Choke tube or heat riser tube "how to" wtih headers

[Bradsp8]

I have headers on my EB which is a stock 75 302 with stock carb and need to know how to connect the choke tubes now that there are no manifolds. Can anyone send me a diagram or explain how I'm to use the choke tubes? Where do they connect to the carb as well as to the headers? My idle speed takes forever to drop down and I think it's because of the lack of a choke tube kit to send heat to the automatic choke. Thanks for any assistance you can offer.

 

[broncnaz]

There are kits availible to add heat risers to headers. I think MR gasket offers them. but they are really little more than a piece of sheet metal held to the header with hose clamps and allow the heat tubes to connect to them. Easily made at home. Or you could convert to a full electric choke or a manual choke setup.

 

[blubuckaroo]

I've made a stove to go on one of the header tubes to gather heat and connect to the choke tube. It worked ok but I later converted to electric choke which works much better.

 

[Bradsp8]

Googling "choke tube" and "heat riser tube" for Ford 302 I think I found some good info. Looks like there are two lines in play here. One from the manifold to the back of the choke thermostat that draws hot air into the carb. Then another line from the air horn out the rear of the carb that is dumping the air from the carb. Evidently it's a circuit that is closed and operational due to being a vacuum system. Problem I have is my headers have no place for these two conncections like my manifold did. I hope this makes sense as I'm still learning.

 

[MarsChariot]

I did this recently on my (super awesome) Autolite 4100 on the '76. There is a kit that has a bendable tube with the correct connector to hook up to the carb end. (Throw away the little rounded cup thingy that they supply with it since you cannot seal that and in our vehicle there is just too much dust in the environment to run that choke tune open to the air like that.) Run that tube down along the side of your headers with as much of the tube in contact with the header as possible. But you should feed that tube with clean air from the air horn where there is a little tube sticking out and back (waiting for you to make use of it) just above the choke tube connection. Now take a 3 foot section of 3/16 brake line and bend it in parallel with the main heat tube, except on the far end loop it back inside the heat tube. Secure it with high temp aluminum tape or something (not required). Use a short piece of vacuum hose to connect the carb end to the air hose. Now you have a closed loop fully operational choke heat tube, young Skywalker.

 

[red hot71]

I did this years ago when I installed a 4100 on my bronco I used 1/4 soft copper tubing and bought at the same hardware store a 180' elbow that I soidered at the bottom to make my return back to the carb. I think I used 1 maybe 2 hose clamps to clamp it to the tube that was easist to get to,oh also crush nut and ferros all common pluming stuff

 

[pcf_mark]

Here is a link to the kit http://www.oreillyauto.com/site/c/detail/DOR3/55111.oap?pt=N0286&ppt=C0142 It does look like parts store stuff.

I did not consider that the hot air drawn into this tube is fed to the engine. I guess the sock looking thing in the photo is an air filter? Maybe an all metal spark arrestor could take the heat to avoid the loop back to the air cleaner.

 

[Tomdee]

pfc_mark-The sock is insulation that slide over the steel tube. BluBuckroo is correct, Elect. choke is the way to go,Less problems and a cleaner look!
Tom D.

 

[MarsChariot]

The sock-looking thing goes on the tube, and both insulates it and protects things from it when it warms up. I had that little set up for years and always cast an evil eye at it because of its dust sucking characteristic.