It’s Amateur Hour… Temp Question?

I’m running a ’73 350 in my truck with a stock/new radiator and the temp gauge always reads towards hot when the motor is warmed up, but does not boil over, so I assume that it’s within the designed limits. Occasionally, it peaks out (in traffic/low speeds) but more concerning, sometimes at random; for instance, this morning on the way to work with the outside temp 26 degrees. Only a couple of times have I seen a couple of bubbles coming out of my overflow on the radiator (not this morning though). Could it be that my stock ’58 truck gauge is not designed to the parameters of the 350, or maybe I have to go to a different thermostat, or a high flow water pump. The motor is stock from a ’73 Camaro. Thanks for any insight you could provide.

 

The sender you are using is probably not going to work with that 58 gauge.You might try an original sender from whatever the original engine that was in that truck.

 

Next time you drive it. Steal your wifes kitchen temp gauge.
Stick it in your radiator and see if its actually reading hot.
A high temp near boil at 26 degrees outside would concern me.
It'll never make it during hot weather.
If its really running hot. Check your timing and see if you are advanced enough.

 

I would start with a thermostat, its easy and pretty cheap. My own opinon on high flow water pumps is that they dont keep the water in the radiator as long as it should to cool off. What temp thermostat do you have now?

I just re-read your post, when the your temp guage is at hot is that when you see it boiling out of the overflow, or is the overflow just puking at random?

 

I'm not sure, and that brings up another question. Should I use a 180, 195, or 160 degree thermostat, as I am in the dessert and temps can run from freezing to really hot.

Thanks for all of the great feedback.

 

Consider checking replacing your radiator cap too.
IF.. you are running hot it may not be working and holding enough pressure. The higher a cap pressure the higher the boiling point on your engine coolant system.
I never liked 160 degree thermostats. the engine does not warm up enough to burn off gasses and condensation within the engine at those temp. Most operating temps for SB's are at 180 minimum.

 

Start with a thermstat, but "blowing bubbles" means either the block is making steam, or process gasses/pressure is leaking into the water jackets. Block making steam could be an air pocket.

 

Hey guys, thanks for all of the help! I'll try the thermostat, and go from there. I would have had no idea about the sending unit for the '58.

 

being that I'm from Reno, and my truck is a '73 with a 350, I would also suggest the thermostat first. As the temps got colder, my thermo went out. It was 5 degrees on the way to work, yet my temp was close to 220! It was sticking closed.

Another thing to check is that you always have a full radiator, with no air bubbles. As it overheated once or twice, it puked all my collant out. That only made the problem worse.

The stock thermo is 195, and I've never had a problem in summer with mine. My temp guage always read well below the 195 it should be, around 160? Not optimum for performance but I've tried all the thermos and it doesn't make a difference. Must be a bum sender?

 

Thanks Lance, that's good to know as I just got to the area.