Heat riser valve and air cleaner

[druid318]

So I ran a search and couldn't quite find what I'm looking for. Maybe I'm searching the wrong terms though.

I am the new owner of a Town Panel, it has a slant six engine, 225 I think. It was rebuilt around 97 or so from the paperwork I have. It has the Super Six intake on it. I was warned that it didnt like to start when it is cold out. I assumed that meant winter, not all the time. My first tank of good gas I got almost 13mpg in town, my second tank averaged 7mpg.

I took a look at the carb, and I know next to nothing about them. The air cleaner wasn't on tight at all, so I fixed that last night by replacing the nut with a wingnut and tightening it down. The one nut on the top is holding the entire air cleaner on, so when that is loosened the thing will just fall off. That doesn't seem right to me.

Anyway. I noticed the air cleaner has second hole coming out the bottom. It has a flapper of some sort inside that doesn't seem to do anything. I also noticed what looked like a pair of mounting holes on the bottom of the air cleaner that has nothing attached to it. Is this smog stuff from a later engine that has been removed or is there supposed to be a down pipe from this to pull warm air when the car is cold? If so where the hell is it supposed to run to? I couldn't find any pictures online that helped.

Also, I have a spare Super Six setup. The entire carb, intake, and exhaust is there in one piece. I noticed there is a spring there that is missing on my the one installed on the truck. It is the spring that is oposite the counter weight for what I beleive is called the Heat Riser. I found a couple of part numbers for springs for the heat riser, but I don't see anything in stock. Is this something that would be available somewhere? I would prefer to not steal the spring off the spare setup if I can avoid it. The hardware store sells springs, but I would hate to put a spring on here that isn't going to work correctly.

Also, is there a difference between Super Six setups, one has what looks like a C at the end of the casting number, the other does not. 4041043 C

 

[druid318]

The first picture is the spare intake, sitting on my workbench. Just so you can see the spring I am referring to.

 

[Killer6]

The first picture is the spare intake, sitting on my workbench. Just so you can see the spring I am referring to.

The small tension spring can be replaced w/any quality like piece, it is simply there to stabilize the heat riser shaft so it doesn't rattle. The clock-spring behind the weight
is responsible for the correct opening/closing function of the riser, as long as the shaft rotates freely and the clock-spring is intact, it should operate fine w/or w/o the one
You've pictured. As far as starting is concerned, that generally is choke operation, so You'll have to verify if it's functioning OK.

 

[druid318]

The heat riser valve on this one rotates either direction by hand and stays there. Looks to just be loose. I didn't notice the clock spring, but I will take another look at it. The truck starts, it just dies repeatedly when the engine isn't warmed up.

There is a knob for a manual choke, but it is being used to control flow to the heater isntead. I think I saw an electric choke in there, maybe that is bad as well.

Seems like everything in the engine bay has been put together hodgepodge. Makes it hard for me to tell what is really broken and what is simply missing because it doesn't match up to all the other parts.

I do know the heat riser valve is not working as intended by the factory though. Any ideas on where to get springs? Is it even possible to replace the broken springs without pulling the exhaust off the truck?

I'll take a better look at the spare setup I have to see how it all goes together. Worst case I may just swap the entire spare setup to the truck.

 

[BillGrissom]

I think all Super-Six had a Carter BBD carburetor. You can find an online manual to download free, probably on www.slantsix.org. It looks like you have a vacuum port open in 1st photo, but that is your spare. Get a hand vacuum pump (Mighty-Mite or Harbor Freight cheapie) and verify that the "choke pull-off" and the air snorkle diverter hold vacuum. Alt, push the stem in, block the vac port w/ your finger, and see if it stays in until you release your finger. You need an air bellows off the lower cleaner port which goes down to a sheet-metal "hot air collector" bolted to the exhaust manifold. That only matters for faster warm-ups and wasn't added until the mid 1970's, so not essential. If you later change to fuel injection, none of those "carburetor kludges" matters. There is only so much you can do with a carburetor design and it got very complicated by the mid 1980's.

 

[leblanc]

When I had a slant 6 in my 76 Dart Sport it had a 2 barrel and like BillGrissom said the air cleaner does not absolutely need to be connected to the heat riser valve. All I had was a chrome air cleaner on top of the carb with no connections. Although I only ran it in the summertime it ran fine.

 

[druid318]

Thanks for the help guys. I'm going to check on the choke when I get time. I replaced the air filter and tightened it down and the truck is running better. Still a little hard to keep running when cold, and it doesn't shut off well, but it runs decent.