Thermostat question.........

[BobT-47P15]

I have found 3 thermostats..........the left one is smaller diameter and may not even be for a

Plymouth.......might have been for my old Toyota.

 

The middle one is a 180 degree item of older style.

 

The right one is older.......and the top is missing from the box.....don't know what

temperature it is.  Marked #16 and has the number 162 on it also.  

 

Do any of these look right for a P15 with a 230 engine?

 

Or........any suggestions what to use?   The bypass is connected.

 

 

[40desoto]

none of them..   I believe for the thermostat housing you are using you need something like this.   *Note the thermostat in the picture did not work with the thermostat housing in the picture. I believe it will work with the housing you are using

 

Edited January 13, 2014 by 40desoto

[48mirage]

Bob,

 

For the engine you show with  the external bypass you are looking for a 160 degree thermostat.  You say a P15 with a 230.  I'm pretty sure Plymouth didn't get the 230 until the P24.  The thermostat on the right of the picture looks like it might be right and the one in the middle looks like what is in my '49 Dodge with a 230, but I also have the rubber donut like in 40desoto's pic.

[_shel_ny]

There is about 1" clearance down into the head from the top where the stat sits. If that one on the right extends down more than that it is not going to work.

[Don Coatney]

Bob,

 

For the engine you show with  the external bypass you are looking for a 160 degree thermostat.  You say a P15 with a 230.  I'm pretty sure Plymouth didn't get the 230 until the P24.  The thermostat on the right of the picture looks like it might be right and the one in the middle looks like what is in my '49 Dodge with a 230, but I also have the rubber donut like in 40desoto's pic.

Are you saying an engine with an external by-pass requires a 160 degree thermostat? If so why? In my opinion a 180 degree thermostat actually works better in an engine with a healthy cooling system as it helps eliminate moisture and condensation in the crankcase.

 

Also a thermostat does not care what size engine it goes into as long as it fits the hole.  

[BobT-47P15]

Well......it's a 1957 model engine ..... that's why is a 230.   I should have mentioned that originally.

 

Anyone have a part number from NAPA or someplace for a stat that is right?

[40desoto]

There was a previous thread that discussed a thermostat with some good pics.  Looks like the thermostat housing might be the same as yours.  If so the Napa part number for the thermostat in those pictures is   155   (the 180 degree one)

Hope this helps;

http://p15-d24.com/topic/33566-thermostat-old-style-vs-new/

[_shel_ny]

Why does your 1957 engine have an external bypass housing? I thought those went out around 1951.

 

 

 

Edit: Stant 13926 , or Gates 33026 if you want 160 degree

Edited January 13, 2014 by shel_ny

[BobT-47P15]

The head is from a 1950 Dodge engine........

 

Head  the seller gave me when I bought the engine was not as good condition as the

one that's on there......so my mechanic said use the better head.  Therefore, mix and match.

That arrangement has done fine for the past 20 years or so.

[Young Ed]

Bob If you do end up using that old one on the right in your picture boil it first and make sure it works. If you use a thermometer in the water you should get a decent idea of what temp it is. 

[BobT-47P15]

Thanks for the input guys................

[Dodgeb4ya]

The thermostat on the right looks correct. There also is a round rubber gasket that goes on the top of that type of thermostat to seal it to the upper outlet hole in the  housing.

Definately put in in warming water and  check at what temp it starts to open!

[BobT-47P15]

I just looked in the bottom of the box for that right hand thermostat.  Small envelope in there containing

a rubber gasket (shown on stat in this pic)......plus a small screw.  On the envelope it says "For 1941 or

later model cars, insert self tapping screw contained in this package in small leak hole and screw down

tight."  

 

With gasket,,,,,,,,,,,,

 

 

Leak hole..........

 

[_shel_ny]

That hole will let the trapped air escape

 

Apparently there will be no trapped air.

Edited January 15, 2014 by shel_ny

[BobT-47P15]

I suppose the air escape is a good thing.

But why would they say to plug the hole for any car newer than 1941?   Difference in the way

the system works somehow? 

[greg g]

my 46 with internal bypass used large one on the right hand side.  I believe the biggest problem with that type is they are often times installed upside down.  Are the instructions specific to which end  goes up.

[Don Coatney]

Rule of thumb for what ever that means, the spring (or bellows) always goes into the head as it must be fully saturated with coolant in order to work. If there is an air pocket in the system surrounding the thermostat it will not work.

[greg g]

air in the system is a relatively new phenomenon.  With the coolant level higher than the stat, air shuld take care of itself.  With newer cars and lower radiators it became more problimatic and systems were equipped with burpers to address the situation.

[Don Coatney]

air in the system is a relatively new phenomenon.  With the coolant level higher than the stat, air shuld take care of itself.  With newer cars and lower radiators it became more problimatic and systems were equipped with burpers to address the situation.

Ever have an engine freeze up due to low antifreeze level? This happened to me a long, long time ago when driving my dads 1952 Chevy. The coolant froze in the lower portion of the radiator stopping circulation. First indication was the heater started blowing cold air. The temperature gauge showed the engine to be running cooler than normal as the bulb was no longer submerged and the same with the thermostat as all water in the block had boiled out and escaped from the radiator overflow. The engine was grossly overheated but did not indicate such due to air and not water in the engine block.

[Grdpa's 50 Dodge]

If you can get a correct stat in a Failsafe it is a bit of insurance.  My understanding is if they overheat they lock open and dont over heat the car.  Running with a stuck open stat beats driving with a stuck shut one!!!

[BobT-47P15]

Lots of good info gentlemen.   Thanks.     

 

Guess I will try the big one on the right........but it will have to wait til I get the car back.

 

Dale is trying to get the car put back together......about ready to try and start it after sitting for

around 3 years.  I can mess with odds and ends after it returns home.  I had a bunch to "knick

knack" wiring under the hood to hook up the extra horns, the siren, the hood ornament light and

an underhood light.  I didn't draw a diagram when I hooked up those things..........but I wish now that

I had.  Will try to do better in the future.

 

Another thing I have done that helps me with wiring things under the hood, that appear on the wiring

diagram for the car.     Since there are so many wires crisscrossing one another, etc......I get a piece

of paper and pencil and map out only the part of the system I'm dealing with.  I study on the manual

with my  magnifying glass and draw my  own picture -- which makes it easier for me.   Just passing this

on in case anyone else might find it helpful.