'24 exhaust downpipe

[occrj]

Hi all,

I took the exhaust system off mine today as it was blowing at the manifold/downpipe joint, and also has a hole further back so I'll probably get a new system made up using this as a pattern.

My question is: at the top of the downpipe, just below the mounting flange, there are a number of drilled holes (ie intentional holes, not rusted out) around the circumference. What are these for? all they appear to do is leak exhaust gases, are they necessary or can I just ignore them when I have a new system made up? Maybe someone made up the downpipe from another system and these holes shouldn't be there?

thanks, Richard.

[MikeC5]

Awful strange there Richard. It would seem to defeat the purpose of ducting carbon monoxide out behind you and not up through the floor boards. I'm not an expert but I can tell you that the rusted pipe that was on my 25 had no such holes nor did the replacement I bought from Meyers. I sure wouldn't duplicate that feature.

[Pete K.]

Those holes were put there for the car's heater. The Dodges used a cast iron assembly that bolted to the exhaust pipe, robbed hot gasses from pipe when lever was pulled inside car, in turn heating a coil that gave off the heat. Someone took off the heater bypass unit and left the holes. I have one of these units here.

[occrj]

Ah I've read something about Dodge heaters (saloons/sedans only?), I think I can omit that feature in the replacement pipework - thanks

Richard

[MikeC5]

The heater bled bled off the exhaust but where did it eventually dump?

[Pete K.]

The heat exchanger part in the cabin was a coil with many round fins on it, like baseboard heat. As far as I can see, since the unit I have was never installed on my Dodge, the exhaust recycled back through itself and out the exhaust pipe it would go. The exhaust gasses moving through the regular system provides a lower pressure, whereas there had to be movement of hot gasses, as a slow heat-up it would seem to be. The part that connected to the "collar valve around the pipe" where the holes are was a round flex tube that connected the coil unit mounted in the rear floor of the sedans. I have parts to a much shorter version too, where a short flex tube came up to a floor register on the front passenger side toe board. It has a small knob that you can adjust the heat flow, but I do not see any trace of a coil unit to this one. I'm assuming the pipe collar valve was not a valve at all, just a collar, to collect the heat from the forward part of the exhaust pipe. Some time not too long ago, I posted a photo of one type valve and controls I have here.

[1930]

Having never had one of these set-ups myself I am at a loss and am trying to understand how this works myself, if you could clarify and maybe add some pictures or point me in a direction of one of your past posts Pete it would help possibly. Ive had quite a few bugs that had the heat exchangers and am clear on how these worked but this does not sound like the same set-up.

More conventional heaters came into play I believe late 27 and certainly were on the market by 28 as I have brochures showing this but these early floor units have baffled me

[Pete K.]

Jason, here's the two photo's I posted some time ago of the one type heater valve and controls. Click to enlarge them. The large portion of the assembly is the cast iron collar that secures to the exhaust pipe. One would cut a hole in the bottom of the exhaust pipe. It has a butterfly valve in it not unlike a carburetor would have. That has a long rod attached to it, and a flange that screws to the floorboard. The end knob controls the valve opening, like an old stove damper would control the heat. This unit seems to have two outlets for perhaps a front and rear heater coil set-up. The flex pipe is not shown but it attaches to the iron collar and would run up to the floorboard heater coil. A gentleman posted a photo of a rear passenger compartment heater coil unit at the time of my older post of this contraption. This is so rusted, I can't move any of the parts unto itself to really see it function.

[1930]

Thanks, I do not remember seeing these pictures, I will do a search of your posts so I can find the original discussion and hopefully get a view of the coil deal, I have seen the vents but not the coil that would heat up.