My engine temperature is remaining around 220. The temperature will not drop when the vehicle is traveling on the highway.

The radiator is aluminum and is made by Northern. The radiator core has 2 rows of 1" tubes. I filled the radiator with water and a bottle of waterwetter.

Attached to the aluminum radiator is a 16" electric fan that produces 2000 cfm. The electric fan is a puller that is located between the radiator and engine.

The engine, a 440, has been freshly rebuilt. The engine does not have an engine fan attached to it. The water pump is brand new. The water pump housing is factory original. The timing is set at 36 degrees. The carb has 94 jets and a power plug.

The car performs excellent despite its overheating. Any advice? Thanks!

What is the all in timing? Do you know what your AFR is or have you read the plugs.Could be the timing is odd or it's too lean.

For one, the cfm of the puller fan jumps out and two, I'd put a QF 4-window p/v in the primary and jet down accordingly then adjust pvcr's for best top end afr's/power.......... No wideband............ Is there a shroud or is the fan tied to the rad like most........

Agree the fan is way too small but that should not affect temps on a steady roll. The way electric fans are rated, you need 5,000 CFM minimum... or better adapt an OEM fan like the Chevy HHR, Lincoln Mark IV or other. Or just put a mechanical fan and thermal clutch with good shroud.

How wide is the radiator (22" or 26")? A big block prefers a 26" radiator but sometimes the job can get done with 22". It could just need more radiator.

I would confirm temp with a known good mech gauge. take stat out just for an hour for a drive to see if it is opening all the way. take the fan off & go out on the highway quickly to see if it is restricting airflow. what do the plugs show? As said is mixture/timing in the ballpark. at the highway speed where it runs hot you might duplicate that RPM in your driveway & see what the adv is at that point (if you have a dialback or timing tape). post any news. EDIT what does it run at at lower speeds? MORE EDIT is the rad fairly new? if in doubt you could run a garden hose in the top & get a ballpark figure if it is flowing reasonably enough out the bottom nipple.

I run the HHR fan in HOT climates and it blows away anything else I've used so far along w/the new and improved Morose elec water pump..............

Good point by RR... a smaller fan becomes a big restriction to free flowing air when rolling. Suggest you address the fan part first and see where that gets you.

Overheating while driving on the freeway indicates that either then engine is running too hot (ignition timing wrong or carb jetting wrong) or that the radiator is just too small.

Either get the car on a chassis dyno to tune the engine or buy yourself a wideband kit. Do you have vacuum advance? The ignition timing should be at least 40 degrees if not up to 50 degrees when you are just cruising down the highway with a small load on it. If you don't have enough ignition timing then the engine will be running less efficient than it could be.

Can you take the electric fan off and try an engine fan with a shroud? Are you sure the water pump is pumping a lot of water? Some pumps don't pump as much as other ones. Also, you might consider checking the pulley ratio to make sure that you are spinning the pump fast enough. If you are going to be doing highway driving rather than drag racing you'll want a lot of pump speed. Don't put drag race parts like a small crank pulley on a highway car since they will cause overheating.

1. at highway speed (anything above 35 unless it's a truck) the fan is completely unnecessary, and an electric with a shroud may be restricting air flow.
2. can any air enter the nose of the car without going through the radiator core (bad hood-to-cowl and rad support seals)? Fix that.
3. let me guess: no vacuum spark?
4. add power valve, or you're liquid cooling with rich mixture.
5. core face area may be too small, you need about 1 square inch per HP, core thickness is nice but it doesn't have the same value.
6. if this is auto with the ATF cooler in the rad, you need an aux ATF cooler.

What size jets?

I just saw this on fb but

Not sure of pricing.

Maybe can get idea from pictures.

https://www.facebook.com/SDConcepts/posts/10155283646780729

What kind of a waterpump do you have ? I dont like the cast impeller pumps so if you have that by a hv mp or milodon and see to that you have the corekt pullys

Either the water pump is bad, or you are turning it too slow or both.

The biggest mistake I see is under driving the water pump. I run mine at 6% over crank speed. I also use a Milodon pump as it moves way more coolant.

Water temp gauge accuracy been checked?

Do you run a thermostat? If so what temp?
If not a restrictor or none in place of it? Not allowing the coolant sufficient "radiator" time will not allow sufficient cooling time.

Is the radiator inlet lower than the thermostat housing? If so there may be an air bubble preventing the water from circulating. My Dart is set up this way and I have to jack the front end up when filling the radiator to get all the air out.

Put the t-stat in a pot of water, on the stove, and confirm it's opening all the way when the water nears boiling.

Lots of good suggestions. The only clunker was about residence time in the radiator. That is a perfect example of an idea that seems like it makes sense but doesn't when one applies engineering logic to it.

R.

This myth has persisted for decades... and if true would violate at least one law of thermodynamics. Besides, if the coolant flows too slowly, it's possible to get hot spots and steam bubbles in the heads. Vapor is not a very good coolant compared to liquid.

Edit: Looks like R. and I were typing at the same time

Looks like most suggestions are covered here. The obvious is to check the gauge first of all. Second decide how hot is too hot. 220 operating temp is fairly normal these days. Does it climb to 220 and stop there or will it continue to climb? Also one thing that gets overlooked a lot is ignition timing. When you say 36 I assume you mean its locked out at 36, which should be ok but might check that. Is the exhaust getting hot, as in the headers. That would be an indication of retarded timing for sure as would increased operating temps.