The Stovebolt Site Forums The Shop Area Engine Shop 1950 3100 Carter 730s Carb

I have a 1950 3100 Chevrolet with a 216. It came with a Carter 730S carb. I have never had the engine running, but I feel like that day is getting closer. I have a question on the carb. I have attached two pictures of the carb and in the second picture I have put an arrow by the open inlet near the choke. I am wondering what gets attached to this inlet?? I hope someone can help me out on this.

Thanks, Jerry

The heat tube to activate the automatic choke.

Jon.

OK, but where would the other end of the heat tube connect? Thank you for the quick reply.

Don't know.

The 3100 would have come with a Rochester B with manual choke.

You now have a carburetor with an automatic choke.

If there is no place to attach the heat tube (generally on the exhaust manifold); one may fabricate a "heat stove" to use to supply heat to the automatic choke:

Heat stove fabrication

Jon.

Thank you Jon! Great information. I will let you know if it works out.

Carbking What about letting your engine get raw air that way ??

Many car companies allowed raw air anyway.

Pontiac, for one, ran TWO choke lines: (1) first line from a fitting on the air intake of the carburetor (below the air cleaner, thus filtered air) to the heat stove, (2) the second line from the heat stove to the choke.

I never did like the cheaper set-ups where unfiltered air was introduced to the carburetor, but then no one asked me

In the case of the OP, either the hot air line MUST be installed, or the choke butterfly MUST be fixed in the open position; or the engine is going to run exceptionally rich, if it runs at all.

As far as calibration is concerned, the amount of air entering this area is limited by a restrictor in the vacuum source circuit to the automatic choke. Thus the calibration takes this into account.

Jon

The choke stove tube on Chevy V8's used to run all the way through the passenger's side exhaust manifold, and drew heated air, not exhaust gas, into the choke housing. When the tube would burn or rust out after several years, the carb would draw hot exhaust gas and soot into the choke and really mess things up!
Jerry

Jon,

I made up a heat stove and line to the carb. Thank you for your knowledge and help. I hope to be starting the motor in a month or so.

Jerry

Let us know how it runs.

Jon.

So I now have the truck finished and on the road. The choke opens up to wide open after a drive, but as soon as I shut off the motor the choke butterfly completely closes and then does not reopen, so hot start does not work. If I get out of the truck and open the choke butterfly the truck restarts. Any ideas on how to fix for hot starts?

OEM choke stove tubes were steel, used a woven fiberglass insulator sleeve, and were as short as possible to minimize heat loss. You probably need to lose the loop in the tubing and insulate it so enough heat makes it to the choke housing to be effective. That copper tube will dissipate a lot of heat in a hurry. If the fast idle linkage is adjusted properly, holding the gas pedal to the floor during a hot start will force the choke open. It's called a "choke unloader" and it's designed into the carburetor. No need to manually open the choke plate.
Jerry

Wow! So that's what a 1950 216 looks like! I've never seen one so clean and neat and shiny!

Jerry is correct about the steel choke tube (tubing insulation used to be available from NAPA, have not tried recently).

The choke should NOT close immediately, regardless of the material used for the tube. Check that the fast idle linkage is correctly adjusted.

Jon

Thanks for the replies. Do you have any idea where I could get the procedure for the fast idle adjust? Also, if I was to push the gas pedal to the floor for a hot start would that shoot in a big squirt of fuel from the accelerator pump? And could that cause a flooding condition right off the bat?

Jerry

The 730s is an aftermarket carburetor; but it essentially the same as the O.E. 715s Studebaker.

The reference section of your local library should have an older "Motors" manual that would cover adjustment of the type WE used on the Studebaker.

Look at the sections on "unloader" and "fast idle". Going from memory, there is a spring on the fast idle cam inside the choke housing that can be installed wrong.

Jon.

I’m going to admit my ignorance. No idea you could find such a thing in a public library.

Many libraries have a "reference" section. They won't allow the books to leave the library, but generally they will allow one to peruse the books at the library.

Jon.

What's a library?

I have a 1949 (I think) Motors Manual at home. I will try to remember to look and see what it says.

I was able to find these pics from the Studebaker forum site and doing a search. I will try to go through these. I am not very experienced with these carbs, but willing to learn.....

Finally remembered to pull my Motors Manual out. Has 0 information on carbs in the Studebaker section. The Carter Down Draft W-Type carb specs table does not show a 730 or 715 at all, so I've got nothing helpful.

Jon, Jerry, Otto and Eric,

I was able to lengthen my gas pedal arm and that now allows the throttle to open all the way. I have now driven it a few times and it appears that is helping with the hot start issue I was having. I want to thank all of you for your help! I have attached a picture of my truck.

Jerry

NICE TRUCK!

Jon

Jerry m A month or so ? I must not be very patient,I'd wanna hear it tonight. Have learned not to let them get side-lined in the garage to easy to lose interest but whatever !!

EchoBravoSierra Those books all have different advice,read on bearing changing in the truck,all different.So done it the way we done it 60 years ago,keeps 30 pound gage pegged 9000 miles so far runs fine !!

Glad to hear it, Jerry M.

Good looking truck.