Pre-war (up to 1942) 1936, 346 Thermostat, where can I find one

[Dennis Rizzuto Jr]

Im sure they are like hens teeth, but does anyone know where I might find a thermostat for my 36 Fleetwood? From what I have read they were the same until 41.
Is there another option for a thermostat that can be intergraded into the cooling system? Any information would be great. Thank you,
Dennis

[Tom Boehm]

I have good news and bad news. The good news is the thermostat is not necessary to run the car. A lot of guys just wire the shutters open. Most collector car driving is in the summer anyway. In winter driving I'm sure operating shutters help the engine run better. If you don't have one at all, it's probably not hard to find a non working one to install to close up the hole.

The bad news is it's getting very difficult to find a working one. Allcads of the 40's and bill Hirsch used to carry them but I don't know if they still do. They were expensive. These were called Sylphon thermostats when the cars were new.

Here is a link to a previous thread from 2019 about this exact topic. Pay close attention to posts # 4, #5, #6. Maybe some of these leads are still good.

 https://forums.cadillaclasalleclub.org/index.php?topic=157727.0

[Dennis Rizzuto Jr]

Hi Tom, and thank you for the information. Fortunately I do have one in the radiator and my shutters are wired open. I purchased the car a month ago, and it is a wonderful survivor. It runs great, just appear to be running hot according to the gage. When it was 50 out the car ran in the 175-190 degrees, and when it was 35 out it ran around 155. I still need to flush out the system and replace a couple of freeze plugs which should give me an idea of what's in the block. The car has 76400 original miles I believe. The previous owner passed away so I'm unable to get much info. He did own the car since 1989 and was a member of this club. Thanks again, Dennis

[LaSalle5019]

The thermostat will probably not help it from running hot since you already have you shutters wired open. Cleaning any sludge out of the block and radiator will help with that so you are on the right path there.

Like you, my thermostat failed and my shutters are just wired open. The problem with that is, unless the ambient temperature is warm out, the engine takes a long time to heat up and also ends up running cold, which also isn't good for your engine. Hirsch has replacement sylphons but the cost seems to go up $100 every few months (currently at $600).

I'm pretty much a purist at heart but I also like to drive my vintage cars so I will compromise when necessary. That said my 1939 LaSalle has an electric fuel pump for starting and a couple of removable modifications to keep the fuel pump/lines as cool as possible. To solve the temperature regulation problem without spending $600, I was considering adding either a manual push/pull cable under the dash that would control the shutters or installing an electronic shutter control by adding a thermocouple, an electric servo (like from an RC model) and a simple logic circuit that will act like a thermostat.

[LaSalle5019]

Dennis,
Were you the one asking about water jackets and flow through the flathead blocks prior to the site going down and losing info? If so, here you go.
The coolant is pulled from the bottom of the radiator in through the pump inlet

From there it goes into the right side of the block. You can see much of that water jacket with the pump removed.

Part of the water is diverted through the center of the block and feeds the left side water jacket

From each side of the block, the water is forced through the heads and out into the top of the radiator

You will notice that the gasket blocks off some of the ports

The water outlet on the right head has a smaller hole as compared to the water outlet on the left head. This is to balance the flow between each side as the left side of the block is a longer run so the outlet has less restriction.

[Dennis Rizzuto Jr]

Hi Scott, thank you very much. Seems strange why they would allow the gasket to block of some of the water flow. That looks like a vey nice engine you have there.

[Brad Ipsen CLC #737]

It is not the gasket.  The actual casting has a smaller hole.  If this was not done most of the water flow would stay on right side because it is the easiest path back to the radiator.  In the past some have thought the smaller hole was a casting mistake and enlarged it.  The result is not good.