normal water temp on 350 engine?

Question

what is the normal water temperature for a 1970 350 engine? I know these run hotter than other engines but this one goes up to 220-225, when idleing but drops to about 200-215 when driving.

Cooling system has been flushed many times and water circulates well.


Engine is in a 86 Camaro z28. Water pump, radiator, and shroud are new, has a machanical fan.

Ok, the radiator is NEW, the thermostat is NEW, and the water temp gauge is NEW, aftermarket mechanical one and is in the head where the original sensor went.

Answer 1

Dear 350-

You are still running a little too hot.

Here is a couple of things I learned working for GM.

The larger the radiator the better. The idea is to remove as much heat from the coolant as possible. Normally if you are building the engine for a Custom Rod, you might want to consider a 3 or 4 core radiator. This gives you the extra cooling capacity you are going to need when you decide to go out and play.

Here is how I learned it.

Take a look at a vehicle with a towing package, (for example),
a 2500 or 3500 series truck.

These trucks are equipped with large capacity cooling systems. This is good for the coolant, but you need to consider the removal of additional heat through a couple of other items.

Consider adding an external oil cooler to your engine. This not only adds oil capacity, but the radiator that it comes with also removes engine heat just like the radiator for your coolant. Several aftermarket kits are available through you local speed shop.

Also consider adding an external transmission oil cooler to your system if you are running an automatic. I reccommend against using the one that is built into the stock radiator from GM. This one just forces your radiator to work extra hard, and the stock cooling fan will just barely keep up with the heat exchange demand.

Consider adding an extra pusher fan to the front side of the radiator after adding these two additional coolers. The fans are normally spliced into a Thermal Switch located on either the engine block or the Thermostat housing.

Be sure to purchase a 185F degree thermostat. This will allow it to open a little on the early side and get the coolant moving through the entire system.

Lastly. You need to find a Low Pressure/High Volume water pump. These are available from Eidelbrock. They are not cheap. Stay away from the High Pressure pumps. Higher pressure does not equal more coolant flow, it equals blown freeze plugs and failing head gaskets.

Mix your coolant 50/50 and use Distilled Water in the coolant mix. This prevents electrolsis from starting between the dis-similar metals in the system, (Aluminum Radiator, Brass Heater Core and Cast Iron Block and Cylinder Heads). It also helps prevent rust and scale from starting in a freshly built engine. Also add 1/4 cup of canola oil to the mix. This will seal the block and heads and help the coolant work more efficently. Another material called "Water Wetter" is also available if you prefer using that.

You may also consider going entirely with electical fans in the whole system. These kits are also available from GM Performance Parts, and many other parts catalogs.

Keep in mind that heat is the enemy of engines. The more of it you can remove, the longer your engine will last.

Good Luck

Answer 2

I think those had a 180 or 195 thermostat. The 195 was the winter thermostat that made the heater hotter. There was also a 165 for the summer. People usually ran the middle one. good luck.

Answer 3

**Check the clutch on the fan** - very common failure point. If it isn't working right, it tends to slip too much, which manifests itself as hotter idling temperatures..

Also take a look at your fan. If it's not the right one for the job, you can see the difference. Summit Racing sells a 7-blade fan that has a wierd blade setup (like the 70's to 80's GM truck/van setups) that works extremely well.

Answer 4

put a 160 degree Robert Shaw thermostat in it and you didn't say if you have a radiator shroud on the car but if you don't put one on, thats good for 10 degrees drop in temp, also try adding water wetter to your anti-freeze, it will drop the temp by 10 degrees, you can buy it at summit racing.

Answer 5

Just flushing the radiator may not be enough, you may need a new radiator. Also, have you replacede the thermostat? It should have a 195 deg thermostat in it. Also, you may have a temp guage or sender problem.

Answer 6

u need a clutch fan and at least a 3 to 4 core radiator the normal temp is 185f

Answer 7

This tempurature is perfectly fine. The reason radiators get presurized is so they can get hotter than 212 degrees without boiling. So going 10 degrees above 212 is the way its supposed to be.

Answer 8

That temperature sounds about right. If you're running for performance you may consider using an electric fan. I'd also replace the radiator cap because if it isn't holding the proper pressure you'll run hot.

Answer 9

The normal water temperature is 170, you can get different thermostats that run cooler or hotter depending on what you want to run.

Answer 10

195 degree thermostat to satisfy smog requirements.
185 degree thermostat is better for performance. Heat kills.