VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 RAREST option ever

This item was discussed a ferw days back. Several guys guessed what it could be. Turns out it's called a radio muffler for a 7 tube 37 radio. This is really rare. I don't even have a radio and I want it.

If you're interested email me for contact info. I'd bet 99% of 37 chevy owners have never seen one of these.

Are u looking for one ??? I believe I have acouple if not I no I have one left for sure I'd trade it if u have any 37 stuff let me know thanks

The muffler is also used on the 1938 and 1939 radios, and is not an option, but part of the installation kit that came with the radio when it was purchased from the dealer.

Actually, there are several of these mufflers installed on cars and with radios that have been removed from cars at some time, and not re-installed.

(And before you ask, NO! they are not chrome plated).

What is the purpose of this "muffler" ?

To cool the radio. There are two large knockouts above & behind the valve cover that allow cooling air to the radio. The "muffler" covers those holes. Steve posted a link the other day to a car that had one on it & Ray educated the rest of us as to what it was.

Yeah...but but the chrome...It's so cool...! ( That's for you Steve...)

The radio I am familiar with mounts above the pedals. The speaker mounts in the location that you are talking about.

The '38 has the exact same thing. There are two knock out plugs with little tabs to grab and break the plugs off the firewall leaving holes. The louvered thing is called a muffler for some reason and has two tabs at the top for self tapping screws that go into little holes already in the firewall and a tab at the middle bottom that fits over the stud holding the speaker to the firewall and a nut holds it there. It then covers the holes in the firewall. It is only used on the Super Heterodyne 7 tube radio with the firewall speaker. Literature talks about equalizing the pressure behind the speaker that's up tight against the firewall pad on the cabin side. They were probably worried about something they didn't need to be worried about.

posted by rd1937

The only thing I see that it would do for sure is to let cold air in during the winter.

I was wondering about that. Brrrr!

It seems to me it would be another source for warm air. Since the air comes from the engine compartment, it is already warmed some. As it blows over the hot radio tubes, the air should pick up more heat as the purpose for the muffler is to cool the radio. Of course, this would not hold true if the radio was not on. Beamer

I thought you'd still have the speaker cone as a "barrier" to keep the cold out...? smiles...

I 'think' the radio box mounts over the pedals and only the speaker goes behind the holes, or so I've read. I've never seen one with the remote speaker mounted before. My Delco with the built in speaker mounts over the pedals. I thought about the possibility of the speaker blocking the air but I don't know how well it fits, how well it seals the area.

That's correct the radio box with its tubes and rectifiers is mounted away from the speaker over the pedals and steering column. The speaker is remote either on the header above the windshield on the 6 tube model or on the firewall on the 7 tube model. The firewall speaker does sit tightly against the firewall mat so it's not like a lot of air is coming in to the car. And no air gets to the radio itself so it can't cool or warm it. They thought in those early days that the pumping of the speaker cone would generate pressure that needed to be disipated. The header speaker sits off the headliner in a little piece of fiber board so they didn't think it would create the pressure. BTW that header board is in every car from the factory and you can feel the hole under the headliner for the speaker on all your '37 and '38 cars. One thing not mentioned for possible use of the muffler is to have your radio on while you work on your engine and li9sten to tunes. Ha Ha. And if a guy were mounting a firewall speaker these days he could just not open the holes. They really are not necessary for anything.

rd1937 is on the track. As the name implies, it is a muffler. The speaker, as such, blocks one end of the speaker case. If the space behind the speaker did not provide an exit for the air movement generated by the speaker it would sound "muffled". The holes in the firewall provide a relief for this pressure. This now generates another problem. Liquid could enter the holes and get the speaker wet, and in the case of the 1939, tubes wet. Therefore the need to cover the holes with the special "muffler". Can you hear me?

Originally Posted by Tiny

The only thing I see that it would do for sure is to let cold air in during the winter.

Not to mention fumes...........

It did not allow engine compartment fumes, cold air or heat to enter the cabin.