oldmercsrule

Please excuse the photo quality: note the small hole in the original tube, (see above).

The factory choke heater tube broke off. I was able to get the remaining rusted tube remains out of the manifold. There is no direct hole into the manifold to access exhaust gas, and it appears the heat actually comes from convection from the manifold heater tube (see below inside the manifold) that the choke heat tube touches.

I am guessing the small hole allows the vacuum to pull air and heat to the choke thermal coil. Please let me know if I'm on the correct path, before I trim and drill the replacement choke heater tube

1955Super88

I have a 55 324 4 barrel and a 56 324 2 barrel and neither have a hole in the choke tube that I can see.

oldmercsrule

Thanks for checking.

There is no hole in the bottom of the 4 barrel manifold, (stove?), that allows exhaust gas to flow into the heater tube itself, (unless it is so rusted shut that whatever hole there was back in the day is totally blocked). The bottom of the stove in the actual manifold looks totally sealed, (and not rusty), as far as I can see. I did clean out the old tube remains with a drill bit and very minor drilling, (so I could have messed that up).

That hole would, (or potentially could), provide the ability for the vacuum to pull unfiltered air up the tube to the carb, and if said tube was sufficiently heated from convection from the lower tube, (illustrated in the chamber below), it may heat the coil enough to open the choke.

I hadn't gotten any reply, (and being impatient), I already drilled a small very similar hole in the replacement tube. The original hole is clearly man made and not the result of rust. (Who knows if this was the factory or a prior owner).

I will be assembling the carb and firing up the old girl soon, and if the choke does not work I will prolly ponder a manual choke set up.

Thanks again for your attention.