:eek::confused: I'm about to cleco it to the cowl and work my way forward. I guess all that work on the radiator support will need to be redone.
 
Thanks Dozer. I'll figure it out. Just a little frustrated. If I had an original radiator that has both side brackets it might be easier. What would be the fun in that.
 
Making a 36 grill fit a 37

Had some time to work on the truck a little. A 36 hood has a little less angle to it than the 37. When you put a 36 grill in front of a 37 hood there ends up being a valley where the two meet. I cut the shell from where the sides of the hood and the top meet to where the top of the grill bars. I added an inch at the rear tapering to the front. I still have some more work to do welding and hammer and dolly work but it fits much better.
 

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