Automobile (Firebird 400) Thermostat

[nyone]

A thermostat for a 70 pontiac firebird with 400 engine is $8 (eight dollars) at Autozone.

Plus about $10 in the coolant you would loose, plus the $4 gasket. If you want to throw parts at something sure it's a great place to start.

Or you could warm the thing up and feel for a temp drop across the rad and hoses..this is free.

 

[LouNY]

It takes quite a good sized and well shrouded electric fan to cool a V8 by it's self. It would need to cover most of the radiator and have enough air being pulled or pushed through to make it impossible to keep a newspaper on the front half of the engine.

 

[MossRoad]

Plus about $10 in the coolant you would loose, plus the $4 gasket. If you want to throw parts at something sure it's a great place to start.

Or you could warm the thing up and feel for a temp drop across the rad and hoses..this is free.

I wouldn't loose $10 in coolant, and the gasket comes with the thermostat.

Also, I was just listing the price of the part if he has to replace it. It's a 5 minute job.

 

[Rebeldad1]

After years of experience.... Stant superstat only. couple bucks more but bulletproof. 195 would be stock.

Fan and correct shroud a must.

 

[scootr]

Is he ready to sell yet? I'd be a buyer

 

[Williy]

Put the thermostat in backwards?? I don't believe you
can do that in very many cars or trucks as all the ones
that I have seen no room to do so so impossible??
Let it run with the cap off to see if the pump is working
There are times that I have seen the radiator hoses look
good and a little vacuum and they collapse. IMHO an
engine flush would be first thing I would do then procede
Oil is OK??

willly

 

[4570Man]

The sketchy fan setup seems to be the obvious starting place. Make sure it has a good shroud that’s actually important and make sure it’s moving enough air. The vast majority of equipment overheating problems are dirty radiators. People say they’re clean and they’re really not. But that’s probably less likely for a car. Also check to make sure it’s actually overheating. If it’s steaming out coolant that part is established but don’t just trust the gauge.

 

[Fuddyduddy1952]

I'll ask my wife tomorrow, she's asleep now, a Pontiac aficionado (seriously). She built the 455 for her bracket car. I know Pontiacs tend to run hot (thin wall block). I know she always ran a modified pump with an impeller plate & divorced choke Holleys since they heat so fast. 38° max timing (I believe...I'll ask). Electric fan on drag car only, not street. 4 core radiator. She runs a restrictor plate instead of thermostat. Flex fan & shroud.
I'll ask tomorrow...other modifications (something to do with water passage?).
We used to check thermostat temp in auto class another lifetime ago, put a feeler gauge in it, suspended in pan of water string tied to feeler gauge. Thermometer...heat water watching temperature...when thermostat drops that's it's opening temperature.
She runs wetter water with coolant.
After 2am....zzzzzzzzz

 

[RustyA]

50+ year old vehicles with radiator of unknown heat shedding capacity, no fan shroud and electric fan that may or may not be properly functioning to provide airflow. I had a 1967 Mustang convertible that always overheated at low speeds like parades. Previous owner had removed shroud from original radiator. Installed correct shroud with a new radiator and it never overheated again in 10 years of use. Old radiator weighed a significant amount more than new due to buildup of crud over 40 years of use, stop leak, and lack of maintenance. Just sharing my experience, my original radiator was probably less than 25% functional plus no shroud to direct airflow. Today I would use infrared thermometer in various locations across the front of the radiator to know it was 3/4 full of crud.

 

[Fuddyduddy1952]

I'm talking to wife now. Pictures would help, big difference between '69 & '70,'71,'72.
However, it needs to have solid Pontiac factory fan. Electric is add-on. Fan with shroud. At least a 3 core radiator. A thermostat is ok, (she runs a restrictor).
She wants to know if it has an 8 or 11 bolt pump. The divider plate clearance is critical and should have impeller plate (impeller to divider (.050"-.100" clearance).
Bottom line is I would start with year of car, year of engine (verify cu.in. and year motor, it could have been changed). Verify radiator (3 core?). Solid factory fan & shroud.
She runs 11 bolt timing cover/pump:
Napa DPW1301280 pump
Pontiac sleeve assembly GM 9796347
Check Butler Performance which has a good description, pictures, explanation.