505 Overheating!!

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!

I agree the fan setup would restrict air flow at speed when power and cooling needs increase... plenty at idle though.

36 degrees timing should be enough.

Can you get to the highway without too much stop and go? I would try removing the fan and shroud entirely and run it down the highway that way as a diagnostic. If it runs cool rolling w/o the fan that would give a big clue.

As feets has noted before, some fan shrouds block air flow at speed and cause cooling issues.

to prevent that, we both cut flaps into the shroud, so they would open at speed, but get sucked closed when at idle.

you mighy pull them and cruise somewhere you can maintain 40 mph for a while to prove one way or another.
If you still over heat, keep working the problem like mentioned above, but if it stops you need to cut up the shroud a bit.

^^^^^^^^^^^^^^Good call!

You know I never thought about that. I had bought the shroud and fan set up that Champion sells but after looking at them the fans were junk. After some reading I found a lot of guys would put these Taurus fans on because they pull around 4800 cfm's. After I received them from Rock Auto, both shrouds have the same size holes for the fans and covers the whole radiator so I didn't think anything of it. I guess I'm gonna have to think of a way to get some air thru the shroud. Thanks.

I have a 528 on the street in a Cuda, block is half filled and I had the same problem, the car will idle all day in the summer and sit on 175f but on the highway at 65mph it will creep up. One thing I have done is set up an engine oil cooler after seeing 260f on the oil temp gauge, that helped a lot but there is still work to do. Im at 35 total with twin fans and electric pump.

Early 440 source pump housing had a bad design water galleries. ..i had one a toss it in the bin.

I heard that but supposedly fix it. I know a few people who has their pump now with no issues, just saying.

Not sure where my pump came from, my builder got it

is the radiator sealed to the core support so you are taking advantage of all the possible air flow at speed instead of sucking in radiant heat from the engine compartment ? also, is there a good escape path for the air in the engine compartment ?

you can see the slots cut in.

Its the shroud , Dartgirl had the same problem with her 70 RR , it was fine at idle but on the road it would get too hot , it was the aftermarket shroud.

Put a 180 thermo in it , the 160 is nothing more than a flow restriction once the engine warms up ... open all the time.

What Ahy and John said, I would pull the schroud/fan assy & start it up cold & head out to the highway. it'll be warmed up by the time you get out there & see what develops. EDIT keep an eye on temps on the way home since there is very little low speed cooling (pull over for a cooldown if needed)

Fan on backwards

Are the fans pulling or pushing air? They should be pulling it through the radiator. If they are pushing air it could cause a no air flow situation at cruise... Just a thought....

They are pulling air thru the radiator. These fans are so good I'm afraid they are going to suck a small child thru when they are crossing in front of the car.

I'm anxiously awaiting resolution on this one

I have a 505 and drive it everywhere with a very simple setup:

440Source pump and housing
Original '65 manual transmission radiator
Mopar clutch fan with Hayden Jaguar clutch (shorter for clearance)
36° total timing that, for the most part, is locked out..
No thermostat
No fan shroud

Car never overheats, even when hotlapping at the track. It will creep over 200°F on the highway at 70mph but never gets higher.

The 440Source pump is a scapegoat as is the b.s. about water not staying in the radiator long enough to get cooled off!

X2

Based on your pic your my vote is your shroud is blocking air flow when moving...

There are some very intelligent posts here & some reasonable (but wrong) guesses. I worked through a non-stoked 440 cooling problem very similar to yours last month & I'm also running a 26" 3-row Champion now. I was overheating with a 3-core C-body brass w/factory fan/shroud & two pusher fans in front.

Anyway... back to your issue.

If you overheat at speed, but not at idle then you have one of the following:

1. electric fans actually HURTING your airflow at speed (was my problem).
2. radiator is plugged up (unlikely if it's new)
3. cavitation (which I have personally never seen in a BB Mopar).
4. lower radiator hose missing a spring (common with cheap hoses).

Personally, I believe your problems will go away if you put a modified factory fan shroud on that Champion radiator, the correctly spaced water pump (fan 1" from radiator, no more) and a stock-type fan (not a flex fan).

The coolant that cools the best is water (+ water wetter for iron heads or Lucas/Royal Purple for aluminum heads).

Thermostat does not affect how hot you run in most cases, but you can increase your coolant flow (sometimes helps) by removing the thermostat. I have personally never seen the need to run a "coolant restrictor" like they do in some Chevy's & I've run many motors without thermostats.

I remember a horror story once where the guy couldn't ever get it figured out and i deleted the thermostat till one year he pulled the engien apart and the original freeze plugs were inside water jackets cause the machine shop dropped the ball. i've also heard that with more rows, 3 or 4, the last row gets heated up by the first 2 or 3 and so it doesn't really do much.

I agree about the thermostat. I have never had a car run hotter when the thermostat was removed as they always ran cooler or the same if it has another problem. Ron

Wow! This is a lot of ideas I have to try. I did run it without the thermostat but put it back in just to try if it had any difference in temp. It had one. I love the idea of electric fans but from I'm reading, stock might be the way to go. I'm gonna work on it this weekend and I'll let you know what happens. I don't have much nice weather left in Michigan before that dreadful white stuff flys. 😞

Hey we're the best

This is a Jensen Interceptor rad fans & shroud note the simple blow through flaps,Jensen's where notorious for overheating we would recore the rad with a 4 row staggered core & install VW Rabbit/Bosch cooling fans.
http://i1119.photobucket.com/albums/k627/davefinic/PH%20Thread/photo_zps5d0a4f27.jpg

A stock type fan system has served me well with a warm 496B which is street driven and road raced. I run a re-pop thermal fan clutch and 6 blade fan. Both from Bouchillon. Also an aftermarket radiator and matching shroud. The shroud is big and open. Cooling performance on a roll is excellent. Based on data logging with an EFI setup, it holds right at 180 degree stat temp while moving. The factory gauge holds at the low end of the operating range. On a long stop in hot weather and AC running, it warms up a little but no overheating. Overall I am very happy with the stock type fan and cooling setup.

I need to clarify one point. My comment about the temp creeping to 200° on the highway is on a very warm 90° plus day. Most of the time it stays happy around 180° in reasonable temps.

Providing the tuning and all else is in order that would indicate that the radiators thermal efficiency is marginal for the application.