Proper engine coolant temp

[cashmoneyspeed]

Here's what I'm working with and the results I've gotten.

'86 regal with a sbc v8 engine and Ceramic header with a full 2 1/4" exhaust pipe to the differential. Vehicle is currently 450lbs heavier than stock and I'm running on 155/80 13 tires with stock rear gearing.

I'm using a dual 1" core aluminum radiator, single 16" electric puller fan with full shroud around radiator. 180 degree t-stat. No heater box or core. 30amp relay with temp sensor that turns the fan on at 195 degrees.

Yesterday it was 90 degrees out and in traffic during the day it stayed around 200 degrees on the digital gauge and got as high as 222. This was doing city driving for about 40 miles and the max of 45mph. Last night cruising, it had cooled down to the 70's and my temps stayed in the 195-232 range. Seemed like it stayed hotter with shorter stops in traffic and cooler ambient temperature. I didn't have any problems at all but wanted to see what comments people had with similar setups. So far I'm happy with the single fan setup.

 

[cashmoneyspeed]

 

[Blacktiger355]

You may need to get a larger 3 or 4 core radiator. Or swap to a dual fan design. My 350 did not like the 2 core at all. Same as yours it ran kinda on the hot side.

 

[565bbchevy]

You may need to get a larger 3 or 4 core radiator. Or swap to a dual fan design. My 350 did not like the 2 core at all. Same as yours it ran kinda on the hot side.

An aluminum radiator with two cores is not the same as a two core copper/brass radiator (which I'm guessing you are referring to).
I only have a two core aluminum radiator with 1.25" tubes cooling my street driven 565 Big Block Chevy. Though I do have a dual fan set up that works better than a single fan.

That radiator with that fan should have no issues cooling what appears to be a mild 350 I would be looking at the rest of the cooling system for any issues.
I would make sure that the water pump and thermostat are functioning correctly and if the plastic piece under your core support is missing find or make a replacement since that directs air up to the radiator.
I'm sure a dual fan set up would help since it covers more area but I would make sure that everything else is working properly before I went that route.
Also I can't tell from the picture but it looks like you just have an overflow catch can rather that a coolant recirculating catch can, which returns coolant back to the system when it cools down.

 

[Blacktiger355]

You may need to get a larger 3 or 4 core radiator. Or swap to a dual fan design. My 350 did not like the 2 core at all. Same as yours it ran kinda on the hot side.

An aluminum radiator with two cores is not the same as a two core copper/brass radiator (which I'm guessing you are referring to).
I only have a two core aluminum radiator with 1.25" tubes cooling my street driven 565 Big Block Chevy. Though I do have a dual fan set up that works better than a single fan.

That radiator with that fan should have no issues cooling what appears to be a mild 350 I would be looking at the rest of the cooling system for any issues.
I would make sure that the water pump and thermostat are functioning correctly and if the plastic piece under your core support is missing find or make a replacement since that directs air up to the radiator.
I'm sure a dual fan set up would help since it covers more area but I would make sure that everything else is working properly before I went that route.
Also I can't tell from the picture but it looks like you just have an overflow catch can rather that a coolant recirculating catch can, which returns coolant back to the system when it cools down.

Ah yes, you are correct. Re-read his post. Yeah for sure check out the rest of the system. Also where is your temp sensor located on the block? Maybe you are getting a false reading?

 

[Blacktiger355]

Also, it is hard to tell from the pics, but your upper radiator hose looks to have an odd dip mid way, that may be limiting your flow of coolant. The straighter the better. Also maybe try a high flow thermostat.

 

[pontiacgp]

The shroud is covering too much of the rad. Shrouds like that ought to have flap doors that allow air to pass and will shut when the fan is pulling air. If your switch closes at 195º what temp does it open?

 

[seawolf18]

A straighter shot to the top of the radiator might get the coolant through the radiator faster and more efficiently. You might want to try some redline water wetter. it is supposed to make your coolant more efficient and get your temps down. A friend of mine used it in his camaro, and it dropped his coolant temp 15-20 degrees. I have found that a more accurate temp reading by putting the temp sensor probe in the intake witch is the top of the cooling system, instead of the passenger side head. I take the plug out of the intake to the right of the thermostat and stick it in there. I agree with the other poster as well, that your fan shroud is blocking a lot of the cooling fins on your radiator.

 

[cashmoneyspeed]

The fan switch from speedway motors that I have says it opens between 185-215 but I found that it kicks the fan on at about 210-215 and turns off at 202-205. It is a stock 305 with just an exhaust system on it. The temp switch is on the front of the Intake manifold. The digital gauge sensor is on the driver side of the block. (False reading due to the ceramic headers?????? Just a thought)

I was worried about the upper hose looking like that part is smaller and looking into possibly a fancier hose. I know a few people running the metal flex hoses but I've also seen them blow off quite a few times.

When I was looking at shrouds, I did see others that had roughly 6-12 1 1/2" holes in them so I tried it out first without citing any and will drill a few before I polish the shroud.

I do not have the plastic shield under the radiator support that directs airflow, took it off 45,000 miles ago with multiple engine setups and fans and never an issue. I really don't want to put one back on either as it will just get damaged from driving low.

Water wetter I have and have used before. I just didn't want to start out with it in the system quite yet as it doesn't seem to add more than 3-5 extra degrees in my experience. Ill add it after I'm sure the coolant in the system is what is staying there for the next 2 years.

Now as I said, the car ran fine yesterday and this is just what I found. The last 2 years I had the same everything except I was running a stock radiator made for the 307, a different 16" electric fan, and a shroud made of cardboard along with a crappy analog gauge. The only time I ever overheated with that setup was when the old fan didn't turn on on a 90 degree day. I went with a brand new fan, aluminum shroud and larger radiator to help with the extra 700 lbs of hydraulics going into the trunk. The trunk is currently empty.

 

[seawolf18]

Your fan coming on 210-215 degrees seems alful hot to me, for a car running a 180 degree thermostat. I would think it should be coming on at 190-200 degrees. You can try rigging a temp. air dam under the front and see if that makes a difference on the rad temps as well. I talked to my buddy about the water wetter he used in his car. He said his temps ran about 10 degrees cooler, not the 15-20 degrees I stated earlier.