Slowly getting the gremlins out of the new build. Last one is overheating. Whats weird is when I'm at a stop light or stuck in traffic, the fans will cool it off to about 170-180 all day. The problem is when I'm traveling the heat will go up to 220 and then I pull over to let it cool down. I have a 160 thermostat in it, dual Ford Taurus fans (which will suck a small bird thru the rad), 26' 3 row Champion aluminum radiator. I do have a 440 source waterpump housing and pump on the front. I just bought them last year and the website says they have the Large Cooling ports as opposed to the old smaller ports. Do you think the water punp needs changed to a Milodon or a Mopar?

I have heard of similar problems caused by the water not staying in the radaitor long enough to cool the coolant off I would swap that 160 thermostat out to a 190 or 195F and see if that stabilizes the temperures in all driving conditions

I would start by verifying you readings with a thermocouple probe and digital meter. it is the most accurate way to determine the actual readings. The probe should be placed as close as possible to the Thermostat or existing temperature sender.
I have seen a number of aftermarket gauges be off by as much as 40 degrees and usually on the on the warmer end. Should you confirm the readings,

What you are describing indicates, one of the following,

A tuning issue, IE: lean mixture, too much or not enough timing, or possibly a restricted exhaust.

Undersized radiator, or inadequate air flow through the radiator. The air flow can be compromised by the fans / shroud design if it has one. it can also be comprised by openings in the radiator support that can allow the air to go around rather than through the radiator core.
only other possibilities I can think of is If the lower hose is sucking shut at increased RPM or a loose impeller on the water pump.

Keep us posted

One more thing just popped into my head, Pulley ratios being off causing the pump to be driven to fast or not fast enough.

I'd put a Milodon pump in an oem iron housing.........after verifying the lower hose has a spring in it and isn't being sucked in.

Have you checked your plugs to verify that you aren't running too lean?

Also the thermostat isn't doing anything at 160

You dont have enough water flow, something is restricting it somewhere. I would change the pump to a regular non scroll (vane) type & if still bad then change the housing to an OE iron one with the source scroll pump back in it & if still bad then keep the iron housing & change the source pump to a regular vane type. housing (restricted) or pump (scroll type not pumping enough at speed)

If it's cooling at idle, I would look at the tune to see if it's lean. Where's the timing set at? I've always run my stuff at 34* total. I'm going through the same thing right now, trying to get the thing to stay within the normal parameters. The heater should work killer for the upcoming cool months!

If that was the case he would over heat at idle.

Either he has too muck flow and no time to cool in the radiator or he's running too lean.

I vote for the later

You have a crap ton of non-stock stuff on there.

Have you verified that the pulley ratios are close to stock?

Not running an underdrive setup are we?

I have a 440 source pump & housing, 512 cid, cold ac, in temps of 105 + my car runs 185, make sure the new radiator did not get plugged up with rust flakes from the block.

(1) yes if the flow was real inadequate it would overheat at idle but I think he has enough flow to cool at idle but not enough flow at higher speeds where more eng heat needs more cooling. (2) (just me) I believe that too fast of flow being an issue is an old wives tale (& the Nascar Stewart water pump mfr are of the same belief) cuz if one block of coolant is moveing faster thru the rad (& gets cooled less) then that means that the next block of water arrives faster & begins getting cooled faster & all it reaches an equilibrium & that reports of people speeding up the flow (pulleys/vanes) & reporting running hotter, I believe they made some OTHER change in addition to that at the same time that is the real cause. One change at a time is a hard & fast rule & causes alot of problems if not adhered to. OP, post the outcome!

True. It's an old wives tale and it's false. Basic laws of thermodynamics state otherwise.

Basically, the rate of heat transfer is proportional to the differential in heat. If the hot water stays in the radiator, then yes it cools down more, BUT the rate of heat transfer ALSO slows down (and meanwhile the water in your engine bock is STILL heating UP...seems like people forget that part) SO the best thing you can do is keep transferring more of the hottest liquid (that's from the block) straight to the radiator as fast as you can for the fastest heat transfer away from your block and to the atmosphere.

If you are still overheating after you know you have as good of a water flow as can be reasonably expected, then the function of your radiator is suspect (not enough capacity, bad airflow from bad shrouding, etc.)

And cavitation from poorly designed water housing/water pumps can mean that spinning the water pump faster results in LESS water flow, which people improperly interpret as "too much water flow", when it's really the opposite.

Please keep us updated as I am sweating the same issue. I was going to try removing my thermostat???

Do you have a spring in your lower radiator hose? Mine was collapsing at speed and causing the same problem. I added a spring and fixed the problem.

Dave, more info please, overheating at idle or stoplight to stoplight or at higher speeds? what idle timing? no vac leaks?-(that is a long(er) shot but never hurts to ask. flex or rigid fan? schroud? how far is fan into schroud? radiator in good shape? any parts or adjustment changes preceding the onset? mixture/puller ratio in the ballpark (longer shots still).

It sounds like the fans are getting the job done at a stop. That is at least very good.

Hot rolling is often radiator or tune up related. Not enough radiator, not enough ignition advance or lean. Hopefully you are rolling at speed with at least 34 degrees ignition advance... even more with vacuum advance would be better.

I like Champion radiators and one one on a PU. That said, I wonder if a 3 core is enough for a 505. The higher end AL radiators do have more cooling capacity vs Champion per my understanding. My 496 runs right at stat temperature (180) while rolling - including across the desert and on a road track - with a Mancini "Muscle Car" radiator.

Another thing to check is air restriction caused by the electric fan/shroud. It works really well at idle but could it be blocking air flow at speed? Can you post a pic?

As far as water pump and housing goes, I doubt the housing is an issue. The 440 source WP may be a bit weak. I like and run a high volume pump with anti-cavitation plate slightly overdriven. That said it does not sound to me like you have a pump issue.

I would look at the radiator itself and look for any potential air flow blockage caused by the electric fan setup.

Well you guys gave me a bunch to look at so first thing I'll try is the tuning. I have a Firecore dizzy and we locked it out at 36 degrees. Here's a pic of the radiator

So your running 36 degrees all the time...on the street? Why? And why a 160 thermostat ?

First thing I see is the radiator airflow is terrible because of the fan housing. You are getting very little airflow through it. It looks from that picture that over half the radiator is blocked off.

That radiator and fan setup looks bitchen!
You could stand to have a little less timing. Jetting and fattening up the idle a little may help. I just drove mine up a big hill at 83* temps outside and it got a little on the warm side. I put it's first tank of 91 in it and opened the hood while I did it. Took off and basically coasted down the hill in high gear and it cooled right down. The road is a windy sucker going up and down for about 10 miles. Made it just fine. I was nervous though...Found a little coolant leak when I got home, loose bottom hose clamp. Keep on with updates!